HHA 2015 Five Yearly Review Comparison of LiDAR and Bathymetry data sets
DLM7531-RT001-R02-00 November 2017 HHA 2015 Five Yearly Review Comparison of LiDAR and Bathymetry data sets
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Document permissions Confidential - client Project number DLM7531 Project name HHA 2015 Five Yearly Review Report title Comparison of LiDAR and Bathymetry data sets Report number RT001 Release number R02-00 Report date November 2017 Client Harwich Haven Authority Client representative John Brien Project manager Nigel Feates Project director Mike Dearnaley
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Date Release Prepared Approved Authorised Notes 10 Nov 2017 02-00 NGF JS MPD 31 Aug 2017 01-00 NGF JS MPD
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Prepared Approved Authorised
© HR Wallingford Ltd
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DLM7531-RT001-R02-00 HHA 2015 Five Yearly Review Comparison of LiDAR and Bathymetry data sets
Contents
1. Background ______1 2. Bathymetry and LiDAR data ______1 3. Previously reported intertidal and subtidal volumes and areas______1 4. Analysis of LiDAR data ______3 5. Analysis of bathymetry data ______7 6. Combined LiDAR and bathymetry data______8 7. Analysis of intertidal and subtidal areas and volumes ______8 7.1. Comparison of 2005, 2010 and 2015 combined data sets ...... 10 7.1.1. Orwell estuary...... 10 7.1.2. Stour estuary...... 15 8. Conclusions______20 9. References ______20
Figures Figure 4.1: Embayment areas and overview of erosion and accretion between +1 mCD and +4 mCD in the Orwell estuary between 2005 and 2015...... 5 Figure 4.2: Embayment areas and overview of erosion and accretion between +1 mCD and +4 mCD in the Stour estuary between 2005 and 2015...... 6 Figure 7.1: Overview of erosion and accretion patterns between 2005 and 2015 in the Orwell and Stour estuaries...... 9 Figure 7.2: Erosion and accretion patterns between 2005 and 2015 in Area 1 of the Orwell estuary .....11 Figure 7.3: Erosion and accretion patterns between 2005 and 2015 in Area 2 of the Orwell estuary .....12 Figure 7.4: Erosion and accretion patterns between 2005 and 2015 in Area 3 of the Orwell estuary .....13 Figure 7.5: Erosion and accretion patterns between 2005 and 2015 in Area 4 of the Orwell estuary .....14 Figure 7.6: Erosion and accretion patterns between 2005 and 2015 in Area 1 of the Stour estuary...... 16 Figure 7.7: Erosion and accretion patterns between 2005 and 2015 in Area 2 of the Stour estuary...... 17 Figure 7.8: Erosion and accretion patterns between 2005 and 2015 in Area 3 of the Stour estuary...... 18 Figure 7.9: Erosion and accretion patterns between 2005 and 2015 in Area 4 of the Stour estuary...... 19
Tables Table 3.1: Orwell estuary: Previously reported intertidal volume and area between 0 mCD and +4 mCD...... 2 Table 3.2: Orwell estuary: Previously reported subtidal volume and area below 0 mCD ...... 2 Table 3.3: Stour estuary: Previously reported intertidal volume and area between 0 mCD and +4 mCD...... 2 Table 3.4: Stour estuary: Previously reported subtidal volume and area below 0 mCD ...... 2 Table 4.1: Orwell estuary: Summary of control point check results...... 3 Table 4.2: Stour estuary: Summary of control point check results ...... 4 Table 7.1: Orwell estuary intertidal volume and area between 0 mCD and +4 mCD...... 10 Table 7.2: Orwell estuary subtidal volume and area below 0 mCD...... 10
DLM7531-RT001-R02-00 HHA 2015 Five Yearly Review Comparison of LiDAR and Bathymetry data sets
Table 7.3: Stour estuary intertidal volume and area between 0 mCD and +4 mCD ...... 15 Table 7.4: Stour estuary subtidal volume and area below 0 mCD ...... 15
DLM7531-RT001-R02-00 HHA 2015 Five Yearly Review Comparison of LiDAR and Bathymetry data sets
1. Background
HR Wallingford was commissioned to undertake a programme of activities for provision of input to the 2015 Harwich Haven Authority Five Yearly Review and Appendices. This activity, required the comparison of bathymetry and LiDAR data sets of the Stour and Orwell estuaries measured in 2005/2006, 2010/2011 and 2015/2016. Based on the results of the comparisons calculations of level, surface area and volume differences have been carried out. 2. Bathymetry and LiDAR data
Bathymetric data provides a means to consider the spatial extent of the subtidal area of the estuaries. Knowledge of the subtidal area can be used to estimate the intertidal area based on the assumption that the total area of the estuaries are fixed by flood defences or rising ground. The bathymetric data typically extends up to a maximum of +2 m Chart Datum (CD). Hence the bathymetric data does not provide a direct means to analyse the full extent of changes over the intertidal area. Light Detection and Ranging (LiDAR) data provides full coverage of the upper intertidal but does not reliably cover the lowest part of the intertidal area (between approximately +1 mCD and CD). The LiDAR data can be reliably used to estimate the surface area and the changes in intertidal volume between about +1 mCD and +4 mCD. For the purpose of this study, the analyses of intertidal and subtidal volumes and areas has been undertaken based on a combined bathymetry and LiDAR surface of the Stour and Orwell estuaries. This analysis method was first adopted when comparing the 2005/2006 and the 2010/2011 bathymetry and LiDAR data sets (Royal Haskoning and HR Wallingford, 2011). The methodology adopted was to crop both the Orwell and Stour estuary bathymetry data sets at a level of +1 mCD. The bathymetry data could then be used to represent the estuaries below +1 mCD. The LiDAR data sets were cropped below +1 mCD and above +4 mCD. The LiDAR could then be used to represent the estuaries between the levels of +1 mCD and +4 mCD. The two data sets were then combined and uniform raster grids with 10 m spacing created. Where appropriate in the following sections of this report, the 2005/2006 combined data set is referred to as 2005, the 2010/2011 combined data as 2010 and the 2015/2016 combined data as 2015. 3. Previously reported intertidal and subtidal volumes and areas
The previously reported (Royal Haskoning and HR Wallingford, 2011) intertidal and subtidal volumes and areas, calculated based on the combined 2005 and the 2010 bathymetry and LiDAR data sets, are shown Table 3.1 and Table 3.2 for the Orwell estuary and Table 3.3 and Table 3.4 for the Stour estuary. The figures for intertidal volume are a measure of sediment volume above a datum, so a negative number represents erosion of sediment. The figures for subtidal volume are a measure of sub-tidal water volume, so a negative number represents accretion of sediment.
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Table 3.1: Orwell estuary: Previously reported intertidal volume and area between 0 mCD and +4 mCD Volume change Year Planar area (m2) Area change (m2) Volume (m3) (m3) 2005 6,440,800 - 11,205,500 -
2010 6,535,920 95,120 gain 10,986,100 -219,400 erosion Source: Royal Haskoning and HR Wallingford (2011) Table 3.2: Orwell estuary: Previously reported subtidal volume and area below 0 mCD Volume change Year Planar area (m2) Area change (m2) Volume (m3) (m3) 2005 4,199,010 - 16,752,800 -
2010 4,102,860 -96,150 loss 16,196,100 -556,700 accretion Source: Royal Haskoning and HR Wallingford (2011) Table 3.3: Stour estuary: Previously reported intertidal volume and area between 0 mCD and +4 mCD Volume change Year Planar area (m2) Area change (m2) Volume (m3) (m3) 2005 16,879,300 - 28,697,000 -
2010 16,990,200* 110,900* gain 29,174,600* 477,600* accretion Source: Royal Haskoning and HR Wallingford (2011) *Note: 2010 River Stour intertidal volumes and areas revised May 2012 to reflect the analysis of data areas common to both the 2005 and 2010 surveys. Table 3.4: Stour estuary: Previously reported subtidal volume and area below 0 mCD Volume change Year Planar area (m2) Area change (m2) Volume (m3) (m3) 2005 10,037,500 - 42,438,800 -
2010 9,941,150 -96,350 loss 41,600,600 -838,200 accretion Source: Royal Haskoning and HR Wallingford (2011)
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4. Analysis of LiDAR data
The 2015 LiDAR data was provided by Merrett Survey in the form of 2 m gridded ASCII tile files with elevations (z) referenced to Ordnance Datum Newlyn (ODN). The 2005 and 2010 LiDAR data was provided by the Unit of Landscape Mapping (ULM) at the University of Cambridge in the same format. Prior to about 2004, the vertical accuracy of LiDAR surveys was quoted to be up to 25 cm. After this time, the accuracy for vertical levels has been quoted as being ± 5 cm to ±15 cm. The error between two successive surveys can therefore be more than this. The planimetric accuracy of a LiDAR survey is defined as being 1/2000th of the flying height, so for a typical flight altitude of 800 m an error of up to approximately 40 cm in spatial location can be expected. Since the 2011 reporting period a number of improvements have been made to the LiDAR data processing and analysis procedures used by HR Wallingford and in particular, the importance of undertaking an elevation consistency check of all of the LiDAR surveys to ensure optimum comparability between data sets has been recognised. For this study, an elevation consistency check was made on each of the three LiDAR data sets using the 2005 data set as the reference date set. This check involved extracting the reported LiDAR elevation at control points, or “hard points”, within the vicinity of each of the Stour and Orwell estuary embayment areas considered as shown in Figure 4.1 and Figure 4.2. The “hard points” selected for interrogation were generally along the centreline of roads as the elevation at these locations would not normally be expected to change significantly between surveys. The number of control points evaluated within each embayment area varied (between 2 and 11 points) depending on the availability of suitable “hard point” features. A summary of the control point check results for the Orwell and Stour estuary LiDAR data is provided in Table 4.1and Table 4.2. For each embayment area, the number of control points used, the average elevation differences are provided. Table 4.1: Orwell estuary: Summary of control point check results 2010 to 2005 2015 to 2005 Embayment # Control points Average elevation difference Average elevation difference 1 7 -0.10 m -0.03 m 2 5 -0.07 m -0.05 m 3 4 0.02 m 0.03 m 4 5 -0.05 m -0.05 m 5 5 -0.05 m -0.05 m 6 5 -0.03 m -0.01 m 7 6 -0.04 m -0.06 m Source: HR Wallingford
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Table 4.2: Stour estuary: Summary of control point check results 2010 to 2005 2015 to 2005 Embayment # Control points Average elevation difference Average elevation difference 1 10 0.11 m 0.02 m 2 7 0.03 m 0.01 m 3 10 0.02 m -0.03 m 4 11 -0.03 m -0.04 m 5 3 0.06 m -0.01 m 6 2 0.03 m 0.04 m 7 3 0.00 m -0.01 m Source: HR Wallingford The uncertainty in the measured intertidal volumetric differences between surveys is composed of random and systematic errors. Because each volume comparison is based on a large number of LiDAR data points the contribution of random errors to the calculated volume comparison becomes small, even though the vertical error in an individual point measurement may be significant (i.e. up to +/-15 cm). The systematic errors (for instance, differences in alignment between the integrated navigation system and the laser) on the other hand, do not cancel and will be different for different flights. The vertical systematic errors can be larger than the (real) average change in bed level between surveys and therefore calculated volume differences between LiDAR surveys can be dominated by the systematic error, rather than the real change. The extent of any systematic error in the intertidal surveys was examined by examining differences in measured height between surveys at the control points. These showed changes of several centimetres between surveys in some areas of the Stour and Orwell (Table 4.1 and Table 4.2). Based on the results of the control point checks summarised in Table 4.1 and Table 4.2 the elevation of the 2010 and 2015 LiDAR data within each of the extracted estuary embayment areas was adjusted by subtracting the calculated average control point elevation difference from each of the 2010 and 2015 data sets to match the average control point elevation measured in the 2005 reference data set. The 2010 and 2015 adjusted LiDAR data sets were then reclassified such that only data between +1 mCD and +4 mCD was included for analysis. Following this, the separate embayment areas for each estuary were combined together to give corrected 2010 and 2015 data sets and exported as 10 m grid files. The 2015 LiDAR grid file was subtracted from 2005 LiDAR grid file and plots of difference in elevation were prepared using a +/- 0.1 m banding in the areas of smallest change. Figure 4.1 and Figure 4.2 show an overview of the erosion and accretion that has taken place between +1 mCD and +4 mCD within each of the embayment areas in the Orwell and Stour estuaries between 2005 and 2015.
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Figure 4.1: Embayment areas and overview of erosion and accretion between +1 mCD and +4 mCD in the Orwell estuary between 2005 and 2015 Source: HR Wallingford
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Figure 4.2: Embayment areas and overview of erosion and accretion between +1 mCD and +4 mCD in the Stour estuary between 2005 and 2015 Source: HR Wallingford
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Following the corrections to each of the surveys using the fixed points (to overcome the observed systematic bias), the biggest contribution to the uncertainty in the calculated volume differences is given by the uncertainty in the mean fixed point differences. An estimate of the potential range of this uncertainty is given by twice the standard deviation of the mean of all the fixed point differences between surveys, multiplied by the intertidal area. The standard deviation of the mean all of the control point elevation differences between 2005 and 2010 in the Orwell and Stour estuaries was calculated to be 0.012 m and 0.015 m for the Orwell and Stour, respectively. If it is assumed that the intertidal area (between +1 mCD and +4 mCD) of Orwell estuary is about 6.5 Mm2 then the uncertainty in the measured volume equates to +/- 78,000 m3. For the Stour estuary, which has a larger intertidal area of about 17 Mm2, the uncertainty in the measured volume equates to +/- 255,000 m3. These values are in the region of, or larger than, the measured changes over the period 2005-2015 (see Section 7) indicating that the measured changes as a whole are similar to or lower than the range of uncertainty in the measurement method. In terms of average vertical change, the average change observed is + 0.021 m (Orwell) and + 0.012 m (Stour) but the mean error in all of the measurements is estimated to be +/- 0.012 m and +/- 0.015 m, respectively1, which again is of a similar magnitude to the observed overall net change. Note that at any particular location erosion or accretion may have occurred which is much larger than these overall net values and which is significantly larger than the (individual) measurement error of up to 0.15 m. Section 7 shows intertidal changes in bed level in both the Orwell and Stour which are in excess of this level. In conclusion, as a whole, the observed changes within the Stour and Orwell are within the “noise” of the measurement system and so can be considered as small. At specific locations, however, there are significant changes which cannot be attributed to measurement uncertainty. 5. Analysis of bathymetry data
The 2016 bathymetry data of the Orwell and Stour estuaries was provided by Harwich Haven Authority in the form of 40 separate x, y, z ASCII files with elevations (z) referenced to Chart Datum (CD). All of the bathymetry files were merged together using the Feature Manipulation Engine (FME) and a Triangular Irregular Network (TIN) surface created using the 3D Analyst toolset within ESRI ArcGIS, and converted to a 10 m raster file. The 2016 gridded bathymetry data was then reclassified such that only data below +1 mCD was retained in the data set. The uncertainty in the measured bathymetric volumetric differences between surveys is again composed of random and systematic errors. As for LiDAR, the contribution of random errors to the calculated volume comparison becomes small, even though the vertical error in an individual point measurement may be significant. Any systematic errors may however contribute significantly to differences in volume between surveys. Unlike, the LiDAR, however, there is no evidence of significant systematic error, and Harwich Haven Authority reduce systematic error by employing the same detailed methodology for each survey. The
1 The error in any individual measurement is +/- 0.15 m but this is not the relevant error to consider for estuary-wide changes as the individual errors over many different measurements cancel each other out, reducing in a much smaller mean error.
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uncertainty in the measured bathymetric volumetric differences is therefore unknown but expected to be smaller than that arising in the LiDAR volume comparisons. 6. Combined LiDAR and bathymetry data
The adjusted 2010 and 2015 LiDAR raster surfaces (see Section 4) were combined with the 2011 and 2016 bathymetry data sets and the resulting merged raster surfaces were exported as points. The resulting point files were then interpolated back to raster images using the Nearest Neighbour interpolation routine within 3D Analyst toolset. This interpolation effectively filled in any small gaps that previously existed between the LiDAR data and the bathymetry data at +1 mCD. The extents of the Orwell and Stour estuaries were then clipped out of the raster images such that volumes and areas above and below 0 mCD could be calculated using the Surface Volume tool within 3D Analyst for each estuary individually. 7. Analysis of intertidal and subtidal areas and volumes
Intertidal and subtidal volumes and areas were calculated for the 2005, 2010 and 2015 combined surfaces using the ArcGIS Spatial Analyst Surface Volume tool. For the purpose of these calculations intertidal refers to areas and volumes between 0 mCD and +4 mCD and subtidal refers to areas and volumes below 0 mCD. It should be noted here that the intertidal and subtidal volumes and planar areas calculated for the 2005 and 2010 combined data sets in Sections 7.1.1 and 7.1.2 are not identical to those quoted in Royal Haskoning and HR Wallingford (2011) and shown in Table 3.1 to Table 3.4. The reason for this is due to improvements made to the data processing and analysis procedures adopted since the 2011 reporting period and most notably the control point analysis of the LIDAR data sets. Since the Royal Haskoning and HR Wallingford (2011) report was prepared the 2010 LiDAR data set has been adjusted based on the results of the control point analysis described in Section 4. This adjusted LiDAR surface has been used in the current study to recalculate changes in intertidal and subtidal volumes and planar areas in relation to the 2005 LiDAR surface. As all three combined data sets analysed are enclosed by the same boundary file the total planar area (intertidal plus subtidal) calculated for the Orwell and Stour estuaries from one survey to another is identical. For reference, an overview of the erosion and accretion patterns observed for the combined surfaces in the Orwell and Stour estuaries for 2005 to 2015 is shown in Figure 7.1. Also shown in this figure is the position of the 0 mCD contour in 2005 and 2015.
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Figure 7.1: Overview of erosion and accretion patterns between 2005 and 2015 in the Orwell and Stour estuaries Source: HR Wallingford
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7.1. Comparison of 2005, 2010 and 2015 combined data sets
7.1.1. Orwell estuary
Analysis of intertidal and subtidal planar area and volume changes in the Orwell estuary between 2005 and 2015 have been carried out based on the combined data surfaces. The results of this analysis are provided in Table 7.1 and Table 7.2. Table 7.1: Orwell estuary intertidal volume and area between 0 mCD and +4 mCD Area change Volume change Volume change Year Area (m2) (m2) Volume (m3) (m3) 2005 to 2015 (m3) 2005 6,386,627 - 10,527,475 - -
2010 6,473,583 86,956 gain 10,336,007 -191,468 erosion -
2015 6,596,099 122,516 gain 10,665,451 329444 accretion 137,976 accretion Source: HR Wallingford Table 7.2: Orwell estuary subtidal volume and area below 0 mCD Area change Volume change Volume change Year Area (m2) (m2) Volume (m3) (m3) 2005 to 2015 (m3) 2005 4,189,873 - 16,617,406 - -
2010 4,102,917 -86,956 loss 16,088,471 -528,935 accretion -
2015 3,980,401 -122,516 loss 16,460,622 372,152 erosion -156,784 accretion Source: HR Wallingford Table 7.1 and Table 7.2 demonstrate that in the intertidal zone (between 0 mCD and +4 mCD) of the Orwell estuary there was a loss of intertidal volume (erosion) of about 191,500 m3 between 2005 and 2010. Between 2010 and 2015 the intertidal zone accreted by about 330,000 m3. Between 2005 and 2015 the intertidal zone accreted by about 138,000 m3. Distribution of this volume change over the intertidal area equates to a net accretion of about 0.021 m. In the subtidal zone (below 0 mCD) of the Orwell estuary there was loss of subtidal volume (accretion) of about 530,000 m3 between 2005 and 2010. Between 2010 and 2015 the subtidal zone eroded by about 372,000 m3. Between 2005 and 2015 the subtidal zone accreted by about 156,500 m3. Distribution of this volume change over the subtidal area equates to a net accretion of about 0.04 m. Between 2005 and 2015, the trend for both the intertidal and subtidal zones is one of accretion at an average annual rate of about 13,800 m3 in the intertidal zone and 15,700 m3 in the subtidal zone.
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Figure 7.2: Erosion and accretion patterns between 2005 and 2015 in Area 1 of the Orwell estuary Source: HR Wallingford
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Figure 7.3: Erosion and accretion patterns between 2005 and 2015 in Area 2 of the Orwell estuary Source: HR Wallingford
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Figure 7.4: Erosion and accretion patterns between 2005 and 2015 in Area 3 of the Orwell estuary Source: HR Wallingford
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Figure 7.5: Erosion and accretion patterns between 2005 and 2015 in Area 4 of the Orwell estuary Source: HR Wallingford
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7.1.2. Stour estuary
Analysis of intertidal and subtidal planar area and volume changes in the Stour estuary between 2005 and 2015 have been carried out based on the combined data surfaces. The results of this analysis are provided in Table 7.3 and Table 7.4. Table 7.3: Stour estuary intertidal volume and area between 0 mCD and +4 mCD Area change Volume change Volume change Year Area (m2) (m2) Volume (m3) (m3) 2005 to 2015 (m3) 2005 16,828,224 - 27,709,810 - -
2010 16,916,194 87,970 gain 27,673,606 -36,203 erosion -
2015 17,061,070 144,876 gain 27,965,316 291,710 accretion 255,507 accretion Source: HR Wallingford Table 7.4: Stour estuary subtidal volume and area below 0 mCD Area change Volume change Volume change Year Area (m2) (m2) Volume (m3) (m3) 2005 to 2015 (m3) 2005 10,087,276 - 42,320,455 - -
2010 9,999,306 -87,970 loss 41,565,792 -754,663 accretion -
2015 9,854,430 -144,876 loss 41,628,497 62,705 erosion -691,958 accretion Source: HR Wallingford Table 7.3 and Table 7.4 demonstrate that in the intertidal zone (between 0 mCD and +4 mCD) of the Stour estuary there was a loss of intertidal volume (erosion) of about 36,000 m3 between 2005 and 2010. Between 2010 and 2015 the intertidal zone accreted by about 291,500 m3. Between 2005 and 2015 the intertidal zone accreted by about 255,500 m3. Distribution of this volume change over the intertidal area equates to a net accretion of about 0.015 m. In the subtidal zone (below 0 mCD) of the Stour estuary there was loss of subtidal volume (accretion) of about 754,500 m3 between 2005 and 2010. Between 2010 and 2015 the subtidal zone eroded by about 62,500 m3. Between 2005 and 2015 the subtidal zone accreted by about 692,000 m3. Distribution of this volume change over the subtidal area equates to a net accretion of about 0.070 m. Between 2005 and 2015, the trend for both the intertidal and subtidal zones is one of accretion at an average annual rate of about 25,500 m3 in the intertidal zone and 69,000 m3 in the subtidal zone. This trend of accretion between 2005 and 2015 in the intertidal and subtidal zones is the same as that observed in the Orwell estuary over the same period.
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Figure 7.6: Erosion and accretion patterns between 2005 and 2015 in Area 1 of the Stour estuary Source: HR Wallingford
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Figure 7.7: Erosion and accretion patterns between 2005 and 2015 in Area 2 of the Stour estuary Source: HR Wallingford
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Figure 7.8: Erosion and accretion patterns between 2005 and 2015 in Area 3 of the Stour estuary Source: HR Wallingford
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Figure 7.9: Erosion and accretion patterns between 2005 and 2015 in Area 4 of the Stour estuary Source: HR Wallingford
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8. Conclusions
When considered as a whole, the observed overall changes within the Stour and Orwell over the period 2005 to 2015 are within or a similar magnitude to the “noise” of the measurement system and so can be considered as small. At specific locations, however, there are significant changes (both accretion and erosion) which cannot be attributed to measurement uncertainty. 9. References
Royal Haskoning and HR Wallingford (2011). Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA: Interim Report. Report to Harwich Haven Authority. October 2011.
DLM7531-RT001-R02-00 20 HR Wallingford is an independent engineering and environmental hydraulics organisation. We deliver practical solutions to the complex water-related challenges faced by our international clients. A dynamic research programme underpins all that we do and keeps us at the leading edge. Our unique mix of know-how, assets and facilities includes state of the art physical modelling laboratories, a full range of numerical modelling tools and, above all, enthusiastic people with world-renowned skills and expertise.
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REPORT
Monitoring of Saltmarsh in the Stour and Orwell Estuaries
2015
Client: Harwich Haven Authority
Reference: RDCR001D01 Revision: 01/Final Date: 23 October 2015
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HASKONINGDHV UK LTD.
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Document title: Monitoring of Saltmarsh in the Stour and Orwell Estuaries
Reference: RDCR001D01 Revision: 01/Final Date: 23 October 2015
Project number: 9Y0158 Author(s): Stuart Dawks
Drafted by: Stuart Dawks
Checked by: Matt Simpson
Date / initials: MS 23/10/15
Approved by: Matt Simpson
Date / initials: MS 23/10/15
Classification Project related
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23 October 2015 RDCR001D01 i
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Table of Contents
1 INTRODUCTION 3
2 METHODOLOGY 4 2.1 Survey Design 4 2.2 Digitising of the saltmarsh areas 5 2.2.1 Assessment of aerial photographs and LiDAR data 5 2.2.2 Software 6 2.2.3 Model 6
3 RESULTS 9 3.1 Results from 2015 Survey 9 3.2 Comparison with previous surveys 9
4 Conclusion 13
Table of Tables
Table 1- Total saltmarsh coverage in the Stour and Orwell ...... 9 Table 2 - Comparison in saltmarsh extent between 2010 and 2015 ...... 9
Table of Figures
Figure 1 – Aerial photography coverage for the 2015 survey Figure 2 - LiDAR coverage for the 2015 survey Figure 3 - LiDAR and aerial imagery comparison Figure 4 - Clip extent of aerial photographs Figure 5 - Converted image to ESRI raster Figure 6 - Converted raster within colour bands Figure 7 - Final polygons after manual clean (green) with clip polygon (red) Figure 8 - 2015 saltmarsh extent for the Stour Figure 9 - 2015 saltmarsh extent for the Orwell
Appendices
Appendix Title
23 October 2015 RDCR001D01 ii
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1 INTRODUCTION
A number of schemes have been completed within the Stour and Orwell Estuaries in recent years which resulted in the adoption of a number of mitigation and monitoring actions to meet licensing and consent conditions. These actions were agreed and detailed within mitigation and monitoring agreements. A comprehensive suite of monitoring is undertaken through the agreements including bathymetric surveys, ecological surveys, aerial photography and Light Detection and Ranging (LiDAR) measurements.
One aspect of the monitoring is to determine any changes in the patterns of erosion and accretion within the saltmarsh habitats. HHA is therefore required to monitor the extent of this habitat; this is undertaken using aerial photography and LiDAR measurement. By monitoring the area of saltmarsh within the two estuaries it is possible to identify areas of change either in terms of erosion or accretion.
The aims of the current study are to:
1) Digitise the areas of saltmarsh visible on the 2015 aerial photography; and,
2) Compare the areas of saltmarsh calculated from the 2005, 2010 and 2015 survey and identify any increase or decrease in extent over the course of the saltmarsh monitoring.
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2 METHODOLOGY
2.1 Survey Design
The survey techniques for monitoring of saltmarsh extent have included the capture of LiDAR and high resolution aerial photographs.
For the 2015 survey, aerial imagery was captured at a resolution of 10cm for the extent shown in Figure 1. LiDAR data was captured at a resolution of 1m for the extent shown in Figure 2.
Figure 1 – Aerial photography coverage for the 2015 survey
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Figure 2 - LiDAR coverage for the 2015 survey
The LiDAR and aerial imagery data were captured in British National Grid projection and were reviewed against the locations of known features to check accuracy of data collection; both sets of data were found to be accurate for use in the assessment of saltmarsh extent. The 2015 aerial photographs are of higher resolution than those collected in previous surveys and have less shadowing.
2.2 Digitising of the saltmarsh areas
2.2.1 Assessment of aerial photographs and LiDAR data
The areas of saltmarsh within the study area were digitised using a part-automated and part-manual process. The automatic process used the attributed colour map within the aerial photograph images; this is the same process that was used during the 2005 and 2010 saltmarsh capture.
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The potential to use the LiDAR data to determine saltmarsh extent based on level / elevation was explored and a number of sample analyses were performed. However, this revealed a number of problems with this approach, namely:
the saltmarsh elevation is sloped from the front to the rear, so no single level could be used to determine the extent as the level to determine the rear of the saltmarsh areas was higher than that of the front slope of saltmarsh.
the elevation of the saltmarsh area varies significantly around the estuaries, which would require different levels being used for different areas of saltmarsh.
the LiDAR data had a lower resolution than the aerial imagery (see Figure 3) and when compared to the 2005 and 2010 extents the areas defined by the LiDAR were not comparable to the previous data collected and, therefore, a valid comparison of saltmarsh extent between 2005, 2010 and 2015 would not be possible.
Figure 3 - LiDAR and aerial imagery comparison.
2.2.2 Software
The automation process was carried out in ArcGIS 10.3 using the spatial analysis extension and the creation of a bespoke model for the Harwich Haven Authority aerial images. The software allowed the automation of the process which took into account the different type of vegetation around the saltmarsh as well as different soil and light classifications. All outputs were manually checked and edited to maximise on the accuracy of the saltmarsh extent and tidal channels
2.2.3 Model
An initial inspection was undertaken from the 2015 aerial photographs to determine the colour banding of the saltmarsh in an area. These bandings included the different variation of saltmarsh colour as well as accounting for shadowing and other colour variations within the images. Once a range of values were determined, this classification was reviewed against the other saltmarsh areas within the estuary and then input into the model. This was the same process undertake for the 2010 analysis, with the classification banding being revised for the new aerial survey images.
The aerial photographs were clipped using a 100m buffer of the previously modelled 2010 extent, to determine the approximate location of areas of saltmarsh; the use of clipped images is more efficient to perform the modelling analysis on and to process in order to calculate saltmarsh extent).
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Each saltmarsh area was given a unique identification name, which corresponded with the 2010 analysis, to enable the comparison of extent between years to be undertaken. The images were then input to the saltmarsh analysis model.
The model process consists of five steps in order to output the most accurate and usable saltmarsh extent. These steps are:
1) Conversation from ECW image into an ESRI raster grid with the colour value taken from the ECW pixel value. 2) Reclassification of the grid image to identify those colours within the input banding. 3) Conversion from an ESRI grid format into a polygon showing the extent of saltmarsh (between the colour bandings). 4) Calculation of polygon areas. 5) Removal of all polygons under 2 metres (small islands of colour, which included mud and seaweed).
An example of the result from these steps can be seen in Figures 4 to 7.
Figure 4 - Clip extent of aerial photographs
Figure 5 - Converted image to ESRI raster
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Figure 6 - Converted raster within colour bands
Figure 7 - Final polygons after manual clean (green) with clip polygon (red)
The outputs from the models were manually checked by eye and any areas that were not saltmarsh have been removed, or added if they had been excluded from the model analysis. The checks also filled small holes, which where saltmarsh or analysis error, and then finally checked for topological correctness.
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3 RESULTS
3.1 Results from 2015 Survey
The results of the analysis of the 2015 aerial photographs are presented in Table 1. An overview of the 2015 saltmarsh extent in the Stour and Orwell is included in Figures 8 and 9.
Table 1- Total saltmarsh coverage in the Stour and Orwell
Location 2015 Saltmarsh Area (ha)
Harbour 4.03 Lower Orwell 30.34 Lower Stour 57.22
Mid Stour 22.24
Upper Orwell 11.44
Upper Stour 29.15 Total 154.42
3.2 Comparison with previous surveys
The saltmarsh extent calculated from the 2015 survey has been compared against the previous 2005 and 2010 surveys. The results are presented in Table 2 for each zone of the estuarine system (a summary is presented in Table 3). Table 3 identifies that an increase in extent of 16.11ha (11.63%) occurred between 2005 and 2010 and a decrease of 0.28ha (0.18%) between 2010 and 2015.
Table 2 - Comparison in saltmarsh extent between 2005, 2010 and 2015
Extent (m2) Change (%) Location* 2005 to 2010 to 2005 to 2005 2010 2015 2010 2015 2015 Harbour Stour RB 10,669 22,233 25,144 108 13 136 Lower Stour RB 302,109 335,134 333,640 11 0 10 Mid Stour RB 1 92,197 110,541 109,428 20 -1 19 Upper Stour RB 1 82,022 91,432 85,141 11 -7 4 Upper Stour RB 2 9,597 14,287 14,398 49 1 50 Upper Stour RB 3 23,963 29,375 28,590 23 -3 19 Upper Stour RB 4 1,915 1,941 1,992 1 3 4 Upper Stour RB 5 10,884 8,990 8,084 -17 -10 -26 Upper Stour RB 6 30,501 32,228 27,051 6 -16 -11 Upper Stour LB 3 4,548 4,978 4,962 9 0 9 Upper Stour LB 2 114,327 128,585 118,011 12 -8 3 Upper Stour LB 1 3,122 3,325 3,293 7 -1 5
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Mid Stour LB 4 831 1,062 1,313 28 24 58 Mid Stour LB 3 83,011 97,491 99,961 17 3 20 Mid Stour LB 2 6,461 6,236 6,236 -3 0 -3 Mid Stour LB 1 8,083 7,741 5,463 -4 -29 -32 Lower Stour LB 223,945 223,115 238,517 0 7 7 Harbour Orwell RB 217 7,407 5,646 3,313 -24 2,502 Lower Orwell RB 1 36,341 39,370 33,537 8 -15 -8 Lower Orwell RB 2 145,577 151,841 157,316 4 4 8 Upper Orwell RB 1 51,061 54,697 54,470 7 0 7 Upper Orwell RB 2 10,847 11,647 11,156 7 -4 3 Upper Orwell RB 3 17,372 16,128 15,521 -7 -4 -11 Upper Orwell LB 2 21,265 24,678 25,164 16 2 18 Upper Orwell LB 1 4,424 7,152 8,092 62 13 83 Lower Orwell LB 3 19,612 26,855 27,464 37 2 40 Lower Orwell LB 2 57,873 74,444 81,771 29 10 41 Lower Orwell LB 1 3,668 4,298 3,357 17 -22 -8 Harbour Orwell LB 9,466 10,022 9,495 6 -5 0
*=LB=left bank, RB=right bank when viewed from the head to the mouth of the estuaries
Table 3 – Summary of change in saltmarsh extent between 2005, 2010 and 2015
2005 2010 2015 Difference Difference Percentage Percentage Location Saltmarsh Saltmarsh Saltmarsh 2005-2010 2010-2015 Difference Difference Area (ha) Area (ha) Area (ha) (ha) (ha) 2005-2010 2010-2015
Harbour 2.04 3.97 4.03 1.93 0.06 94.87 1.51 Lower Orwell 26.31 29.68 30.34 3.37 0.66 12.82 2.22 Lower Stour 52.61 55.82 57.22 3.21 1.40 6.11 2.51 Mid Stour 19.06 22.31 22.24 3.25 -0.07 17.05 -0.31 Upper Orwell 10.50 11.43 11.44 0.93 0.01 8.89 0.09 Upper Stour 28.09 31.50 29.15 3.41 -2.35 12.15 -7.46 Total 138.59 154.70 154.42 16.11 -0.28 11.63 -0.18
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Figure 8 - 2015 saltmarsh extent for the Stour
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Figure 9 - 2015 saltmarsh extent for the Orwell
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4 Conclusion
The LiDAR data collected as part of the study was of sufficiently high resolution to accurately determine the locations of the saltmarsh; however, its use in determining extent in manner that would be comparable to the 2005 and 2010 data was found to be very limited.
The use of the 2015 aerial imagery to calculate saltmarsh extent, using the same methodology as that adopted for the 2010 analysis, was deemed to be accurate and enabled a comparable analysis to that undertaken for the 2005 and 2010 data to be undertaken. The spatial resolution of the data was also sufficient for comparison of previously determined extents to be undertaken.
Comparison of the saltmarsh extent within the estuary system based on the 2015 survey with the results of the 2005 and 2010 surveys shows an increase in saltmarsh extent within the estuary system of 15.8ha over the monitoring period, equating to approximately 1.6ha/year on average. Over the last 5 years (between 2010 and 2015), a very minor decrease in extent is recorded. The magnitude of change is considered within the margin of error of the analysis.
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Appendix A
Figures
Saltmarsh Extents 2015
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23 October 2015 APPENDIX RDCR001D01 A1
royalhaskoningdhv.com
Stour and Orwell Estuaries Annual Benthic Monitoring Report: 2015 survey
For Harwich Haven Authority
Project No.: I-HHA-110/001
June 2016
www.thomsonecology.com
2015 Benthic Monitoring Report Stour and Orwell Estuaries
London & South East Compass House Surrey Research Park Guildford GU2 7AG . UK t: +44 (0)1483 466 000
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Enquiries e: [email protected] w: www.thomsonecology.com
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Project Number Report No. Revision No. Date of Issue
I-HHA-110 1 1 30/06/2016
Name Signature Position
Authors Sarah Marjoram Marine Consultant
Daniel Bastreri Principal Marine Consultant
Reviewer Dr Ruth Barnich Principal Taxonomist
Client Contact: John Brien Reference. I-HHA-110/001
Disclaimer:
Copyright Thomson Unicomarine Limited. All rights reserved. No part of this report may be copied or reproduced by any means without prior written permission from Thomson Unicomarine Limited. If you have received this report in error, please destroy all copies in your possession or control and notify Thomson Ecology Limited. This report has been prepared for the exclusive use of the commissioning party and unless otherwise agreed in writing by Thomson Unicomarine Limited, no other party may use, make use of or rely on the contents of the report. No liability is accepted by Thomson Ecology Limited for any use of this report, other than for the purposes for which it was originally prepared and provided. Opinions and information provided in the report are on the basis of Thomson Ecology Limited using due skill, care and diligence in the preparation of the same and no explicit warranty is provided as to their accuracy. It should be noted and it is expressly stated that no independent verification of any of the documents or information supplied to Thomson Ecology Limited has been made.
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Contents
Summary ...... 6 1. Introduction ...... 7 1.1 Background ...... 7 1.2 The Brief and Objectives ...... 8 2. Methodology ...... 9 2.1 Design of survey programme ...... 9 2.2 Field work ...... 11 2.3 Laboratory work ...... 11 2.4 Data analysis ...... 12 3. Results ...... 15 3.1 Particle size analysis ...... 15 3.2 Macrofaunal analysis ...... 15 4. Discussion ...... 22 5. References ...... 24 Appendices ...... 26 Appendix 1: Particle Size Analysis ...... 26 Appendix 2: Dominant 20 species in each cluster group ...... 28 Appendix 3: Raw abundance and biomass data ...... 33 Appendix 4: Total biomass per m2 at each sampling station ...... 83 Appendix 5: Biotope descriptions ...... 84 Appendix 6: Biotopes identified in 2014 and 2015 ...... 86
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Tables
Table 1: Sample groups determined from the 2003 survey ...... 10 Table 2: Univariate analysis results showing highest and lowest values ...... 16 Table 3: PSA results ...... 26 Table 4: The top 20 abundant species in each cluster group, by number of individuals per m2 28 Table 8: Raw macrofaunal abundance data for Stour Estuary sampling station ...... 33 Table 9: Raw macrofaunal abundance data for Orwell Estuary sampling stations ...... 43 Table 10: Raw biomass data for Stour Estuary sampling stations 150 to 180 ...... 53 Table 11: Raw biomass data for Stour Estuary sampling stations 181 to 549 ...... 63 Table 12: Raw biomass data for Orwell Estuary sampling stations...... 73 Table 13: Total biomass per m2 in Stour Estuary sampling stations 150 to 180 ...... 83 Table 14: Total biomass per m2 in Stour Estuary sampling stations 181 to 549 ...... 83 Table 15: Total biomass per m2 in Orwell Estuary sampling stations ...... 83
Figures
Figure 1: Location of annual monitoring stations in the Stour and Orwell estuaries, with sample groups and target biotopes...... 10 Figure 2: Number of taxa found at each sampling station...... 16 Figure 3: Number of individuals per square meter found at each sampling station...... 17 Figure 4: Biomass in gram per square metre found at each sampling station...... 18 Figure 5: SIMPROF cluster dendrogram of macrofaunal data from each sampling station. Symbols show stations which are more than 50% similar. Red lines indicate that these samples cannot be significantly differentiated...... 19 Figure 6: Non-metric multidimensional scaling ordination of the sampling stations based on relative species abundances...... 20 Figure 7: Sampling stations and the assigned cluster groups ...... 20 Figure 8: Distribution of biotopes assigned to each group, by station ...... 21
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Summary
The results of the 2015 survey indicate that the Stour and Orwell Estuaries continue to support relatively abundant and diverse macrobenthic communities, which are typical of coastal and estuarine waters in SE England. These benthic communities are dominated by detritivore, mainly deposit-feeder species, such as the mud snail Peringia ulvae, polychaetes of the genera Streblospio and Tharyx, oligochaetes and nematodes.
The biotopes identified in 2015 are also typical of estuarine habitats. Both littoral biotopes (HedMac and CirCer) contain species that are valuable food resources to mobile species, such as bottom-feeding fish, crabs and birds. Wildfowl feed on a variety of species, for example the ragworm Hediste diversicolor is an important prey species for bar-tailed godwit and curlew. The bivalve Macoma balthica is part of the diet of shelduck and the mud snail Peringia ulvae, the catworm Nephtys hombergii and the mud shrimp Corophium volutator are target prey species for redshank.
21 Stations out of 44 were identified as having the same biotope as in 2014. Due to the shallow nature of the estuaries and the presence of sampling stations on the edge of the intertidal extent some biotopes have changed from being classified as being littoral sediment to sublittoral sediment.
The most stable areas within this sampling regime are the upper reaches of the Stour Estuary and the majority of the subtidal stations. The Orwell Estuary appears to have more variation in biotopes than the Stour. This may be because the mouth of the estuary is more exposed to the North Sea, which could result in more wave exposure and movement of sediment, compared to the Stour Estuary which is protected by the presence of Harwich Dock.
Despite the apparent difference in the presence and distribution of biotopes between the Stour and Orwell Estuaries, ANOSIM analysis on the abundance data indicates that the macrofaunal communities present in these estuaries are statistically similar, and that this result is significant.
No rare or protected species were found in this survey. However seven invasive non-native species, as listed by Eno et al. (1997), were identified.
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1. Introduction
1.1 Background
1.1.1 A wide scale monitoring programme of the Stour and Orwell Estuaries benthic communities was introduced by Harwich Haven Authority (HHA) in 1997, as part of the compensation, mitigation and monitoring agreement under their 1998-2000 Capital Dredge Licence. The monitoring programme, which was later amended to meet the requirements of the Trinity III Extension consent, had an original frequency of five years.
1.1.2 The first survey was undertaken in 1997, when 154 stations were sampled. Two benthic biological samples and one sample for particle size analysis (PSA) were taken at each station. The biological samples were analysed by Thomson Unicomarine (then Unicomarine) and the PSA by HR Wallingford. The results were reported by Unicomarine (Dyer, 2000).
1.1.3 The second survey was undertaken in 2003, when 267 stations were sampled in the Stour, Orwell and Harwich approaches. One benthic biological sample and one PSA samples were taken at each station, and analysed by Unicomarine. The data acquired during these surveys was reported by Dyer et al. (2004) and have been used in other research (Dyer & Worsfold, 2004; Worsfold & Dyer, 2004; Worsfold, 2005 and Bryant & McNulty 2007). The results of the 1997 and 2003 surveys were also used to inform a report on environmental trends in the Stour and Orwell Estuaries (Royal Haskoning, 2007).
1.1.4 The five year interval between surveys made variations in benthic abundance, diversity and distribution difficult to interpret. For this reason, an annual monitoring programme involving fewer samples was agreed. Sampling each year should result in an effective long-term monitoring programme with enough data points to detect trends. The full details of surveys undertaken between 1997 and 2016, including reports on the results can be found in Annex I.
1.1.5 The emphasis of the annual surveys is on monitoring rather than on biotope mapping. Survey sites consist of stations within a selection of biotopes in each estuary or different parts of an estuary, to allow comparison between the benthos of similar biotopes. This comparison should help highlight any areas that are showing trends in benthic populations.
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1.1.6 Biomass data are also incorporated into annual reports to allow comparisons with bird data. The annual benthic data (abundance and biomass) will allow relationships between prey availability and bird numbers to be compared more easily and with a more robust data set to support any findings.
1.1.7 It was agreed at the annual Steering Group in 2007 that Unicomarine should present the data in a report each year. The format of the benthic reports has changed throughout the years following discussions at the meeting of the monitoring programme steering group. Since 2010 following discussion at the steering group meeting on 13th March 2010 the benthic report now contains summary information of the biotopes recorded from the past two survey years as an appendix.
1.1.8 The annual benthic data reports have been used to inform Royal Haskoning’s annual mitigation and monitoring reports for the Stour and Orwell estuaries (Royal Haskoning, 2007, 2008, 2010, 2011 & 2012). The original proposal was to compare results with data from the Blackwater Estuary but that project was discontinued after the final surveys in 2009 (Dyer & Worsfold, 2009).
1.2 The Brief and Objectives
1.2.1 Thomson Unicomarine has been commissioned by HHA to carry out the 2015 annual benthic survey and present the results. Comparisons with previous year results, including abundance, distribution and fluctuation of benthic communities in relation to PSA and qualitative comparisons of biotope assignments will be presented in the 2012- 2015 report.
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2. Methodology
2.1 Design of survey programme
2.1.1 Samples were collected from 44 stations belonging to 11 sample groups from both estuaries. These include four sample groups for the Orwell (OrA-D) and seven for the Stour (StA-G). Groups of samples were selected using data from the 2003 survey to represent typical biotopes, and these are shown in Figure 1. Four grab samples were taken within each of these groups, at locations sampled in 2012, 2013, 2014, to allow comparison between these years. Samples were also taken at these sites between 1997 and 2011. Two exceptions to this are St. 548 & St. 549 which were only added to the survey programme in 2008.
2.1.2 The sampling stations are mapped in Figure 1; and Table 1 includes the list of biotope assignments based on analysis of data from the 2003 survey (Worsfold, 2005). Each of the four sampling points within any particular group belong to a single biotope (following Connor et al., 2004), using the 2003 data, although there may have been more than one (2003) cluster group included in a biotope. Each group has four stations, of similar community type, that were meant be treated as replicates. There are four sample groups for the Orwell (OrA-D) and seven for the Stour (StA-G). Sample groups are summarised in Table 1 and Figure 1.
2.1.3 Following the definition of Connor et al. (2004), a biotope is a combination of a habitat and its associated community of biological species. A habitat includes one or more substrata, such as sand, mud, rock, together with its physical and chemical properties – hydrodynamic regime, turbidity, dissolved oxygen salinity, etc. An assemblage of populations of species, each adapted to these specific properties and associated with a particular habitat is defined as a community.
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Figure 1: Location of annual monitoring stations in the Stour and Orwell estuaries, with sample groups and target biotopes.
Table 1: Sample groups determined from the 2003 survey
Group colour in EUNIS Biotope recorded Description Area found maps Nephtys hombergii, Macoma Dark A2.311 LS.LMu.MEst.NhomMacStr balthica and Streblospio Intertidal Blue shrubsolii in littoral sandy mud Ragworms & bivalves; Hediste Pale A2.312 LS.LMu.MEst.HedMac diversicolor and Macoma Intertidal blue balthica in littoral sandy mud Dark Ragworms: Hediste diversicolor Upper estuarine A2.322 LS.LMu.UEst.Hed Green in littoral mud intertidal Aphelochaeta marioni and Yellow A5.322 SS.SMu.SMuVS.AphTubi Tubificoides spp. in variable Subtidal salinity infralittoral mud Fan worms: Sabella pavonina Purple A5.432 SS.SMx.IMx.SpavSpAn with sponges and anemones on Subtidal infralittoral mixed sediment
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2.2 Field work
2.2.1 Sampling was undertaken by Thomson Unicomarine and HHA staff between the 3rd and the 5th of August 2015 from the HHA vessel ‘Egret’. Two samples were taken at each station, using a 0.04 m² Shipek grab, one for particle size analysis (PSA) and one for benthic biological analysis. Sampling at all stations was successful. The biological samples were sieved over a 0.5 mm mesh and fixed in a formaldehyde solution on the day of sampling.
2.3 Laboratory work
2.3.1 PSA was conducted at Thomson Unicomarine’s laboratory following procedures laid out in the National Marine Biological Analytical Quality Control (NMBAQC) Scheme’s best practice guidelines (Mason, 2011) and Thomson Unicomarine’s PSA standard operating procedures (Finbow & Argent, 2012).
2.3.2 Analysis of the macrobenthic samples was undertaken according to the agreed specifications, using Thomson Unicomarine’s standard operating procedures (TEM09, 2013). All biological analyses were conducted at Thomson Unicomarine’s laboratory by Thomson Unicomarine staff with internal quality control procedures at each stage of the process.
2.3.3 After several days in preservative, the biological samples were sieved at 0.5mm and all biota extracted using low power stereo microscopes. In-house quality control procedures were carried out, to reduce the risk of biota being missed. After these procedures were completed, the sediment residues (sediment from which biota had been extracted) were discarded. The extracted biota were preserved in 70% industrial denatured alcohol (IDA). Countable fauna removed from the samples were identified to the most accurate taxonomic level practicable, usually species, and individuals counted. Non-countable taxa, such as colonial fauna, plants and algae, were recorded as present (‘P’). High power compound microscopes were used to confirm the identity of some species.For quality control purposes and to allow future taxonomic comparisons, the extracted fauna will be kept at Thomson Unicomarine for a minimum of 2 years after analysis.
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2.4 Data analysis
PSA
2.4.1 The sieve and laser data were merged to produce a continuous particle size distribution which was entered into the GRADISTAT program (Blott & Pye, 2001) to obtain derived statistics. PSA data were converted into simplified proportions of eight size categories (Wentworth, 1922). These are shown in Appendix 1.
Macrobenthic data
2.4.2 All statistical analyses were carried out using the PRIMER (Plymouth Routines in Multivariate Ecological Research) suite of applications version 6.1.13 (Clarke & Warwick, 1994; Clarke & Gorley, 2006).
Univariate analysis
2.4.3 Total numbers of taxa (S) and individuals (N), Margalef’s index (d, species richness),
Pielou’s index (J’, evenness) and Shannon-Wiener (H'(loge), diversity) were calculated for each sample using the DIVERSE component of PRIMER. Non-countable taxa were excluded from the calculations of total numbers of individuals and diversity indices, but included when calculating the total numbers of taxa. Table 2 contains a summary of the results of the univariate analyses, showing the highest and lowest values for each test.
Multivariate analysis
Cluster Analysis
2.4.4 The clustering technique compares the abundance of each taxon in each sample with its abundance in each of the other samples. The result is a matrix of similarity indices comparing each sample with all the other samples. This similarity matrix is represented diagrammatically as a dendrogram. Samples that are similar link together towards the bottom of the figure and those that are less similar link towards the top of the diagram. The scale is an index from 0% to 100% and should be viewed as a relative indicator of similarity. It does not indicate the proportion of species in common. The analysis used Bray-Curtis similarity on square root transformed data and the group averaging cluster algorithm (Clarke & Gorley, 2006). Taxa recorded only as present were given a unitary value of 1.
2.4.5 The similarity profile (SIMPROF) test was carried out as part of the clustering routine. This permutational test identifies clusters of samples that cannot be statistically separated at the 5% significance level and marks them on the dendrogram using red
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lines. Black branches on the cluster denote samples that are statistically different from one-another at the 5% significance level.
Multi-Dimensional Scaling (MDS)
2.4.6 Non-metric multidimensional scaling (MDS) was used to further examine the grouping of stations described above employing relevant statistical considerations (Clarke & Warwick, 2001). The technique uses as a starting point the same Bray-Curtis similarity matrix used for the cluster analysis. An iterative process places sample points onto a 2- dimensional plane in a configuration where the inter-sample similarities are most closely represented. It is important to note that, although the MDS plot is bounded by a box, the box does not represent either axes or scale. Two samples with a high similarity index will appear close together while those less similar will appear further apart. The ‘correct’ configuration of sample points will be multidimensional and the plot is the best possible 2-dimensional representation of this multidimensional configuration. The technique should be viewed as complementary to cluster analysis, offering a different perspective of the same information.
Characteristic biota
2.4.7 The data were examined further to determine the characteristic fauna of the communities recognised by the groupings of samples described above. A list of samples in each cluster group was made and the mean number of individuals of each recorded taxon (with countable individuals) in the samples assigned to each of the cluster groups was calculated and converted to average numbers per square metre. The resulting lists represent, in decreasing order, the numerically dominant taxa in each group. Only the top 20 taxa are given in each list (Appendix 2).
Biotope Assignment
2.4.8 The characteristic biota of the cluster groups were used to assign biotopes, and to corresponding EUNIS codes, following the most recent classification (Connor et al., 2004).
2.4.9 Comparative tables produced by Connor et al. (2004) were used to assign biotopes to cluster groups. These tables enable a rapid comparison of the species composition and the principal physical characteristics between user-defined sets of biotopes. The table allows the user to list the characteristic biota of each cluster group and provides a percentage value of core biotope records within which the given species is recorded. These percentages are totalled for each biotope. The biotope with the highest total percentage was selected as the biotope that best represented that cluster group.
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Data Mapping
2.4.10 Sampling points from the 2015 survey were plotted onto maps using ESRI ArcGIS (Numbers of taxa per sample, individuals and total biomass (both calculated as values per m²), SIMPROF cluster groups and extrapolated biotopes were also plotted.
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3. Results
3.1 Particle size analysis
3.1.1 Results from the PSA indicate that the majority of samples are gravelly sandy mud (Appendix 1, Tables 3 to 6), and that the proportions of silt/clay were high at the majority of the stations. Two stations (152 and 154, both subtidal and on the inner Stour Estuary) were predominantly pebbles, and seven stations predominantly sand. These included three intertidal stations (158, 163 and 191) and one subtidal (249) in the Inner Stour Estuary; two intertidal stations (258 and 263) in the Inner Orwell Estuary and one subtidal station (285) in the Outer Orwell Estuary.
3.1.2 There is little correlation between sediment composition and cluster group, with samples within a single cluster group representing a range of sediment types.
3.2 Macrofaunal analysis
3.2.1 As in previous years, most of the macrobenthic species found in the samples represent biological communities considered to be typical of estuarine habitats, normally associated with fine and mixed sediments in estuaries of SE England (Bolam, 2003; Chesman et al., 2004; ABPmer, 2007; Attrill et al., 1996; Attrill, 1998; P&O - London Gateway, 2004).
Univariate analysis
3.2.2 The total number of taxa, number of individuals per m2 and biomass per m2 are presented in Figures 2, 3 and 4 respectively. The raw data, including full macrobenthic abundance and biomass data matrix is presented in Appendix 3. The total biomass in each sample is presented in Appendix 4 in grams per square meter.
3.2.3 In total 278 different taxa were recorded in the samples taken in 2015. The number of taxa recorded at each station varied from 12 at St. 150 to 88 at St. 189.
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Table 2: Univariate analysis results showing highest and lowest values
Test Highest Stour or Inter- or Lowest Stour or Inter- or Orwell subtidal Orwell subtidal
Number of 3095 (St. 260) Orwell Subtidal 25 (St. 296) Orwell Intertidal individuals
Number of taxa 88 (St. 189) Stour Subtidal 12 (St. 150) Stour Intertidal
Margalef’s species 12.5 (St. 189) Stour Subtidal 1.84 (St. 150) Stour Intertidal richness (d)
Pielou’s evenness 0.95 (St. 296) Orwell Subtidal 0.26 (St. 549) Stour Intertidal (J)
Shannon Weiner 3.27 (St. 289) Orwell Subtidal 0.70 (St. 549) Stour Intertidal (H’(loge))
Figure 2: Number of taxa found at each sampling station.
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3.2.4 The number of individuals per m2 is shown below in Figure 3.
Figure 3: Number of individuals per square meter found at each sampling station.
3.2.5 There was a relatively low variation in the number of individuals recorded at each sampling station. The lowest number of individuals (25) was recorded at station 296 in the Orwell. This station is in the subtidal area close to the mouth of the estuary, in an area with the highest proportion of silt (71.4 %) and 25.4 % of fine to medium sand.
3.2.6 The highest number of individuals (3095) was found at station 260, also within the Orwell. This station is in the intertidal zone in the inner estuary, and in contrast with station 296, it has a mixed particle size distribution, with 24.4 % of silt, 11.3 % pebbles, and 52.3 % of medium to very coarse sand and granules.
3.2.7 The taxa which were present in the highest numbers were round worms (Nematoda), mud snails (Peringia ulvae), polychaete worms (Streblospio sp. and Tharyx sp.), and the oligochaete Tubificoides amplivasatus.
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Figure 4: Biomass in gram per square metre found at each sampling station.
3.2.8 Biomass at each station is shown in Figure 4. There were relatively large variations in biomass. Station 189 (Stour, subtidal) had the highest biomass per m2 at 9,992.8 g/m2 and station 295 (Orwell, subtidal) showed the lowest at 0.39 g/m2.
3.2.9 The taxa which contributed the highest biomass per m2 for the survey as a whole were slipper limpet (Crepidula fornicata), common cockle (Cerastoderma edule), Pacific oyster (Crassostrea gigas), peacock worm (Sabella pavonina) and the Manila clam (Tapes philippinarum).
Multivariate analysis
3.2.10 Multivariate analyses were carried out to explore the relationships between stations and investigate similarities in the species assemblage found at each station.
3.2.11 The hierarchical agglomerative clustering function in PRIMER was used to produce a dendrogram using the Bray-Curtis similarity measure. The samples are fused into groups, and then into larger clusters starting with the highest mutual similarities then gradually lowering the similarity level at which groups are formed (Clark and Warwick, 1994). Figure 5 shows the dendrogram produced in PRIMER, illustrating the relationship between the samples taken at all stations.
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Figure 5: SIMPROF cluster dendrogram of macrofaunal data from each sampling station. Symbols show stations which are more than 50% similar. Red lines indicate that these samples cannot be significantly differentiated.
3.2.12 A similarity profile (SIMPROF) test was also carried out on the data, to detect statistically significant evidence of genuine clusters (e.g. that samples in that group appear to show evidence of multivariate pattern).
3.2.13 The SIMPROF test shows that the macrofaunal composition at stations 306, 260, 155 and 207 are statistically different from the macrofaunal communities at the other stations. Stations 260 (Orwell, inner estuary), 204 (Stour, outer estuary) and 155 (Stour, inner estuary) are intertidal. Station 306, in the outer Orwell Estuary is subtidal.
3.2.14 Stations have also been put into 14 groups which were identified through the clustering test as being more than 50% similar.
3.2.15 This is illustrated further using Multi-Dimensional Scaling (MDS) (Figure 6). Stations and groups that have similar species compositions occupy the same area within the plot. This indicates that stations in groups C, D, E and M have similar macrofaunal communities. Stations in groups F and A appear to be different from other groups. However, the SIMPROF test carried out and illustrated in Figure 5 suggests that this difference is not statistically significant.
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Figure 6: Non-metric multidimensional scaling ordination of the sampling stations based on relative species abundances.
3.2.16 The cluster groups identified for each station are also illustrated in Figure 7.
Figure 7: Sampling stations and the assigned cluster groups
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Biotope assignment
3.2.17 Using the 20 most abundant species present, the biotope of each cluster group was identified. Three biotopes were identified, two littoral sediment biotopes (LS.LMu.MEst.HedMac and LS.LMx.Mx.CirCer), and one subtidal (SS.SMx.SMxVS.CreMed) (descriptions of these biotopes are included in Appendix 5). 33 stations were identified as littoral biotopes and of these 18 were classified as HedMac biotopes and 15 as CirCer biotopes. 11 stations were identified as the subtidal CreMed biotope.
3.2.18 The stations and their biotopes are presented in the map in Figure 8 in order to illustrate the distribution of these biotopes.
Figure 8: Distribution of biotopes assigned to each group, by station
3.2.19 The littoral HedMac biotope is more prevalent in the Stour Estuary than the Orwell, especially in the upper reaches of the estuary.
3.2.20 Further investigation into this difference between the Stour and Orwell Estuaries was carried out using the Analysis of Similarities (ANOSIM) test within PRIMER.
3.2.21 ANOSIM calculates an R value (the similarity between groups) and the significance of that value. R = 1 only indicates that all samples within a group are more similar to each
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other than any samples from different groups. An R value close to 0 indicates that similarities between and within sites are the same on average.
3.2.22 This test reveals that the species assemblages in the Stour and Orwell Estuaries are equally similar to each other (R = 0.103), and that this result is statistically significant (less than 5%) at 1%.
3.2.23 The biotope assignments in 2014 and 2015 are presented in Appendix 6. Between 2014 and 2015 the subtidal biotope SS.SMx.SMxVS.CreMed has increased, replacing the SS.SMx.SMuVS.AphTubi and SS.SMx.IMx.SpavSpAn subtidal biotopes. The CreMed biotope is characterised by the presence of the slipper limpet Crepidula fornicata, an invasive gastropod which can reach extremely high densities in muddy, sheltered estuarine conditions.
3.2.24 Intertidal biotopes are still dominated by the LS.LMu.MEst.HedMac biotope, which is the most prevalent biotope in both 2014 and 2015. In 2015 the biotope LS.LMx.Mx.CirCer is present, suggesting that the intertidal sediments have become more mixed, moving away from the fine sediment portion in 2014. This biotope supports a diverse range of polychaete and oligochaete worms as well as the cockle Cerastoderma edule.
4. Discussion
4.1.1 The results of the 2015 survey indicate that the Stour and Orwell Estuaries continue to support relatively abundant and diverse macrobenthic communities, which are typical of coastal and estuarine waters in SE England. These benthic communities are dominated by detritivore, mainly deposit-feeder species, such as the mud snail Peringia ulvae, polychaetes of the genera Streblospio and Tharyx, oligochaetes and nematodes.
4.1.2 The biotopes identified are also typical of estuarine habitats. Both littoral biotopes (HedMac and CirCer) contain species that are valuable food resources to predator communities. Large mobile species, such as bottom-feeding fish, crabs and birds are important predators in marine soft-bottom communities and they are important regulators of species abundance (Ambrose, 1994). Wildfowl feed on a variety of species, for example Hediste diversicolor is an important prey species for bar-tailed godwit and curlew, Macoma balthica form part of the diet of shelduck and the mud snail Peringia ulvae, the catworm Nephtys hombergii and the mud shrimp Corophium volutator are target prey species for redshank.
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4.1.3 21 Stations were identified as having the same biotope as in 2014. Due to the shallow nature of the estuaries and the presence of sampling stations on the edge of the intertidal extent some biotopes have changed from being classified as being littoral sediment to sublittoral sediment.
4.1.4 The most stable areas within this sampling regime are the upper reaches of the Stour Estuary and the majority of the subtidal stations. The Orwell Estuary appears to have more variation in biotopes than the Stour. This may be because the mouth of the estuary is more exposed to the North Sea, which could result in more wave exposure and movement of sediment, compared to the Stour Estuary which is protected by the presence of Harwich Dock.
4.1.5 Despite the apparent difference in the presence and distribution of biotopes between the Stour and Orwell Estuaries, ANOSIM analysis on the abundance data indicates that the macrofaunal communities present in these estuaries are statistically similar, and that this result is significant.
4.1.6 No rare or protected species were found in this survey. However invasive non-native species, as listed by Eno et al. (1997), were identified:
The Australasian barnacle Austrominius modestus (found at 5 stations, 1 more than 2014) The slipper limpet Crepidula fornicata (found at 11 stations, 2 more than 2014) The American ostracod Eusarsiella zostericola (found at 39 stations, 16 more than 2014) The sand gaper Mya arenaria (found at 5 stations, 9 less than 2014) The Manila clam Tapes philippinarum (found at 5 stations, 1 less than 2014).
4.1.7 A comparison with data collected between 2012 and 2015 is provided in a separate report.
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5. References
Associated British Ports Marine Environmental Research Ltd (2007) Benthic ecology of the Thames Estuary., Report No. R. 1381. Ambrose, W.G. (1984) Role of predatory infauna in structuring marine soft-bottom communities. Marine Ecology Progress Series 17, 109-115 Blott, S.J. & Pye, K. (2001) GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms, 26, 1237–1248. Attrill, M.J., Ramsay, P.M., Thomas, R.M. and. Trett, M.W. (1996) An estuarine biodiversity hotspot. Journal of the Marine Biological Association of the United Kingdom 76, 161-175 Attrill, M.J. (1998) The benthic macroinvertebrate communities of the Thames Estuary. In: A Rehabilitated Estuarine Ecosystem: The Environment and Ecology of the Thames Estuary. (Attrill, M.J., ed.) pp. 85-112. London: Kluwer Academic Publishers Bolam, S.G. (2003) Spatial patterns of estuarine macrobenthic assemblages: relationships with hydrodynamic regime, CEFAS. Report No: FD1905/CEFAS1 Bryant, C. & McNulty, S. (2007) Environmental trends on the Stour and Orwell Estuaries. Royal Haskoning report 9R6009/303462/BBoro to Harwich Haven Authority. Connor, D.W., Allen, J.H., Golding, N., Howell, K. L., Lieberknecht, L.M., Northen, K.O.& Reker, J.B. (2004) The marine habitat classification for Britain and Ireland. Version 04.05. JNCC, Peterborough, ISBN 1 861 07561 8 (internet version). Chesman, B.S., Burt, G.R. and Langston, W.J. (2006) Characterisation of the European Marine Sites: Essex Estuaries European Marine Site. Marine Biological Association of the United Kingdom Occasional Publication 17. pp 198. (2006) ISSN: 02602784. Clarke, K.R. and Gorley, R.N. (2006) PRIMER v6: User Manual/Tutorial. PRIMER-E Ltd. Clarke, K.R. and Warwick, R.M. (1994) Change in marine communities: an approach to statistical analysis and interpretation. Plymouth: Plymouth Marine Laboratory, pp. 144. Dyer, M.F. (2000) Stour and Orwell estuary benthic survey 1997. Report to Harwich Haven Authority. Unicomarine report StrOrw97, January 2000. Dyer, M.F., Ashelby, C.W., & Worsfold, T.M. (2004) A Comparison of the sediment characteristics of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHASED04 to Harwich Haven Authority, January 2004. Dyer, M.F. & Worsfold, T.M. (2004) Comparison of the intertidal benthos of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHAStrOrw03int to Harwich Haven Authority, February 2004. Dyer, M.F. & Worsfold, T.M. (2009) Intertidal invertebrate survey of the upper Blackwater estuary from Beeleigh Weir to Decoy Point: April and September 2009. Unicomarine Report Essuf09 to Essex and Suffolk Water, November, 2009. Eno, N.C., Clark, R.A. & Sanderson, W.G. (1997) Non-native marine species in British waters: a review and directory. Joint Nature Conservation Committee, 152 pp
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Finbow, L. & Argent, J. (2012) Thomson Unicomarine standard operating procedure for the processing of particle size samples Version 2.0. Thomson Unicomarine, February 2012. Mason, C. (2011) NMBAQC’s Best Practice Guidance, Particle Size Analysis (PSA) for Supporting Biological Analysis. National Marine Biological AQC Coordinating Committee, 2011. P&O (2004) The (London Gateway Port) Harbour Empowerment Order 202. Environmental Statement Chapters 1 to 10. Royal Haskoning (2007) Environmental Trends on the Stour and Orwell Estuaries. January 2007. Royal Haskoning (2008) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2008. November 2008. Royal Haskoning (2010) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2009. March 2010. Royal Haskoning (2011) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2010/11. March 2011. Royal Haskoning (2012) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2011/12. March 2011 TEM09 (2013) Benthic Invertebrate Sample Analysis. Issue 005. Richard Gianfrancesco. June 2013. Wentworth, C.K. (1922) A scale of grade and class terms for clastic sediments. Journal of Geology, 30, 377-392. Worsfold, T.M. & Dyer, M.F. (2004) Comparison of the subtidal benthos of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHAStrOrw03sub to Harwich Haven Authority, March 2004. Worsfold, T. M. (2005) Stour, Orwell and Harwich approaches benthos: review of data commissioned by Harwich Haven Authority, biotope distribution update and partial review of current knowledge for the area. Unicomarine Report HHABiot05 to Harwich Haven Authority, November 2005.
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Appendices
Appendix 1: Particle Size Analysis
Table 3: PSA results
Station STN150 STN152 STN153 STN154 STN155 STN157 STN158 STN163 STN169 STN171 STN172 STN174 STN179 Pebble 18.5 42.8 1.3 47.8 3.3 2.6 3.2 34.9 5.8 3.1 4.2 0.0 1.6 Granule 4.3 5.1 0.6 3.5 0.3 5.5 0.2 6.8 2.2 4.3 1.4 0.7 11.6 V. coarse sand 1.6 3.8 1.7 3.6 0.8 3.5 0.6 11.4 3.5 1.9 1.1 2.1 10.5 Coarse sand 2.9 9.4 5.0 13.1 10.2 6.1 18.7 10.9 2.9 2.2 2.4 0.6 21.1 Medium sand 5.4 16.4 13.6 16.7 32.8 11.0 51.0 15.6 6.2 5.6 4.8 3.6 18.7 Fine sand 6.3 7.0 14.9 4.5 24.2 12.6 19.5 9.5 6.6 7.7 5.8 8.3 3.4 V. fine sand 7.7 2.2 11.0 1.5 5.1 12.6 0.3 2.8 9.4 10.9 9.6 13.7 2.9 Silt Clay 53.2 13.2 52.0 9.4 23.3 46.2 6.5 8.1 63.3 64.4 70.9 71.1 30.1 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
Station STN180 STN181 STN189 STN191 STN192 STN193 STN194 STN195 STN204 STN206 STN207 STN208 STN249 Pebble 3.2 5.2 25.9 25.2 16.7 2.3 9.3 0.0 0.3 11.6 1.0 5.6 8.7 Granule 1.5 0.5 7.3 16.3 6.1 0.3 4.2 0.5 0.3 4.6 0.6 1.3 0.4 V. coarse sand 1.2 0.7 6.5 19.2 3.1 0.4 3.8 0.9 1.7 2.8 0.5 0.8 0.4 Coarse sand 7.3 3.7 17.6 13.9 3.4 1.1 3.8 4.2 1.9 3.0 6.6 1.8 17.4 Medium sand 15.3 14.0 21.5 11.8 11.2 23.6 8.2 6.3 8.8 8.0 16.2 6.5 47.0 Fine sand 12.7 13.9 5.4 2.8 11.7 35.5 8.7 7.1 20.0 9.5 12.9 8.1 17.8 V. fine sand 10.7 7.4 1.4 1.7 6.7 11.5 9.7 9.8 18.3 9.2 12.4 10.7 1.1 Silt Clay 48.0 54.5 14.5 9.0 41.1 25.2 52.3 71.2 48.7 51.4 49.9 65.2 7.1 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
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Station STN258 STN260 STN261 STN263 STN267 STN269 STN272 STN275 STN285 STN289 STN295 STN296 STN300 Pebble 13.9 11.3 8.2 9.3 15.4 22.5 17.3 8.6 13.7 2.3 0.1 0.0 0.1 Granule 3.5 4.8 0.8 2.4 5.6 6.1 3.9 1.0 4.9 11.5 0.1 0.1 0.4 V. coarse sand 4.8 8.6 1.7 3.2 3.7 2.7 4.7 1.1 6.9 4.2 0.9 0.6 1.2 Coarse sand 12.5 17.7 1.9 0.0 1.8 1.9 2.6 5.1 31.6 3.6 3.2 2.5 2.1 Medium sand 27.4 21.2 9.3 27.5 19.7 4.7 8.6 8.2 33.6 6.1 8.3 5.7 5.7 Fine sand 15.2 8.2 24.3 46.8 22.4 5.8 9.8 8.7 3.6 6.1 9.7 7.8 11.4 V. fine sand 3.1 3.9 18.3 4.7 8.7 7.1 7.7 10.4 0.3 7.0 10.2 11.9 20.8 Silt Clay 19.5 24.4 35.5 6.1 22.7 49.3 45.3 56.8 5.3 59.0 67.3 71.4 58.3 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
Station STN301 STN303 STN306 STN548 STN549 Pebble 0.3 11.5 1.8 1.0 2.3 Granule 4.1 7.0 3.2 0.4 7.9 V. coarse sand 4.1 5.8 4.8 1.3 5.5 Coarse sand 1.1 9.9 2.9 5.7 7.2 Medium sand 3.5 13.5 5.0 11.6 9.3 Fine sand 5.5 7.8 5.0 17.5 7.9 V. fine sand 10.1 5.7 7.5 18.1 8.7 Silt Clay 71.3 38.7 69.7 44.3 51.3 100.00 100.00 100.00 100.00 100.00
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Appendix 2: Dominant 20 species in each cluster group
Table 4: The top 20 abundant species in each cluster group, by number of individuals per m2
Mean # Mean # per Mean # per Group Samples Species Group Samples Species Group Samples Species per m2 m2 m2 A 295, 296 Tharyx "species A" 325 B 306 Corophium volutator 925 C 285, 289 Exogone naidina 2600 Eusarsiella 75 Pariambus typicus 850 Syllidia armata 1537.5 zostericola Monocorophium 75 Tubificoides pseudogaster 200 Melinna palmata 675 acherusicum Nephtys hombergii 75 Exogone naidina 150 Achelia echinata 650 Pariambus typicus 75 Cheirocratus 125 NEMATODA 525 Streblospio 75 Streblospio 125 Crepidula fornicata 475 Chaetozone 62.5 NEMATODA 100 Pariambus typicus 412.5 zetlandica Macoma balthica 50 Tubificoides amplivasatus 100 ACTINIARIA 337.5 Nucula 50 Eusarsiella zostericola 75 Sabella pavonina 337.5 Exogone naidina 37.5 Sphaerosyllis 75 Aora gracilis 262.5 Ampharete 25 Syllidia armata 75 Ampharete lindstroemi 225 lindstroemi AMPHIPODA 25 Capitella 50 Ammothea hilgendorfi 212.5 Ampharete 25 Chaetozone zetlandica 50 Mediomastus fragilis 187.5 lindstroemi Apocorophium 25 Mediomastus fragilis 50 Anoplodactylus pygmaeus 175 lacustre Cossura pygodactyla 25 Tubificoides benedii 50 Cheirocratus intermedius 175 Mesopodopsis 25 Achelia echinata 25 Eumida sanguinea 162.5 slabberi BIVALVIA 25 Ampharetidae 25 Lepidonotus squamatus 150 Cirratulidae 25 AMPHIPODA 25 Stenothoe marina 150 Polydora cornuta 25 Achelia echinata 25 Chaetozone zetlandica 137.5 Conopeum seurati 25 Cheirocratus intermedius 25 Cumella pygmaea 137.5 SS.SMx.SMxVS.Cre A5.422 SS.SMx.SMxVS.CreMed A5.422 SS.SMx.SMxVS.CreMed A5.422 Med
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Mean # Mean # Mean # Group Samples Species Group Samples Species Group Samples Species per m2 per m2 per m2 549, 154, 191,189, D 195,303 NEMATODA 12362.5 E Exogone naidina 3931.25 F 152, 150, Peringia ulvae 3090 179,192 153 Tritaeta gibbosa 4875 NEMATODA 2325 Hediste diversicolor 1975 COPEPODA 3437.5 Aora gracilis 1658.33 Streblospio 1550 Sabella pavonina 3137.5 Cirratulidae 1518.75 PODOCOPIDA 1400 Exogone naidina 2312.5 Sphaerosyllis 1250 Semelidae 1150 Pariambus typicus 1200 Crepidula fornicata 1206.25 Leptocheirus pilosus 1075 Aoridae 1175 Pariambus typicus 1093.75 Baltidrilus costatus 1062.5 Tubificoides pseudogaster 1050 Syllidia armata 712.5 Nereididae 650 Tubificoides amplivasatus 837.5 Aoridae 662.5 Melita palmata 600 ASCIDIACEA 650 Tubificoides amplivasatus 637.5 Cyathura carinata 475 Microdeutopus stationis 650 Tubificoides pseudogaster 637.5 Austrominius modestus 450 Cossura pygodactylata 550 Cossura pygodactylata 633.33 Aoridae 425 Tubificoides Ericthonius punctatus 550 Achelia echinata 512.5 418.75 pseudogaster Cirratulidae 450 Aphelochaeta marioni 443.75 Nematostella vectensis 375 Achelia echinata 400 Syllis columbretensis 443.75 Balanus crenatus 225 AMPHIPODA 400 Tharyx "species A" 383.33 Idotea baltica 175 Monocorophium sextonae 375 Cheirocratus sundevallii 375 Eteone cf. longa 162.5 Syllidia armata 350 Tritaeta gibbosa 350 Manayunkia aestuarina 150 Mediomastus fragilis 325 Munna minuta 325 NEMATODA 133.33 Parexogone hebes 275 Dexamine spinosa 237.5 Eusarsiella zostericola 125 LS.LMx.Mx.CirCer A2.421 SS.SMx.SMxVS.CreMed A5.422 LS.LMu.MEst.HedMac A2.312
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Mean # Mean # Mean # Group Samples Species Group Samples Species Group Samples Species per m2 per m2 per m2 G 300,301 Streblospio 2375 H 260 Corophium volutator 42900 I 155 Tharyx "species A" 2175 Phoronis 925 Streblospio 12475 Cirratulidae 1675 Cossura pygodactylata 625 Tharyx "species A" 5000 Tubificoides benedii 1000 Tubificoides amplivasatus 450 NEMATODA 2775 Macoma balthica 975 Exogone naidina 375 Polydora cornuta 2575 Peringia ulvae 575 Tharyx "species A" 237.5 BIVALVIA 2375 Tharyx killariensis 400 Nephtys hombergii 225 Mya arenaria 1550 Phyllodoce mucosa 325 Nephtys 212.5 Tubificoides benedii 1550 Retusa obtusa 225 Nucula 200 Baltidrilus costatus 1075 Eusarsiella zostericola 200 Cirratulidae 175 Austrominius modestus 825 Hediste diversicolor 125 NEMATODA 162.5 Cerastoderma 725 Nereididae 75 Aphelochaeta marioni 150 Hediste diversicolor 700 Streblospio 75 Macoma balthica 125 Macoma balthica 575 Aoridae 50 Pygospio elegans 100 Nereididae 475 Chironomidae (larva) 50 Eteone cf. longa 50 Peringia ulvae 400 Eteone 50 Eusarsiella zostericola 37.5 Tubificoides pseudogaster 400 Microdeutopus 50 Ampelisca brevicornis 25 Capitellidae 350 Parvicardium exiguum 50 CRUSTACEA 25 Pygospio elegans 250 CHLOROPHYTA 25 DECAPODA 25 Eteone 175 NEMERTEA 25 Hediste diversicolor 25 Cerastoderma edule 150 ULVOPHYCEAE 25 LS.LMx.Mx.CirCer A2.421 LS.LMu.MEst.HedMac A2.312 LS.LMu.MEst.HedMac A2.312
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Mean # Mean # Mean # Group Samples Species Group Samples Species Group Samples Species per m2 per m2 per m2 194, 206, 158, 269, 272, 267, 163, 209, 169, J 207 Tubificoides benedii 2675 K 258, 275, 261, Tharyx "species A" 7942.85 L Tharyx "species A" 13100 171, 193, 174, 263 157, 172 Tubificoides Tubificoides 2550 Streblospio 5710.71 4485 amplivasatus amplivasatus Cirratulidae 2275 NEMATODA 3460.71 Peringia ulvae 4454.5 NEMATODA 1950 Cirratulidae 2675 Tubificoides benedii 3638.8 Aoridae 1275 Tubificoides swirencoides 2450 Eusarsiella zostericola 3322.7 Austrominius modestus 1025 Tubificoides amplivasatus 1931.25 NEMATODA 1509 Galathowenia 575 Macoma balthica 862.5 Cirratulidae 1500 Aphelochaeta marioni 475 Cirriformia tentaculata 800 Macoma balthica 1482.5 Tubificoides THORACICA 425 Tubificoides benedii 758.3 1208.3 pseudogaster Melita palmata 375 Cossura pygodactylata 712.5 Edwardsiidae 991.6 Cirriformia tentaculata 275 Peringia ulvae 654.16 Abra tenuis 961.1 Chaetozone zetlandica 200 Tubificoides pseudogaster 592.85 Streblospio 857.5 Eusarsiella zostericola 200 Aoridae 525 Cossura pygodactylata 842.85 Microdeutopus Lepidochitona cinerea 200 Exogone naidina 437.5 721.875 gryllotalpa Austrominius Melinna palmata 175 Cardiidae 387.5 600 modestus Microdeutopus 150 Mya arenaria 368.75 OPISTHOBRANCHIA 600 gryllotalpa Melitidae 125 BIVALVIA 310 Aoridae 545.83 Nephtys hombergii 125 Pygospio elegans 306.25 Phyllodoce mucosa 480 Macoma balthica 100 Jassa 275 Chironomidae (larva) 428.57 Ampharete lindstroemi 75 Melita palmata 275 Tubificoides 380 LS.LMx.Mx.CirCer A2.421 LS.LMx.Mx.CirCer A2.421 LS.LMu.MEst.HedMac A2.312
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Group Samples Species Mean # per m2 Group Samples Species Mean # per m2 M 181,249 Pariambus typicus 6137.5 N 548,180,204 Tubificoides amplivasatus 1458.3 NEMATODA 1675 BIVALVIA 1041.6 Cossura pygodactylata 1425 Tharyx "species A" 866.6 Tubificoides amplivasatus 1337.5 Peringia ulvae 858.3 Tharyx "species A" 1275 Phoronis 800 Achelia laevis 775 Cossura pygodactylata 783.3 Nephtys 762.5 Eusarsiella zostericola 766.6 Exogone naidina 600 Streblospio 725 Eumida sanguinea 500 NEMATODA 658.3 Eusarsiella zostericola 475 Allomelita pellucida 550 Sphaerosyllis 437.5 Pygospio elegans 550 Streblospio 400 Microdeutopus gryllotalpa 475 Tubificoides 350 Cirratulidae 400 Dexamine spinosa 325 Tubificoides pseudogaster 350 OPISTHOBRANCHIA 325 Nephtys hombergii 333.3 Tubificoides swirencoides 300 Melinna palmata 150 Melinna palmata 287.5 Hediste diversicolor 125 COPEPODA 250 Nephtys 100 Microprotopus maculatus 237.5 Pariambus typicus 100 Aoridae 212.5 Macoma balthica 75 SS.SMx.SMxVS.CreMed A5.422 LS.LMx.Mx.CirCer A2.421
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Appendix 3: Raw abundance and biomass data
Table 5: Raw macrofaunal abundance data for Stour Estuary sampling station
Sampling station
Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Abra 1 6 6 Abra alba Abra tenuis 30 52 21 28 64 15 118 13 1 5 ACARINA 2 3 Achelia echinata 29 20 5 28 16 Achelia laevis 31 ACTINIARIA 1 1 2 12 4 1 ACTINOPTERYGII 1 3 Alcyonidium condylocinereum 1 1 Alcyonidium diaphanum 1 1 Alcyonidium gelatinosum 1 Alcyonidioides mytili 1 Alcyonidium parasiticum 1 Alderia modesta 1 Alitta virens 5 Allomelita pellucida 2 22 Amathia lendigera 1 Ammodytes 1 Ammothea hilgendorfi 1 1 Ampelisca 1 1 Ampelisca brevicornis 1 Ampharete lindstroemi 1 4 3 Ampharetidae 4 1 1 2 3 Amphicteis
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Amphicteis gunneri 1 Amphilochus manudens 9 2 Amphilochus neapolitanus 8 Amphipholis squamata 1 AMPHIPODA 1 16 1 1 Amphiuridae 8 Anguinella palmata 1 1 1 1 1 1 ANIMALIA 1 1 1 1 1 1 1 1 1 Anoplodactylus petiolatus 4 1 Anoplodactylus pygmaeus 2 1 Aora gracilis 14 40 145 Aoridae 17 2 50 6 38 3 26 18 1 5 35 47 51 8 Aphelochaeta marioni 10 3 18 6 37 8 1 19 7 1 Apherusa bispinosa 1 3 2 22 5 Apocorophium acutum Apocorophium lacustre ARANEAE 1 1 Aricidea minuta ASCIDIACEA 1 12 8 3 12 26 Ascidiella 3 Ascidiella aspersa 4 2 5 4 5 5 Ascidiella scabra 2 Aspidelectra melolontha Austrominius modestus 18 47 41 1 Balanus balanus 2 Balanus crenatus 9 Baltidrilus costatus 84 1 Barentsia 1 1 Bicellariella ciliata 1 1 1 1 1
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 BIVALVIA 1 1 7 1 44 5 1 3 49 24 32 1 Bodotria arenosa 1 Bodotria scorpioides 1 2 Bowerbankia 1 1 1 1 1 BRACHYURA 1 Bugula 1 1 1 1 Bugula plumosa 1 Callipallene tiberi 4 7 Campanulariidae 1 Capitella 5 1 Capitellidae 2 20 Carcinus maenas 1 Cardiidae 1 2 1 25 46 19 2 2 1 4 2 1 2 Caridion 1 CEPHALASPIDEA 1 2 1 2 1 1 Cerastoderma 1 Cerastoderma edule 2 14 2 1 Cerastoderma glaucum 10 1 Chaetozone gibber 1 2 Chaetozone zetlandica 2 8 1 4 8 Cheirocratus 2 8 Cheirocratus intermedius Cheirocratus sundevallii 15 Chironomidae (larva) 2 6 1 4 1 1 1 78 28 2 1 CHLOROPHYTA 1 1 1 1 1 1 1 1 1 1 1 1 Ciona intestinalis 2 1 Cirratulidae 67 114 1 34 196 107 74 32 2 135 18 18 2 1 91 9 30 1 Cirriformia tentaculata 2 4 12 1 2 11
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Cliona 1 1 COLLEMBOLA 1 Conopeum reticulum 1 Conopeum seurati 1 1 Corella parallelogramma 2 1 Corophiidae 1 Corophium arenarium Corophium volutator Cossura pygodactylata 2 12 9 72 61 78 50 3 12 63 49 22 2 1 29 14 Crangon crangon 1 1 1 Crassostrea gigas 1 Crepidula fornicata 77 1 4 81 6 29 CRUSTACEA CUMACEA Cumella pygmaea 3 11 9 7 Cyathura carinata 16 22 1 2 DECAPODA 1 1 DEMOSPONGIAE 1 Dendrodoa grossularia 5 Dexamine spinosa 20 16 3 1 DIPTERA Dorvilleidae 1 Edwardsiidae 40 4 1 75 Electra crustulenta 1 1 1 Electra monostachys Electra pilosa 1 Endeis spinosa 1 Ensis ensis ENTEROPNEUSTA 1
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Epigamia alexandri 2 Ericthonius punctatus 22 Erinaceusyllis erinaceus 1 2 2 Eteone 1 1 2 3 1 1 2 Eteone cf. longa 11 2 Eudendrium Eudorella truncatula 2 Eulalia 1 Eumida 1 Eumida sanguinea 20 18 2 6 Eunereis longissima Eunicidae 1 Eusarsiella zostericola 9 8 66 137 14 283 439 151 11 12 44 27 1 2 2 170 71 1 34 77 8 43 14 1 Exogone naidina 1 2 2 79 1 28 277 106 167 32 158 1 7 16 1 Fabriciidae 1 1 Filicrisia geniculata Galathowenia 1 7 2 23 1 GASTROPODA 19 3 7 1 1 1 Gattyana cirrhosa Gitana sarsi 1 6 3 2 Glycera 3 5 1 1 Glycera tridactyla 1 1 Gobius niger 1 Gracilaria 1 1 Grandidierella japonica 1 5 15 6 Grania 2 Harmothoe 7 4 1 Harmothoe imbricata 3 9 5 5 1 Hediste diversicolor 101 60 214 19 5 6 2 5 1
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Hydrallmania falcata 1 HYDROZOA Idotea 14 4 2 1 3 Idotea baltica 7 Idotea chelipes 1 6 4 3 1 INSECTA 1 Iphimedia minuta Ischyroceridae Jaera albifrons 2 Jassa Lagotia viridis 1 1 1 Lekanesphaera levii 1 2 3 Lemnaceae 1 1 1 1 Lepidochitona cinerea 8 10 2 3 8 1 Lepidonotus squamatus 5 2 Leptocheirus pilosus 43 Leptochelia dubia 1 LEPTOTHECATA Liocarcinus 1 Liocarcinus pusillus Lysidice ninetta 1 Macoma balthica 2 1 1 39 39 31 60 33 24 23 9 3 353 1 15 4 6 Manayunkia aestuarina 2 14 2 4 11 6 29 Medicorophium affine 1 Mediomastus fragilis 1 7 1 Melinna palmata 4 7 1 19 3 2 4 4 12 4 9 4 7 3 8 1 Melita 3 Melita palmata 24 2 2 15 1 Melitidae 1 1 5
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Mesopodopsis slabberi Microdeutopus 2 2 21 2 Microdeutopus anomalus 3 2 Microdeutopus gryllotalpa 19 10 5 2 158 12 22 6 3 19 Microdeutopus stationis Microprotopus maculatus 5 1 17 Monocorophium acherusicum 1 Monocorophium sextonae 15 Munna kroyeri 4 Munna minuta 23 3 2 Mya arenaria MYODOCOPIDA 7 Myrianida 1 MYSIDA 1 1 1 NEMATODA 3 12 1 4 17 68 148 46 66 47 42 48 129 146 30 154 106 12 476 2 23 78 127 29 Nematostella vectensis 15 NEMERTEA 1 1 1 1 7 1 1 Nephtys 1 1 1 8 4 8 11 11 4 34 1 2 1 3 4 1 4 Nephtys hombergii 2 4 5 9 6 5 3 9 3 5 7 10 7 25 4 5 4 6 1 Nephtys kersivalensis 1 Nereididae 26 3 6 3 1 3 25 1 2 Notomastus 1 1 Nototropis guttatus Nucula 1 3 Nymphon brevirostre 1 Nymphon gracile Odostomia 1
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 OLIGOCHAETA 1 9 1 1 1 1 1 Ophiocten affinis OPHIUROIDEA 1 1 Ophryotrocha 1 1 OPISTHOBRANCHIA 24 2 Palaemon Parexogone hebes 1 1 11 1 11 Pariambus typicus 5 3 39 75 5 297 16 35 49 1 51 3 1 2 Parvicardium exiguum 2 1 Patellidae 1 Peringia ulvae 108 26 112 217 23 165 336 386 139 173 37 163 2 83 1 292 14 13 242 13 7 155 PHAEOPHYCEAE 1 Pharidae 1 1 1 Pholoe inornata 1 1 Phoronis 4 2 1 14 1 1 32 Phyllodoce mucosa 13 4 93 7 13 5 3 3 1 1 3 57 4 3 1 1 2 Phyllodocidae 2 Platynereis dumerilii 2 8 5 1 Plumulariidae 1 1 PODOCOPIDA 56 POLYCHAETA 1 1 1 1 1 1 1 1 1 Polycirrus 1 Polydora ciliata 2 2 Polydora cornuta 1 1 1 7 Polynoidae 1 1 POLYPLACOPHORA 1 9 3 2 Pomatoschistus minutus 2 PORIFERA 1 1 1 Portunidae 1 1
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Proceraea 2 1 Prosphaerosyllis tetralix 1 1 4 Protodorvillea kefersteini 1 Pseudopolydora pulchra Pterothamnion plumula 1 PYCNOGONIDA Pycnogonum littorale 1 Pygospio elegans 1 9 17 2 1 12 22 1 1 Retusa obtusa 9 1 9 1 1 2 16 4 RHODOPHYTA 1 1 1 1 1 1 Sabella pavonina 1 1 1 99 Sabellidae 2 Sabelliphilus elongatus 7 Scoloplos armiger Scrobicularia plana 2 3 3 4 3 6 Scrupocellaria reptans 1 Scrupocellaria scrupea Semelidae 46 1 Sertulariidae 1 1 SIPUNCULA Sphaerodorum gracilis 1 Sphaerosyllis 2 48 1 26 39 30 83 17 Spionidae 1 1 Spiophanes bombyx 1 1 Stenothoe marina 3 2 Streblospio 52 126 2 68 3 55 1 1 72 65 25 3 10 9 63 4 3 76 10 2 47 1 Sycon ciliatum 1 1 1 1 1 1 Syllidae 2 1 Syllidia armata 24 51 11 28 25
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Taxon Name
150 152 153 154 155 157 158 163 169 171 172 174 179 180 181 189 191 192 193 194 195 204 206 207 209 548 549 Syllis 4 Syllis columbretensis 4 1 24 10 33 Syllis gracilis 4 3 4 Syllis hyaline 2 Syllis pulvinata 3 4 Tapes philippinarum 3 2 1 Terebellidae 1 1 TEREBELLOMORPHA Tharyx "species A" 1 3 87 1413 598 698 192 181 544 1053 43 11 4 6 36 501 236 9 25 146 202 36 Tharyx killariensis 16 13 7 20 12 2 THORACICA 1 2 17 Thoralus cranchii THRACIOIDEA Tritaeta gibbosa 11 17 195 Tubificoides 1 1 29 14 43 2 Tubificoides amplivasatus 160 3 277 231 303 64 34 44 74 23 6 39 114 421 55 41 40 102 181 90 Tubificoides benedii 1 7 3 40 231 549 410 1 7 5 2 8 4 80 107 19 2 3 Tubificoides pseudogaster 6 4 12 45 55 11 9 22 70 55 39 14 3 12 161 42 48 3 4 Tubificoides swirencoides 12 TURBELLARIA 1 ULVOPHYCEAE 1 1 1 1 Vesicularia spinosa
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Table 6: Raw macrofaunal abundance data for Orwell Estuary sampling stations
TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Abra Abra alba 1 Abra tenuis 1 1 ACARINA Achelia echinata 32 20 1 Achelia laevis ACTINIARIA 1 1 2 5 22 7 ACTINOPTERYGII Alcyonidium condylocinereum 1 Alcyonidium diaphanum Alcyonidium gelatinosum Alcyonidioides mytili 1 Alcyonidium parasiticum Alderia modesta Alitta virens 1 Allomelita pellucida Amathia lendigera Ammodytes Ammothea hilgendorfi 4 13 Ampelisca Ampelisca brevicornis 1 Ampharete lindstroemi 1 4 14 1 8 Ampharetidae 2 4 1 1 Amphicteis 1 Amphicteis gunneri Amphilochus manudens Amphilochus neapolitanus 7 2 2 Amphipholis squamata
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 AMPHIPODA 1 1 1 1 5 1 1 1 Amphiuridae 3 Anguinella palmata 1 1 1 1 1 ANIMALIA 1 1 1 1 1 Anoplodactylus petiolatus 2 5 Anoplodactylus pygmaeus 7 Aora gracilis 13 8 Aoridae 12 16 1 43 42 3 Aphelochaeta marioni 6 1 Apherusa bispinosa 1 Apocorophium acutum 1 Apocorophium lacustre 1 ARANEAE Aricidea minuta 2 ASCIDIACEA 3 Ascidiella Ascidiella aspersa 4 1 Ascidiella scabra 2 Aspidelectra melolontha 1 Austrominius modestus 33 Balanus balanus Balanus crenatus Baltidrilus costatus 43 Barentsia 1 Bicellariella ciliata 1 1 BIVALVIA 7 20 95 6 20 1 15 1 1 1 Bodotria arenosa Bodotria scorpioides 3 2 Bowerbankia
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 BRACHYURA Bugula Bugula plumosa Callipallene tiberi 2 4 Campanulariidae Capitella 1 1 1 2 Capitellidae 1 14 Carcinus maenas Cardiidae 18 40 8 5 2 20 3 Caridion CEPHALASPIDEA Cerastoderma 4 29 10 Cerastoderma edule 10 6 10 1 Cerastoderma glaucum Chaetozone gibber Chaetozone zetlandica 3 8 4 1 2 2 Cheirocratus 5 Cheirocratus intermedius 10 4 1 Cheirocratus sundevallii Chironomidae (larva) 2 1 CHLOROPHYTA 1 1 Ciona intestinalis 1 Cirratulidae 37 2 386 3 2 1 1 7 Cirriformia tentaculata 32 2 5 7 Cliona COLLEMBOLA Conopeum reticulum 1 1 Conopeum seurati 1 COPEPODA 1 170 Corella parallelogramma
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Corophiidae Corophium arenarium 1 Corophium volutator 1716 37 Cossura pygodactylata 64 5 44 56 9 1 10 40 22 1 Crangon crangon Crassostrea gigas Crepidula fornicata 2 1 37 1 1 CRUSTACEA 1 CUMACEA 1 Cumella pygmaea 1 10 1 1 Cyathura carinata 1 DECAPODA 1 1 DEMOSPONGIAE Dendrodoa grossularia Dexamine spinosa 13 1 DIPTERA 1 1 Dorvilleidae Edwardsiidae Electra crustulenta 1 1 1 Electra monostachys 1 Electra pilosa Endeis spinosa Ensis ensis 1 ENTEROPNEUSTA Epigamia alexandri 1 Ericthonius punctatus 5 Erinaceusyllis erinaceus Eteone 7 1 3 2 Eteone cf. longa 1 2 1 Eudendrium 1
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Eudorella truncatula 1 1 Eulalia Eumida Eumida sanguinea 7 6 1 Eunereis longissima 1 Eunicidae Eusarsiella zostericola 11 5 2 6 4 6 1 6 2 1 3 2 1 1 3 Exogone naidina 20 1 34 169 39 1 2 15 27 6 Fabriciidae 1 Filicrisia geniculata 1 Galathowenia GASTROPODA Gattyana cirrhosa 1 Gitana sarsi 1 Glycera 1 1 4 1 Glycera tridactyla Gobius niger Gracilaria Grandidierella japonica 2 Grania Harmothoe Harmothoe imbricata Hediste diversicolor 28 1 Hydrallmania falcata HYDROZOA 1 4 Idotea 1 Idotea baltica Idotea chelipes INSECTA Iphimedia minuta 1
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Ischyroceridae 1 Jaera albifrons Jassa 11 Lagotia viridis 1 1 1 1 Lekanesphaera levii Lemnaceae 1 1 1 Lepidochitona cinerea 2 Lepidonotus squamatus 6 Leptocheirus pilosus Leptochelia dubia LEPTOTHECATA 1 1 Liocarcinus Liocarcinus pusillus 1 Lysidice ninetta Macoma balthica 36 23 20 8 79 35 29 2 5 5 Manayunkia aestuarina 2 4 Medicorophium affine Mediomastus fragilis 2 13 25 2 Melinna palmata 4 1 1 53 1 Melita 1 Melita palmata 11 Melitidae 1 Mesopodopsis slabberi 1 Microdeutopus Microdeutopus anomalus Microdeutopus gryllotalpa 6 7 Microdeutopus stationis 26 Microprotopus maculatus 14 2 Monocorophium acherusicum 4 3 Monocorophium sextonae 1
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Munna kroyeri Munna minuta Mya arenaria 10 62 6 11 32 MYODOCOPIDA Myrianida 2 2 MYSIDA NEMATODA 5 135 111 272 110 289 36 101 26 34 8 7 6 513 4 Nematostella vectensis NEMERTEA 1 1 1 Nephtys 27 4 1 5 7 9 1 1 6 11 2 1 Nephtys hombergii 12 6 6 3 4 14 8 9 3 9 3 1 Nephtys kersivalensis Nereididae 2 1 19 1 19 5 4 1 1 Notomastus 3 4 2 Nototropis guttatus 1 Nucula 1 1 3 14 2 1 Nymphon brevirostre Nymphon gracile 2 Odostomia OLIGOCHAETA 1 1 1 1 1 Ophiocten affinis 1 OPHIUROIDEA Ophryotrocha OPISTHOBRANCHIA 13 Palaemon 1 Parexogone hebes 11 Pariambus typicus 194 1 30 3 3 1 45 34 Parvicardium exiguum 2 Patellidae Peringia ulvae 12 16 37 41 47 2 18
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 PHAEOPHYCEAE Pharidae Pholoe inornata Phoronis 1 37 Phyllodoce mucosa 1 6 2 Phyllodocidae 1 Platynereis dumerilii Plumulariidae PODOCOPIDA POLYCHAETA 1 1 1 1 1 Polycirrus Polydora ciliata Polydora cornuta 103 6 15 3 2 1 1 Polynoidae 1 1 POLYPLACOPHORA 1 3 Pomatoschistus minutus PORIFERA Portunidae 1 Proceraea 2 Prosphaerosyllis tetralix 2 Protodorvillea kefersteini 1 Pseudopolydora pulchra 2 Pterothamnion plumula PYCNOGONIDA 1 Pycnogonum littorale Pygospio elegans 1 10 1 34 5 9 4 Retusa obtusa RHODOPHYTA 1 Sabella pavonina 3 24 152 Sabellidae
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Sabelliphilus elongatus Scoloplos armiger 1 1 1 Scrobicularia plana 5 Scrupocellaria reptans Scrupocellaria scrupea 1 1 Semelidae Sertulariidae 1 1 SIPUNCULA 1 Sphaerodorum gracilis Sphaerosyllis 9 4 3 Spionidae Spiophanes bombyx Stenothoe marina 4 8 Streblospio 23 265 499 249 85 229 205 133 433 4 5 1 14 176 2 5 Sycon ciliatum Syllidae Syllidia armata 58 65 3 3 Syllis 3 Syllis columbretensis 4 Syllis gracilis 1 Syllis hyalina Syllis pulvinata Tapes philippinarum 2 2 Terebellidae TEREBELLOMORPHA 1 1 Tharyx "species A" 91 297 200 3 65 633 925 182 119 3 13 16 3 2 1 Tharyx killariensis 1 THORACICA Thoralus cranchii 1 THRACIOIDEA 1 14
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TaxonName
249 258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306 Tritaeta gibbosa Tubificoides 8 2 Tubificoides amplivasatus 33 69 11 209 20 1 18 12 4 Tubificoides benedii 2 62 9 80 4 2 2 Tubificoides pseudogaster 13 4 16 25 33 12 31 37 24 2 8 Tubificoides swirencoides 98 TURBELLARIA ULVOPHYCEAE Vesicularia spinosa 1 1
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Table 7: Raw biomass data for Stour Estuary sampling stations 150 to 180
TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Abra 0.0001 0.0691 Abra alba Abra tenuis 0.6082 0.4409 0.072 0.9359 0.9456 0.1335 ACARINA Achelia echinata 0.0116 Achelia laevis ACTINIARIA 0.0009 0.0001 0.4656 ACTINOPTERYGII 0.0074 Alcyonidium condylocinereum Alcyonidium diaphanum Alcyonidium gelatinosum Alcyonidioides mytili Alcyonidium parasiticum Alderia modesta 0.0006 Alitta virens 0.5584 Allomelita pellucida Amathia lendigera Ammodytes Ammothea hilgendorfi Ampelisca 0.0001 Ampelisca brevicornis Ampharete lindstroemi Ampharetidae 0.0006 0.0002 Amphicteis Amphicteis gunneri Amphilochus manudens Amphilochus neapolitanus
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Amphipholis squamata AMPHIPODA Amphiuridae Anguinella palmata ANIMALIA Anoplodactylus petiolatus 0.0002 Anoplodactylus pygmaeus Aora gracilis Aoridae 0.0028 0.0001 0.0261 0.0028 0.0086 0.0003 0.0013 0.0036 0.0005 Aphelochaeta marioni 0.0089 Apherusa bispinosa 0.0002 Apocorophium acutum Apocorophium lacustre ARANEAE 0.0001 0.0001 Aricidea minuta ASCIDIACEA 0.0031 Ascidiella Ascidiella aspersa Ascidiella scabra Aspidelectra melolontha Austrominius modestus Balanus balanus Balanus crenatus Baltidrilus costatus 0.0443 0.0001 Barentsia Bicellariella ciliata BIVALVIA 0.0577 0.009 0.0371 0.0012 0.2821 Bodotria arenosa
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Bodotria scorpioides Bowerbankia BRACHYURA Bugula Bugula plumosa Callipallene tiberi Campanulariidae Capitella 0.0002 Capitellidae 0.0001 0.0006 Carcinus maenas Cardiidae 0.0001 0.0003 0.0001 0.0154 0.057 0.0271 0.0001 0.0004 Caridion CEPHALASPIDEA 0.0045 0.0001 0.0025 0.0007 Cerastoderma 0.105 Cerastoderma edule 3.3795 26.3844 0.0654 Cerastoderma glaucum Chaetozone gibber 0.0263 Chaetozone zetlandica Cheirocratus 0.0001 Cheirocratus intermedius Cheirocratus sundevallii Chironomidae 0.0006 0.0036 0.0002 0.0007 0.0002 CHLOROPHYTA Ciona intestinalis Cirratulidae 0.0306 0.0136 0.0166 0.0023 0.0184 0.0141 0.0249 Cirriformia tentaculata 0.0009 Cliona COLLEMBOLA 0.0002
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Conopeum reticulum Conopeum seurati COPEPODA 0.0001 0.0001 0.0001 Corella parallelogramma Corophiidae Corophium arenarium Corophium volutator Cossura pygodactylata 0.0004 0.0001 0.0001 0.0021 0.0016 0.0003 Crangon crangon 0.0787 Crassostrea gigas Crepidula fornicata 69.74 0.0001 CRUSTACEA CUMACEA Cumella pygmaea 0.0002 Cyathura carinata 0.0235 0.0185 DECAPODA DEMOSPONGIAE Dendrodoa grossularia Dexamine spinosa 0.0088 DIPTERA Dorvilleidae Edwardsiidae 0.0185 0.0001 0.0015 Electra crustulenta Electra monostachys Electra pilosa Endeis spinosa Ensis ensis ENTEROPNEUSTA
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Epigamia alexandri Ericthonius punctatus Erinaceusyllis erinaceus Eteone 0.0001 0.0011 0.0003 0.0017 0.0001 Eteone cf. longa 0.0098 0.0005 Eudendrium Eudorella truncatula Eulalia Eumida Eumida sanguinea Eunereis longissima Eunicidae Eusarsiella zostericola 0.0007 0.0011 0.0119 0.0117 0.0017 0.048 0.0187 0.0267 0.0013 0.0008 0.0098 Exogone naidina 0.0001 0.0001 0.0001 0.0018 0.0001 Fabriciidae Filicrisia geniculata Galathowenia 0.0001 GASTROPODA 0.0082 0.0014 0.0067 Gattyana cirrhosa Gitana sarsi 0.0001 Glycera 0.0003 Glycera tridactyla 0.0005 Gobius niger Gracilaria Grandidierella japonica 0.0034 0.0047 0.0153 Grania Harmothoe Harmothoe imbricata 0.0253 0.0547
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Hediste diversicolor 3.8776 0.1975 1.3752 0.1798 0.1735 0.0239 Hydrallmania falcata HYDROZOA Idotea 0.0029 0.0004 0.0004 0.0001 Idotea baltica 0.0598 Idotea chelipes 0.0018 0.0413 INSECTA Iphimedia minuta Ischyroceridae Jaera albifrons Jassa Lagotia viridis Lekanesphaera levii 0.0045 Lemnaceae Lepidochitona cinerea 0.01 Lepidonotus squamatus Leptocheirus pilosus 0.0085 Leptochelia dubia 0.0001 LEPTOTHECATA Liocarcinus 0.0005 Liocarcinus pusillus Lysidice ninetta Macoma balthica 0.2793 0.2709 0.0012 0.5861 0.693 2.6528 0.4497 0.9544 0.3565 0.3544 0.0874 0.0636 Manayunkia aestuarina 0.0001 0.0001 0.0001 0.0004 0.0016 0.0001 Medicorophium affine Mediomastus fragilis 0.0001 Melinna palmata 0.003 0.0275 0.1767 0.0131 Melita
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Melita palmata 0.0287 0.001 Melitidae 0.0071 0.0014 Mesopodopsis slabberi Microdeutopus 0.0009 0.0001 Microdeutopus anomalus 0.001 0.0004 Microdeutopus gryllotalpa 0.0166 0.007 0.0094 0.0004 Microdeutopus stationis Microprotopus maculatus Monocorophium acherusicum Monocorophium sextonae Munna kroyeri Munna minuta Mya arenaria MYODOCOPIDA Myrianida 0.0001 MYSIDA 0.001 0.0045 0.0001 NEMATODA 0.0001 0.0001 0.0001 0.0001 0.0001 0.0017 0.002 0.0002 0.0002 0.0001 0.0001 0.0001 Nematostella vectensis 0.008 NEMERTEA 0.0027 0.0299 0.0013 0.0006 Nephtys 0.0001 0.0005 0.0004 0.0256 0.0014 0.0154 0.0287 0.011 0.0021 Nephtys hombergii 0.1963 0.5666 0.7107 0.42 0.7326 0.4925 0.1524 0.3162 Nephtys kersivalensis Nereididae 0.0012 0.0001 0.0073 0.0018 Notomastus Nototropis guttatus Nucula 0.0001 Nymphon brevirostre Nymphon gracile
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Odostomia 0.001 OLIGOCHAETA 0.0012 0.0002 0.0009 Ophiocten affinis OPHIUROIDEA 0.0001 0.0004 Ophryotrocha OPISTHOBRANCHIA 0.0076 Palaemon Parexogone hebes 0.0001 Pariambus typicus 0.0001 0.0003 0.0019 0.0047 0.0001 Parvicardium exiguum 0.3193 Patellidae Peringia ulvae 0.1888 0.0641 0.1405 1.5151 0.0846 0.854 1.3964 1.3071 0.5392 0.7371 0.1096 0.0804 0.0024 0.0218 PHAEOPHYCEAE Pharidae Pholoe inornata Phoronis 0.0254 0.0245 0.0017 0.1596 Phyllodoce mucosa 0.0166 0.0028 0.0577 0.0035 0.0358 0.0069 0.0058 0.0004 Phyllodocidae 0.0001 Platynereis dumerilii Plumulariidae PODOCOPIDA 0.0067 POLYCHAETA 0.0002 0.0005 0.0001 0.0001 0.0026 0.0009 Polycirrus Polydora ciliata Polydora cornuta 0.0001 0.0004 0.0015 Polynoidae POLYPLACOPHORA 0.0001 Pomatoschistus minutus
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
PORIFERA Portunidae 0.0038 Proceraea Prosphaerosyllis tetralix Protodorvillea kefersteini Pseudopolydora pulchra Pterothamnion plumula PYCNOGONIDA Pycnogonum littorale Pygospio elegans 0.0001 0.0029 0.0004 0.0001 0.0001 Retusa obtusa 0.0075 0.0069 0.0217 0.0011 0.0055 0.0058 RHODOPHYTA Sabella pavonina Sabellidae Sabelliphilus elongatus Scoloplos armiger Scrobicularia plana 2.2622 1.2758 0.1096 0.0436 Scrupocellaria reptans Scrupocellaria scrupea Semelidae 0.0618 Sertulariidae SIPUNCULA Sphaerodorum gracilis Sphaerosyllis (Type 1) 0.0001 0.0022 0.0004 Spionidae 0.0001 Spiophanes bombyx 0.0012 Stenothoe marina Streblospio 0.0125 0.0219 0.0001 0.0146 0.0001 0.0057 0.0002 0.0001 0.0068 0.0098 0.0025 0.0001 0.0012
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TaxonName
150 152 153 154 155 157 158 163 169 171 172 174 179 180
Sycon ciliatum Syllidae 0.0001 Syllidia armata 0.0049 Syllis Syllis columbretensis 0.0119 Syllis gracilis Syllis hyalina Syllis pulvinata Tapes philippinarum 0.1542 Terebellidae 0.0001 TEREBELLOMORPHA Tharyx "species A" 0.0001 0.0023 0.0548 0.3534 0.2274 0.2551 1.0782 0.0094 0.1085 0.1524 0.0063 Tharyx killariensis 0.0088 0.0062 0.0251 0.0028 THORACICA 0.0007 Thoralus cranchii THRACIOIDEA Tritaeta gibbosa 0.0019 Tubificoides 0.0001 0.0001 0.0001 Tubificoides amplivasatus 0.0138 0.0013 0.0201 0.0128 0.015 0.0046 0.0025 0.0022 Tubificoides benedii 0.0006 0.002 0.0013 0.0097 0.0636 0.3039 0.1538 0.0007 0.0019 0.0001 Tubificoides pseudogaster 0.001 0.0011 0.0001 0.008 0.0045 0.0008 0.0008 0.0016 0.0064 0.0029 0.0001 Tubificoides swirencoides TURBELLARIA 0.0023 ULVOPHYCEAE Vesicularia spinosa
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Table 8: Raw biomass data for Stour Estuary sampling stations 181 to 549
TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Abra 0.0173 Abra alba Abra tenuis 0.2425 0.0258 0.0015 0.028 ACARINA 0.0001 0.0001 Achelia echinata 0.02 0.0024 0.0141 0.0045 Achelia laevis 0.0167 ACTINIARIA 1.0414 0.9784 0.068 0.0218 ACTINOPTERYGII 0.0001 Alcyonidium condylocinereum Alcyonidium diaphanum Alcyonidium gelatinosum Alcyonidioides mytili Alcyonidium parasiticum Alderia modesta Alitta virens Allomelita pellucida 0.0147 0.1054 Amathia lendigera Ammodytes 0.0007 Ammothea hilgendorfi 0.0005 0.0001 Ampelisca 0.0001 Ampelisca brevicornis 0.0005 Ampharete lindstroemi 0.0095 0.0369 0.0251 Ampharetidae 0.0001 0.0252 0.014 Amphicteis Amphicteis gunneri 0.0002 Amphilochus manudens 0.0012 0.0001 Amphilochus neapolitanus 0.0009
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Amphipholis squamata 0.0006 AMPHIPODA 0.0025 0.0055 0.0018 0.0011 Amphiuridae 0.0027 Anguinella palmata ANIMALIA 0.0012 Anoplodactylus petiolatus 0.0001 Anoplodactylus pygmaeus 0.0003 0.0001 Aora gracilis 0.0096 0.0073 0.098 Aoridae 0.0026 0.0101 0.0184 0.0165 0.0054 0.0025 Aphelochaeta marioni 0.0001 0.0075 0.0012 0.0297 0.0061 0.0001 0.0249 0.0108 0.0001 Apherusa bispinosa 0.0014 0.0004 0.0097 0.0032 Apocorophium acutum Apocorophium lacustre ARANEAE Aricidea minuta ASCIDIACEA Ascidiella Ascidiella aspersa Ascidiella scabra Aspidelectra melolontha Austrominius modestus Balanus balanus Balanus crenatus Baltidrilus costatus Barentsia Bicellariella ciliata BIVALVIA 0.0006 0.0001 0.0002 0.0292 0.1031 0.0018 0.0784 0.0001 Bodotria arenosa 0.0003
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Bodotria scorpioides 0.0003 0.0006 Bowerbankia BRACHYURA 0.0003 Bugula Bugula plumosa Callipallene tiberi 0.0006 0.0007 Campanulariidae Capitella 0.0001 Capitellidae Carcinus maenas 0.0185 Cardiidae 0.0002 0.007 0.0223 0.0143 0.0002 Caridion 0.0026 CEPHALASPIDEA 0.0002 0.0002 Cerastoderma Cerastoderma edule 11.0368 Cerastoderma glaucum 1.2795 0.1693 Chaetozone gibber 0.0013 Chaetozone zetlandica 0.0225 0.0628 0.0022 0.0262 0.0197 Cheirocratus 0.0066 Cheirocratus intermedius Cheirocratus sundevallii 0.0057 Chironomidae 0.0001 0.0003 0.0244 0.0048 0.0003 0.0001 0.0001 CHLOROPHYTA Ciona intestinalis Cirratulidae 0.0197 0.0054 0.0863 0.0005 0.0066 0.0002 0.0011 0.0019 0.0019 0.0099 0.0001 Cirriformia tentaculata 0.1547 0.2928 0.0003 0.2192 0.1622 Cliona COLLEMBOLA
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Conopeum reticulum Conopeum seurati COPEPODA 0.0005 0.0001 0.0002 0.0006 0.0001 0.0004 0.006 Corella parallelogramma Corophiidae 0.0001 Corophium arenarium Corophium volutator Cossura pygodactylata 0.0013 0.0001 0.0003 0.0034 0.0005 0.0018 0.0001 0.0001 0.0002 0.0025 0.0002 Crangon crangon 0.1128 0.0511 Crassostrea gigas 242.44 Crepidula fornicata 21.4325 147.57001 1.2616 131.1525 CRUSTACEA CUMACEA Cumella pygmaea 0.0007 0.0007 0.0003 Cyathura carinata 0.0025 0.0081 DECAPODA 0.0069 0.0008 DEMOSPONGIAE Dendrodoa grossularia Dexamine spinosa 0.0029 0.0206 0.0033 0.0017 DIPTERA Dorvilleidae 0.0001 Edwardsiidae 0.0255 Electra crustulenta Electra monostachys Electra pilosa Endeis spinosa 0.0001 Ensis ensis ENTEROPNEUSTA 0.0289
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Epigamia alexandri 0.0001 Ericthonius punctatus 0.0075 Erinaceusyllis erinaceus 0.0001 0.0001 0.0002 Eteone 0.0015 0.0001 Eteone cf. longa Eudendrium Eudorella truncatula 0.0003 Eulalia 0.0042 Eumida 0.0001 Eumida sanguinea 0.0122 0.0147 0.0007 0.0017 Eunereis longissima Eunicidae 0.147 Eusarsiella zostericola 0.0035 0.0001 0.0002 0.0001 0.0398 0.0135 0.0003 0.0032 0.017 0.0004 0.0029 0.0013 0.0023 0.0001 Exogone naidina 0.0004 0.0094 0.0015 0.001 0.0008 0.0048 0.0001 0.0002 0.0002 0.0002 0.0001 Fabriciidae 0.0001 0.0001 Filicrisia geniculata Galathowenia 0.0045 0.0004 0.0072 0.0001 GASTROPODA 0.0001 0.0006 0.0002 Gattyana cirrhosa Gitana sarsi 0.0003 0.0001 0.0001 Glycera 0.0004 0.0001 0.0001 Glycera tridactyla 0.0201 Gobius niger 7.93 Gracilaria Grandidierella japonica 0.0132 Grania 0.0001 Harmothoe 0.0285 0.0183 0.0019 Harmothoe imbricata 0.0269 0.023 0.0024
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Hediste diversicolor 0.0796 0.002 0.0206 Hydrallmania falcata HYDROZOA Idotea 0.0011 Idotea baltica Idotea chelipes 0.0184 0.0003 0.0039 INSECTA 0.0001 Iphimedia minuta Ischyroceridae Jaera albifrons 0.0002 Jassa Lagotia viridis Lekanesphaera levii 0.0142 Lemnaceae Lepidochitona cinerea 0.0013 0.0202 0.0122 0.0038 0.0027 Lepidonotus squamatus 0.0611 0.019 Leptocheirus pilosus Leptochelia dubia LEPTOTHECATA Liocarcinus Liocarcinus pusillus Lysidice ninetta 0.0018 Macoma balthica 2.0215 0.0376 0.057 0.0015 0.0053 Manayunkia aestuarina 0.0007 Medicorophium affine 0.0001 Mediomastus fragilis 0.0016 0.0003 Melinna palmata 0.0942 0.0997 0.0394 0.1074 0.1437 0.1218 0.1084 0.0479 0.0499 0.1424 0.0287 0.0078 0.1699 0.0107 Melita 0.0001
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Melita palmata 0.0041 0.0372 0.0025 Melitidae 0.0025 Mesopodopsis slabberi Microdeutopus 0.0128 0.001 Microdeutopus anomalus Microdeutopus gryllotalpa 0.0788 0.0154 0.0167 0.0021 0.0033 0.0164 Microdeutopus stationis Microprotopus maculatus 0.0003 0.0001 0.0014 0.0013 Monocorophium acherusicum 0.0005 Monocorophium sextonae 0.0033 Munna kroyeri 0.0001 Munna minuta 0.0027 0.0002 0.0001 Mya arenaria MYODOCOPIDA 0.0011 Myrianida MYSIDA NEMATODA 0.0005 0.009 0.0001 0.0005 0.0005 0.0005 0.0042 0.0001 0.0001 0.0002 0.001 0.0001 0.0001 Nematostella vectensis NEMERTEA 0.0045 0.0091 0.0003 Nephtys 0.1092 0.0001 0.0003 0.0008 0.0011 0.0021 0.0022 0.0062 0.0747 Nephtys hombergii 0.0692 0.0804 0.4143 0.5173 0.3362 0.3605 0.0982 0.1262 0.1036 0.1842 0.2674 0.0352 Nephtys kersivalensis 0.0288 Nereididae 0.0001 0.0001 0.0029 0.0001 0.0265 0.0001 Notomastus 0.0359 0.0001 Nototropis guttatus 0.0004 Nucula 0.0045 Nymphon brevirostre 0.0006 Nymphon gracile
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Odostomia OLIGOCHAETA 0.0078 0.0003 0.008 0.0004 Ophiocten affinis OPHIUROIDEA Ophryotrocha 0.0001 0.0002 OPISTHOBRANCHIA 0.0045 0.0001 Palaemon Parexogone hebes 0.0001 0.0012 0.0001 0.0002 Pariambus typicus 0.0203 0.0028 0.0028 0.005 0.0001 0.0044 0.0001 0.0001 0.0001 0.0111 Parvicardium exiguum 0.0973 Patellidae 0.0012 Peringia ulvae 0.0001 0.5578 0.0329 0.0037 0.5067 0.0161 0.0029 0.0913 PHAEOPHYCEAE Pharidae 0.0001 0.0053 0.0003 Pholoe inornata 0.0007 0.0001 Phoronis 0.0001 0.0006 0.2054 0.0015 Phyllodoce mucosa 0.0001 0.0001 0.0005 0.0511 0.002 0.0027 0.0005 0.0005 0.0003 Phyllodocidae Platynereis dumerilii 0.0109 0.0039 0.6524 0.0161 Plumulariidae PODOCOPIDA POLYCHAETA 0.0061 0.0004 0.0067 Polycirrus 0.0098 Polydora ciliata 0.0002 0.0001 Polydora cornuta 0.0061 Polynoidae 0.0013 0.0002 POLYPLACOPHORA 0.0124 0.0001 0.0002 Pomatoschistus minutus 0.0082
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
PORIFERA Portunidae 0.0043 Proceraea 0.0003 0.0001 Prosphaerosyllis tetralix 0.0001 0.0001 0.0001 Protodorvillea kefersteini 0.0001 Pseudopolydora pulchra Pterothamnion plumula PYCNOGONIDA Pycnogonum littorale 0.077 Pygospio elegans 0.0006 0.0032 0.0001 0.0001 0.0001 Retusa obtusa 0.0214 0.0051 RHODOPHYTA Sabella pavonina 0.0004 0.0011 0.0205 35.5 Sabellidae 0.0003 Sabelliphilus elongatus Scoloplos armiger Scrobicularia plana 1.7163 0.0124 Scrupocellaria reptans Scrupocellaria scrupea Semelidae 0.0001 Sertulariidae SIPUNCULA Sphaerodorum gracilis 0.0001 Sphaerosyllis (Type 1) 0.0009 0.0017 0.0021 0.0037 0.0009 0.0002 Spionidae 0.0019 Spiophanes bombyx 0.0008 Stenothoe marina 0.0004 0.0001 Streblospio 0.0005 0.0038 0.0004 0.0001 0.0095 0.0016 0.0001 0.0056 0.0024 0.0001
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TaxonName
181 189 191 192 193 194 195 204 206 207 209 249 548 549
Sycon ciliatum Syllidae 0.0001 Syllidia armata 0.0152 0.0033 0.004 0.0038 Syllis 0.0009 Syllis columbretensis 0.0001 0.0401 0.0051 0.0169 Syllis gracilis 0.0009 0.0035 0.0006 Syllis hyalina 0.0001 Syllis pulvinata 0.0002 0.0004 Tapes philippinarum 0.0991 0.0375 Terebellidae 0.0001 TEREBELLOMORPHA Tharyx "species A" 0.0007 0.0006 0.0009 0.0072 0.1392 0.0427 0.0022 0.0017 0.0298 0.0442 0.0061 0.0063 Tharyx killariensis 0.001 0.0001 THORACICA Thoralus cranchii THRACIOIDEA Tritaeta gibbosa 0.0063 0.064 Tubificoides 0.0004 0.0015 0.0002 Tubificoides amplivasatus 0.0031 0.0022 0.0011 0.0019 0.0081 0.005 0.0061 0.0042 0.002 0.0041 0.0076 0.0011 0.0044 Tubificoides benedii 0.0009 0.0062 0.0017 0.0214 0.0459 0.003 0.0003 0.002 Tubificoides pseudogaster 0.0001 0.0011 0.0063 0.0046 0.0029 0.0001 0.0001 0.0006 Tubificoides swirencoides 0.0005 TURBELLARIA ULVOPHYCEAE Vesicularia spinosa
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Table 9: Raw biomass data for Orwell Estuary sampling stations
TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Abra Abra alba 0.0931 Abra tenuis 0.0158 0.0046 ACARINA Achelia echinata 0.0148 0.0113 0.0004 Achelia laevis ACTINIARIA 1.5834 0.1048 0.5844 3.1085 1.0505 ACTINOPTERYGII Alcyonidium condylocinereum Alcyonidium diaphanum Alcyonidium gelatinosum Alcyonidioides mytili Alcyonidium parasiticum Alderia modesta Alitta virens 0.2481 Allomelita pellucida Amathia lendigera Ammodytes Ammothea hilgendorfi 0.006 0.0714 Ampelisca Ampelisca brevicornis 0.0056 Ampharete lindstroemi 0.0144 0.0205 0.1159 0.0019 0.0197 Ampharetidae 0.0073 0.0009 0.0005 0.0003 Amphicteis 0.0007 Amphicteis gunneri Amphilochus manudens Amphilochus neapolitanus 0.0013 0.0002 0.0006
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Amphipholis squamata AMPHIPODA 0.0013 0.0026 0.0174 0.0028 0.0018 0.0004 0.0001 0.0005 Amphiuridae 0.0038 Anguinella palmata ANIMALIA 0.0001 Anoplodactylus petiolatus 0.001 0.0004 Anoplodactylus pygmaeus 0.0016 Aora gracilis 0.0069 0.0063 Aoridae 0.0034 0.0001 0.0597 0.0079 0.0005 Aphelochaeta marioni 0.0055 0.0003 Apherusa bispinosa 0.0008 Apocorophium acutum 0.0005 Apocorophium lacustre 0.0007 ARANEAE Aricidea minuta 0.0011 ASCIDIACEA Ascidiella Ascidiella aspersa Ascidiella scabra Aspidelectra melolontha Austrominius modestus Balanus balanus Balanus crenatus Baltidrilus costatus 0.0154 Barentsia Bicellariella ciliata BIVALVIA 0.0016 0.0197 0.0006 0.0004 0.0002 0.0007 0.0006 0.0002 0.0002 Bodotria arenosa
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Bodotria scorpioides 0.0011 0.0003 Bowerbankia BRACHYURA Bugula Bugula plumosa Callipallene tiberi 0.0001 0.0001 Campanulariidae Capitella 0.0001 0.0002 0.0006 0.0001 Capitellidae 0.0001 0.0014 Carcinus maenas Cardiidae 0.0079 0.0655 0.148 0.0013 0.0002 0.0134 0.0008 Caridion CEPHALASPIDEA Cerastoderma 0.1074 0.9061 0.0368 Cerastoderma edule 58.9354 25.9684 18.1262 Cerastoderma glaucum Chaetozone gibber Chaetozone zetlandica 0.002 0.0071 0.0017 0.0001 0.0009 0.0002 Cheirocratus 0.0023 Cheirocratus intermedius 0.0097 0.0056 0.0029 Cheirocratus sundevallii Chironomidae 0.0001 CHLOROPHYTA Ciona intestinalis Cirratulidae 0.0011 0.0002 0.0372 0.0001 0.0003 0.027 0.0003 0.0025 Cirriformia tentaculata 2.479 0.0542 0.0161 0.2598 Cliona COLLEMBOLA
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Conopeum reticulum Conopeum seurati COPEPODA 0.0001 0.0084 Corella parallelogramma Corophiidae Corophium arenarium 0.0001 Corophium volutator 3.1342 0.0145 Cossura pygodactylata 0.0005 0.0018 0.0004 0.0005 0.0001 0.0034 0.0017 0.0016 0.0001 Crangon crangon Crassostrea gigas Crepidula fornicata 0.0025 0.0173 110.28 0.0001 0.001 CRUSTACEA 0.0001 CUMACEA 0.0001 Cumella pygmaea 0.0001 0.0005 0.0001 0.0001 Cyathura carinata 0.0009 DECAPODA 0.0001 0.0001 DEMOSPONGIAE Dendrodoa grossularia Dexamine spinosa 0.0024 DIPTERA 0.0022 0.0024 Dorvilleidae Edwardsiidae Electra crustulenta Electra monostachys Electra pilosa Endeis spinosa Ensis ensis 0.0293 ENTEROPNEUSTA
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Epigamia alexandri 0.0001 Ericthonius punctatus 0.0008 Erinaceusyllis erinaceus Eteone 0.0025 0.0002 0.0006 0.0001 Eteone cf. longa 0.0007 0.0001 0.0008 Eudendrium Eudorella truncatula 0.0001 0.0003 Eulalia Eumida Eumida sanguinea 0.0028 0.0099 0.0002 Eunereis longissima 0.0061 Eunicidae Eusarsiella zostericola 0.0005 0.0001 0.0009 0.0004 0.0007 0.0001 0.0001 0.0003 0.0001 0.0013 0.0002 0.0001 0.0001 0.0004 Exogone naidina 0.0001 0.0006 0.0042 0.0017 0.0001 0.0001 0.0002 0.0013 0.0002 Fabriciidae 0.0001 Filicrisia geniculata Galathowenia GASTROPODA Gattyana cirrhosa 0.0067 Gitana sarsi 0.0001 Glycera 0.0001 0.0001 0.0041 0.0002 Glycera tridactyla Gobius niger Gracilaria Grandidierella japonica 0.0062 Grania Harmothoe Harmothoe imbricata
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Hediste diversicolor 0.2363 0.1454 Hydrallmania falcata HYDROZOA 0.0006 Idotea 0.0001 Idotea baltica Idotea chelipes INSECTA Iphimedia minuta 0.0001 Ischyroceridae 0.0013 Jaera albifrons Jassa 0.0042 Lagotia viridis Lekanesphaera levii Lemnaceae Lepidochitona cinerea 0.0256 Lepidonotus squamatus 0.0116 Leptocheirus pilosus Leptochelia dubia LEPTOTHECATA Liocarcinus Liocarcinus pusillus 0.0048 Lysidice ninetta Macoma balthica 0.792 0.0139 0.1189 0.3337 0.0293 0.3625 0.0567 0.2575 0.0034 0.0087 Manayunkia aestuarina 0.0001 0.0004 Medicorophium affine Mediomastus fragilis 0.0008 0.0073 0.0112 0.0005 Melinna palmata 0.0273 0.0001 0.8118 0.0016 Melita 0.0002
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Melita palmata 0.0118 Melitidae 0.0004 Mesopodopsis slabberi 0.0001 Microdeutopus Microdeutopus anomalus Microdeutopus gryllotalpa 0.0147 0.0019 Microdeutopus stationis 0.0089 Microprotopus maculatus 0.0001 Monocorophium acherusicum 0.0022 0.0006 Monocorophium sextonae 0.0003 Munna kroyeri Munna minuta Mya arenaria 0.0316 0.825 0.0034 0.5301 0.0138 MYODOCOPIDA Myrianida 0.0003 0.0001 MYSIDA NEMATODA 0.0009 0.0005 0.0017 0.0005 0.0009 0.0005 0.0009 0.0005 0.0001 0.0001 0.0001 0.0001 0.0005 0.0001 Nematostella vectensis NEMERTEA 0.0136 0.0007 0.0001 Nephtys 0.0063 0.001 0.0114 0.0127 0.0108 0.0041 0.0001 0.0167 0.0032 0.0002 0.0002 Nephtys hombergii 0.3046 0.5503 0.26 0.1112 0.8096 0.2092 0.342 0.0382 0.1745 0.0046 0.0166 Nephtys kersivalensis Nereididae 0.0001 0.0047 0.0001 0.0036 0.0011 0.0008 0.0001 0.0001 Notomastus 0.1625 0.1252 0.1084 Nototropis guttatus Nucula 0.0001 0.0011 0.0026 0.0086 0.0009 0.0024 Nymphon brevirostre Nymphon gracile 0.0011
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Odostomia OLIGOCHAETA 0.0004 0.0001 0.0091 0.0007 0.0004 Ophiocten affinis 0.0074 OPHIUROIDEA Ophryotrocha OPISTHOBRANCHIA Palaemon 0.0001 Parexogone hebes 0.0018 Pariambus typicus 0.0001 0.0026 0.0001 0.0003 0.0002 0.0044 0.002 Parvicardium exiguum 0.4833 Patellidae Peringia ulvae 0.0468 0.1128 0.05 0.1711 0.062 0.0084 0.0111 PHAEOPHYCEAE Pharidae Pholoe inornata Phoronis 0.1935 Phyllodoce mucosa 0.0012 0.0097 0.0036 Phyllodocidae 0.0001 Platynereis dumerilii Plumulariidae PODOCOPIDA POLYCHAETA 0.0003 0.0006 0.0001 0.0043 0.0009 Polycirrus Polydora ciliata Polydora cornuta 0.0714 0.0016 0.0051 0.001 0.0028 0.0008 0.0001 Polynoidae 0.0008 0.0001 POLYPLACOPHORA 0.0001 0.0008 Pomatoschistus minutus
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
PORIFERA Portunidae 0.0108 Proceraea 0.0008 Prosphaerosyllis tetralix 0.0002 Protodorvillea kefersteini 0.0007 Pseudopolydora pulchra 0.0016 Pterothamnion plumula PYCNOGONIDA 0.0001 Pycnogonum littorale Pygospio elegans 0.0013 0.0001 0.0042 0.0032 0.0005 0.0004 Retusa obtusa RHODOPHYTA Sabella pavonina 0.0875 1.4023 16.0338 Sabellidae Sabelliphilus elongatus Scoloplos armiger 0.0002 0.0001 0.0001 Scrobicularia plana 0.1692 Scrupocellaria reptans Scrupocellaria scrupea Semelidae Sertulariidae SIPUNCULA 0.0001 Sphaerodorum gracilis Sphaerosyllis (Type 1) 0.0002 0.0001 Spionidae Spiophanes bombyx Stenothoe marina 0.0009 0.0041 Streblospio 0.0419 0.0273 0.0478 0.0073 0.0088 0.0491 0.0093 0.0603 0.0005 0.0008 0.0001 0.0013 0.0162 0.0001 0.0006
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TaxonName
258 260 261 263 267 269 272 275 285 289 295 296 300 301 303 306
Sycon ciliatum Syllidae Syllidia armata 0.0191 0.0166 0.0004 0.0004 Syllis 0.0002 Syllis columbretensis 0.0027 Syllis gracilis 0.0015 Syllis hyalina Syllis pulvinata Tapes philippinarum 2.9822 17.32 Terebellidae TEREBELLOMORPHA 0.0182 0.1065 Tharyx "species A" 0.0677 0.0748 0.0007 0.0113 0.1023 0.2681 0.0255 0.0104 0.0021 0.0054 0.0038 0.0007 0.0002 0.0001 Tharyx killariensis 0.0004 THORACICA Thoralus cranchii 0.0789 THRACIOIDEA 0.0001 0.0061 Tritaeta gibbosa Tubificoides 0.0004 0.0001 Tubificoides amplivasatus 0.0092 0.001 0.0051 0.0005 0.0001 0.0012 0.0014 0.0001 Tubificoides benedii 0.0001 0.0279 0.0006 0.012 0.0016 0.0009 0.0001 Tubificoides pseudogaster 0.0004 0.0004 0.0017 0.0005 0.0001 0.0061 0.0045 0.0009 0.0007 0.0001 Tubificoides swirencoides 0.0042 TURBELLARIA ULVOPHYCEAE Vesicularia spinosa
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Appendix 4: Total biomass per m2 at each sampling station
Table 10: Total biomass per m2 in Stour Estuary sampling stations 150 to 180
Station 150 152 153 154 155 157 158 163 169 171 172 174 179 180
Total biomass per m2 111.98 7.91 102.95 46.36 33.12 104.98 232.51 56.25 773.81 68.48 58.77 29.08 1769.99 18.01
Table 11: Total biomass per m2 in Stour Estuary sampling stations 181 to 549
Station 181 189 191 192 193 194 195 204 206 207 209 249 548 549
Total biomass per m2 548.06 9992.87 45.04 3313.20 90.23 58.71 935.67 17.14 74.98 293.01 17.04 8.20 17.26 4.33
Table 12: Total biomass per m2 in Orwell Estuary sampling stations
Station 258 260 261 263 267 269 272 275 285 289 295 296 300 301
Total biomass per m2 1548.70 786.47 21.08 113.57 15.85 996.16 10.48 13.21 2782.92 161.10 0.39 7.49 4.61 10.38
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Appendix 5: Biotope descriptions
LS.LMu.MEst.HedMac - Hediste diversicolor and Macoma balthica in littoral sandy mud
Biotope description
Mainly mid and lower shore sandy mud or mud in lower estuaries, sheltered bays and marine inlets, often subject to variable salinity. The main characterising species are the ragworm Hediste diversicolor, the baltic tellin Macoma balthica, and the oligochaetes Tubificoides benedii and T. pseudogaster. Further polychaetes that are often common or abundant include Pygospio elegans, Streblospio shrubsolii, Tharyx killariensis, Aphelochaeta marioni, Capitella capitate and Manayunkia aestuarina. The oligochaete Heterochaeta costata and the mud shrimp Corophium volutator may be abundant. The mud snail Peringia ulvae is often common. Other species which occur in a significant proportion of samples include the polychaetes Eteone longa and Nephtys hombergii, and bivalves such as the cockle Cerastoderma edule and Abra tenuis. The sand gaper Mya arenaria is superabundant in about a quarter of the samples for this biotope. M. arenaria is probably present in a higher proportion of areas of this biotope, but may be missed in core samples due to its size.
Situation
HedMac may occur on the mid/lower shore of lower estuarine shores, with HedMacEte or MacAre on the upper shore. HedMacScr, Hed.Str, NhomAph, and Hed.Cvol may be present on the same shore.
Temporal variation
Enteromorpha spp. and Ulva lactuca may form mats on the surface of the mud during the summer months, particularly in areas of nutrient enrichmnent.
From: http://www.jncc.gov.uk/marine/biotopes/biotope.aspx?biotope=JNCCMNCR00000375
LS.LMx.MxCirCer – Cirratulids and Cerastoderma edule in littoral mixed sediment
Biotope description
Sheltered mixed sediments, usually subject to variable salinity conditions. Banks of shell may be present. The infauna is very diverse, dominated by a range of polychaetes including Exogone naidina, Sphaerosyllis sp., Pygospio elegans, Chaetozone gibber, Cirriformia tentaculata, Aphelochaeta marioni, Capitella capitata, Mediomastus fragilis, and Melinna palmata. The oligochaetes Tubificoides benedii and T. pseudogaster are abundant, as is the cockle
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2015 Benthic Monitoring Report Stour and Orwell Estuaries
Cerastoderma edule. A large range of amphipods may occur, including Melita palmata, Microprotopus maculatus, Aora gracilis and Corophium volutator. The bivalves Abra alba and A. nitida may occur. The barnacle Austrominius modestus can be abundant where the sediment has stones on the surface. Epifaunal algae may occur attached to stable cobbles on the sediment surface.
Situation
Mid shore, lower shore, as extension of shallow sublittoral biotope.
Temporal variation
Not known.
From: http://www.jncc.gov.uk/marine/biotopes/biotope.aspx?biotope=JNCCMNCR00001583
SS.SMx.SMxVS.CreMed – Crepidula formicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment
Biotope description
Variable salinity mixed sediment characterised by the slipper limpet Crepidula fornicata and the polychaetes Mediomastus fragilis and Aphelochaeta marioni. Other numerically important taxa include the oligochaetes Tubificoides benedii, syllids such as Exogone naidina and Sphaerosyllis, and Nephtys hombergii. Lepidonotus squamatus and Scoloplos armiger may also be common. Shell debris and cobbles are colonised by the ascidians Ascidiella aspersa, Ascidiella scabra, Molgula sp. and Dendrodoa grossularia (the ascidians may not be recorded adequately by remote infaunal survey techniques).
Situation
This biotope occurs in the lower estuary where currents allow a stable environment to develop. It is associated with oyster beds and relict oyster beds, (Ost) in southern England and Wales. It may be found adjacent to or in conjunction with AphTubi and AphPol. It may be associated with VsenAsquAps and possibly form a component of SundAasp.
Temporal variation
No temporal data available.
From: http://www.jncc.gov.uk/marine/biotopes/biotope.aspx?biotope=JNCCMNCR00001200
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Appendix 6: Biotopes identified in 2014 and 2015
Area Sampling group Site 2014 2015
Stour GpStA 150 LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStA 152 LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStA 153 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStA 154 LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStB 155 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 157 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 158 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 163 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 169 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 171 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 172 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 174 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStD 179 SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStD 180 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStD 181 SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStD 249 SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStE 193 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 194 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 548 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStE 549 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStF 189 SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStF 191 SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 192 SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 195 SS.SMx.IMx.SpavSpAn LS.LMx.Mx.CirCer Stour GpStG 204 LS.LMu.MEst.NhomMacStr LS.LMx.Mx.CirCer Stour GpStG 206 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 207 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStG 209 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 258 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrA 260 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 261 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrA 263 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 267 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 269 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 272 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 275 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrC 285 LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrC 289 no sample SS.SMx.SMxVS.CreMed Orwell GpOrC 303 SS.SMx.IMx.SpavSpAn LS.LMx.Mx.CirCer Orwell GpOrC 306 LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrD 295 LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrD 296 LS.LMu.MEst.NhomMacStr SS.SMx.SMxVS.CreMed Orwell GpOrD 300 LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrD 301 SS.SMu.SMuVS.AphTubi LS.LMx.Mx.CirCer
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Stour and Orwell Estuaries benthic monitoring programme: Review of macrobenthic data from 1997 to 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
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2 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Project Number Report No. Revision No. Date of Issue
I-HHA-110 1 1 30th June 2016
Name Signature Position
Authors Sarah Marjoram Marine Consultant
Daniel Bastreri Principal Marine Consultant
Reviewer Dr Ruth Barnich Principal Taxonomist
Client Contact: John Brien Reference: I-HHA-110/002
Disclaimer:
Copyright Thomson Unicomarine Limited. All rights reserved. No part of this report may be copied or reproduced by any means without prior written permission from Thomson Unicomarine Limited. If you have received this report in error, please destroy all copies in your possession or control and notify Thomson Ecology Limited. This report has been prepared for the exclusive use of the commissioning party and unless otherwise agreed in writing by Thomson Unicomarine Limited, no other party may use, make use of or rely on the contents of the report. No liability is accepted by Thomson Ecology Limited for any use of this report, other than for the purposes for which it was originally prepared and provided. Opinions and information provided in the report are on the basis of Thomson Ecology Limited using due skill, care and diligence in the preparation of the same and no explicit warranty is provided as to their accuracy. It should be noted and it is expressly stated that no independent verification of any of the documents or information supplied to Thomson Ecology Limited has been made.
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Contents
Summary ...... 7 1. Introduction ...... 8 1.1 Background ...... 8 1.2 The Brief and Objectives ...... 9 2. Methodology ...... 10 2.1 Design of survey programme ...... 10 2.2 Field work ...... 12 2.3 Laboratory work ...... 12 2.4 Data analysis ...... 13 3. Results ...... 16 3.1 Particle size analysis ...... 16 3.2 Macrofaunal analysis ...... 17 4. Discussion ...... 33 5. Conclusion...... 35 6. References ...... 36 Appendices ...... 38 Appendix 1: PSA data from 2012, 2013, 2014 and 2015 by sampling station .... 38 Appendix 2: Graphical representation of the PSA results from 2012 to 2015 by sampling station...... 49 Appendix 3: Biotopes identified from 2003 to 2015 ...... 64 Appendix 4: PERMANOVA results ...... 67 Appendix 5: ANOSIM results ...... 68
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Tables
Table 1: Sample groups determined from the 2003 survey ...... 11 Table 2: Number of individuals recorded in each survey year...... 18 Table 3: Total number species (S) recorded in each survey year...... 18 Table 4: Average Margalef's diversity index (d) for each survey year...... 19 Table 5: Average Shannon Wiener Diversity Index (H'(log e)) for each survey year...... 20 Table 6: Average Pielou's Evenness (J) for each survey year...... 21 Table 7: Average biomass recorded in surveys carried out from 2008 to 2015 ...... 22 Table 8: Biotopes identified between 2003 and 2015 ...... 26 Table 9: Percentage of biotopes in the total number of samples, 2003 – 2015 ...... 26 Table 10: Results on the variance between the different years, between the Stour and Orwell and the intertidal and subtidal communities...... 67 Table 11: Results on the interactive effects between years and location (Stour or Orwell), between years and intertidal and subtidal, between location and intertidal and subtidal, and the interaction between all three factors...... 67 Table 12: The relationship in community composition between years ...... 68 Table 13: The relationship between community composition in the Stour and Orwell in the same year ...... 68 Table 14: The relationship between the Stour samples over the different years ...... 68 Table 15: The relationship between the Orwell samples over the different years ...... 69 Table 16: The relationship between intertidal communities over the different years ...... 69 Table 17: The relationship between subtidal communities over the different years ...... 69 Table 18: The relationship between intertidal and subtidal communities in the same year .. 70 Table 19: The relationship between intertidal communities within the Stour over the different years ...... 70 Table 20: The relationship between intertidal communities within the Orwell over the different years ...... 70 Table 21: The relationship between subtidal communities within the Stour over the different years ...... 71 Table 22: The relationship between subtidal communities within the Orwell over the different years ...... 71
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Figures
Figure 1: Location of annual monitoring stations in the Stour and Orwell estuaries, with sample groups and target biotopes ...... 11 Figure 2: Total number of individuals recorded in each survey year, with trend line...... 18 Figure 3: Total number of species recorded in each survey year, with trend line...... 18 Figure 4: Average Margalef's Diversity Index (d) for each survey year, with trend line...... 19 Figure 5: Average Shannon Wiener Diversity Index (H'(log e)) for each survey year, with trend line...... 20 Figure 6: Average Pielou's evenness (J) for each survey year, with trend line...... 21 Figure 7: Average biomass (g/m2) recorded in surveys carried out from 2008 to 2015...... 22 Figure 8: Number of individuals (N) by estuary and by habitat...... 22 Figure 9: Number of species (S) by estuary and by habitat...... 23 Figure 10: Shannon Wiener Diversity Index (H’(log e)) by estuary and by habitat...... 23 Figure 11: Biotopes assigned to survey stations in 2003 ...... 25 Figure 12: Biotopes assigned to survey stations in 2015 ...... 25 Figure 13: Multidimensional scaling plot showing the relationship between the community compositions sampled in 2012, 2013, 2014 and 2015...... 29
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Summary
The results of the 2015 survey, and comparison of the macrobenthic community data between 1997 and 2015 show that abundance, diversity and biomass have remained relatively stable during this period.
Comparing both estuaries, the abundance of macrobenthic communities has increased in the Stour Estuary between 1997 and 2015 at subtidal sites, and remained stable at intertidal sites. In contrast, an increase in abundance has been observed at intertidal sites in the Orwell Estuary during the same period, while it remained relatively stable in subtidal sites. Biomass values also remained relatively constant over this period, though there were significant differences in the total biomass recorded in 2013 and 2015, with values largely exceeding those of 2014 and the other years.
Whilst the data show that similar benthic communities have been present in the Stour and Orwell since the commencement of the monitoring programme, there have been notable changes between years and shifts between biotopes for many stations. Between 2003 and 2015, the distribution of the biotopes originally identified in 2003 have changed significantly, and only nine sample sites are within the same biotope in 2015 as in 2003. Only one of the biotopes identified in 2003 (LS.LMu.MEst.HedMac) is still represented in the samples in 2015. These changes represent shifts in the distribution of biotopes between 2003 and 2015, but not necessarily changes in the overall extent of these biotopes
The reasons for these changes are difficult to determine but could result from changes in hydrology or sediment dynamics of the estuary, spatial shifts in biotopes or a combination of both. They may also be a result of the sampling strategy and its power to detect change with certainty.
Further studies are required to establish whether the observed differences over the period in consideration respond to long term changes, natural short-term cyclical variations or any specific change in the parameters considered in the monitoring programme.
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1. Introduction
1.1 Background
1.1.1 A wide scale monitoring programme of the Stour and Orwell Estuaries benthic communities was introduced in 1997, as part of the compensation, mitigation and monitoring agreement under the 1998-2000 Capital Dredge Licence. The monitoring programme, which was later amended to meet the requirements of the Trinity III Extension consent, had an original frequency of five years.
1.1.2 The first survey was undertaken in 1997, when 154 stations were sampled with a 0.04 m² Shipek grab. Two benthic biological samples and one sample for particle size analysis (PSA) were taken at each station. The biological samples were analysed by Thomson Unicomarine (then Unicomarine) and the PSA by HR Wallingford. The results were reported by Unicomarine (Dyer, 2000).
1.1.3 The second survey was undertaken in 2003, when 267 stations were sampled in the Stour, Orwell and Harwich approaches, also with a 0.04 m² Shipek grab. One benthic biological sample and one PSA samples were taken at each station, and analysed by Unicomarine. The data acquired during these surveys was reported by Dyer et al. (2004), and have been used in other research (Dyer & Worsfold, (2004), Worsfold & Dyer (2004), Worsfold (2005), and Bryant & McNulty (2007). The results of the 1997 and 2003 surveys were also used to inform a report on environmental trends in the Stour and Orwell Estuaries (Royal Haskoning, 2007).
1.1.4 The five year interval between surveys made variations in benthic abundance, diversity and distribution difficult to interpret. For this reason, an annual monitoring programme, involving fewer samples was agreed. Sampling each year should result in an effective long-term monitoring programme with enough data points to detect trends.
1.1.5 Sampling each year should result in an effective long-term monitoring programme with enough data points to detect trends. The emphasis of the annual surveys is on monitoring rather than on biotope mapping. Survey sites consist of stations within a selection of biotopes in each estuary or different parts of an estuary, to allow comparison between the benthos of similar biotopes. This comparison should help highlight any areas that are showing trends in benthic populations.
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1.1.6 Biomass data are also incorporated into annual reports to allow comparisons with bird data. The annual benthic data (abundance and biomass) will allow relationships between prey availability and bird numbers to be compared more easily and with a more robust data set to support any findings.
1.1.7 It was agreed at the annual Steering Group in 2007 that Unicomarine should present the data in a report each year. The format of the benthic reports has changed throughout the years following discussions at the meeting of the monitoring programme steering group. Since 2010 following discussion at the steering group meeting on 13th March 2010 the benthic report now contains summary information of the biotopes recorded from all the survey years as an appendix.
1.1.8 The annual benthic data reports have been used to inform Royal Haskoning’s annual mitigation and monitoring reports for the Stour and Orwell estuaries (Royal Haskoning, 2007, 2008, 2010, 2011 & 2012). The original proposal was to compare results with data from the Blackwater Estuary but that project was discontinued after the final surveys in 2009 (Dyer & Worsfold, 2009).
1.1.9 A summary of the surveys undertaken to date is shown below with report format.
Original/base line June/August 1997 5-yearly repeat July 2003 (with biotope mapping) Year 1 July 2008 Year 2 July 2009 (basic) Year 3 July 2010 (basic + biotope) Year 4 July 2011 (basic + analysis of past data) Year 5 July/August 2012 (basic + biotope ) Year 6 September 2013 (basic + biotope) Year 7 July 2014 (basic + biotope) Year 8 August 2015 (survey + analysis of past data)
1.2 The Brief and Objectives
1.2.1 Thomson Unicomarine has been commissioned by Harwich Haven Authority to carry out the 2015 annual benthic survey and present the results in the 2015 Annual Monitoring Report (I-HHA-110/001, Marjoram & Bastreri, 2015). This report presents the results of comparison of macrobenthic data between 1997 and 2015, including abundance, distribution and fluctuation of benthic communities in relation to particle size distribution and qualitative comparisons of biotope assignments.
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2. Methodology
2.1 Design of survey programme
2.1.1 Since 2008, samples have been collected from 44 stations belonging to 11 sample groups from both estuaries. These include four sample groups for the Orwell (OrA-D) and seven for the Stour (StA-G). Groups of samples were selected using data from the 2003 survey to represent typical biotopes, and these are shown in Figure 1. Four grab samples were taken within each of these groups, at locations sampled in 2012, 2013 and 2014, to allow comparison between these years. Samples were also taken at these sites between 1997 and 2011. Two exceptions to this are St. 548 & St. 549 which were only added to the survey programme in 2008.
2.1.2 A list of sampling stations is provided in Appendix 1 and mapped in Figure 1; the list includes biotope assignments based on analysis of data from the 2003 survey (Worsfold, 2005). Each of the four sampling points within any particular group belong to a single biotope (following Connor et al., 2004) using the 2003 data, although there may have been more than one (2003) cluster group included in a biotope. Each group has four stations, of similar community type, that were intended to be treated as replicates. There are four sample groups for the Orwell (OrA-D) and seven for the Stour (StA-G). Sample groups are summarised in Table 1 and Figure 1.
2.1.3 Following Connor’s (2004) definition, a biotope is a combination of a habitat and its associated community of biological species. A habitat includes one or more substrata, such as sand, mud, rock, together with its physical and chemical properties – hydrodynamic regime, turbidity, dissolved oxygen salinity, etc. An assemblage of populations of species, each adapted to these specific properties and associated with a particular habitat is defined as a community.
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Figure 1: Location of annual monitoring stations in the Stour and Orwell estuaries, with sample groups and target biotopes
Table 1: Sample groups determined from the 2003 survey
Group colour in EUNIS Biotope recorded Description Area found maps Nephtys hombergii, Macoma Dark A2.311 LS.LMu.MEst.NhomMacStr balthica and Streblospio sp. in Intertidal Blue littoral sandy mud Ragworms & bivalves; Hediste Pale A2.312 LS.LMu.MEst.HedMac diversicolor and Macoma Intertidal blue balthica in littoral sandy mud Dark Ragworms: Hediste diversicolor Upper estuarine A2.322 LS.LMu.UEst.Hed Green in littoral mud intertidal Aphelochaeta marioni and Yellow A5.322 SS.SMu.SMuVS.AphTubi Tubificoides spp. in variable Subtidal salinity infralittoral mud Fan worms: Sabella pavonina Purple A5.432 SS.SMx.IMx.SpavSpAn with sponges and anemones on Subtidal infralittoral mixed sediment
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2.2 Field work
2.2.1 Sampling was undertaken by Thomson Unicomarine and HHA staff between the 3rd to the 5th of August 2015 from the HHA vessel ‘Egret’. Two samples were taken at each station, using a 0.04 m² Shipek grab, one for particle size analysis (PSA) and one for benthic biological analysis. Sampling at all stations was successful. The biological samples were sieved over a 0.5 mm mesh and fixed in a formaldehyde solution on the day of sampling.
2.3 Laboratory work
2.3.1 PSA was conducted at Thomson Unicomarine’s laboratory following procedures laid out in the National Marine Biological Analytical Quality Control (NMBAQC) Scheme’s best practice guidelines (Mason, 2011) and Thomson Unicomarine’s PSA standard operating procedures (Finbow & Argent, 2012).
2.3.2 Analysis of the macrobenthic samples was undertaken according to the agreed specifications, using Thomson Unicomarine’s standard operating procedures (TEM09, 2013). All biological analysis were conducted at Thomson Unicomarine’s laboratory by Thomson Unicomarine staff with internal quality control procedures at each stage of the process.
2.3.3 After several days in preservative, the biological samples were sieved at 0.5mm and all biota extracted using low power stereo microscopes. In-house quality control procedures were carried out, to reduce the risk of biota being missed. After these procedures were completed, the sediment residues (sediment from which biota had been extracted) were discarded. The extracted biota were preserved in 70% industrial denatured alcohol (IDA). Countable fauna removed from the samples were identified to the most accurate taxonomic level practicable, usually species, and individuals counted. Non-countable taxa, such as colonial fauna, plants and algae, were recorded as present (‘P’). High power compound microscopes were used to confirm the identity of some species. For quality control purposes and to allow future taxonomic comparisons, the extracted fauna will be kept at Thomson Unicomarine for a minimum of 2 years after analysis.
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2.4 Data analysis
PSA
2.4.1 The sieve and laser data were merged to produce a continuous particle size distribution which was entered into the GRADISTAT program (Blott & Pye, 2001) to obtain derived statistics. PSA data were converted into simplified proportions of eight size categories (Wentworth, 1922). These are shown in Appendix 1.
Macrobenthic data
2.4.2 All statistical analyses were carried out using the PRIMER (Plymouth Routines in Multivariate Ecological Research) suite of applications version 6.1.13 (Clarke & Warwick, 1994; Clarke & Gorley, 2006).
Univariate analysis
2.4.3 Total numbers of taxa (S) and individuals (N), Margalef’s index (d, species richness),
Pielou’s index (J’, evenness) and Shannon-Wiener (H'(loge), diversity) were calculated for each sample using the DIVERSE component of PRIMER. Non- countable taxa were excluded from the calculations of total numbers of individuals and diversity indices, but included when calculating the total numbers of taxa. Table 2 contains a summary of the univariate analyses, showing the highest and lowest values for each test.
Multivariate analysis
Multi-Dimensional Scaling (MDS)
2.4.4 Non-metric multidimensional scaling (MDS) was used to further examine the grouping of stations described above employing relevant statistical considerations (Clarke & Warwick, 2001). The technique uses as a starting point the same Bray- Curtis similarity matrix used for the cluster analysis. An iterative process places sample points onto a 2-dimensional plane in a configuration where the inter-sample similarities are most closely represented. It is important to note that, although the MDS plot is bounded by a box, the box does not represent either axes or scale. Two samples with a high similarity index will appear close together while those less similar will appear further apart. The ‘correct’ configuration of sample points will be multidimensional and the plot is the best possible 2-dimensional representation of this multidimensional configuration. The technique should be viewed as complementary to cluster analysis, offering a different perspective of the same information.
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Characteristic biota
2.4.5 The data were examined further to determine the characteristic fauna of the communities recognised by the groupings of samples described above. A list of samples in each cluster group was made and the mean number of individuals of each recorded taxon (with countable individuals) in the samples assigned to each of the cluster groups was calculated and converted to average numbers per square metre. The resulting lists represent, in decreasing order, the numerically dominant taxa in each group. Only the top 20 taxa are given in each list. Average numbers of taxa per sample and mean numbers of individuals per square metre are also included.
Biotope Assignment
2.4.6 The characteristic biota of the cluster groups were used to assign biotopes, and to corresponding EUNIS codes, following the most recent classification (Connor et al., 2004).
2.4.7 Comparative tables produced by Connor et al. (2004) were used to assign biotopes to cluster groups. These tables enable a rapid comparison of the species composition and the principal physical characteristics between user-defined sets of biotopes. The table allows the user to list the characteristic biota of each cluster group and provides a percentage value of core biotope records within which the given species is recorded. These percentages are totalled for each biotope. The biotope with the highest total percentage was selected as the biotope that best represented that cluster group.
Data Mapping
2.4.8 Sampling points from the 2015 survey were plotted onto maps using ESRI ArcGIS (Numbers of taxa per sample, individuals and total biomass (both calculated as values per m²) and extrapolated biotopes were also plotted.
Comparison with previous data
2.4.9 Further analyses were carried out comparing data from 2015 survey with data from the previous annual surveys to look for temporal changes. Univariate indices (total numbers of taxa (S) and individuals (N), Margalef’s index (d, species richness),
Pielou’s index (J’, evenness) and Shannon-Wiener (H'(loge), diversity) were compared for all stations sampled in 1997, 2003, 2004, 2009, 2010, 2011, 2012, 2013, 2014 and 2015.
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2.4.10 Biotopes identified during survey years 2008 to 2015 were compared and described against the target biotopes assigned in 2003.
2.4.11 Multivariate analyses were undertaken using the data from the last four annual surveys (2012, 2013, 2014 and 2015). There have been some minor changes in the way certain taxa are recorded in the fourteen years since the 1997 survey. The taxon list for the combined surveys has, therefore, been standardised so that data are comparable between years.
2.4.12 Statistical analyses were carried out using the PRIMER suite of applications along with the PERMANOVA+ (Permutational ANOVA and MANOVA) add-on Version 1.0.3 (Anderson et al., 2008).
2.4.13 ANOSIM (analysis of similarity) tests were also undertaken using PRMER. ANOSIM operate on a resemblance matrix (Bray-Curtis). ANOSIM calculates an R value (the similarity between groups) and the significance of that value. R = 1 only if all samples within a group are more similar to each other than any samples from different groups. An R value close to 0 indicates similarities between and within sites are the same on average.
2.4.14 Given a matrix of rank dissimilarities between a set of samples, each solely belonging to one treatment group, the ANOSIM tests whether we can reject the null hypothesis that the similarity between groups is greater or equal to the similarity within the groups.
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3. Results
3.1 Particle size analysis
3.1.1 PSA data for each station between 2012 and 2015 is presented in tables in Appendix 1 and graphically in Appendix 2.
3.1.2 Comparison of the 2012 to 2015 data shows that particle size remained relatively constant at most sites during this period, with only slight variations. In the Stour Estuary, four stations (152,154, 191 and 249) showed a slight increase in the proportion of coarser sediments, and one station (192) showed an increase in the contents of silt/clay. In the Orwell Estuary, the contents of coarse material increased slightly in ten stations (260, 261, 267, 269, 272, 275, 300, 301, 263 and 285). Stations 258 and 289 had an increase in fine material. These variations are described in more detail below.
3.1.3 In the Stour estuary, most intertidal sites are predominately silt/clay, though stations 155, 158 and 193 have coarse and medium sand present as well. Station 163 was dominated by pebbles most years, and stations 152, 154 and 191 showed variation between 2012 and 2015, with higher content of pebbles in 2015. Station 158 shows variation from high content of coarse and medium particle size in 2012 and 2014 to high content of silt/clay in 2013 and 2015.
3.1.4 In the subtidal samples of the Stour Estuary, station 249 was composed of a mix of silt/clay and medium sand in 2012 (+/-30%) but changed to medium sand in 2013, 2014 and 2015 (47-51%).The rest of the stations (179, 181, 189, 192 and 195) are mainly silt/clay with medium/coarse sand present. Pebble is present in stations 189 and 192 above 20% in some years. Station 192 has changed from pebble/medium sand dominance (25% and 29%) to silt/clay dominance (35-60%), while station 195 has been very consistent throughout the years (variation of 1-3% in all size categories.
3.1.5 In the Orwell Estuary, intertidal stations 258 and 260 are very mixed in terms of particle size in all years. No category has higher than 27% dominance in station 258. It has shifted from pebble dominance in 2012 (25%) to medium sand dominance in 2013, 2014 and 2015 (26/27%). Station 260 is dominated by silt/clay but only at 40% in 2012 decreasing to 24% in 2015 (medium sand is 21% and coarse sand is 17% in 2015). Stations 261, 267, 269, 272, 275, 300 and 301 are consistently dominated by
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silt/clay, although this has decreased from 80-70% in 2012 to 40-60% in 2015. Only station 301 has remained with consistent content of silt/clay above 70%. The fraction of fine/medium sand in station 263 has increased in 2014-2015 in relation to 2012 and 2013, when there was a higher content of silt.
3.1.6 In the Orwell subtidal, stations, 295, 296 and 306 are all predominately silt/clay and consistent between years. Station 285 is dominated by coarser particles, but it was 60% silt/clay in 2013. Station 289 was predominately pebble in 2012 (88%), however there has been a gradual change to silt/clay through 2013 (48% pebble, 31% silt/clay) to 2015 (60% silt/clay). Station 303 is more mixed, with 30-40% silt/clay with all other particle sizes present between 10% and 20%. The percentage of pebble and silt/clay were similar in this station in 2013.
3.2 Macrofaunal analysis
3.2.1 As in previous years, most of the macrobenthic species found represent biological communities considered to be typical of estuarine fine and mixed sediment of SE England (Bolam, 2003; Chesman et al., 2006; ABPmer, 2007; Attrill et al., 1996; Attrill, 1998; P&O - London Gateway, 2004)
Comparison with previous years
3.2.2 The number of individuals (N), taxa (S), Margalef’s index (d, species richness),
Pielou’s index (J’, evenness) and Shannon-Wiener (H' loge), diversity and biomass for all comparable stations between 1997 and 2015 were calculated. The results are shown in Tables 2 to 7 and Figures 2 to 7.
3.2.3 Overall abundance, measured in total number of individuals per year shows very consistent values between 1997 and 2015. There was a decline in abundance between 2003-2009 and 2011-2012, but the general trend is to increase.
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Table 2: Number of individuals recorded in each survey year.
Year 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015 Number of 838.3 646.8 503.7 405.6 702.7 495.3 501 987 914 919.9 individuals (N)
Number of Individuals 1200
1000
800
600
400
200
0 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 2: Total number of individuals recorded in each survey year, with trend line.
Table 3: Total number species (S) recorded in each survey year.
Year 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015 Number of species (S) 254 287 208 212 212 173 178 242 227 276
number of species 350
300
250
200
150
100
50
0 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 3: Total number of species recorded in each survey year, with trend line.
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3.2.4 The total number of taxa – largely determined to species level - has also remained consistently stable over this period. Number of taxa (or S, richness) provides the simplest measure of diversity, but it takes no account of the relative species abundance. On the other hand, Margalef’s diversity index (d), a secondary univariate measurement derived from both abundance (N) and number of species (S), is a simple measure of species richness adjusting for a total number of individuals
Table 4: Average Margalef's diversity index (d) for each survey year.
Year 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015 Margalef’s diversity 4.361 4.089 4.16 4.317 4.128 3.679 3.73 4.67 4.31 5.089 index (d)
Margalef's diversity index (d) 6
5
4
3
2
1
0 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 4: Average Margalef's Diversity Index (d) for each survey year, with trend line.
3.2.5 As it can be observed in table and plot, diversity (measured as d) has also remained stable over the period in consideration.
3.2.6 Simple species richness measurements take no account of the relative abundance of individuals among species. This is considered in the Shannon – Wiener index (H), which is calculated from the proportion of each species in the sample. In this case, the sample is the totality of macrobenthic organisms recorded each year, in all sites. H is a combined measure of species richness and evenness, and increases with species richness and evenness. When only one taxa is responsible for most of the abundance and the others are very rare, the H approaches zero. In a sample containing only one species, even if the abundance (N) is high, H equals zero.
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Table 5: Average Shannon Wiener Diversity Index (H'(log e)) for each survey year.
Year 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015 Shannon Wiener (H’(log e)) diversity 1.935 1.873 2.01 2.035 1.908 1.855 1.84 2.08 2.08 2.22 index
H (Shannon Wiener) 2.5
2
1.5
1
0.5
0 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 5: Average Shannon Wiener Diversity Index (H'(log e)) for each survey year, with trend line.
3.2.7 As it can be seen in table 6 and figure 8 (above), the Shannon – Wiener index has also remained remarkably constant over the period of study.
3.2.8 Another derived index is Pielou’s Evenness, based on H' (Shannon - Wiener diversity index) and S, the total number of taxa in a sample, across all samples in the dataset.
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Table 6: Average Pielou's Evenness (J) for each survey year.
Year 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015 Average Pielou’s evenness (J) 0.587 0.597 0.655 0.678 0.61 0.625 0.63 0.61 0.63 0.652
J' (Pielou's eveness) 0.7
0.68
0.66
0.64
0.62
0.6
0.58
0.56
0.54 1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 6: Average Pielou's evenness (J) for each survey year, with trend line.
3.2.9 Pielou’s index also shows that diversity has remained stable between 1997 and 2015, with a trend to increase since 2010.
3.2.10 Finally, biomass measured as grams per square meter has also remained relatively constant over the period in consideration, as it is shown in table 8 and figure 10 (below). There are however significant differences in the samples between total biomass recorded in 2013 and 2015, with values largely exceeding those of 2014 and the other years.
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Table 7: Average biomass recorded in surveys carried out from 2008 to 2015
Year 2008 2009 2010 2011 2012 2013 2014 2015 Biomass (g/m2) 252.8 153.4 281.1 306.4 296.4 625.9 282.5 585.1
Biomass per m2 700
600
500
400
300
200
100
0 2008 2009 2010 2011 2012 2013 2014 2015
Figure 7: Average biomass (g/m2) recorded in surveys carried out from 2008 to 2015.
3.2.11 Number of individuals (N) and diversity (S and d) are also shown separately for intertidal and subtidal areas in both estuaries in figures 11, 12 and 13 (below).
N (number of individuals) 1400
1200
1000
800
600
400
200
0 Stour Intertidal Stour Subtidal Orwell Intertidal Orwell Subtidal
1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 8: Number of individuals (N) by estuary and by habitat.
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S (number of species) 70
60
50
40
30
20
10
0 Stour Intertidal Stour Subtidal Orwell Intertidal Orwell Subtidal
1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 9: Number of species (S) by estuary and by habitat.
Shannon Wiener Diversity Index (H'(log e)) 3
2.5
2
1.5
1
0.5
0 Stour Intertidal Stour Subtidal Orwell Intertidal Orwell Subtidal
1997 2003 2008 2009 2010 2011 2012 2013 2014 2015
Figure 10: Shannon Wiener Diversity Index (H’(log e)) by estuary and by habitat.
3.2.12 Abundance of macrobenthic communities (measured in number of species, N) has increased in the Stour estuary between 1997 and 2015 at subtidal sites, and remained stable at intertidal sites.
3.2.13 In the Orwell Estuary, an increase in the abundance has been observed at intertidal sites between 1997 and 2015, while it remained relatively stable in subtidal sites.
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3.2.14 The diversity of the macrobenthic communities (measured as number of species, S, and Shannon Wiener Diversity (H) measured as has remained stable in the Orwell estuary (inter and sub tidal).
3.2.15 In the Stour, diversity has increased in intertidal and subtidal sites.
3.2.16 In both estuaries, subtidal communities have more species than intertidal communities.
Summary
3.2.17 Overall abundance, measured in total number of individuals per year shows relatively consistent values between 1997 and 2015. There was a decline in abundance between 2003-2009 and 2011-2012, but increasing again in 2013, 2014 and 2015. The general trend is to increase.
3.2.18 The total number of taxa – largely determined to species level - has also remained consistently stable over this period. However, it has increased in the Stour estuary in both subtidal and intertidal habitats.
3.2.19 Biomass, measured as grams per square meter has also remained relatively constant between 1997 and 2015, with a trend to increase. However, there are significant differences in the values recorded in 2013, 2014 and 2015, with a decrease observed in 2014. Biomass values are high again in 2015.
Biotope analysis
3.2.20 The target biotopes were assigned in 2003, based on the dominant taxa of each group defined by the cluster analysis output from PRIMER. The same methodology was used to determine the biotopes present in each of the following survey years. These are presented in Appendix 3. For comparison, the biotopes assigned in 2003 and 2015 are presented in Figures 11 and 12.
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Figure 11: Biotopes assigned to survey stations in 2003
Figure 12: Biotopes assigned to survey stations in 2015
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3.2.21 The biotopes identified in the survey years from 2003 to 2015 are listed and described in Table 9.
Table 8: Biotopes identified between 2003 and 2015
EUNIS Code Description LS.LMu.UEst.Hed Hediste diversicolor in littoral mud LS.LMu.MEst.HedMac Hediste diversicolor and Macoma balthica in littoral sandy mud LS.LMu.MEst.NhomMacStr Nephtys hombergii, Macoma balthica and Streblospio sp. in littoral sandy mud SS.SMu.SMuVS.AphTubi Aphelochaeta marioni and Tubificoides spp. in variable salinity infralittoral mud SS.SMx.IMx.SpavSpAn Sabella pavonina with sponges and anemones on infralittoral mixed sediment SS.SCS.SCSVS Sublittoral coarse sediment in variable salinity (estuaries) SS.SMu.SMuVS.PolCvol Polydora ciliata and Corophium volutator in variable salinity infralittoral firm mud or clay SS.SMu.SMuVS.NhomTubi Nephtys hombergii and Tubificoides spp. in variable salinity infralittoral soft mud SS.SMx.SMxVS.CreMed Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment LR.FLR.Eph.BLitX Barnacles and Littorina spp. on unstable eulittoral mixed substrata LS.LMx.Mx.CirCer Cirratulids and Cerastoderma edule in littoral mixed sediment
3.2.22 The presence of each biotope was calculated as a percentage of the total number of samples taken (44, 43 in 2014) and is provided in Table 10.
Table 9: Percentage of biotopes in the total number of samples, 2003 – 2015
Biotope 2003 2008 2009 2010 2011 2012 2013 2014 2015 LS.LMu.MEst.NhomMacStr 18.2 0 29.5 13.6 0 0 2.3 4.7 0 LS.LMu.MEst.HedMac 36.4 50 38.6 47.7 59.1 52.3 50 67.4 40.9 LS.LMu.UEst.Hed 9.1 18.2 9.1 9.1 9.1 9.1 11.4 7.0 0 LR.FLR.Eph.BLitX 0 0 0 0 0 6.8 50 0 0 SS.SMu.SMuVS.PolCvol 0 6.8 2.3 0 0 9.1 11.4 0 0 SS.SMu.SMuVS.AphTubi 18.2 11.4 6.8 9.1 15.9 4.5 4.5 9.3 0 SS.SMu.SMuVS.NhomTubi 0 0 2.3 4.5 11.4 0 0 0 0 SS.SMx.IMx.SpavSpAn 18.2 11.4 11.4 15.9 4.5 2.3 13.6 4.7 0 SS.SMx.SMxVS.CreMed 0 0 0 0 0 15.9 6.8 7.0 25.0 SS.SCS.SCSVS 0 2.3 0 0 0 0 0 0 0 LS.LMx.Mx.CirCer 0 0 0 0 0 0 0 0 34.1
3.2.23 The distribution of biotopes has changed significantly from the 2003 assignments, with only 9 sample sites still classified with the same biotope (LS.LMu.MEst.HedMac) (Appendix 3). The most prevalent biotope is the LS.LMu.MEst.HedMac biotope, which was the most abundant biotope in all survey years, and it is the only one recorded in 2003 that is still present in the sampling locations. This biotope is present
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in 49.1% of the samples over the years from 2003 to 2015. In some years this biotope represented over half of the samples (2008, 2011, 2012, 2013 and 2014) (Table 10). This was also the only biotope that was found in all of the survey years. Together with the biotope LS.LMu.UEst.Hed this littoral sandy mud environment, dominated by Hediste diversicolor represents 58.2% of the biotopes identified throughout the survey years.
3.2.24 SS.SMx.IMx.SpavSpAn, SS.SMu.SMuVS.AphTubi and LS.LMu.MEst.NhomMacStr are the next most abundant biotopes, representing 25.6% of the biotopes identified throughout all survey years. SS.SMx.IMx.SpavSpAn and SS.SMu.SMuVS.AphTubi are both subtidal biotopes which are typical of coasts and estuaries sheltered from wave action but are subject to moderately strong tidal speeds.
3.2.25 SS.SMu.SMuVS.AphTubi was present in all years apart from 2015, representing between 7% and 19% of the biotopes identified between 1997 and 2015. This biotope is typical of estuarine habitats with variable salinity, which support stable, cohesive muddy environments dominated by the polychaete Aphelochaeta marioni and the oligochaete Tubificoides spp. along with other polychaete species.
3.2.26 The SS.SMx.IMx.SpavSpAn biotope is typical of stable mixed sediments supporting a diverse epifaunal community, including the peacock worm Sabella pavonina as well as sponges and hydroids. The infaunal community is less well known but is likely to include polychaete worms, bivalves and crustaceans. SS.SMx.IMx.SpavSpAn was found in all years apart from 2015, representing between 2% and 19% of the biotopes identified in those years.
3.2.27 LS.LMu.MEst.NhomMacStr was present in 2003, 2009, 2010, 2013 and 2014 and represented between 2% and 30% of the biotopes identified in these years. It is a soft mud biotope which supports an infaunal community which is dominated by polychaete and oligochaete worms. This habitat is found in mid estuary conditions in variable salinity where it is sheltered from wave exposure.
3.2.28 Some biotopes have only been found in single years. These are LS.LMx.Mx.CirCer, SS.SCS.SCSVS and LR.FLR.Eph.BLitX. They are characterised by mixed sediment habitats, with some large pebbles and cobbles which support a diverse community of infauna and epifauna. These are unstable habitats, due to the nature of the substratum and as such the diversity and density of flora and fauna can be low.
3.2.29 The biotope SS.SMx.SMxVS.CreMed was present in 2012, 2013, 2014 and 2015, making up between 6% to 25% of the biotopes identified in these years. This biotope
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is typical of sheltered estuarine habitats where currents allow a stable environment to develop. The mixed muddy sediment supports a diverse community, including the slipper limpet Crepidula fornicata, polychaete and oligochaete worms, and ascidians.
3.2.30 SS.SMu.SMuVS.PolCvol was recorded in 2008, 2009, 2012 and 2013, representing between 3% and 12% of the biotopes identified in these years. Typical of estuarine sediments this biotope is also present in sheltered environments that enable stable, firm mud and clay habitats with high content of detritus to establish. This habitat supports a ‘turf’ of polychaetes, along with crustaceans and oligochaete worms.
3.2.31 SS.SMu.SMuVS.NhomTubi was recorded in 2009, 2010 and 2011, representing from 2% to 12% of the biotopes identified in these years. This biotope is found in areas of silt deposition in soft and sandy muds, but may not form a stable habitat. It may be found adjacent to AphTubi, separated by the abundance of Aphelochaeta marioni and its more cohesive sediments. This biotope is typical of estuarine habitats with strong tidal streams and is dominated by polychaete worms.
Summary
3.2.32 Between 2003 and 2015 the biotopes identified have changed significantly – only 9 sample sites are still identified with the same biotope in 2015 as in 2003.
3.2.33 LS.LMu.MEst.HedMac was the most abundant biotope identified in 2003, and is still the most abundant biotope in 2015. In the sample sites at the head of the Stour Estuary (StA), the biotope has changed from LS.LMu.UEst.Hed to the HedMac biotope which indicates that although the substrate has not altered, the abundance of Macoma balthica has increased.
3.2.34 The majority of samples are still characterised as littoral (intertidal) sediment which is dominated by the fine and muddy portions of sediment particle sizes. The change in biotopes is therefore as a result of slight changes in the species composition, changing the dominant or most abundant species over the years.
3.2.35 In the subtidal samples the biotopes have changed from mixed sediment, and fine sand and mud dominated by polychaete worms to a more mixed, coarse sediment environment which supports communities of Crepidula fornicata as well as polychaete worms.
3.2.36 This change is a result of the colonisation of the invasive slipper limpet, C. fornicata. This species can accumulate in large numbers and form ‘stacks’ in order to breed which may result in this species occurring in high densities. This species reaches its highest densities in wave protected muddy areas such as estuaries.
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Multivariate analysis
3.2.37 Multivariate analyses were carried out to explore the relationships in species composition between the years, and to identify those relationships that are statistically significant.
MDS
3.2.38 A multi-dimensional scaling (MDS) plot illustrating the relationship between samples from the surveys conducted from 2012 to 2015 is presented in Figure 14. The samples are coded to differentiate between the years and whether the sample was located in intertidal or subtidal habitats. The relatively high observed stress value of 0.19 indicates that whilst the plot gives a good overall representation of the high dimensional structure, it should not be used to interpret finer detailed relationships between compact groupings (Clark and Warwick 2001).
Figure 13: Multidimensional scaling plot showing the relationship between the community compositions sampled in 2012, 2013, 2014 and 2015.
3.2.39 The plot indicates that the species composition within the majority of samples taken from intertidal habitats show similarity as they are grouped quite closely. There is more variation in the subtidal samples, indicated by the spread of data points
3.2.40 Samples taken from intertidal and subtidal stations in 2012 are relatively more dispersed than those taken from intertidal stations in 2015. This suggests that the
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variation in the species composition within these sites was larger in 2012 than in 2015.
PERMANOVA
3.2.41 Statistical tests using the PERMANOVA module for PRIMER indicate that there is statistical variance in the species composition between the years, between the Stour and Orwell estuaries and between intertidal and subtidal communities (significance of p=<0.05).
3.2.42 This result (presented in Appendix 4, Table 10) indicates that the composition of the macrobenthic communities within at least one of the years between 2012 and 2015 differs from the others. These results also indicate that there is a difference between the Stour and Orwell Estuaries, and between intertidal and subtidal habitats.
3.2.43 PERMANOVA will also test for the interactive effect between the years, the location and the zones (Appendix 4, Table 11). The test for interactive effect between the years and zone (intertidal and subtidal), and the locations (Stour and Orwell) and zones is significant (<0.05). This suggests that the differences reported in Table 10 between the Stour and Orwell, and between the years is due to variations in the intertidal and subtidal communities.
ANOSIM
3.2.44 To explore these relationships further, ANOSIM was carried out on the macrofaunal abundance data. ANOSIM calculates an R value (the similarity between groups) and the significance of that value. R = 1 only if all samples within a group are more similar to each other than any samples from different groups. An R value close to 0 indicates similarities between and within sites are the same on average.
3.2.45 ANOSIM was used to find out whether:
1. The species composition of the sample sites in any given year was the same as the species composition in the other years. 2. The species composition in the Stour was the same as the species composition in the Orwell in the same year. 3. The species composition within each estuary has changed between the different years. 4. There were any differences in species composition between the different zones in each estuary over the different years – samples were split into intertidal and subtidal samples and compared.
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3.2.46 The results of the tests are presented in Appendix 5 and indicate that:
1. Similarities in species composition of all the sampling sites in each year was the same on average as the species composition in the other years (R = <0.5; significance = <5%) (Appendix 5, Table 12). 2. Species composition in samples taken from the Stour are the same, on average, as those taken from the Orwell in the same year (R = <0.5; significance = <5%) (Appendix 5, Table 13). 3. The species composition within the Stour between and within years is the same on average (R = <0.5; significance = <5%) (Appendix 5, Table 14), and that the species composition within the Orwell between and within years is also the same on average (R = <0.5; significance = <5%) (Appendix 5, Table 15). 4. No difference in the intertidal communities between years were detected (R = <0.5; significance = <5%) (Appendix 5, Table 16). No difference between years were detected in the subtidal communities (R = <0.5; significance = <5%, except for the relationship between these communities in 2013 and 2014, where R = 0.088, but the result was not significant at 7.2%) (Appendix 5, Table 17).
3.2.47 The results also show that there are differences in the community composition between the intertidal and subtidal stations in the same year (R = ≥0.5; significance = <5%) (Appendix 5, Table 18).
3.2.48 Following these results, further ANOSIM tests were also carried out to determine whether there were any differences in the intertidal and subtidal communities between the different estuaries. These found that:
1. The intertidal communities within the Stour have not changed throughout the years (R = <0.5; significance = <5%) (Appendix 5, Table 19). 2. The intertidal communities within the Orwell have not changed throughout the years (R = <0.5; significance = <5%) (Appendix 5, Table 20). 3. The subtidal communities within the Stour show some variation between years, especially between 2015 and the years 2014, 2013 and 2012 (R=0.484, 1.6%; R=0.504, 0.9% and R=0.629, 0.4% respectively) (Appendix 5, Table 21). 4. The subtidal communities within the Orwell have not changed throughout the years, however these results were not statistically significant (R=<0.5; significance = >5%). This may be due to the small amount of subtidal samples taken from the Orwell every year (Appendix 5, Table 22).
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Summary of multivariate analyses
3.2.49 ANOSIM has identified that the similarities within and between sites are the same, on average when comparing years, estuaries and zones. However, the PERMANOVA results has identified differences between the estuaries and the years. The PERMANOVA results agree with the ANOSIM results that there are differences in the community composition of the intertidal and subtidal. The interactive tests indicate that there is a significant interaction between the year and the zone, and the estuary and the zone, which suggests that the key variation that PERMANOVA is identifying is present in the distinction between intertidal and subtidal communities.
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4. Discussion
4.1.1 The results of the 2015 survey, and comparison of the macrobenthic community data between 1997 and 2015 show that abundance, diversity and biomass have remained relatively stable during this period.
4.1.2 Comparing both estuaries, the abundance of macrobenthic communities has increased in the Stour Estuary between 1997 and 2015 at subtidal sites, and remained stable at intertidal sites. In contrast, an increase in abundance has been observed at intertidal sites in the Orwell Estuary during the same period, while it remained relatively stable in subtidal sites. Biomass values also remained relatively constant over this period, though there were significant differences in the total biomass recorded in 2013 and 2015, with values largely exceeding those of 2014 and the other years.
4.1.3 The diversity of the macrobenthic communities has remained stable in the Orwell estuary, both at intertidal and subtidal habitats, while it has increased in all intertidal and subtidal sites in the Stour. The MDS analysis suggests that there is more variation in the subtidal samples than in those taken from intertidal habitats. This suggests that there are changes in the structure of subtidal communities over time, but this variation is not significant. The observed changes may be due to variations in the hydrodynamic and sediment transportation patterns, spatial shifts in biotopes, or natural variations in the dynamics of the benthic populations.
4.1.4 The variation in faunal assemblage between intertidal and subtidal sites was larger in 2012 than in 2013, 2014 and 2015.
4.1.5 Whilst the data show that similar benthic communities have been present in the Stour and Orwell since the commencement of the monitoring programme, there have been notable changes between years and shifts between biotopes for many stations. Between 2003 and 2015, the distribution of the biotopes originally identified in 2003 have changed significantly, and only nine sample sites are within the same biotope in 2015 as in 2003. Only one of the biotopes identified in 2003 (LS.LMu.MEst.HedMac) is still represented in the samples in 2015.
4.1.6 LS.LMu.MEst.HedMac, which was the most abundant biotope in 2003, continues to be most abundant biotope in 2015. In the sampling sites at the head of the Stour Estuary the biotope has changed from LS.LMu.UEst.Hed to the HedMac biotope which indicates that although the substrate has not altered, the abundance of
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Macoma balthica has increased. Since most of the sites are still characterised as littoral (intertidal) habitats dominated by the fine sediment, the change in biotopes is therefore a result of changes in the species composition, changing the dominant or most abundant species over the years. However, these changes are not significant.
4.1.7 In the subtidal samples the biotopes have changed from mixed sediment, and fine sand and mud dominated by polychaete worms to a more mixed, coarse sediment environment which supports communities of Crepidula fornicata as well as polychaete worms. This explains the variation detected in subtidal communities by the multivariate analyses undertaken to assess changes in community structure.
4.1.8 This change is also related to the colonisation of the invasive slipper limpet, C. fornicata. Slipper limpets can accumulate in large numbers and form ‘stacks’ in order to breed, which may result in this species occurring in high densities. This species reaches its highest densities in wave protected muddy areas such as estuaries.
4.1.9 These changes represent shifts in the distribution of biotopes between 2003 and 2015, but not necessarily changes in the overall extent of these biotopes. As it was highlighted in the 2011 report, there are small-scale spatial variations even within two replicate samples taken for PSA and biological analysis at the same target location in 2011. Since the analyses of trends and variations in the macrobenthic populations in this study is based on single samples (as opposed to replicate samples), there is limited scope to detect a certain level of change with certainty. Areas where the substrate exhibits a high level of natural spatial or temporal variability (typical of estuaries) require a specific level of replication (Ware & Kenny, 2011). This level of replication must strike a balance between the statistical power requirements for assessing certainty and the magnitude of change that needs to be detected. Further studies should incorporate this consideration to the requirement of establishing whether the observed differences between years represent long-term change or short-term cyclical variations.
4.1.10 The very dynamic character of the estuarine environment, resulting from the interaction between the hydrodynamic regime, sediment movement and coastal morphology also determine variability in physico-chemical characteristics such as dissolved oxygen, salinity, temperature, and bed dynamics.
4.1.11 As a result of these conditions, estuaries are naturally stressed environments and their associated fauna is adapted to these conditions (Elliott & Quintino, 2007). Biological populations also respond to changes in ecological pressures, such as food or prey availability, predation and competition between and within species. In addition
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to naturally dynamic conditions and ecological changes, population dynamics and ecological succession also affect the distribution and abundance of biological communities, so it is difficult to explain the variability observed in the benthic communities in the Orwell and Stour estuaries. Statistical analysis of sediment data may also help determine whether changes in the biological data correlate with changes in sediment composition over time
5. Conclusion
5.1.1 The abundance, biomass and diversity of macrobenthic communities in the Stour and Orwell estuaries have remained relatively stable between 1997 and 2003.
5.1.2 The results of the monitoring programme have also shown evidence of changes in the distribution of the biotopes over this period. The reasons for these changes are difficult to determine but could result from changes in hydrology or sediment dynamics of the estuary, spatial shifts in biotopes or a combination of both. They may also be a result of the sampling strategy and its power to detect change with certainty.
5.1.3 Further studies are required to establish whether the observed differences over the period in consideration respond to long term changes, natural short-term cyclical variations or any specific change in the parameters considered in the monitoring programme.
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6. References
Anderson, M.J., Gorley, R.N. and Clarke, K.R. (2008) PERMANOVA+ for PRIMER: Guide to Software and Statistical Methods. PRIMER-E: Plymouth, UK. 214pp. Associated British Ports Marine Environmental Research Ltd (ABPmer) (2007) Benthic ecology of the Thames Estuary., Report No. R. 1381. Attrill, M.J., Ramsay, P.M., Thomas, R.M. and Trett, M.W. (1996) An estuarine biodiversity hotspot. Journal of the Marine Biological Association of the United Kingdom, 76: 161-175. Attrill, M.J. (1998) The benthic macroinvertebrate communities of the Thames Estuary. In: A Rehabilitated Estuarine Ecosystem: The Environment and Ecology of the Thames Estuary. (Attrill, M.J., ed.) pp. 85-112. London: Kluwer Academic Publishers. Bolam, S.G. (2003) Spatial patterns of estuarine macrobenthic assemblages: relationships with hydrodynamic regime, CEFAS. Report No: FD1905/CEFAS1. Blott, S.J. and Pye, K. (2001) GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms 26, 1237–1248. Bryant, C. and McNulty, S. (2007). Environmental trends on the Stour and Orwell Estuaries. Royal Haskoning report 9R6009/303462/BBoro to Harwich Haven Authority. Chesman, B.S., Burt, G.R. and Langston, W.J. (2006) Characterisation of the European Marine Sites: Essex Estuaries European Marine Site. Marine Biological Association of the United Kingdom Occasional Publication 17. pp 198. (2006) ISSN: 02602784. Clarke, K.R. and Gorley, R.N. (2006) PRIMER v6: User Manual/Tutorial. PRIMER-E Ltd. Clarke, K.R. and Warwick, R.M. (1994) Change in marine communities: an approach to statistical analysis and interpretation. Plymouth: Plymouth Marine Laboratory, pp. 144. Connor, D.W., Allen, J.H., Golding, N., Howell, K. L., Lieberknecht, L.M., Northen, K.O. and Reker, J.B. (2004). The marine habitat classification for Britain and Ireland. Version 04.05. JNCC, Peterborough, ISBN 1 861 07561 8 (internet version). Dyer, M.F. (2000) Stour and Orwell estuary benthic survey 1997. Report to Harwich Haven Authority. Unicomarine report StrOrw97, January 2000. Dyer, M.F., Ashelby, C.W., and Worsfold, T.M. (2004) A Comparison of the sediment characteristics of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHASED04 to Harwich Haven Authority, January 2004. Dyer, M.F. and Worsfold, T.M. (2004) Comparison of the intertidal benthos of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHAStrOrw03int to Harwich Haven Authority, February 2004. Dyer, M.F. and Worsfold, T.M. (2009) Intertidal invertebrate survey of the upper Blackwater estuary from Beeleigh Weir to Decoy Point: April and September 2009. Unicomarine Report Essuf09 to Essex and Suffolk Water, November, 2009.
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Elliott, M. and Quintino, V. (2007) The Estuarine Quality Paradox, Environmental Homeostasis and the difficulty of detecting anthropogenic stress in naturally stressed areas. Marine Pollution Bulletin, 54: 640-645. Finbow, L. and Argent, J. (2012) Thomson Unicomarine standard operating procedure for the processing of particle size samples Version 2.0: Thomson Unicomarine, February 2012. Mason, C. (2011) NMBAQC’s Best Practice Guidance, Particle Size Analysis (PSA) for Supporting Biological Analysis. National Marine Biological AQC Coordinating Committee, 2011. P&O (2004) The (London Gateway Port) Harbour Empowerment Order 202. Environmental Statement Chapters 1 to 10. Royal Haskoning (2007) Environmental Trends on the Stour and Orwell Estuaries. January 2007. Royal Haskoning (2008) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2008. November 2008. Royal Haskoning (2010). Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2009. March 2010. Royal Haskoning (2011) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2010/11. March 2011. Royal Haskoning (2012) Mitigation and Monitoring for the Stour and Orwell Estuaries SPA and Hamford Water SPA. Annual review 2011/12. March 2011. TEM09 (2013). Benthic Invertebrate Sample Analysis. Issue 005. Richard Gianfrancesco. June 2013. Ware, S.J. & Kenny, A.J. (2011) Guidelines for the Conduct of Benthic Studies at Marine Aggregate Extraction Sites (2nd Edition). Marine Aggregate Levy Sustainability Fund, 80 pp. ISBN: 978 0 907545 70 5 Wentworth, C.K. (1922). A scale of grade and class terms for clastic sediments. Journal of Geology, 30, 377-392. Worsfold, T.M. and Dyer, M.F. (2004) Comparison of the subtidal benthos of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHAStrOrw03sub to Harwich Haven Authority, March 2004. Worsfold, T. M. (2005) Stour, Orwell and Harwich approaches benthos: review of data commissioned by Harwich Haven Authority, biotope distribution update and partial review of current knowledge for the area. Unicomarine Report HHABiot05 to Harwich Haven Authority, November 2005.
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Appendices
Appendix 1: PSA data from 2012, 2013, 2014 and 2015 by sampling station
Station 150 2012 150 2013 150 2014 150 2015 pebble 12.9 0.0 0.0 18.5 granule 0.6 0.0 0.0 4.3 V. coarse sand 0.6 0.0 0.0 1.6 Coarse sand 1.2 0.4 8.2 2.9 Medium sand 3.0 2.8 7.4 5.4 Fine sand 3.3 4.0 8.2 6.3 V. fine sand 5.6 7.5 12.6 7.7 Silt Clay 72.9 85.3 63.6 53.2
Station 152 2012 152 2013 152 2014 152 2015 pebble 33.4 31.4 0.0 42.8 granule 4.8 4.6 0.0 5.1 V. coarse sand 3.7 3.4 0.0 3.8 Coarse sand 5.7 5.9 17.5 9.4 Medium sand 10.4 10.9 16.3 16.4 Fine sand 6.4 6.7 10.2 7.0 V. fine sand 4.7 4.9 10.8 2.2 Silt Clay 31.0 32.3 45.2 13.2
Station 153 2012 153 2013 153 2014 153 2015 pebble 0.0 0.0 0.0 1.3 granule 0.0 0.0 0.0 0.6 V. coarse sand 0.0 0.0 0.0 1.7 Coarse sand 4.7 0.4 14.0 5.0 Medium sand 18.1 2.8 8.7 13.6 Fine sand 17.3 4.0 7.2 14.9 V. fine sand 7.4 7.5 9.8 11.0 Silt Clay 52.5 85.3 60.3 52.0
Station 154 2012 154 2013 154 2014 154 2015 pebble 34.6 35.7 13.5 47.8 granule 4.1 3.4 2.1 3.5 V. coarse sand 2.6 1.9 1.8 3.6 Coarse sand 4.7 4.7 9.3 13.1 Medium sand 6.8 6.9 9.5 16.7 Fine sand 4.0 4.0 5.0 4.5 V. fine sand 4.1 4.3 6.9 1.5 Silt Clay 39.1 39.2 51.9 9.4
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Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Station 155 2012 155 2013 155 2014 155 2015 pebble 0.0 1.5 0.0 3.3 granule 0.0 0.5 0.0 0.3 V. coarse sand 0.0 0.9 0.0 0.8 Coarse sand 2.0 17.0 22.3 10.2 Medium sand 11.5 18.4 30.8 32.8 Fine sand 12.4 8.6 10.2 24.2 V. fine sand 7.8 6.3 3.3 5.1 Silt Clay 66.3 46.7 33.4 23.3
Station 157 2012 157 2013 157 2014 157 2015 pebble 0.0 13.9 0.0 2.6 granule 0.0 0.7 0.0 5.5 V. coarse sand 0.0 0.6 0.0 3.5 Coarse sand 3.5 4.7 10.6 6.1 Medium sand 7.5 7.0 11.4 11.0 Fine sand 9.6 9.3 12.3 12.6 V. fine sand 12.2 11.3 13.2 12.6 Silt Clay 67.1 52.6 52.5 46.2
Station 158 2012 158 2013 158 2014 158 2015 pebble 0.0 5.6 0.0 3.2 granule 0.0 0.2 0.0 0.2 V. coarse sand 0.0 0.4 0.0 0.6 Coarse sand 13.6 14.4 11.4 18.7 Medium sand 37.4 14.3 15.9 51.0 Fine sand 21.5 4.5 7.1 19.5 V. fine sand 3.3 5.2 7.6 0.3 Silt Clay 24.3 55.5 57.9 6.5
Station 163 2012 163 2013 163 2014 163 2012 pebble 9.3 47.7 65.1 34.9 granule 0.4 25.4 8.8 6.8 V. coarse sand 5.9 4.2 4.9 11.4 Coarse sand 14.3 4.1 8.5 10.9 Medium sand 23.8 7.0 6.1 15.6 Fine sand 16.8 4.6 1.7 9.5 V. fine sand 4.3 1.0 0.5 2.8 Silt Clay 25.2 6.1 4.4 8.1
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Station 169 2012 169 2013 169 2014 169 2015 pebble 12.7 10.7 0.0 5.8 granule 1.8 0.9 0.0 2.2 V. coarse sand 1.3 0.9 0.0 3.5 Coarse sand 2.3 2.0 10.3 2.9 Medium sand 5.3 2.6 10.0 6.2 Fine sand 5.9 5.3 10.1 6.6 V. fine sand 7.2 10.1 13.5 9.4 Silt Clay 63.2 67.5 56.1 63.3
Station 171 2012 171 2013 171 2014 171 2015 pebble 0.0 11.7 0.0 3.1 granule 0.0 8.6 0.0 4.3 V. coarse sand 0.0 0.4 0.0 1.9 Coarse sand 0.6 1.8 2.3 2.2 Medium sand 3.0 2.4 3.0 5.6 Fine sand 4.0 4.8 6.0 7.7 V. fine sand 7.6 9.1 11.5 10.9 Silt Clay 84.8 61.2 77.1 64.4
Station 172 2012 172 2013 172 2014 172 2015 pebble 7.1 10.7 0.0 4.2 granule 1.5 1.2 0.0 1.4 V. coarse sand 1.1 0.7 0.0 1.1 Coarse sand 1.3 2.6 4.8 2.4 Medium sand 3.8 4.3 4.6 4.8 Fine sand 5.2 4.9 6.2 5.8 V. fine sand 7.1 8.5 11.1 9.6 Silt Clay 72.8 66.9 73.2 70.9
Station 174 2012 174 2013 174 2014 174 2015 pebble 0.0 0.0 0.0 0.0 granule 0.0 0.0 0.0 0.7 V. coarse sand 0.0 0.0 0.0 2.1 Coarse sand 0.7 2.6 3.0 0.6 Medium sand 2.4 3.5 3.8 3.6 Fine sand 3.4 5.2 6.4 8.3 V. fine sand 7.9 10.5 11.8 13.7 Silt Clay 85.6 78.1 75.0 71.1
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Station 179 2012 179 2013 179 2014 179 2015 pebble 17.5 16.1 0.5 1.6 granule 6.0 6.0 3.4 11.6 V. coarse sand 2.6 1.7 4.2 10.5 Coarse sand 3.8 3.5 47.3 21.1 Medium sand 5.7 5.0 17.7 18.7 Fine sand 3.5 3.2 0.0 3.4 V. fine sand 4.2 4.7 2.4 2.9 Silt Clay 56.8 59.9 24.4 30.1
Station 180 2012 180 2013 180 2014 180 2015 pebble 1.6 0.0 0.0 3.2 granule 1.2 0.0 0.0 1.5 V. coarse sand 1.1 0.0 0.0 1.2 Coarse sand 4.4 9.9 13.8 7.3 Medium sand 8.1 11.7 14.1 15.3 Fine sand 8.9 9.5 11.4 12.7 V. fine sand 10.9 10.3 11.1 10.7 Silt Clay 63.8 58.6 49.6 48.0
Station 181 2012 181 2013 181 2014 181 2015 pebble 0.0 0.0 0.0 5.2 granule 0.0 0.0 0.0 0.5 V. coarse sand 0.0 0.0 0.0 0.7 Coarse sand 5.2 5.7 15.8 3.7 Medium sand 27.1 7.6 17.8 14.0 Fine sand 22.1 5.5 6.4 13.9 V. fine sand 4.7 10.4 7.3 7.4 Silt Clay 41.0 70.8 52.7 54.5
Station 189 2012 189 2013 189 2014 189 2015 pebble 16.5 15.9 16.0 25.9 granule 1.4 1.6 1.8 7.3 V. coarse sand 1.2 1.4 2.1 6.5 Coarse sand 7.8 2.9 15.6 17.6 Medium sand 7.4 5.7 17.9 21.5 Fine sand 3.1 4.0 5.1 5.4 V. fine sand 4.1 4.3 3.0 1.4 Silt Clay 58.4 64.2 38.5 14.5
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Station 191 2012 191 2013 191 2014 191 2015 pebble 52.1 4.7 0.0 25.2 granule 20.5 3.4 0.0 16.3 V. coarse sand 11.9 5.0 0.0 19.2 Coarse sand 4.6 7.0 5.4 13.9 Medium sand 3.3 7.2 6.4 11.8 Fine sand 1.0 5.1 8.2 2.8 V. fine sand 0.9 8.8 12.9 1.7 Silt Clay 5.8 58.9 67.0 9.0
Station 192 2012 192 2013 192 2014 192 2015 pebble 29.0 0.0 26.3 16.7 granule 7.1 0.0 7.7 6.1 V. coarse sand 6.0 0.0 5.1 3.1 Coarse sand 11.7 12.0 2.3 3.4 Medium sand 26.0 9.1 7.7 11.2 Fine sand 8.7 6.7 9.2 11.7 V. fine sand 0.4 9.6 6.2 6.7 Silt Clay 11.0 62.6 35.5 41.1
Station 193 2012 193 2013 193 2014 193 2015 pebble 0.0 1.9 2.4 2.3 granule 0.0 0.5 0.2 0.3 V. coarse sand 0.0 0.2 0.2 0.4 Coarse sand 0.9 19.8 1.0 1.1 Medium sand 20.3 43.8 21.7 23.6 Fine sand 30.0 14.7 32.3 35.5 V. fine sand 10.7 0.7 11.2 11.5 Silt Clay 38.1 18.4 30.9 25.2
Station 194 2012 194 2013 194 2014 194 2015 pebble 7.2 7.3 8.1 9.3 granule 2.1 3.3 3.7 4.2 V. coarse sand 1.9 2.7 2.8 3.8 Coarse sand 1.4 2.7 4.1 3.8 Medium sand 4.3 4.0 8.7 8.2 Fine sand 5.0 6.1 9.4 8.7 V. fine sand 9.7 9.9 10.5 9.7 Silt Clay 68.5 64.0 52.8 52.3
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Station 195 2012 195 2013 195 2014 195 2015 pebble 0.0 0.0 0.0 0.0 granule 0.0 0.0 0.0 0.5 V. coarse sand 0.0 0.0 0.0 0.9 Coarse sand 6.7 5.8 5.3 4.2 Medium sand 6.2 6.9 6.3 6.3 Fine sand 4.6 6.0 5.9 7.1 V. fine sand 7.7 8.5 9.1 9.8 Silt Clay 74.8 72.8 73.5 71.2
Station 204 2012 204 2013 204 2014 204 2015 pebble 0.0 0.0 0.0 0.3 granule 0.0 0.0 0.0 0.3 V. coarse sand 0.0 0.0 0.0 1.7 Coarse sand 1.7 3.8 5.7 1.9 Medium sand 7.1 14.7 24.4 8.8 Fine sand 15.1 21.0 23.0 20.0 V. fine sand 16.1 13.7 9.3 18.3 Silt Clay 60.0 46.8 37.7 48.7
Station 206 2012 206 2013 206 2014 206 2015 pebble 0.0 0.0 0.0 11.6 granule 0.0 0.0 0.0 4.6 V. coarse sand 0.0 0.0 0.0 2.8 Coarse sand 2.0 1.9 5.1 3.0 Medium sand 5.4 6.0 7.1 8.0 Fine sand 7.8 6.1 9.8 9.5 V. fine sand 9.9 9.0 11.7 9.2 Silt Clay 74.9 77.0 66.3 51.4
Station 207 2012 207 2013 207 2014 207 2015 pebble 0.0 0.0 0.0 1.0 granule 0.0 0.0 0.0 0.6 V. coarse sand 0.0 0.0 0.0 0.5 Coarse sand 1.5 5.7 3.6 6.6 Medium sand 4.4 24.4 4.2 16.2 Fine sand 5.0 23.0 6.8 12.9 V. fine sand 9.2 9.3 12.9 12.4 Silt Clay 79.9 37.7 72.4 49.9
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Station 209 2012 209 2013 209 2014 209 2015 pebble 1.3 5.5 0.0 5.6 granule 0.5 1.1 0.0 1.3 V. coarse sand 0.3 0.9 0.0 0.8 Coarse sand 1.0 1.8 4.9 1.8 Medium sand 3.3 6.5 5.4 6.5 Fine sand 4.0 8.1 7.4 8.1 V. fine sand 8.3 10.9 11.7 10.7 Silt Clay 81.4 65.2 70.6 65.2
Station 249 2012 249 2013 249 2014 249 2015 pebble 1.8 8.9 8.3 8.7 granule 0.2 0.3 0.2 0.4 V. coarse sand 0.3 0.6 0.4 0.4 Coarse sand 18.0 17.3 17.1 17.4 Medium sand 32.5 46.8 51.8 47.0 Fine sand 10.3 17.8 16.7 17.8 V. fine sand 3.2 1.1 0.9 1.1 Silt Clay 33.7 7.0 4.6 7.1
Station 258 2012 258 2013 258 2014 258 2015 pebble 26.1 13.4 16.6 13.9 granule 10.2 3.5 3.8 3.5 V. coarse sand 11.0 4.7 5.2 4.8 Coarse sand 12.9 12.6 15.0 12.5 Medium sand 15.6 27.7 24.2 27.4 Fine sand 6.3 15.3 11.8 15.2 V. fine sand 1.7 3.2 2.8 3.1 Silt Clay 16.2 19.7 20.7 19.5
Station 260 2012 260 2013 260 2014 260 2015 pebble 19.9 14.7 22.4 11.3 granule 4.2 5.2 3.6 4.8 V. coarse sand 4.8 6.4 6.4 8.6 Coarse sand 8.4 19.3 15.7 17.7 Medium sand 9.8 9.4 9.7 21.2 Fine sand 6.6 3.7 4.1 8.2 V. fine sand 5.5 4.3 5.7 3.9 Silt Clay 40.8 36.9 32.4 24.4
44 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Station 261 2012 261 2013 261 2014 261 2015 pebble 0.6 7.3 14.2 8.2 granule 0.2 0.4 2.0 0.8 V. coarse sand 0.2 0.4 2.6 1.7 Coarse sand 0.3 2.0 2.1 1.9 Medium sand 2.7 9.6 9.4 9.3 Fine sand 6.9 25.0 26.4 24.3 V. fine sand 8.6 18.9 13.8 18.3 Silt Clay 80.4 36.4 29.5 35.5
Station 263 2012 263 2013 263 2014 263 2015 pebble 13.0 9.4 0.0 9.3 granule 1.8 0.7 0.0 2.4 V. coarse sand 1.6 0.8 0.0 3.2 Coarse sand 0.5 6.1 0.0 0.0 Medium sand 11.9 28.2 30.3 27.5 Fine sand 23.0 21.4 53.5 46.8 V. fine sand 9.0 2.9 4.2 4.7 Silt Clay 39.1 30.5 12.0 6.1
Station 267 2012 267 2013 267 2014 267 2015 pebble 7.1 0.0 17.4 15.4 granule 1.3 0.0 6.2 5.6 V. coarse sand 1.7 0.0 4.2 3.7 Coarse sand 3.3 8.2 1.5 1.8 Medium sand 14.9 11.0 11.1 19.7 Fine sand 15.0 7.7 16.0 22.4 V. fine sand 7.5 8.1 7.0 8.7 Silt Clay 49.1 64.9 36.6 22.7
Station 269 2012 269 2013 269 2014 269 2015 pebble 0.0 20.3 22.3 22.5 granule 0.0 6.4 6.1 6.1 V. coarse sand 0.0 2.9 2.2 2.7 Coarse sand 0.7 1.9 2.4 1.9 Medium sand 2.0 4.8 5.2 4.7 Fine sand 3.0 5.9 7.1 5.8 V. fine sand 5.8 7.3 5.7 7.1 Silt Clay 88.3 50.3 48.9 49.3
Harwich Haven Authority, Project No.: I-HHA-110/002 45
Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Station 272 2012 272 2013 272 2014 272 2015 pebble 12.6 9.4 11.9 17.3 granule 2.1 1.0 1.7 3.9 V. coarse sand 1.6 0.8 1.8 4.7 Coarse sand 1.3 2.1 4.9 2.6 Medium sand 2.7 3.6 6.3 8.6 Fine sand 3.6 5.5 7.8 9.8 V. fine sand 4.9 9.5 9.6 7.7 Silt Clay 71.2 68.0 55.9 45.3
Station 275 2012 275 2013 275 2014 275 2015 pebble 0.0 8.5 12.0 8.6 granule 0.0 1.1 0.8 1.0 V. coarse sand 0.0 1.2 1.3 1.1 Coarse sand 0.9 0.4 5.1 5.1 Medium sand 3.1 2.2 8.2 8.2 Fine sand 4.1 3.5 5.8 8.7 V. fine sand 9.3 6.7 9.0 10.4 Silt Clay 82.5 76.4 57.7 56.8
Station 285 2012 285 2013 285 2014 285 2015 pebble 20.7 8.0 16.9 13.7 granule 3.9 5.5 2.9 4.9 V. coarse sand 3.5 5.7 3.7 6.9 Coarse sand 14.1 7.6 35.8 31.6 Medium sand 26.5 4.0 18.6 33.6 Fine sand 9.0 2.6 1.0 3.6 V. fine sand 0.8 5.4 2.4 0.3 Silt Clay 21.4 61.2 18.8 5.3
Station 289 2012 289 2013 *no sample* 289 2015 pebble 86.5 47.8 2.3 granule 9.1 5.4 11.5 V. coarse sand 2.9 3.6 4.2 Coarse sand 0.7 1.9 3.6 Medium sand 0.4 3.2 6.1 Fine sand 0.1 3.2 6.1 V. fine sand 0.0 3.7 7.0 Silt Clay 0.3 31.2 59.0
46 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Station 295 2012 295 2013 295 2014 295 2015 pebble 0.0 0.0 0.0 0.1 granule 0.0 0.0 0.0 0.1 V. coarse sand 0.0 0.0 0.0 0.9 Coarse sand 0.5 3.3 6.1 3.2 Medium sand 1.6 8.4 15.2 8.3 Fine sand 3.0 9.9 16.7 9.7 V. fine sand 8.5 10.5 12.3 10.2 Silt Clay 86.4 68.0 49.7 67.3
Station 296 2012 296 2013 296 2014 296 2015 pebble 0.0 0.0 0.0 0.0 granule 0.0 0.0 0.0 0.1 V. coarse sand 0.0 0.0 0.0 0.6 Coarse sand 0.5 2.5 4.5 2.5 Medium sand 1.4 5.7 10.0 5.7 Fine sand 3.4 7.9 12.3 7.8 V. fine sand 6.7 12.1 17.4 11.9 Silt Clay 88.0 71.8 55.7 71.4
Station 300 2012 300 2013 300 2014 300 2015 pebble 1.2 0.0 0.0 0.1 granule 1.1 0.0 0.0 0.4 V. coarse sand 1.0 0.0 0.0 1.2 Coarse sand 2.7 3.2 3.0 2.1 Medium sand 3.9 4.5 3.8 5.7 Fine sand 5.1 6.6 6.6 11.4 V. fine sand 15.3 17.3 13.8 20.8 Silt Clay 69.8 68.5 72.9 58.3
Station 301 2012 301 2013 301 2014 301 2015 pebble 0.0 0.0 0.0 0.3 granule 0.0 0.0 0.0 4.1 V. coarse sand 0.0 0.0 0.0 4.1 Coarse sand 0.3 1.8 2.2 1.1 Medium sand 1.5 3.0 3.5 3.5 Fine sand 4.0 7.7 8.9 5.5 V. fine sand 8.6 13.1 14.5 10.1 Silt Clay 85.7 74.4 70.9 71.3
Harwich Haven Authority, Project No.: I-HHA-110/002 47
Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Station 303 2012 303 2013 303 2014 303 2015 pebble 17.7 30.4 10.2 11.5 granule 9.2 3.1 11.5 7.0 V. coarse sand 11.6 2.4 6.1 5.8 Coarse sand 0.5 8.4 5.0 9.9 Medium sand 12.5 11.4 13.8 13.5 Fine sand 18.4 6.6 14.6 7.8 V. fine sand 6.6 4.9 6.7 5.7 Silt Clay 23.5 32.7 32.1 38.7
Station 306 2012 306 2013 306 2014 306 2015 pebble 0.0 2.5 26.0 1.8 granule 0.0 4.2 2.5 3.2 V. coarse sand 0.0 5.3 2.6 4.8 Coarse sand 0.6 2.9 5.1 2.9 Medium sand 4.0 4.9 5.5 5.0 Fine sand 6.2 4.9 5.8 5.0 V. fine sand 6.9 7.5 7.0 7.5 Silt Clay 82.3 67.8 45.5 69.7
Station 548 2012 548 2013 548 2014 548 2015 pebble 0.0 0.0 0.0 1.0 granule 0.0 0.0 0.0 0.4 V. coarse sand 0.0 0.0 0.0 1.3 Coarse sand 1.7 2.5 9.8 5.7 Medium sand 6.2 5.9 13.9 11.6 Fine sand 11.5 10.5 17.3 17.5 V. fine sand 14.9 14.4 13.8 18.1 Silt Clay 65.7 66.8 45.1 44.3
Station 549 2012 549 2013 549 2014 549 2015 pebble 0.0 0.0 0.0 2.3 granule 0.0 0.0 0.0 7.9 V. coarse sand 0.0 0.0 0.0 5.5 Coarse sand 2.0 2.5 7.9 7.2 Medium sand 4.9 4.2 9.3 9.3 Fine sand 6.5 7.5 10.6 7.9 V. fine sand 10.6 11.3 12.5 8.7 Silt Clay 76.0 74.4 59.7 51.3
48 Harwich Haven Authority, Project No.: I-HHA-110/002
Appendix 2: Graphical representation of the PSA results from 2012 to 2015 by sampling station
150 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
150 2012 150 2013 150 2014 150 2015
152 - Stour Intertidal 50.0
40.0
30.0
20.0
10.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
152 2012 152 2013 152 2014 152 2015
153 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
153 2012 153 2013 153 2014 153 2015
www.thomsonecology.com
Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
154 - Stour Intertidal 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
154 2012 154 2013 154 2014 154 2015
155 - Stour Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
155 2012 155 2013 155 2014 155 2015
157 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
157 2012 157 2013 157 2014 157 2015
50 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
158 - Stour Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
158 2012 158 2013 158 2014 158 2015
163 - Stour Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
163 2012 163 2013 163 2014 163 2012
169 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
169 2012 169 2013 169 2014 169 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
171 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
171 2012 171 2013 171 2014 171 2015
172 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
172 2012 172 2013 172 2014 172 2015
174 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
174 2012 174 2013 174 2014 174 2015
52 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
180 - Stour Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
180 2012 180 2013 180 2014 180 2015
191 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
191 2012 191 2013 191 2014 191 2015
193 - Stour Intertidal 50.0
40.0
30.0
20.0
10.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
193 2012 193 2013 193 2014 193 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
194 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
194 2012 194 2013 194 2014 194 2015
204 - Stour Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
204 2012 204 2013 204 2014 204 2015
206 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
206 2012 206 2013 206 2014 206 2015
54 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
207 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
207 2012 207 2013 207 2014 207 2015
209 - Stour Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
209 2012 209 2013 209 2014 209 2015
548 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
548 2012 548 2013 548 2014 548 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
549 - Stour Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
549 2012 549 2013 549 2014 549 2015
179 - Stour Subtidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
179 2012 179 2013 179 2014 179 2015
181 - Stour Subtidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
181 2012 181 2013 181 2014 181 2015
56 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
189 - Stour Subtidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
189 2012 189 2013 189 2014 189 2015
192 - Stour Subtidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
192 2012 192 2013 192 2014 192 2015
195 - Stour Subtidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
195 2012 195 2013 195 2014 195 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
249 - Stour Subtidal 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
249 2012 249 2013 249 2014 249 2015
258 - Orwell Intertidal 30.0 25.0 20.0 15.0 10.0 5.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
258 2012 258 2013 258 2014 258 2015
260 - Orwell Intertidal 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
260 2012 260 2013 260 2014 260 2015
58 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
261 - Orwell Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
261 2012 261 2013 261 2014 261 2015
263 - Orwell Intertidal 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
263 2012 263 2013 263 2014 263 2015
267 - Orwell Intertidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
267 2012 267 2013 267 2014 267 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
269 - Orwell Intertidal 100.0
80.0
60.0
40.0
20.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
269 2012 269 2013 269 2014 269 2015
272 - Orwell Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
272 2012 272 2013 272 2014 272 2015
275 - Orwell Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
275 2012 275 2013 275 2014 275 2015
60 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
300 - Orwell Intertidal 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
300 2012 300 2013 300 2014 300 2015
301 - Orwell Intertidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
301 2012 301 2013 301 2014 301 2015
285 - Orwell Subtidal 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
285 2012 285 2013 285 2014 285 2015
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
289 - Orwell Subtidal 100.0
80.0
60.0
40.0
20.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
289 2012 289 2013 289 2015
295 - Orwell Subtidal 100.0
80.0
60.0
40.0
20.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
295 2012 295 2013 295 2014 295 2015
296 - Orwell Subtidal 100.0
80.0
60.0
40.0
20.0
0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
296 2012 296 2013 296 2014 296 2015
62 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
303 - Orwell Subtidal 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
303 2012 303 2013 303 2014 303 2015
306 - Orwell Subtidal 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 pebble granule V. coarse Coarse sand Medium Fine sand V. fine sand Silt Clay sand sand
306 2012 306 2013 306 2014 306 2015
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Appendix 3: Biotopes identified from 2003 to 2015
Sampling Area Site 2003 (Target biotope) 2008 2009 group Stour GpStA 150 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 152 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 153 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 154 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStB 155 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 157 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 158 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 163 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 169 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStC 171 LS.LMu.MEst.NhomMacStr LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStC 172 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStC 174 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStD 179 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi Stour GpStD 180 SS.SMu.SMuVS.AphTubi LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStD 181 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi Stour GpStD 249 SS.SMu.SMuVS.AphTubi LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStE 193 LS.LMu.MEst.HedMac LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStE 194 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 548 LS.LMu.MEst.HedMac LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStE 549 LS.LMu.MEst.HedMac LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStF 189 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn Stour GpStF 191 SS.SMx.IMx.SpavSpAn SS.SCS.SCSVS SS.SMx.IMx.SpavSpAn Stour GpStF 192 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi Stour GpStF 195 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn Stour GpStG 204 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Stour GpStG 206 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 207 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 209 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Orwell GpOrA 258 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 260 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 261 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 263 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 267 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 269 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 272 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Orwell GpOrB 275 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr Orwell GpOrC 285 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn Orwell GpOrC 289 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn Orwell GpOrC 303 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn LS.LMu.MEst.NhomMacStr Orwell GpOrC 306 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi LS.LMu.MEst.NhomMacStr Orwell GpOrD 295 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.PolCvol SS.SMu.SMuVS.PolCvol Orwell GpOrD 296 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.PolCvol SS.SMu.SMuVS.NhomTubi Orwell GpOrD 300 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.PolCvol LS.LMu.MEst.NhomMacStr Orwell GpOrD 301 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi LS.LMu.MEst.NhomMacStr
www.thomsonecology.com
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Sampling Area Site 2010 2011 2012 group Stour GpStA 150 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 152 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 153 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStA 154 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.UEst.Hed Stour GpStB 155 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 157 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 158 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 163 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 169 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 171 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 172 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 174 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStD 179 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStD 180 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStD 181 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStD 249 SS.SMx.IMx.SpavSpAn LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 193 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 194 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 548 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 549 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStF 189 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 191 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 192 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi Stour GpStF 195 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.NhomTubi SS.SMx.IMx.SpavSpAn Stour GpStG 204 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 206 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 207 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac SS.SMu.SMuVS.AphTubi Stour GpStG 209 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 258 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LR.FLR.Eph.BLitX Orwell GpOrA 260 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LR.FLR.Eph.BLitX Orwell GpOrA 261 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 263 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 267 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 269 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LR.FLR.Eph.BLitX Orwell GpOrB 272 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrB 275 LS.LMu.MEst.NhomMacStr LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrC 285 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Orwell GpOrC 289 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn SS.SMx.SMxVS.CreMed Orwell GpOrC 303 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.NhomTubi SS.SMx.SMxVS.CreMed Orwell GpOrC 306 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.PolCvol Orwell GpOrD 295 SS.SMu.SMuVS.NhomTubi SS.SMu.SMuVS.NhomTubi SS.SMu.SMuVS.PolCvol Orwell GpOrD 296 SS.SMu.SMuVS.NhomTubi SS.SMu.SMuVS.NhomTubi SS.SMu.SMuVS.PolCvol Orwell GpOrD 300 LS.LMu.MEst.NhomMacStr SS.SMu.SMuVS.NhomTubi SS.SMu.SMuVS.PolCvol Orwell GpOrD 301 LS.LMu.MEst.NhomMacStr SS.SMx.IMx.SpavSpAn LS.LMu.MEst.HedMac
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Sampling Area Site 2013 2014 2015 group Stour GpStA 150 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStA 152 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStA 153 SS.Smu.SMuVS.PolCvol LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStA 154 LS.LMu.UEst.Hed LS.LMu.UEst.Hed LS.LMu.MEst.HedMac Stour GpStB 155 LS.LMu.UEst.Hed LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 157 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 158 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStB 163 LS.LMu.UEst.Hed LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 169 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 171 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 172 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStC 174 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStD 179 SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStD 180 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStD 181 SS.SMu.SMuVS.AphTubi SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStD 249 SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStE 193 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 194 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStE 548 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStE 549 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStF 189 SS.SMx.IMx.SpavSpAn SS.SMx.SMxVS.CreMed SS.SMx.SMxVS.CreMed Stour GpStF 191 SS.SMx.IMx.SpavSpAn SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 192 SS.SMx.SMxVS.CreMed SS.SMu.SMuVS.AphTubi SS.SMx.SMxVS.CreMed Stour GpStF 195 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn LS.LMx.Mx.CirCer Stour GpStG 204 LS.LMu.MEst.HedMac LS.LMu.MEst.NhomMacStr LS.LMx.Mx.CirCer Stour GpStG 206 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Stour GpStG 207 SS.SMu.SMuVS.AphTubi LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Stour GpStG 209 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 258 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrA 260 SS.Smu.SMuVS.PolCvol LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac Orwell GpOrA 261 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrA 263 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 267 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 269 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 272 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrB 275 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrC 285 SS.SMx.IMx.SpavSpAn LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrC 289 SS.SMx.IMx.SpavSpAn no sample SS.SMx.SMxVS.CreMed Orwell GpOrC 303 SS.SMx.IMx.SpavSpAn SS.SMx.IMx.SpavSpAn LS.LMx.Mx.CirCer Orwell GpOrC 306 SS.Smu.SMuVS.PolCvol LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrD 295 SS.Smu.SMuVS.PolCvol LS.LMu.MEst.HedMac SS.SMx.SMxVS.CreMed Orwell GpOrD 296 SS.Smu.SMuVS.PolCvol LS.LMu.MEst.NhomMacStr SS.SMx.SMxVS.CreMed Orwell GpOrD 300 LS.LMu.MEst.HedMac LS.LMu.MEst.HedMac LS.LMx.Mx.CirCer Orwell GpOrD 301 LS.LMu.MEst.NhomMacStr SS.SMu.SMuVS.AphTubi LS.LMx.Mx.CirCer
66 Harwich Haven Authority, Project No.: I-HHA-110/002
Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Appendix 4: PERMANOVA results
Table 10: Results on the variance between the different years, between the Stour and Orwell and the intertidal and subtidal communities.
Source df SS MS Pseudo-F P(perm) Unique perms
Year 3 32588 10863 4.7195 0.001* 997
Location 1 14224 14224 6.1801 0.001* 998 (Stour/Orwell)
Zone 1 55361 55361 24.053 0.001* 998 (Intertidal/subtidal)
Table 11: Results on the interactive effects between years and location (Stour or Orwell), between years and intertidal and subtidal, between location and intertidal and subtidal, and the interaction between all three factors.
Source df SS MS Pseudo-F P(perm) Unique perms
Year x 3 8567.4 2855.8 1.2408 0.086 999 Location
Year x Zone 3 9486.4 3162.1 1.3739 0.015* 997
Location x 1 11351 11351 4.9319 0.001* 998 Zone
Year x 3 7439.9 2480 1.0775 0.298 998 Location x Zone
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Appendix 5: ANOSIM results
Table 12: The relationship in community composition between years
Groups R Statistic Significance Level %
2012, 2013 0.151 0.1*
2012, 2014 0.128 0.1*
2012, 2015 0.204 0.1*
2013, 2014 0.07 0.1*
2013, 2015 0.12 0.1*
Table 13: The relationship between community composition in the Stour and Orwell in the same year
Groups R Statistic Significance Level %
Stour 2012, Orwell 2012 0.184 0.8*
Stour 2013, Orwell 2013 0.137 2.3*
Stour 2014, Orwell 2014 0.072 12.7
Stour 2015, Orwell 2015 0.155 2.0*
Table 14: The relationship between the Stour samples over the different years
Groups R Statistic Significance Level %
Stour 2012, Stour 2013 0.223 0.1*
Stour 2012, Stour 2014 0.15 0.1*
Stour 2012, Stour 2015 0.264 0.1*
Stour 2013, Stour 2014 0.079 1.2*
Stour 2013, Stour 2015 0.132 0.1 *
Stour 2014, Stour 2015 0.096 0.6*
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Stour and Orwell Estuaries Review of macrobenthic data from1997 to 2015
Table 15: The relationship between the Orwell samples over the different years
Groups R Statistic Significance Level %
Orwell 2012, Orwell 2013 0.067 6.2
Orwell 2012, Orwell 2014 0.086 3.8*
Orwell 2012, Orwell 2015 0.172 0.4*
Orwell 2013, Orwell 2014 0.041 12.3
Orwell 2013, Orwell 2015 0.101 1.7*
Orwell 2014, Orwell 2015 0.101 2.9*
Table 16: The relationship between intertidal communities over the different years
Groups R Statistic Significance Level %
Intertidal 2012, Intertidal 2013 0.181 0.1*
Intertidal 2012, Intertidal 2014 0.165 0.1*
Intertidal 2012, Intertidal 2015 0.235 0.1*
Intertidal 2013, Intertidal 2014 0.082 0.1*
Intertidal 2013, Intertidal 2015 0.136 0.1*
Intertidal 2014, Intertidal 2015 0.129 0.1*
Table 17: The relationship between subtidal communities over the different years
Groups R Statistic Significance Level %
Subtidal 2012, Subtidal 2013 0.17 0.9*
Subtidal 2012, Subtidal 2014 0.133 1.7*
Subtidal 2012, Subtidal 2015 0.289 0.1*
Subtidal 2013, Subtidal 2014 0.088 7.2
Subtidal 2013, Subtidal 2015 0.187 0.9*
Subtidal 2014, Subtidal 2015 0.148 1.3*
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Stour and Orwell Estuaries Review of macrobenthic data from 1997 to 2015
Table 18: The relationship between intertidal and subtidal communities in the same year
Groups R Statistic Significance Level %
Intertidal 2012, Subtidal 2012 0.616 0.1*
Intertidal 2013, Subtidal 2013 0.532 0.1*
Intertidal 2014, Subtidal 2014 0.673 0.1*
Intertidal 2015, Subtidal 2015 0.577 0.1*
Intertidal 2012, Subtidal 2012 0.616 0.1*
Table 19: The relationship between intertidal communities within the Stour over the different years
Groups R Statistic Significance Level %
St/Int 2012, St/Int 2013 0.242 0.1*
St/Int 2012, St/Int 2014 0.171 0.1*
St/Int 2012, St/Int 2015 0.266 0.1*
St/Int 2013, St/Int 2014 0.087 0.1*
St/Int 2013, St/Int 2015 0.135 0.1*
St/Int 2014, St/Int 2015 0.105 0.2*
Table 20: The relationship between intertidal communities within the Orwell over the different years
Groups R Statistic Significance Level %
Or/Int 2012, Or/Int 2013 0.072 7.2
Or/Int 2012, Or/Int 2014 0.061 10.5
Or/Int 2012, Or/Int 2015 0.236 0.1*
Or/Int 2013, Or/Int 2014 0.027 20.4
Or/Int 2013, Or/Int 2015 0.154 0.5*
Or/Int 2014, Or/Int 2015 0.137 2.1*
70 Harwich Haven Authority, Project No.: I-HHA-110/002
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Table 21: The relationship between subtidal communities within the Stour over the different years
Groups R Statistic Significance Level %
St/Sub 2012, St/Sub 2013 0.339 1.5*
St/Sub 2012, St/Sub 2014 0.363 0.4*
St/Sub 2012, St/Sub 2015 0.629 0.4*
St/Sub 2013, St/Sub 2014 0.221 8
St/Sub 2013, St/Sub 2015 0.504 0.9*
St/Sub 2014, St/Sub 2015 0.484 1.6*
Table 22: The relationship between subtidal communities within the Orwell over the different years
Groups R Statistic Significance Level %
Or/Sub 2012, Or/Sub 2013 0.024 32
Or/Sub 2012, Or/Sub 2014 -0.036 55.7
Or/Sub 2012, Or/Sub 2015 0.165 9.3
Or/Sub 2013, Or/Sub 2014 0.063 32.5
Or/Sub 2013, Or/Sub 2015 0.16 10.2
Or/Sub 2014, Or/Sub 2015 0.206 9.5
Harwich Haven Authority, Project No.: I-HHA-110/002 71
Distribution of Marine Invasive Species in Harwich Haven (2010- 2015) For Harwich Haven Authority
Project No.: G-HWH-101-001
February 2016
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Distribution of Marine Invasive Species Harwich Haven Authority
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2 Harwich Haven Authority, Project No.: G-HWH-101/001
Distribution of Marine Invasive Species Harwich Haven Authority
Project Report No. Revision No. Date of Issue Number G-HWH-101 001 001 12/02/2016
Name Signature Position
Author Sarah Marjoram Marine Consultant
Reviewer Daniel Bastreri Principal Marine Consultant
Client Contact: John Brien Reference: G-HWH-101
Disclaimer:
Copyright Thomson Unicomarine Limited. All rights reserved. No part of this report may be copied or reproduced by any means without prior written permission from Thomson Unicomarine Limited. If you have received this report in error, please destroy all copies in your possession or control and notify Thomson Ecology Limited. This report has been prepared for the exclusive use of the commissioning party and unless otherwise agreed in writing by Thomson Unicomarine Limited, no other party may use, make use of or rely on the contents of the report. No liability is accepted by Thomson Ecology Limited for any use of this report, other than for the purposes for which it was originally prepared and provided. Opinions and information provided in the report are on the basis of Thomson Ecology Limited using due skill, care and diligence in the preparation of the same and no explicit warranty is provided as to their accuracy. It should be noted and it is expressly stated that no independent verification of any of the documents or information supplied to Thomson Ecology Limited has been made.
Harwich Haven Authority, Project No.: G-HWH-101/001 3
Distribution of Marine Invasive Species Harwich Haven Authority
Contents
Summary ...... 7 1. Introduction ...... 8 1.1 Background ...... 8 1.2 International and regional agreements ...... 9 1.3 The brief ...... 10 2. Methodology ...... 11 3. Results ...... 13 3.1 INNS found in survey results ...... 13 3.2 Distribution of INNS within the HHA area ...... 19 4. Recommendations ...... 19 4.1 Impacts of species identified ...... 19 4.2 Implications of the BWM Convention and management ...... 21 4.3 Surveying ...... 23 4.4 Marine INNS to look out for ...... 24 5. References ...... 27 Appendix 1 ...... 31 Appendix 2 ...... 32 Appendix 3 ...... 35
4 Harwich Haven Authority, Project No.: G-HWH-101/001
Distribution of Marine Invasive Species Harwich Haven Authority
Tables
Table 1: Surveys carried out within HHA area in the past 5 years ...... 11 Table 2: INNS and number of individuals found in surveys carried out in 2010 ...... 32 Table 3: INNS and number of individuals found in surveys carried out in 2011 ...... 32 Table 4: INNS and number of individuals found in surveys carried out in 2012 ...... 33 Table 5: INNS and number of individuals found in surveys carried out in 2013 ...... 33 Table 6: INNS and number of individuals found in surveys carried out in 2014 ...... 34
Figures
Figure 1: Map of approximate survey sites ...... 12 Figure 2: Total number of individuals of marine INNS recorded in surveys undertaken between 2010 and 2014 ...... 14 Figure 3: The percentage of individuals and species recorded in surveys from 2010 to 2014 which were invasive ...... 15 Figure 4: Sea spider: (http://nathistoc.bio.uci.edu/Pycnogonida/Ammothea.htm) ...... 15 Figure 5: Slipper limpet (http://www.idscaro.net/sci/04_med/class/fam3/species/crepid_fornicata1.htm ...... 15 Figure 6: Australasian barnacle: (http://www.norsas.eu/species/elminius-modestus) ...... 16 Figure 7: American jack-knife clam: (http://www.biopix.com/jackknife-clam-razor-clam-ensis- americanus_photo-40474.aspx) ...... 16 Figure 8: Soft-shelled clam: (http://www.idscaro.net/sci/01_coll/plates/bival/pl_myidae_1.htm) ...... 17 Figure 9: American piddock: (http://www.marinespecies.org/photogallery.php?album=2120&pic=49806) ...... 17 Figure 10: Wireweed: (http://www.marlin.ac.uk/species/detail/1477) ...... 18 Figure 11: Leathery sea squirt: (http://smithsonianscience.si.edu/2012/03/serc-database/) .... 18 Figure 12: Asian shore crab: http://www.takuyamorihisa.com/gallery/animalia/arthropoda/malacostraca/decapoda/varunidae /hemigrapsus/sanguineus/h_sanguineus.html ...... 24 Figure 13: Comb jelly: http://www.uniprot.org/taxonomy/27923 ...... 24 Figure 14: Veined rapa whelk: http://guideltapo.blog.tiscali.it/2005/01/16/la_rapana_venosa_una_specie_invasiva_nel_delta_ _la_mangiamo___1199919-shtml/ ...... 24 Figure 15: Celtodoryx ciocalyptiodes: http://www.european-marine-life.org/02/photo-celtodoryx- ciocalyptoides-wb01.php ...... 25
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Figure 16: Carpet sea squirt: http://www.european-marine-life.org/32/photo-didemnum- vexillum-wb01.php ...... 25 Figure 17: American lobster: http://www.arkive.org/atlantic-lobster/homarus-americanus/ ...... 25 Figure 18: Japanese skeleton shrimp: http://theconversation.com/there-are-no-barriers-to- prevent-marine-invasive-species-20875 ...... 26
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Summary
Harwich Haven Authority (HHA) commissioned Thomson Unicomarine to review benthic surveys undertaken over the past five years (2010 to 2014) in order to identify the abundance and distribution of invasive non-native species (INNS) within their port boundary. Thomson Unicomarine identified 19 benthic core and grab surveys within the HHA area. In total nine invasive species were identified in these surveys. Invasive species were recorded in all but one survey. The total number of invasive individuals recorded in these surveys has increased from 2010 to 2014. However, invasive species, and individuals, make up approximately 3% of the total number of species recorded, which can be considered insignificant. The percentage of invasive species recorded has also decreased from 2010 to 2014, however the percentage of invasive individuals has increased in the same time period. Of the invasive species identified there was one algae (wireweed – Sargassum muticum), one tunicate (leathery sea squirt – Styela clava), one gastropod (slipper limpet – Crepidula fornicata), three bivalves (American jack-knife clam – Ensis americanus; soft-shelled clam – Mya arenaria and American piddock – Petricola pholadiformis) and three crustaceans (sea spider – Ammothea hilgendorfi; Australasian barnacle – Austrominius modestus and American ostracod – Eusarsiella zostericola). Of these species it is considered that four (wireweed, slipper limpet, Australasian barnacle and leathery sea squirt) could have an adverse effect on marine ecology, outcompeting native species and impacting local biodiversity. These species could also have an adverse effect on the operations of the port itself, settling on and fouling ships, ropes, buoys and man-made structures. This could incur an economic cost to HHA for the control and removal of these species. The Ballast Water Management Convention (BWM Convention) aims to prevent the spread of harmful marine organisms by establishing standards and procedures for the management and control of ships’ ballast water and sediments. Once this Convention comes into force (possibly in 2017) ballast water management standards will be phased in over a period of time, affecting international shipping and ports. In undertaking this work HHA have taken an important step towards being able to quantify and describe the presence of INNS within their boundary. This will also enable them to carry out a risk assessment under the BWM Convention and apply for exemptions. Further surveys, including plankton surveys and installing settlement panels are required to provide a comprehensive review of the presence of INNS in HHA’s boundary.
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1. Introduction
1.1 Background
1.1.1 Invasive non-native species (INNS) are “animals, plants or other organisms introduced by man into places out of their natural range of distribution, where they become established and disperse, generating a negative impact on the local ecosystem and species” (IUCN, 2011).
1.1.2 INNS are considered to be one of the greatest threats to global biodiversity. They represent the second most significant cause of species extinction worldwide after habitat destruction (Bax et al., 2003). Invasive species can have major adverse effects on native species where they settle which can have irreversible effects on ecosystem functions and services (Shiganova, 1998). They can also cause significant damage to marine infrastructure (piers and pipelines) and marine based industries such as shipping and offshore exploration (Eno, 1996), having a detrimental effect on the economy and public health levels. The total annual cost of INNS to the British economy is estimated at approximately £1.7 billion (Williams et al. 2010).
1.1.3 Marine invasive species are spread by man through the transportation of goods. They can be transported on ships’ hulls and in their ballast water. Vessels take in water at one destination, which is used as ballast to stabilise the vessels throughout a voyage, and then may discharge it at the next destination. Whilst this practice is essential for safe and efficient shipping operations it can transport a multitude of marine species including bacteria, microbes, small invertebrates, eggs, cysts and larvae of various species. These transported species may survive to establish a reproductive population in the new environment, outcompeting native species and becoming invasive, multiplying into pest proportions. Estimates suggest that movements of ballast water alone account for the transport of 10,000 species every day (Streftaris et al., 2005). Data shows that the rate of invasions is still increasing at an alarming rate and new areas are being invaded all the time (IMO, 2016). The establishment of INNS is likely to increase as the oceans warm (Stachowicz et al. 2002).
1.1.4 In response to this threat to global biodiversity the International Maritime Organisation (IMO) has been developing international legislation to prevent the harmful effects of transporting aquatic organisms in ballast water. Consequently the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) was adopted in 2004. The BWM Convention aims to prevent the spread of harmful marine organisms by establishing standards and procedures for the
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management and control of ships’ ballast water and sediments. All ships in international traffic will be required to manage their ballast water to a certain standard. The ballast water management standards will be phased in over a period of time. Ships should exchange ballast water mid-ocean as an intermediate solution, however it is expected that most ships will be expected to install an on-board ballast water treatment system (HELCOM, 2013).
1.1.5 The BWM Convention will put in place international legislation for the first time and will enter into force 12 months after it has been signed by 30 States representing 35% of world merchant shipping tonnage.
1.1.6 Currently 47 States have ratified the convention, representing 34.35% of the world’s merchant shipping tonnage. The outstanding 0.65% may be met this year as countries such as Argentina and Australia and the Netherlands have confirmed that their ratification of the BWM Convention is in progress (IMO, 2016). This would mean that the BWM Convention could come into force in 2017.
1.2 International and regional agreements
1.2.1 The spread of INNS is a global issue that requires international cooperation and actions. There are a number of international and regional agreements which provide voluntary guidelines and regulations on the prevention of INNS. The following is a non-exhaustive list of agreements the UK is a Contracting Party to.
Marine Strategy Framework Directive (MSFD)
1.2.2 The MSFD (EU Directive 2008/56/EC) provides a legislative framework for an ecosystem-based approach to the management of human activities which supports the sustainable use of marine goods and services. The Directive’s overarching aim is to achieve Good Environmental Status by 2020 in Europe’s marine waters. To achieve this, one descriptor within the MSFD requires that levels of INNS introduced by human activities should be at levels that do not adversely affect native ecosystems.
The Convention of Biological Diversity (CBD)
1.2.3 Article 8(h) of the CBD states that “each contracting Party shall, as far as possible and as appropriate, prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species” (UN, 1992).
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Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)
1.2.4 The aim of CITES is to ensure that international trade of wild animals and plants does not threaten their survival. A provision in article XIV states that the Convention does not affect the right of Parties to adopt domestic measures restricting or prohibiting trade. This provision has been used in Europe to address specific alien species (CITES, 1983).
Bonn Convention on the Conservation of Migratory Species of Wild Animals
1.2.5 The Bonn Convention aims to conserve terrestrial, marine and avian migratory species. Contracting parties are required to protect migratory species by conserving or restoring habitats, prevent, remove, compensate or minimise adverse effects of activities and prevent, reduce or control factors that are endangering migratory species. INNS are considered a threat to migratory species and are addressed in articles III and V (UNEP, 1983).
Directive on the conservation of natural habitats and of wild fauna and flora (Habitats Directive)
1.2.6 The Habitats Directive (92/43/EC) requires Member states to “ensure that the deliberate introduction into the wild of any species which is not native to their territory is regulated so as not to prejudice natural habitats within their natural range or the wild native fauna and flora and, if they consider it necessary, prohibit such introduction” (EC, 1992).
The Wildlife and Countryside Act (WCA) (1981)
1.2.7 Section 14(1) of the WCA makes it illegal to release or allow to escape into the wild any animal which is not ordinarily resident in the UK, or is not a regular visitor.
1.3 The brief
1.3.1 In order to manage and control INNS an understanding of the current abundance and distribution of INNS is required. Thomson Unicomarine was commissioned by Harwich Haven Authority (HHA) to carry out a review of the biological data obtained through the analysis of macrobenthic samples obtained in surveys carried out in the Stour and Orwell estuaries during the past five years for HHA and other organisations. The review will focus on identifying which invasive species are present, their abundance and range within the harbour and surrounding local area and their likely impact on the local environment. The aim of this report is to advise HHA on targeted monitoring for INNS, the management of INNS and recommendations for further actions including advice on exemptions under the BWM Convention.
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2. Methodology
2.1.1 Thomson Unicomarine have been carrying out annual benthic invertebrate sampling within the Stour and Orwell Estuaries for HHA since 2008 and have also been commissioned to process samples taken by other organisations within the HHA area, such as the Environment Agency (EA) and Natural England (NE) over a number of years. Using data collected within the past 5 years Thomson Unicomarine have identified invasive species, their abundance and locations where they are found.
2.1.2 A list of surveys that were undertaken within the past 5 years, and which form the basis of this report, is provided in Table 1. The approximate locations of these surveys is illustrated in Figure 1.
Table 1: Surveys carried out within HHA area in the past 5 years
Year Survey Number of samples 2010 Felixstowe South Reconfiguration Site 18 Inner Gabbard East 27 Stour and Orwell Abundance Study 44 Posford Trimley Marsh Setback Site 24 Trimley-Shotley Enhancement 48 2011 Felixstowe South Reconfiguration Site 18 Inner Gabbard East 27 Stour and Orwell Abundance Study 44 Trimley-Shotley Enhancement 48 Environment Agency WFD Orwell Estuary 25 Environment Agency WFD Stour Estuary 25 2012 Felixstowe South Reconfiguration Site 18 Inner Gabbard East 27 Stour and Orwell Abundance Study 44 Trimley-Shotley Enhancement 48 2013 Environment Agency WFD Stour Estuary 25 Environment Agency WFD Orwell Estuary 25 Natural England Stour and Orwell rMCZ Study 48 2014 Stour and Orwell Abundance Study 43
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Figure 1: Map of approximate survey sites
www.thomsonecology.com
2.1.3 A list of INNS was compiled using the JNCC Review and Directory of Marine Non-native Species (Eno et al., 1997) and the MBA ID Guide (MBA, 2016) (see Appendix 1). These species were then searched for in the benthic species identification results of each of the surveys outlined in Table 1.
2.1.4 These species, the number of individuals and the surveys they were identified in are included in Appendix 2.
2.1.5 Detailed mapping was produced and is presented within an interactive PDF in order to illustrate the locations, and the number of individuals of the INNS found in these surveys and is included in Appendix 3.
2.1.6 The EA and NE were approached on order to gain permission to use their data and receive further information.
2.1.7 Environmental managers of other ports within the eastern and southern coasts of England were also contacted to gain information about their own management strategies for marine INNS.
3. Results
3.1 INNS found in survey results
3.1.1 INNS were recorded in the majority of surveys that were reviewed. Only one survey, the Inner Gabbard East 2011 survey, did not record any INNS. The species, number of individuals and the surveys they were recorded in are presented in Tables 2 to 6 in Appendix 2.
3.1.2 In total 9 marine invasive species were found during the examination of results from the surveys listed in Table 1. These are:
Ammothea hilgendorfi (sea spider) Crepidula fornicata (slipper limpet) Austrominius modestus (Australasian barnacle) Ensis americanus (American jack knife clam) Eusarsiella zostericola (American ostracod) Mya arenaria (soft-shelled clam) Petricola pholadiformis (American piddock) Sargassum muticum (wireweed)
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Distribution of Marine Invasive Species Harwich Haven Authority
Styela clava (leathery sea squirt)
3.1.3 All of these species will have been transported to the HHA area through shipping traffic, either as part of fouling communities on ship’s hulls or within ballast water. However many species are also thought to have been introduced to European and British waters unintentionally with commercial introductions of oysters and may have dispersed further once settled.
3.1.4 There has been a slight increase in the total number of invasive individuals recorded over the 5 year period since 2010 (Figure 2).
Figure 2: Total number of individuals of marine INNS recorded in surveys undertaken between 2010 and 2014
3.1.5 Individually the trends for each species vary. Numbers of A. hilgendorfi, C. fornicata, A. modestus, E. americanus and P. pholadiformis recorded in the surveys have decreased over the period from 2010 to 2014.
3.1.6 Numbers of E. zostericola, M. arenaria, and S. clava have increased over the same period. S. muticum was only found in one trawl sample from the Felixstowe South Reconfiguration survey in 2012.
3.1.7 The number of invasive species found, however, represent on average less than 3% of the total number of species recorded in all the surveys over the 5 year period. Consequently they make up a relatively insignificant proportion of the benthic communities sampled in these surveys.
3.1.8 This is also the case for the number of individuals recorded, however the data suggests that this proportion is increasing (Figure 3).
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Figure 3: The percentage of individuals and species recorded in surveys from 2010 to 2014 which were invasive
3.1.9 Below is a description of the invasive species recorded in these surveys, their impacts, rate of distribution and possible effects on operations and commercial interests.
Sea spider (Ammothea hilgendorfi)
3.1.10 A sea spider originating from the temperate waters of the North Pacific and thought to be introduced as part of fouling communities on ship hulls (Sweet, 2011). This species was first recorded in the UK in Southampton Water in 1978 (Bamber, 1985). Natural dispersal is limited in this species as it has no
planktonic larval stage (JNCC, 2006a), meaning that Figure 4: Sea spider: (http://nathistoc.bio.uci.edu/Pycnogonida/Ammothea.htm) distribution around the UK is a result of further transportation on vessels. There have been no observed adverse impacts on native species or habitats, nor are any negative impacts anticipated. This species does not present a negative impact on human health or the economy (JNCC, 2006a; Sweet, 2011).
Slipper limpet (Crepidula fornicata)
3.1.11 The slipper limpet originates from the eastern coast of Canada and America and is thought to have been introduced to Essex between 1887 and 1890 with
the importation of American oysters (Crassostrea Figure 5: Slipper limpet (http://www.idscaro.net/sci/04_med/class/fam3/species/crepid virginica) (Tyler-Walters, 2011). Its distribution now _fornicata1.htm
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extends from the south coast of Wales, along the south coast of England and north along the east coast of England to the Humber (JNCC, 2006b). Further spreading of this species is aided through a pelagic larval stage (Tyler-Walters, 2011). Aggregations of slipper limpets can prevent the settlement of other species, such as mussels and oysters, and can trap sediments reducing availability of hard substrate. Competition for food may occur with other filter feeding species (JNCC, 2006b). An economic impact to oyster and mussel mariculture has been identified due to loss of habitat, fouling, reducing the value of produce and increasing cleaning and handling time (Tyler-Walters, 2011). To try to limit the spread of this species, and protect shellfish beds that are currently free of this species, the release of live or fresh slipper limpets into the wild is an offence (MMO, 2015).
Australasian barnacle (Austrominius modestus)
3.1.12 Originally from Australasia this species was introduced to European and British waters in the 1940s through transportation on ship hulls (Sweet, 2012). It is also possible that the pelagic larval stage could be transported in ballast water. This barnacle is now found throughout the British Isles as it can spread rapidly during its pelagic larval stage (JNCC, 2006c). A. modestus out-competes the native
Chthalamus and Balanus barnacle species for hard Figure 6: Australasian barnacle: (http://www.norsas.eu/species/elminius- substrate on the coast and appears to have entirely modestus) displaced native barnacles in some places (Sweet, 2012). It is more tolerant of changes in salinity and temperature, can grow at a faster rate and reproduces several times a year. This species is a fouling organism in favourable conditions, settling on hard structures which may incur costs to businesses associated with cleaning and loss of utility.
American jack knife clam (Ensis americanus)
3.1.13 The American jack knife clam inhabits muddy sand in shallow subtidal marine and brackish water environments. It is common off the east coast of England from Kent to the Humber and has been present since the 1980s (Sweet, 2011a). It was introduced to European waters as larvae in ballast water and its spread within Figure 7: American jack-knife clam: Europe has been through the dispersal of pelagic larvae (http://www.biopix.com/jackknife-clam-razor-clam- ensis-americanus_photo-40474.aspx) (JNCC, 2006d). There are no reported direct impacts on native species or habitats. This
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species is exploited commercially in UK waters (Sweet, 2011a) and some parts of continental Europe (JNCC, 2006d).
American ostracod (Eusarsiella zostericola)
3.1.14 This species was introduced unintentionally in association with the importation of American oysters (C. virginica) in the late 1870s. E. zostericola has a low rate of dispersal as juvenile stages are non-dispersive, although adults are capable of swimming. There are no known effects of this species on the environment or commercial interests. (JNCC, 2006e)
Soft-shelled clam (Mya arenaria)
3.1.15 The soft-shelled clam is thought to have been introduced from the American coast during the 16th or 17th century in ship’s bilges. However, there is also some evidence that the Vikings may have transported this species to Europe from America as early as 1245 (Petersen et al. 1992). It has since spread throughout British waters by natural
dispersal of larvae. There are no known negative effects Figure 8: Soft-shelled clam: (http://www.idscaro.net/sci/01_coll/plates/bival/pl_m of this species on the environment or on commercial yidae_1.htm) interests (JNCC, 2006f). This species is edible and is considered a delicacy in America, however its use as a food in Britain is uncommon.
American piddock (Petricola pholadiformis)
3.1.16 This species was introduced from America unintentionally in association with the introduction of the American oyster (C. virginica) in the 1890s to Essex. It has pelagic larvae which have aided its spread throughout European waters. In Britain it can be found living in clay, peat or soft rock shores along the south and east coasts and is most common off the Figure 9: American piddock: (http://www.marinespecies.org/photogallery.php?album= coast of Essex and the Thames estuary (JNCC, 2120&pic=49806) 2006g). There is no evidence that this species is having, or will have, a negative impact on native species or habitats, or commercial interests.
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Wireweed (Sargassum muticum)
3.1.17 S. muticum is native to shores along the north-east Pacific. It is thought that this species first spread to Canadian and American shores, and from there was transported to French waters accidentally with the introduction of the American oyster (C. virginica) (Sewell, 2011). From France it may have reached Britain in the 1970s by natural dispersal or as a fouling organism on boats and shellfish (JNCC, 2006h). This species grows intertidally and subtidally in shallow water on hard surfaces in sheltered coastal waters and estuaries (Sewell, 2011). Wireweed out-competes native seaweed Figure 10: Wireweed: (http://www.marlin.ac.uk/species/detail/1477) species as it is fast growing and can reproduce earlier and at a faster rate. It is associated with a reduction in diversity of native seaweed species and can reduce light penetration, increase sedimentation and influence temperature in rock pools (Sewell, 2011). Wireweed is considered to be a nuisance in shallow water harbours and beaches as it can impair recreational and commercial activities. Its removal from man-made structures can incur economic costs.
Leathery sea squirt (Styela clava)
3.1.18 This species is a solitary sea squirt which attaches to solid surfaces in shallow water. It is thought that this species was introduced to Britain, in Plymouth Sound, on warships returning from Korea in the 1950s (Bishop, 2012). Its spread throughout British waters is due to transport on ship hulls or on transferred oysters (JNCC,
2006i). This species is capable of withstanding salinity Figure 11: Leathery sea squirt: (http://smithsonianscience.si.edu/2012/03/serc- changes and temperature fluctuations which is the database/) reason for its success in British waters (JNCC, 2006i). It can reach high densities and can become the dominant species in shallow waters. There is no evidence that this species displaces native sessile organisms, however at high densities it may compete for food with other suspension feeding invertebrates. There is evidence that other organisms settle on S. clava’s hard tunic which causes a slight increase in biodiversity. This species does have an economic impact through heavy fouling of ropes, buoys, moorings, ships and other hard man-made structures.
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3.2 Distribution of INNS within the HHA area
3.2.1 Marine INNS were found in all surveys but one. Detailed maps of the distribution of these species, and the number of individuals that were recorded can be found in Appendix 3, Figures a – i.
3.2.2 All species are present throughout the Stour and Orwell Estuaries apart from A. hilgendorfi (sea spider) which was only recorded in the Stour Estuary (Appendix 3, Figures a).
3.2.3 The majority of species are also found at the confluence of these estuaries and at the mouth with the North Sea, offshore from Landguard Point. Exceptions to this are M. arenaria (Appendix 3, Figure f) and A. hilgendorfi (Appendix 3, Figure a) which have only been found within the estuaries.
3.2.4 Only two species were recorded within the Inner Gabbard East surveys: M. arenaria and E. americanus (Appendix 3, Figure d). Inner Gabbard East is approximately 35 km offshore from Harwich Haven in an area dominated by sediments with no hard structures to promote settlement of other species. Both these species burrow into sediments and can be found in very high densities.
4. Recommendations
4.1 Impacts of species identified
4.1.1 Of the nine invasive species identified in the surveys, five (A. hilgendorfi, E. americanus, E. zostericola, M. arenaria and P. pholadiformis) are not considered to have an adverse impact on native species and habitats or on commercial interests.
4.1.2 Of the four invasive species that are known to have an adverse impact (C. fornicata, A. modestus, S. muticum and S. clava) all have an adverse impact on native species and/or habitats.
Slipper limpet (C. fornicata)
4.1.3 Slipper limpets were recorded in samples taken throughout the Stour and Orwell estuaries and at Landguard Point, however it occurs in larger numbers in the Stour Estuary (Appendix 3, Figure c). This species was detected in surveys completed in 2011 to 2014.
4.1.4 Slipper limpets have the ability to smother species and alter the nature of sediments, smothering areas previously dominated by bivalves. Colonisation and dominance of an
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area by slipper limpets has been reported to cause changes in species composition, and reductions in species diversity. The slipper limpet also competes with mussels and oysters for food and it is likely that this competition will impact natural and commercial communities. Changes in sediment composition may also adversely affect fish habitat, displacing commercially important species. It is unlikely that this species will have a significant adverse effect on commercial port activities.
4.1.5 Past controls of this species have been unsuccessful and costly (Fitzgerald, 2007). Removal of adults may inadvertently facilitate the further spread of individuals. The release of live or fresh slipper limpets into the marine environment is now an offence and any attempt at controlling their numbers may require disposal on land. Smothering of slipper limpets with a high density of seed mussel is a successful method used in the Menai Strait following the discovery of slipper limpets on mussel beds (Sewell and Sweet, 2011).
4.1.6 It is considered that this species presents a threat to commercial shellfisheries and control of this species would be essential to ensure the continued viability of shellfish stock. This species does not present a significant threat to port activities, however it is thought that large aggregations of this species offshore could affect channel dredging for shipping (Sewell and Sweet, 2011).
Barnacle (A. modestus)
4.1.7 A. modestus was found in benthic surveys in all years along the length of the Stour and Orwell estuaries, in trawls taken near Felixstowe and offshore from Landguard Point (Appendix 3, Figure b).
4.1.8 This barnacle, introduced in the 1940s, is now present on rocky shores throughout the UK and has been described as a ‘naturalised’ member of European intertidal habitats (Tøttrup et al. 2010).
4.1.9 It is a common fouling organism in harbours and estuaries and can displace native barnacle species. An economic impact could be incurred through the removal of barnacles from ship’s hulls.
Wireweed (S. muticum)
4.1.10 Wireweed was recorded in a trawl survey off the shore from Landguard Point in 2012 (Appendix 3, Figure h). Where wireweed occurs invasively it is a visually dominant species that locally changes community structure and species dominance (Strong et al. 2006). Wireweed is associated with harbours, marinas and associated structures, and sheltered inlets with hard and mixed substrates of cobbles and pebbles. It is potentially
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a minor navigation hazard through tangling in propellers and could also foul fishing gear (Critchley et al. 1986).
4.1.11 Management and eradication of this species has been unsuccessful in the past and control of drifting plants and propagules in the water column is difficult. It is considered that the impact of this species is minor (NNSS, 2011). It is considered that wireweed is now naturalised in southern England and will eventually be naturalised throughout the UK (NNSS, 2011).
Leathery sea squirt (S. clava)
4.1.12 The leathery sea squirt was recorded in surveys within the Stour and Orwell estuaries in 2011 and 2012, at Landguard Point in 2012, and within a trawl survey undertaken at Felixstowe in 2011 (Appendix 3, Figure i).
4.1.13 This species can heavily foul ropes, buoys, moorings, ships and other hard man-made structures. Removal of individuals by picking or scraping is the most reliable control method, but this will be costly in terms of time and effort. The species can be killed through lengthy exposure to air and/or extreme temperatures.
Summary
4.1.14 None of the species found in the surveys and described above are considered to be alert species and the Non-native Species Secretariat have not developed Action Plans to help coordinate a nation-wide response.
4.1.15 Local control of some of these species is possible if they are having a negative impact on local communities, commercial interests and the economy.
4.2 Implications of the BWM Convention and management
4.2.1 Article 5(1) of the BWM Convention requires that adequate sediment reception facilities in ports or terminals where cleaning or repair of ballast tanks occurs must be provided for the safe disposal of sediments that does not impair or damage the environment, human health, property or resources.
4.2.2 In addition the MMO decision to make the release of slipper limpets into the marine environment an offence will affect any hull/ballast tank cleaning service procedures that may be offered by HHA.
4.2.3 Exemptions for having to apply regulations B-3 (Ballast Water Management for Ships) or C-1 (Additional Measures) can be granted to:
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ships on voyages between specified ports or locations, or to a ship which operates exclusively between specified ports or locations; ships that do not mix ballast water or sediments other than between the ports or locations specified in the first point
4.2.4 Any exemptions granted are not effective until after a risk assessment has been carried out in accordance with IMO Resolution MEPC.162(56) – Guidelines for Risk Assessment under Regulation A-4 of the BWM Convention and communicated to the IMO and the relevant information circulated to the relevant parties.
4.2.5 There are three risk assessment methods outlined in the Guidelines:
Environmental matching risk assessment Species’ biogeographical risk assessment Species-species risk assessment
4.2.6 Environment matching and species’ biogeographical risk assessment is thought to be best suited to assessments between biogeographical regions. Species-specific risk assessment is thought to be best suited to assessments on a limited number of invasive species within a biogeographical area.
4.2.7 The Guidelines suggest that the Large Marine Ecosystems (LME) scheme is used to determine biogeographical regions. HHA falls into the North Sea ecosystem (LME, 2016).
4.2.8 The data necessary to enable a risk assessment using the species-specific approach includes, but is not limited to:
Biogeographic region of donor and recipient port(s). The presence of all non-indigenous species and native species in the donor port, port region, biogeographic region, not present in the recipient port, to allow identification of target species. The presence of all target species in the donor and recipient ports, port region, and biogeographic region. The difference between target species in the donor and recipient ports, port region, and biogeographic region. Life history information on the target species and physiological tolerances, in particular salinity and temperature, of each life stage, and Habitats type required by the target species and availability of habitat type in the recipient port.
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4.2.9 If a target invasive species is already present in both the recipient port and the donor port, it may be reasonable to exclude that species from the overall risk assessment for that port. However this should only be considered if the species is not being actively controlled, or its continued introduction could increase the probability that it will become established.
4.2.10 Under Regulation A-4.3 any exemptions granted by the port State shall not impair or damage the environment, human health, property or resources of adjacent or other States.
4.2.11 Exemptions from the BWC can be granted for up to five years. However the IMO recommends reviewing granted exemptions every 12 to 36 months (IMO G7 MEPC.162(56)). A review could include a new survey if deemed necessary, and the review frequency may be decided based on, for example, port traffic frequency.
4.2.12 In undertaking this work HHA have taken an important step towards being able to quantify and describe the presence of INNS within their boundary. This will also enable them to carry out a risk assessment under the BWM Convention. Further surveys are required to satisfy the guidelines outlined above and provide a comprehensive review of the presence of INNS in HHA’s boundary.
4.3 Surveying
4.3.1 To be able to respond rapidly to INNS introductions, limit the subsequent spread and minimise impact early detection of INNS settlement is crucial. Monitoring and surveillance of INNS to determine abundance and distribution, and detect introductions rapidly is key for their control and management.
4.3.2 Currently only grab sampling has been reviewed. It is recommended that the annual benthic core and grab samples carried out by Thomson Unicomarine in the Stour and Orwell estuaries should continue in order to continue building a robust database of information. This will then provide a baseline for future monitoring and analysis.
4.3.3 In addition to the above survey scheme, it is recommended that settlement panels are distributed throughout the HHA area and scrapes are taken from offshore buoys in order to monitor settlement of species. It is also recommended that plankton surveys are undertaken to assess species composition and abundance.
4.3.4 Continuing, and introducing these surveys will provide information to inform a risk assessment under the IMO Resolution MEPC.162(56) – Guidelines for Risk Assessment under Regulation A-4 of the BWM Convention.
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4.4 Marine INNS to look out for
Asian shore crab (Hemigrapsus sanguineus)
4.4.1 The Asian shore crab is thought to have been introduced to European waters in ship’s ballast water. This species can spread easily through dispersion of its larvae. It is reported to cause significant reductions
in the common shore crab (Carcinus maenas) due to Figure 12: Asian shore crab: http://www.takuyamorihisa.com/gallery/animalia/arthropoda displacement and competition from the Asian shore /malacostraca/decapoda/varunidae/hemigrapsus/sanguine us/h_sanguineus.html crab. Invertebrates such as mussels, snails, barnacles and polychaetes may also be threatened due to increased predation. It is thought that this species could pose a predation threat to commercial mussel and oyster beds. The Asian shore crab could also compete with juvenile edible crabs (Cancer pagurus) which is a species of economic value. A few individuals of this species have already been recorded in Kent and South Wales. (Sweet and Sewell, 2014)
Comb jelly (Mnemiopsis leidyi)
4.4.2 The comb jelly, or sea walnut, was introduced to the Black Sea with ballast water in the 1980s and since then has spread and been recorded in Danish and Dutch waters. The comb jelly is a veracious predator of zooplankton, fish eggs and larvae. This species has been attributed to declines in planktivorous fish species, such as anchovy, sprat and horse mackerel which had a devastating effect on fisheries in the Black Sea, costing hundreds of millions of US dollars. Impacts have cascaded up Figure 13: Comb jelly: the trophic levels. Declines in dolphin numbers in the Black http://www.uniprot.org/taxonomy/27923 Sea, and seal numbers in the Caspian Sea have also been attributed to the presence of comb jellyfish. (Sweet, 2011b)
Veined rapa whelk (Rapana venosa)
4.4.3 The veined rapa whelk is a very large, active predatory snail which can grow to up to 18 cm in length. It has not been recorded on British shores, however it has been recorded in the North Sea and the Channel. This whelk could outcompete the
native common whelk (Buccinum undatum) as it is Figure 14: Veined rapa whelk: http://guideltapo.blog.tiscali.it/2005/01/16/la_rapana_venosa_ una_specie_invasiva_nel_delta__la_mangiamo___1199919- able to consume large quantities of prey. This shtml/
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reduction in prey could also impact other predators including crabs, birds, fish and starfish. Due to its predatory impact this species is considered to be one of the most unwelcome invasive species worldwide. (Sweet, 2015)
A sponge (Celtodoryx ciocalyptoides)
4.4.4 C. ciocalyptoides is a species of sponge which originates from the North West Pacific. It is thought that it was introduced to European waters through the transfer of Pacific oyster for aquaculture in France and the Netherlands. C. ciocalyptoides is an
Figure 15: Celtodoryx ciocalyptiodes: http://www.european- encrusting sponge and can cover a large area. marine-life.org/02/photo-celtodoryx-ciocalyptoides-wb01.php Consequently it competes successfully with other microbenthic organisms and can overgrow other sessile invertebrates. It is now the dominant benthic megafauna in Dutch inshore waters, displacing native benthic communities. (Henkel, 2011)
Carpet sea squirt (Didemnum vexillum)
4.4.5 The Carpet sea quirt is another import from Asia, likely as a passenger on ship hulls. These colonial invertebrates form a ‘carpet’ on hard surfaces, spreading rapidly and aggressively. Where it has an extensive presence it can change the nature of the seafloor community, smothering and causing a marked decrease in
Figure 16: Carpet sea squirt: http://www.european-marine- native benthic organisms. It also exudes a toxic life.org/32/photo-didemnum-vexillum-wb01.php substance which discourages predators and prevents the larvae of other species from settling on it. (Bishop, 2012a)
American lobster (Homarus americanus)
4.4.6 American lobsters have been introduced to British waters through accidental or deliberate release by the catering industry. It is not thought to have become established in British
waters as yet, however recordings of Figure 17: American lobster: http://www.arkive.org/atlantic- lobster/homarus-americanus/ individuals date back to 1988. American lobsters could outcompete the native European lobster (Homarus gammarus) as they are larger, more aggressive and can inhabit a broader range of habitats. This species could also compete for resources with other environmentally and economically important species. The American lobster carries
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diseases which can be transferred to our native European lobster. The blood disease gaffkemia causes a rapid 100% mortality in European lobsters within a few days of exposure. This could have significant impacts on wild and commercial populations. (Yunnie, 2015)
Japanese skeleton shrimp (Caprella mutica)
4.4.7 Caprella mutica, or the Japanese skeleton shrimp has been introduced to British waters through transportation in ballast water, or as a fouling organism on ship hulls. This shrimp is an aggressive and highly competitive species, outcompeting the
native species (Caprella linearis) for space at a ratio Figure 18: Japanese skeleton shrimp: http://theconversation.com/there-are-no-barriers-to-prevent- of 1:50. The Japanese skeleton shrimp is most marine-invasive-species-20875 commonly found on man-made structures (buoys, pontoons, ropes and boat hulls). They have been recorded blocking water intakes for the feeding systems at fish farms and settling on mussel lines, displacing juvenile mussels, and as such having an economic impact on coastal businesses.
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5. References
Bamber, R.N. (1985). The itinerant sea spider Ammothea hilgendorfi (Böhm) in British waters. Proceedings of Hampshire Field Club & Archaeological Society, 41: 37
Bax, N., A. Williamson, M. Aguero, E. Gonzalez and W. Geeves (2003). Marine invasive alien species: a threat to global biodiversity. Marine Policy 27: 313-323
Bishop, J. (2012). Leathery sea quirt, Styela clava. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3430. Accessed: 27/01/2016
Bishop, J. (2012a). Carpet sea squirt, Didemnum vexillum. GB Non-native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1209. Accessed: 14/01/2016
CITES (1983). Convention on International Trade in Endangered Species of Wild Fauna and Flora
Critchley A.T., W.F. Farnham & S.L. Morell (1986). An account of the attempted control of an introduced marine alga, Sargassum muticum, in southern England. Biological Conservation 35: 313-332.
Eno, N.C. (1996). Non-native marine species in British waters: Effects and controls. Aquatic Conservation-Marine and Freshwater Ecosystems 6: 215-228
Eno, N.C., R.A. Clark and W.G. Sanderson (1997). Non-native marine species in British waters: a review and directory. Joint Nature Conservation Committee (JNCC), Peterborough.
European Commission (EC) (1992) Directive on the Conservation of natural habitats and of wild fauna and flora. Council Directive 92/43/EEC.
Helsinki Commission (HELCOM) (2013). Joint HELCOM/OSPAR Guidelines on the granting of exemptions under the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, Regulation A-4. Adopted by HELCOM Ministerial Meeting, 3 October 2013 in Copenhagen and OSPAR Agreement 2013-09
Henkel, D. (2011) Celtodoryx ciocalyptoides (sponge). Global Invasive Species Database. http://issg.org/database/species/ecology.asp?si=1804&fr=1&sts=&lang=EN. Accessed: 15/01/2016
International Maritime Organisation (IMO) (2016). Status of multilateral Conventions and instruments in respect of which the International Maritime Organisation or its Secretary-
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General performs depository or other functions. As at 11 February 2016. International Maritime Organisation.
International Maritime Organisation (IMO) (2016) Ballast Water Management. http://www.imo.org/en/OurWork/Environment/BallastWaterManagement/Pages/Default.aspx. Accessed on: 27/01/2016
International Union for the Conservation of Nature (IUCN) (2011) Invasive Species. http://www.iucn.org/about/union/secretariat/offices/iucnmed/iucn_med_programme/species/inv asive_species/ Accessed: 27/01/2016
Joint Nature Conservation Committee (JNCC) (2006a) Ammothea hilgendorfi. http://jncc.defra.gov.uk/page-1703. Accessed: 08/12/2015
Joint Nature Conservation Committee (JNCC) (2006b) Crepidula fornicata. http://jncc.defra.gov.uk/page-1711. Accessed 08/12/2015
Joint Nature Conservation Committee (JNCC) (2006c) Elminius modestus. http://jncc.defra.gov.uk/page-1704. Accessed: 08/12/2015)
Joint Nature Conservation Committee (JNCC) (2006d) Ensis americanus. http://jncc.defra.gov.uk/page-1716. Accessed: 08/12/2015
Joint Nature Conservation Committee (JNCC) (2006e) Eusarsiella zostericola. http://jncc.defra.gov.uk/page-1707. Accessed: 08/12/2015.
Joint Nature Conservation Committee (JNCC) (2006f) Mya arenaria. http://jncc.defra.gov.uk/page-1720. Accessed: 08/12/2015
Joint Nature Conservation Committee (JNCC) (2006g) Petricola pholadiformis. http://jncc.defra.gov.uk/page-1717. Accessed: 08/12/2015
Joint Nature Conservation Committee (JNCC) (2006h) Sargassum muticum. http://jncc.defra.gov.uk/page-1677. Accessed: 08/12/2015.
Joint Nature Conservation Committee (JNCC) (2006i). Styela clava. http://jncc.defra.gov.uk/page-1722. Accessed: 08/12/2015
Large Marine Ecosystems of the World (LME (2016) http://lme.edc.uri.edu/index.php?option=com_content&view=category&id=16&Itemid=114 Accessed on: 27/01/2016
Marine Biological Association (MBA) (2016). Identification guide for selected marine non-native species. http://www.mba.ac.uk/bishop/wp-content/uploads/2014/09/84105-MBA-ID-Guide- 38pp-A5-English_reduced-pdf.pdf. Accessed: 27/01/2016
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Marine Management Organisation (MMO) (2015). Slipper limpets not permitted to be used as bait or disposed at sea. https://www.gov.uk/government/news/slipper-limpets-not-permitted-to- be-used-as-bait-or-disposed-at-sea.
NNSS (Non-native species secretariat) (2011). GB Non-native Organism Risk Assessment Scheme: Sargassum muticum. www.nonnativespecies.org
Petersen, K.S., K.L. Rasmussen, J. Heinemeler, and N. Rud (1992). Clams before Columbus? Nature, 359: 679
Sewell, J. (2011) Wireweed, Sargassum muticum. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3141. Accessed: 27/01/2016
Sewell, J. and Sweet, N. (2011) GB Non-native Organism Risk Assessment for Crepidula fornicata. www.nonnativespecies.org
Shiganova, T.A. (1998). Invasion of the Black Sea by the ctenophore Mnemiopsis leidyi and recent changes in pelagic community structure. Fisheries Oceanography 7: 305-310
Streftaris, N., A. Zenetos and E. Papathanassiou (2005). Globalisation in marine ecosystems: The story of non-indigienous species across European seas. Annual Review of Oceanography and Marine Biology 43: 419-453
Stachowicz, J.J., J.R. Terwin, R.B. Whitlach and R.W. Osman (2002). Linking climate change and biological invasions: ocean warming facilitates nonindigenous species invasions. Proceedings of the National Academy of Sciences 99: 15497-15000
Strong J.A, M.J. Dring & C.A. Maggs (2006). Colonisation and modification of soft substratum habitats by the invasive macroalga Sargassum muticum. Marine Ecology Progress Series 321: 87-97.
Sweet, N. (2011) A sea spider, Ammothea hilgendorfi. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=186. Accessed: 27/01/2016
Sweet, N. (2011a) American jack knife clam, Ensis directus. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1322. Accessed: 27/01/2016
Sweet, N. (2011b) American comb jelly, Mnemiopsis leidyi. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3813. Accessed: 15/01/2016
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Sweet, N. (2012) Austrominius modestus. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1301. Accessed: 27/01/2016
Sweet, N. and J. Sewell (2014). Asian shore crab, Hemigrapsus sanguineus. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3818. Accessed: 15/01/2016
Sweet, N. (2015) Veined rapa whelk, Rapana venosa. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=2972. Accessed: 15/01/2016
Tøttrup, A.P., B.K.K. Chan, H. Koskinen and J.T. Høeg (2010). ‘Flying barnacles’: implications for the spread of non-indigenous species. Biofouling 26: 577-582
Tyler-Walters, H. (2011) Slipper limpet, Crepidula fornicata. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1028. Accessed: 27/01/2016.
United Nations (UN) (1992) Convention on Biological Diversity
United Nations Environment Programme (UNEP) (1983) Convention on the Conservation of Migratory Species of Wild Animals.
Williams, F., R. Eschen, A. Harris, D. Djeddour, C. Pratt, R.S. Shaw, S. Varia, J. Lamontagne- Godwin, S.E. Thomas, S.T. Murphy (2010). The economic cost of invasive non-native species on Great Britain. CABI Project No. VM1006
Yunnie, A. (2015) American lobster, Homarus americanus. GB Non-Native Species Secretariat. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1736. Accessed: 15/01/2016
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Appendix 1
A list of marine invasive species identified derived from Eno et al. (1997) and MBA (2016).
Acartia tonsa Crassostrea gigas Pileolaria berkeleyana Agardhiella subulata Crepidula fornicata Pleurosigma simonsenii Ammothea hilgendorfi Diadumene lineata Polysiphonia harveyi Amphibalanus amphitrite Didemnum vexillum Potamopyrgus antipodarum Anguillicola crassus Ensis directus Rapana venosa Antithamnionella Ensis americanus spirographidis Rhithropanopeus harrisii Eriocheir sinensis Antithamnionella ternifolia Sargassum muticum Eusarsiella zostericola Asparagopsis armata Schizoporella japonica Ficopomatus enigmaticus Asterocarpa humilis Solieria chordalis Goniadella gracilis Austrominius modestus Spartina anglica Gonionemus vertens Balanus amphitrite Styela clava Grateloupia turuturu Bonnemaisonia hamifera Thalassiosira punctigera Grateloupia filicina var. Botrylloides violaceus luxurians Thalassiosira tealata Botrylloides diegensis Grateloupia doryphora Tiostrea lutaria Bugula neritina Haliplanella lineata Tricellaria inopinata Caprella mutica Hemigrapsus Undaria pinnatifida Caulacanthus okamurae Heterosiphonia japonica Urosalpinx cinerea Caulacanthus ustulatus Hydroides dianthus Watersipora subatra Celtodoryx ciocalyptoides Hydroides ezoensis Chrysymenia wrightii Janua brasiliensis Clavopsella navis Marenzelleria viridis Clymenella torquata Mercenaria mercenaria Codium fragile fragile Mnemiopsis leidyi Colpomenia peregrina Mya arenaria Colpomenia peregrina Odontella sinensis Corella eumyota Perophora japonica Corophium sextonae Petricola pholadiformis Coscinodiscus wailesii Pikea californica
www.thomsonecology.com
Appendix 2
Table 2: INNS and number of individuals found in surveys carried out in 2010
Surveys Inner Posford Stour and Trimley- Total Species Felixstowe Gabbard Trimley Orwell Shotley individuals East Marsh Ammothea 8 8 hilgendorfi Crepidula 609 609 fornicata Austrominius 4 561 204 769 modestus Ensis 10 2 7 19 americanus Eusarsiella 60 134 3 7 204 zostericola Mya arenaria 123 1 1 125 Petricola 3 4 7 pholadiformis Total 82 2 1437 4 216 1741 individuals
Table 3: INNS and number of individuals found in surveys carried out in 2011
Surveys Inner EA WFD EA WFD Stour and Trimley- Total Species Felixstowe Gabbard Orwell Stour Orwell Shotley individuals East Estuary Estuary Ammothea 1 21 22 hilgendorfi Crepidula 3 84 1 33 768 889 fornicata Austrominius 407 164 17 4 112 704 modestus Ensis
americanus Eusarsiella 43 7 168 197 415 zostericola Mya arenaria 40 40 Petricola 1 1 2 8 13 25 pholadiformis Styela clava 2 2 4 Total 413 333 27 213 1113 2099 individuals
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Distribution of Marine Invasive Species Harwich Haven Authority
Table 4: INNS and number of individuals found in surveys carried out in 2012
Surveys Species Felixstowe Inner Gabbard Stour and Trimley- Total East Orwell Shotley individuals Crepidula 1 89 90 fornicata Austrominius 823 57 880 modestus Eusarsiella 16 82 10 108 zostericola Mya arenaria 2 230 232 Styela clava 2 2 Petricola 2 2 pholadiformis Sargassum Present Present muticum Total 19 2 1224 69 1314 individuals
Table 5: INNS and number of individuals found in surveys carried out in 2013
Surveys Species EA WFD Stour EA WFD Orwell NE MCZ Stour Total individuals Estuary Estuary and Orwell Ammothea 5 5 hilgendorfi Crepidula 272 32 37 341 fornicata Austrominius 584 941 1525 modestus Eusarsiella 495 314 28 837 zostericola Mya arenaria 1 16 17 Petricola 30 1 31 pholadiformis Styela clava 7 7 Total individuals 1357 383 1023 2763
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Table 6: INNS and number of individuals found in surveys carried out in 2014
Surveys Species Stour and Orwell Total individuals Ammothea hilgendorfi 4 4 Crepidula fornicata 298 298 Elminius modestus 125 125 Eusarsiella zostericola 413 413 Mya arenaria 832 832 Total individuals 1672 1672
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Appendix 3
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ORNITHOLOGICAL MONITORING OF THE STOUR AND ORWELL ESTUARIES SPECIAL PROTECTION AREA: WINTERS 1999/2000 TO 2015/2016
July 2016
Suffolk Wildlife Trust Trading Co. Brooke House Ashbocking Ipswich IP6 9JY
Prepared for Suffolk Wildlife Trust by:
Dr Neil Ravenscroft Bramley Cottage Blaxhall IP12 2DX [email protected] Stour-Orwell SPA monitoring 2015/2016
Summary
1. The population of wintering waterbirds of the Stour and Orwell Estuaries Special Protection Area was assessed at low tide during the winter of 2015/2016 as part of an environmental monitoring programme to assess the effects of deepening the approach channel to the ports of Felixstowe and Harwich. This was the seventeenth consecutive winter of monitoring since 1999.
2. Four counts of all waterbirds were undertaken at low tide: one in each of November and December 2015, and one in each of January and February 2016. The estuaries were counted simultaneously and general conditions were good.
3. Distribution maps, population data (means and peaks) and trends since 1999 are presented for 13 key species within the SPA as a whole and for each component estuary. Raw count data for all species are included to complement previous reports.
4. The mean winter populations of six species (wigeon, pintail, ringed plover, grey plover, curlew and redshank) and the peak numbers of six species (wigeon, oystercatcher, ringed plover, grey plover, curlew and redshank) showed a declining trend in the SPA after 2015/2016, continuing the patterns in most of these species in recent winters. Ringed plover and redshank are declining on both estuaries, whereas declines are confined to one estuary for remaining species (oystercatcher and grey plover on the Stour, wigeon and curlew on the Orwell). Pintail shows a decline overall in the SPA but not on either estuary. A further species, turnstone, shows a decline on the Orwell, but not in the SPA.
5. The increase in the mean numbers of brent geese in the SPA continued strongly and those of knot more weakly (both through increases on the Stour). Some populations in winter 2015/2016 were at maxima for the monitoring programme: brent goose (peak population on the Stour); pintail (peak population on the Stour); grey plover (mean and peak population on the Orwell) and dunlin (mean and peak population on the Orwell, mean and peak populations in the SPA). There was an influx of birds during cold weather in February that caused a peak in the winter counts of several species. Programme lows occurred for oystercatcher (mean Stour and SPA populations), knot (mean and peak Orwell populations), redshank (mean and peak Stour populations) and turnstone (Orwell peak population and SPA mean population).
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Contents
1. INTRODUCTION 1.1 Background 4 1.2 The Stour and Orwell Estuaries Special Protection Area 4 1.3 Status of species in the SPA 4 1.4 Objective 5
2. METHODS 2.1 Counts 5 2.2 Data analysis and presentation 5
3. RESULTS 3.1 Trends 6 3.2 Brent goose 7 3.3 Shelduck 7 3.4 Wigeon 9 3.5 Pintail 9 3.6 Oystercatcher 10 3.7 Ringed plover 10 3.8 Grey plover 11 3.9 Knot 11 3.10 Dunlin 12 3.11 Black-tailed godwit 12 3.12 Curlew 13 3.13 Redshank 13 3.14 Turnstone 13
4. References 14
5. Acknowledgements 14
6. Figures 1. The features and place names of the Orwell and Stour estuaries at low tide 16 2. The sections of the Orwell estuary used in low water counts 17 3. The sections of the Stour estuary used in low water counts 18 4. The mean and peak numbers of species on the Orwell, Stour and SPA 1999-2000 to 2015/2016 19
7. Distribution maps of principal species: 1999/2000 & 2015/2016 23
8. Appendices 1. Raw count data for the Orwell 2015/2016 38 2. Raw count data for the Stour 2015/2016 42
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Stour-Orwell SPA monitoring 2015/2016
1. INTRODUCTION 1.1 Background Harwich Haven Authority is monitoring the environment of the Stour and Orwell Estuaries Special Protection Area in order to assess the effects of deepening the approach channel to the Ports of Felixstowe and Harwich. Part of this programme includes assessing any impacts on the bird populations wintering in the SPA.
Monitoring of waders and wildfowl within the Stour and Orwell Estuaries SPA is being undertaken at low water in order to record the distribution of species within the feeding grounds of the estuaries. Winter 2015/2016 was the seventeenth consecutive winter of study of the SPA under the programme of monitoring that commenced in 1999/2000.
1.2 The Stour and Orwell Estuaries Special Protection Area Together, the Stour and Orwell estuaries are a wetland of major international importance comprising extensive mudflats, low cliffs, saltmarsh and small areas of vegetated shingle. They provide wintering habitats for important wetland bird species, particularly wildfowl and waders. They qualify as a Special Protection Area (EEC Directive 79/409 on the Conservation of Wild Birds) and Ramsar site (Ramsar Convention on Wetlands of International Importance) on the basis of these wintering waterbird populations.
At the time of designation in 1992, the SPA regularly supported over 20,000 waterbirds and a number of species in populations that were of national or international importance.A In the most recent five winter period of 2010/2011 to 2014/2015, the SPA supported an average peak of 73466 birds (49665 on the Stour and 23801 on the Orwell), with maxima of 52699 on the Stour and 26121 on the Orwell, both in winter 2014/2015 (Frost et al. 2016).B
1.3 Status of species in the SPA Currently, the Stour supports internationally important populations of five species and nationally important populations of 16 other species. The Orwell supports populations of one and eight species that exceed international and national thresholds respectively.
Although data is recorded for all species, annual reporting of the low water monitoring programme has concentrated since 1999/2000 on ‘key’ species that are notable owing to their status and because they are species characteristic of the SPA at low water. The status of these species has varied during the monitoring programmeC, but currently four of them are internationally important on the Stour (brent goose, knot, dunlin and black-tailed godwit) and seven others are nationally important (Table 1). One is internationally important on the Orwell (black-tailed godwit) and five are nationally important.
A Internationally important sites contain populations composing >1% of East Atlantic flyway populations (waders) and >1% of the NW European population (wildfowl). Nationally important sites contain >1% of the British population. Populations are assessed from the mean of peak numbers in each of the five preceding winters. B Wetland Bird Survey uses monthly ‘core counts’ that are usually performed at high tide at sites across the UK to assess and compare national and international status, but utilises the low tide counts from The Stour and Orwell Estuaries SPA monitoring programme to asses its status. C Qualifying levels for national and international importance also change and therefore changes in status do not necessarily reflect significant changes in local populations.
4
Stour-Orwell SPA monitoring 2015/2016
Table 1: The status of the 13 key wader and wildfowl species of the Stour and Orwell SPA. 2016). Nationally important populations are shown in black and internationally important populations in black bold.
Stour Orwell Brent goose 2439 1737 Shelduck 1859 789 Wigeon 3013 1496 Pintail 429 177 Oystercatcher 937 1673 Ringed plover 344 181 Grey plover 2285 404 Knot 10377 4026 Dunlin 14034 3661 Black-tailed godwit 1848 819 Curlew 1597 695 Redshank 1513 1380 Turnstone 530 241
1.4 Objective Assess the low water wintering populations of waterfowl and their distribution within the Stour and Orwell Estuaries SPA in 2015/2016.
2. METHODS 2.1 Counts The estuaries were divided into the same count sections used for previous low water counts (figs. 2 & 3). Four counts were undertaken, one in each of November (20th) and December (18th) 2015 and one in each of January (18th) and February (16th) 2016. Counts were undertaken simultaneously on both estuaries of the SPA. Each count started 1.5 hours before low water and continued, when necessary, to 1.5 hours beyond low water. All species present on mudflats (and waterbirds on the estuary at low tide) were counted, although counters were not required to count gulls.
All counts were undertaken during good conditions and no problems were reported with accuracy. There were no missed sections in winter 2105/2016 although one section (19) of the Orwell was counted separately from the scheduled November count (four days), as were sections 27-30 in January (the day after) and sections 17- 18 in February (the day before). All other sections on the Orwell and all on the Stour were counted simultaneously.
2.2 Data analysis & presentation Data for 13 key species are presented as mean and peak numbers for the SPA as a whole and for each component estuary using all four counts of the Orwell and the Stour. Key species are those included in citations for the SPA i.e. those occurring in nationally or internationally important numbers, plus other species that have either held this status previously or are prominent in the communities of the estuaries (see Table 1). One species has been removed from detailed reporting (lapwing) because have been variable since the start of monitoring, it is no longer a species of particular status in the SPA, and also it is not necessarily a species characteristic of the low tide community of the SPA.
5
Stour-Orwell SPA monitoring 2015/2016
Overall trends in the mean and peak numbers of each species in the SPA and the component estuaries since the start of monitoring in 1999/2000 to 2015/2016 are investigated using simple non-parametric statistics (Spearman’s correlation coefficient (rs)) (Table 2). Trends indicated by significant correlations (P < 0.05) are divided into three levels according to statistical confidence in the trend (P = 0.05- 0.01; P = 0.01-0.001; and P < 0.001) and presented in tables as weak, medium and high respectively.
Results from winter 2015/2016 are presented alongside those from previous winters (since the first analysis in 2007/2008) to illustrate consistencies in trends (Table 3). The analyses are simple representations of patterns in the absolute numbers of birds within the SPA and do not incorporate the effects of changes in regional and national numbers but reference is made to national trends available in WeBS and other reports1, 2.
Distribution maps of mean winter numbers for these key species were prepared by the BTO from the count data using their WeBS software. A dot equating to one bird is placed randomly within the boundaries of each count section (one dot equals two birds for dunlin and knot). Maps for 2015/2016 are presented alongside those from the first winter or the earliest available winter for comparison. Maps from intervening winters are available in previous annual reports. Objective assessments are made of the distributions of species and changes thereof within the SPA from these maps, drawing on a recent analysis of trends within sections of the estuaries that was conducted after winter 2014/20153.
3. RESULTS 3.1 Trends The mean winter populations of six species show significant declines in the SPA since 1999/2000 (Table 2). Five of these species have shown consistent and strengthening trends after each of the last five winters (pintail, ringed plover, grey plover, curlew and redshank) (Table 3). The mean winter populations of ringed plover and redshank are declining on both estuaries, and those of curlew and grey plover appear restricted to the Orwell and Stour respectively.
Table 2: Trends in the mean and peak numbers of species on the Orwell, Stour and SPA 1999/2000 to 2015/2016. Colours denote an increasing (green) or decreasing (red) population and colour intensity indicates trend confidence (weak, medium or high). See methods and also Table 3.
Mean numbers Peak numbers Orwell Stour SPA Orwell Stour SPA Brent goose Shelduck Wigeon Pintail Oystercatcher Ringed plover Grey plover Knot Dunlin Black-tailed godwit Curlew Redshank Turnstone
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Stour-Orwell SPA monitoring 2015/2016
Two species (oystercatcher and turnstone) show declines on one estuary (Stour and Orwell respectively) and three species now show no trends at all in mean numbers after exhibiting weak trends earlier in the monitoring programme (shelduck, dunlin and black-tailed godwit, Table 3).
Recent increasing trends in the mean populations of two species (brent goose and knot) continued and strengthened in the SPA in 2015/2016, mainly owing to increases on the Stour. Trends in peak numbers largely reflected those in the mean populations of most species, and after 2015/2016 six of the 13 species show a declining trend in the peak number recorded in the SPA.
3.2 Brent goose (fig 4A & map 7.1) The population was stable in the SPA until 2006/2007 at around 2000 birds, usually split about equally between the two estuaries, but it has increased steadily on the Stour since 2007. Most birds occur on the Stour, 3000 so this trend is reflected in
the SPA. The peak 2000 population on the Stour in 2015/2016 was 2401 birds Number (December), and was the 1000 highest yet recorded.
Numbers on the Orwell are 0 usually around 700-800 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Winter birds, but the last three
winters have seen mean The peak (solid) and mean (dashed) population of brent goose on populations of 1100-1400, the Stour 1999/2000 (0) to 2015/2016 (16). almost on parity with the Stour, but there is yet to be any trend of significance on the Orwell.
The national population of brent geese declined and then fluctuated throughout the 1990s and early 2000s but has been increasing since 2003/2004 and is currently at its highest level.2 The increasing population of the SPA would therefore appear to reflect these changes. The distribution of geese has been fairly consistent in the SPA – concentrated in the lower reaches of the Orwell (especially Shotley Marshes, Levington and Thorpe Bay), where most birds occurred in 2015/2016, and in the middle of the Stour. Increases on the Stour have been concentrated along the northern shore, especially around Stutton, Holbrook and Wrabness3, although in 2015/2016 there were large numbers in the vicinity of Erwarton.
3.3 Shelduck (fig 4B & map 7.2) Numbers on the Stour and in the SPA in 2015/2016 were similar to those present at the start of monitoring, continuing the oscillating pattern in these populations. Numbers on the Orwell have dropped in recent winters, falling below 400 birds for the second time in the last three winters. However, there are no overall trends in either estuary or the SPA between 1999/2000 and 2015/2016. A longer term (25 years) medium-level alert exists for the shelduck population in the SPA1 as larger populations used to occur in the 1980s and 1990s.
The national population has been in steady decline since the mid 1990s2 in contrast to the relatively stable (but quite small) population in the SPA. The relatively few birds on the Orwell were quite well spread in 2015/2016, as in most previous winters, but the distribution of the population of the Stour is more patchy and, as in most
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Stour-Orwell SPA monitoring 2015/2016
Table 3: The trends in the populations of species after winters 2007/2008 to 2015/2016. Colours denote an increasing (green) or decreasing (red) trend since 1999/2000 and colour intensity indicates trend confidence (weak, medium or high). See methods for detail.
MEAN ORWELL STOUR SPA NUMBERS 07- 08- 09- 10- 11- 12- 13- 14- 15- 07- 08- 09- 10- 11- 12- 13- 14- 15- 07- 08- 09- 10- 11- 12- 13- 14- 15- 08 09 10 11 12 13 14 15 16 08 09 10 11 12 13 14 15 16 08 09 10 11 12 13 14 15 16 Brent goose Shelduck Wigeon Pintail Oystercatcher Ringed plover Grey plover Knot Dunlin Black-t godwit Curlew Redshank Turnstone
PEAK ORWELL STOUR SPA NUMBERS 07- 08- 09- 10- 11- 12- 13- 14- 15- 07- 08- 09- 10- 11- 12- 13- 14- 15- 07- 08- 09- 10- 11- 12- 13- 14- 15- 08 09 10 11 12 13 14 15 16 08 09 10 11 12 13 14 15 16 08 09 10 11 12 13 14 15 16 Brent goose Shelduck Wigeon Pintail Oystercatcher Ringed plover Grey plover Knot Dunlin Black-t godwit Curlew Redshank Turnstone
8
Stour-Orwell SPA monitoring 2015/2016
previous winters, concentrated in the upper reaches around Mistley and Seafield, Copperas and Bathside Bays. There are shifts in the populations from the lowest reaches to the upper sections of the Stour3. Few birds occur between Holbrook Bay and Shotley along the northern shore.
3.4 Wigeon (fig 4C & map 7.3) For the second winter running, there were small increases in the populations of both estuaries after recent decreases, but the 3000 population of the Orwell is
still in strong decline overall 2000 and these patterns have become reflected in the SPA more recently. Number 1000
These trends result partly from the effects of a large 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 peak in the population early Winter in the monitoring
programme, although The peak (solid) and mean (dashed) population of wigeon on the current population levels on Orwell 1999/2000 (0) to 2015/2016 (16). the Orwell (ca.1000-1100 birds) are below those at the start of monitoring (1300 birds). Numbers on the Stour, which form the bulk of the SPA population, have been more stable at around 2000- 2500 birds since 1999/2000.
The population of wigeon in the UK has been stable during the monitoring programme; it increased between 1999 and 2006 and has declined slightly since2 and this pattern broadly similar to that of the SPA population. The distribution of birds in the SPA has changed very little and birds have been distributed throughout both estuaries in most winters, although, as noted after previous winters, a decline is apparent in the upper reaches of the Stour, particularly around Jacques Bay3.
3.5 Pintail (fig 4D & map 7.4) The mean population of pintail shows a declining trend in the SPA for the sixth consecutive winter, although weaker than in previous winters owing to a large mean population on the Stour in 2015/2016 (757 birds were recorded in the February count, easily the highest monthly count since monitoring began). Mean numbers on the Orwell were below 100 birds for the third time in the past four winters, but so far there is little consistency to suggest any long-term trend in this population. The patterns in the SPA are reflected in a medium term (10 year) medium level alert for the species1.
The national population was stable during the early part of the monitoring programme but underwent a sharp decline in the mid 2000s and has been in decline thereafter2. The distribution of birds is very localised in both estuaries – they are found primarily in Copperas Bay, Seafield Bay and on Mistley foreshore on the Stour, with smaller numbers in Holbrook Bay, and in the upper reaches of the Orwell and on Trimley Marshes. The large February influx to the Stour occurred in Copperas and Seafield Bays. Changes in population have occurred in some of the smaller sections, with declines in Deep Fleet, Erwarton and the head of the Stour estuary, while numbers have decreased at Pin Mill and increased on Pond Ooze on the Orwell.3
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Stour-Orwell SPA monitoring 2015/2016
3.6 Oystercatcher (fig 4E & map 7.5) Mean and peak winter numbers of oystercatchers were very stable until recent winters, but declining trends were recorded for 2000 the Stour for the third consecutive winter and 1500 again this was reflected in the SPA peak population 1000 but not its mean population. Number Trends strengthened in 500 2015/2016 and the mean Stour and SPA populations 0 were the lowest yet 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Winter recorded (715 and 2014
birds). By contrast, the The peak (solid) and mean (dashed) population of oystercatchers population on the Orwell on the Stour 1999/2000 (0) to 2015/2016 (16). has been stable during the monitoring programme. Oystercatcher remains the only key species in the SPA with a larger population on the Orwell, and in 2015/2016 this was once again almost exactly double the size of the Stour population (fig. 4E).
The UK population was stable up to the mid-2000s but has been in decline since2 and the population on the Stour (but not the Orwell) reflects this. The distribution on the Orwell is strongly mid and upper estuary and birds on both estuaries have declined in lower sections and increased in upper sections3.
3.7 Ringed plover (fig 4F & map 7.6) Most measures of the population of ringed plover are in decline now in the SPA (all except peak Orwell 800 population) and these trends strengthened in 2015/2016. Mean numbers 600 in the SPA have halved during the last 17 winters; in 400 the last five winters there Number has been 125-190 birds, 200 compared with 250-400 in the early winters of 0 monitoring. The mean 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Winter population of the Stour has
been below 100 birds for The peak (solid) and mean (dashed) population of ringed plover in the past five winters (56-88 the SPA 1999/2000 (0) to 2015/2016 (16). birds). Mean numbers on the Orwell rose above 100 birds for the second time in seven winters, mainly owing to 222 birds that were recorded in the February count (only 38 were recorded in November 2015). A long-term (25 years) high level alert exists for the population in the SPA1.
The declines in the SPA reflect a long-term decline in the UK since the 1980s2. Birds used to be scattered throughout both estuaries, but as also noted after the most recent winters, practically no birds were recorded in the upper estuary of the Orwell, most birds occurring along the mudflats bordering Shotley marshes. On the Stour in 2015/2016, birds were concentrated in Bathside Bay, the middle sections around Holbrook and Wrabness and at the head of the estuary. These patterns
10
Stour-Orwell SPA monitoring 2015/2016
reinforce declines noted in Deep Fleet, Erwarton, Copperas Bay of the Stour and the heads of both estuaries between 1996-2015.3
3.8 Grey plover (fig 4G & map 7.7) The population of the SPA is still in decline and trends strengthened in 2015/2016. This is owed primarily to the 3000 population of the Stour that was stable until about 2007
but has been in steep 2000 decline since. The populations of the Stour Number and SPA over the past five 1000 winters were about 600- 1000 and 800-1300 birds respectively, compared with 0 about 1500-1800 and 1700- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 2100 respectively up to Winter
2007. The small population The mean population of grey plover in the SPA (dashed) and on on the Orwell has remained the Stour (solid) 1999/2000 (0) to 2015/2016 (16). stable throughout monitoring at around 200 birds, although the highest mean population occurred in 2015/2016 (383 birds) owing to a large influx of birds in February (monthly counts were 199, 197, 193 and 942 birds). These patterns are reflected in a medium term (10 year) medium level alert for the species in the SPA1.
The national population of grey plover has fluctuated; it increased to the mid 1990s then decreased, increased again 2004 to 2008 and has been declining since2. The recent pattern in the SPA therefore appears to reflect the national trend. Birds are still well-distributed in the Stour but some local declines are apparent, particularly in Holbrook and Seafield Bays.3 The large influx of birds into the Orwell in February occurred largely in section 30, by Shotley Marshes.
3.9 Knot (fig 4H & map 7.8) The population of the SPA continued its recent increase and this is entirely owing to the population on the Stour that in 2015/2016 recorded its second highest mean population since monitoring 20000 began (10156 birds, with a peak of 12510 in November). By contrast the 15000 lowest mean and peak population was recorded on 10000 the Orwell (191 birds, with Number monthly counts of 39, 35, 5000 74 and an influx of 616 birds in February), after 0 peak counts of 3000-5000 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 birds in the previous five Winter
winters. The peak (solid) and mean (dashed) population of knot in the SPA 1999/2000 (0) to 2015/2016 (16). The UK population has been erratic but overall it appears stable or has undergone a very slight decline since the mid 1990s2. The pattern in the Stour and in the SPA therefore appear unusual. As in most winters, birds on the Stour showed distinct concentrations in 2015/2016: especially in Jacques and Seafield Bays and recently there have also been relatively
11
Stour-Orwell SPA monitoring 2015/2016
large numbers in Erwarton and Bathside Bays. Recent analysis of shifts in distribution in the SPA showed increases only in Holbrook and Jacques Bay3, but the large numbers that occurred in Erwarton and Bathside Bays in 2015/2016 indicate increasing trends in these sections as well. The small population on the Orwell in 2015/2016 was almost entirely concentrated at Nacton and Levington, and not Mulberry Middle where birds have occurred mainly in recent winters.
3.10 Dunlin (fig 4I & map 7.9) The highest mean population since the start of monitoring at just under 5000 birds was recorded on the Orwell in 2015/2016, with the largest monthly peak yet at 6966 birds (January). Coupled with a recovery of numbers on the Stour after a drop in recent winters, the mean population of the SPA was also the highest yet recorded (17166 birds) in 2015/2016, incorporating the largest peak to date (22700 birds in December). But no overall trends in numbers are apparent on either estuary or in the SPA since 1999/2000.
The population in the SPA has been relatively stable during the monitoring programme in contrast to the national population that has been in steady decline since the mid 1990s, although relatively stable in the shorter term since the mid- 2000s2. However, a long-term high level alert (25 years) exists for the dunlin population in the SPA1, reflecting the large populations that used to occur in the 1980s and 1990s. Birds were well distributed on both estuaries at low tide, although few were recorded on the uppermost stretches of the Orwell where there has been decline (especially Pond and Black Ooze and Redgate).3 The increased population on the Orwell in 2015/2016 resulted in larger numbers at Levington, Thorpe Bay and Shotley in addition to the usual concentrations on Mulberry Middle and Nacton foreshore. Birds were well spread on the Stour, although once again there were few in Seafield Bay where a decline has occurred in recent winters.3
3.11 Black-tailed godwit (fig 4J & map 7.10) After a number of winters during which the population of the large and important population of the Stour appeared to be declining (mirrored by an increase on the Orwell), the population in 2000 2015/2016 maintained its recent recovery. The mean population on the Stour 1500 was the second largest yet recorded at 1551 birds, and 1000 the SPA population has Number been at its highest level in 500 the last three winters. The only trend is a continuing 0 weak increase in peak 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 numbers on the Orwell, Winter
presumably owing to birds The mean numbers of black-tailed godwit on the Stour (white) and from the Stour using the Orwell (black) 1999/2000 (0) to 2015/2016 (16). estuary occasionally.
The UK population has been increasing almost year on year and is still increasing2. Birds appear to have become even more concentrated in their favoured areas in the uppermost reaches of the Stour, especially along Mistley foreshore, continuing the long term trends3 and there were almost no birds in the lower reaches of the estuary in 2015/2016. As in most winters, birds were concentrated mainly in the upper reaches of the Orwell, particularly on Redgate and Pond Ooze.
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Stour-Orwell SPA monitoring 2015/2016
3.12 Curlew (fig 4K & map 7.11) The gentle decline in the SPA population continued in 2015/2016 owing to changes in the Orwell population. In the last few winters the latter has been stable at around 500 birds compared with 700-800 birds during the first nine winters of monitoring. There is no sign of any change in the Stour population with numbers consistently about 800-900 birds throughout the monitoring programme.
1500 The relatively shallow declines in the Orwell and
the stable Stour population 1000 contrast with the UK population that has been Number declining since the mid 500 1990s2. Despite the decline, the only significant decreasing trend on the 0 Orwell has occurred on 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Redgate where numbers Winter
have reduced from 40-130 The peak (solid) and mean (dashed) numbers of curlew on the in early winters to 6-16 in Orwell (dashed) 1999/2000 (0) to 2015/2016 (16). recent winters.3. In winter 2015/2016, there were only 8-14 birds on this section.
3.13 Redshank (fig 4L & map 7.12) There was no sign of recovery in the redshank population of the SPA in 2015/2016, and all measures of population continue to be in strong decline in both estuaries. Both the mean and peak 5000 populations of the Stour were the lowest yet recorded (1052 and 1139 4000 birds), and the population on the Orwell exceeded 3000 that of the Stour in Number 2015/2016. Mean numbers 2000 on the Stour have reduced by about 50% since the 1000 start of monitoring and the 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Orwell by about 40%. Winter
The peak (solid) and mean (dashed) numbers of redshank in the The national population of SPA 1999/2000 (0) to 2015/2016 (16). redshank has been stable overall2 but in decline during the period of the monitoring programme and it is possible that the patterns in the SPA reflect this. But a medium level long-term alert (25 years) exists for the population in the SPA1. Birds are still well spread in the 3 SPA, but are declining primarily in the upper and mid-reaches of both estuaries – in Copperas, Holbrook, Jacques and Seafield bays on the Stour and Mulberry Middle and Pond Ooze on the Orwell. These trends appear to have continued in winter 2015/2016 and the only significant concentration remaining on the Orwell appears to be on Redgate. Increasing proportions are using Trimley Marshes and Bathside Bay on the Stour.
3.14 Turnstone (fig 4M & map 7.13) Numbers of turnstone in the SPA have fluctuated since 1999/2000 and in recent winters they have been at levels similar to the start of monitoring. There are no
13
Stour-Orwell SPA monitoring 2015/2016
population trends in the SPA, but the lowest mean SPA population was recorded in 2015/2016 (356 birds) owing to low populations on both estuaries, ad the lowest peak yet recorded occurred on the Orwell in January (110 birds). The national population is in long-term decline, but increased slightly in the period 2004/2005 to 2007/2008 in a similar manner to that recorded in the SPA2.
Nearly the entire population of the Orwell has occurred on Mulberry Middle in recent winters, but birds were more widespread in the mid and lower reaches of the Orwell in 2015/2016, as in the early winters of monitoring. No birds at all occurred in sections above Mulberry Middle in 2015/2016, strengthening the trend of decline in this part of the estuary.3 Distribution on the Stour appears to have altered little since the start of monitoring, occurring primarily in Holbrook, Erwarton and Copperas Bays, although there is a trend towards increasing numbers in Holbrook.3
4. References 1. Cook, A.S.C.P., Barimore, C., Holt, C.A., Read, W.J. & Austin, G.E. 2013. Wetland Bird Survey Alerts 2009/2010: Changes in numbers of wintering waterbirds in the Constituent Counties of the United Kingdom Special Protection Areas (SPAs) and Sites of Special Scientific Interest (SSSIs). BTO Research Report 641. British Trust for Ornithology, Thetford. 2. Frost, T.M., Austin, C.E., Calbrade, N.A., Holt, C.A., Mullan, H.J., Hearn, R.D., Stroud, D.A., Wotton, S.R. & Balmer, D.E. 2016. Waterbirds in the UK 2014/15. The Wetland Bird Survey. BTO/RSPB/JNCC, Thetford. 3. Ravenscroft, N., Meadows, M. & Warner, J. 2016. Changes in the distribution of birds at low water in the Stour and Orwell Estuaries SPA 1996-2015. Harwich Haven Authority & Natural England.
5. Acknowledgements SWT thanks Harwich Haven Authority who fund the counts as part of their commitment to monitor the environment of the Stour and Orwell estuaries, Neil Calbrade and the WeBS team at the BTO who produced the maps used in this report, and all the counters involved in low water count programme.
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Stour-Orwell SPA monitoring 2015/2016
6. Figures
15
Stour-Orwell SPA monitoring 2015/2016
Fig. 1: The features and place names of the Orwell and Stour estuaries at low tide.
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Stour-Orwell SPA monitoring 2015/2016
Fig. 2: The sections of the Orwell estuary used in low water counts.
1
2 21 0 2 4km 18
3 17 40 22 39
41 35 23 37 36 5 38 11 6 12
19 31 32 24 26 25 33
27
28 34 10 29 30
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Stour-Orwell SPA monitoring 2015/2016
Fig. 3: The sections of the Stour estuary used in low water counts.
0 2 4km
28 31 35 39 30 34 27 29 38 40 21 33 24 26 32 36 37
25 1 22 9 17 5 11 23 13 18 10 8 6 4 3 19 15 20 16 12 14 7 2
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Stour-Orwell SPA monitoring 2015/2016
Fig. 4: The mean (± SEs) and peak numbers of the principal bird species on the Orwell (●), Stour (○) and whole SPA (■) in winters 1999-2000 (0) to 2015/2016 (16).
4A Brent goose Means Peaks
4000 5000
4000 3000
3000 2000 2000
1000 1000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4B Shelduck Means Peaks
4000 5000
4000 3000
3000 2000 2000
1000 1000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4C Wigeon Means Peaks
6000 8000
6000 4000
4000
2000 2000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4D Pintail Means Peaks
800 1000
600 750
400 500
200 250
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
19 Stour-Orwell SPA monitoring 2015/2016
Fig. 4 (contd):
4E Oystercatcher Means Peaks
4000 4000
3000 3000
2000 2000
1000 1000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4F Ringed plover Means Peaks
450 800
600 300
400
150 200
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4G Grey plover Means Peaks
3000 3000
2000 2000
1000 1000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4H Knot Means Peaks
15000 20000
15000 10000
10000
5000 5000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
20 Stour-Orwell SPA monitoring 2015/2016
Fig. 4 (contd):
4I Dunlin Means Peaks
20000 24000
15000 18000
10000 12000
5000 6000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4J Black-tailed godwit Means Peaks
2500 4000
2000 3000
1500 2000 1000
1000 500
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4K Curlew Means Peaks
2500 3000
2000
2000 1500
1000 1000
500
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
4L Redshank Means Peaks
5000 5000
4000 4000
3000 3000
2000 2000
1000 1000
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
21 Stour-Orwell SPA monitoring 2015/2016
Fig. 4 (contd):
4M Turnstone Means Peaks
900 900
600 600
300 300
0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
22 Stour-Orwell SPA monitoring 2015/2016
7. Distribution maps of mean winter numbers for principal species 1999/2000 (or earliest map available) and 2015/2016. Maps for intervening winters were included in the appropriate annual report.
Key Blue: low water Yellow: mudflats Green: Hinterland count sections (saltmarsh, grazing marsh) within the SPA
1 dot is one bird (one dot is two birds for dunlin and knot)
23 Stour-Orwell SPA monitoring 2015/2016
7.1 Brent goose
1999-2000
2015-2016
24 Stour-Orwell SPA monitoring 2015/2016
7.2 Shelduck
1999-2000
2015-2016
25 Stour-Orwell SPA monitoring 2015/2016
7.3 Wigeon
1999-2000
2015-2016
26 Stour-Orwell SPA monitoring 2015/2016
7.4 Pintail
1999-2000
2015-2016
27 Stour-Orwell SPA monitoring 2015/2016
7.5 Oystercatcher
2000-2001
2015-2016
28 Stour-Orwell SPA monitoring 2015/2016
7.6 Ringed plover
1999-2000
2015-2016
29 Stour-Orwell SPA monitoring 2015/2016
7.7 Grey Plover
1999-2000
2015-2016
30 Stour-Orwell SPA monitoring 2015/2016
7.8 Knot (1 dot = 2 birds)
1999-2000
2015-2016
31 Stour-Orwell SPA monitoring 2015/2016
7.9 Dunlin (1 dot = 2 birds)
1999-2000
2015-2016
32 Stour-Orwell SPA monitoring 2015/2016
7.10 Black-tailed godwit
1999-2000
2015-2016
33 Stour-Orwell SPA monitoring 2015/2016
7.11 Curlew
1999-2000
2015-2016
34 Stour-Orwell SPA monitoring 2015/2016
7.12 Redshank
1999-2000
2015-2016
35 Stour-Orwell SPA monitoring 2015/2016
7.13 Turnstone
2000-2001
2015-2016
36 Stour-Orwell SPA monitoring 2015/2016
8. Appendices
1. Orwell low tide data 2015/2016 2. Stour low tide data 2015/2016
37 Stour-Orwell SPA monitoring 2015/2016
Appendix 1: Orwell data 2015/2016
20.11.2015 1 2 21 3 22 23 5 6 19 24 25 26 27 28 29 30 10 11 12 31 32 33 34 35 36 37 38 39 40 41 17 18 Total Little Grebe 2 3 3 2 1 2 11 24 Great C Grebe 7 2 1 6 6 2 13 18 17 1 73 Cormorant 1 1 4 2 1 5 1 35 7 1 27 2 87 Little Egret 1 3 2 2 1 6 1 1 2 5 3 1 2 30 Grey Heron 10 2 1 1 5 6 1 3 1 1 1 6 38 Mute Swan 4 2 2 4 11 3 26 Greylag Goose 81 2 182 6 271 Canada Goose 116 3 36 73 110 1 339 DB Brent Goose 4 93 680 11 100 17 8 913 Shelduck 4 20 3 10 3 13 40 6 13 5 117 Wigeon 2 154 16 92 109 34 22 35 196 304 20 52 29 1065 Gadwall 1 35 33 69 Teal 33 17 935 237 1222 Mallard 2 2 11 4 25 68 5 68 185 Pintail 40 19 1 27 24 4 115 Shoveler 1 85 86 Pochard 9 11 20 Tufted Duck 11 23 34 Goldeneye 5 7 12 RB Merganser 2 2 17 21 Water Rail 1 1 Moorhen 4 4 7 1 1 17 Coot 2 1 158 102 263 Oystercatcher 1 1 15 14 32 29 2 16 21 5 7 4 294 589 275 64 1369 Avocet 1 1 1 42 19 53 1 10 128 Ringed Plover 26 5 3 4 38 Golden Plover 2 2 Grey Plover 14 3 17 2 5 2 9 94 53 199 Lapwing 16 68 1 117 46 81 323 183 835 Knot 15 24 39 Dunlin 1 53 56 33 220 322 799 4 1488 Snipe 3 1 4 Black-t Godwit 6 15 77 17 20 1 4 39 1 7 1 14 295 9 506 Bar-t Godwit 24 1 25 Curlew 2 14 13 4 19 16 58 4 13 1 2 21 34 121 115 67 5 509 Redshank 98 37 278 65 19 28 72 17 35 46 2 3 91 72 132 135 142 1272 Turnstone 2 8 46 2 4 14 76 Kingfisher 1 1 2 Black Swan 1 1
38 Stour-Orwell SPA monitoring 2015/2016
18.12.2015 1 2 21 3 22 23 5 6 19 24 25 26 27 28 29 30 10 11 12 31 32 33 34 35 36 37 38 39 40 41 17 18 Total Great N Diver 2 1 1 4 Little Grebe 2 6 1 6 2 17 Great C Grebe 6 26 2 5 2 4 1 2 5 13 18 2 86 Cormorant 21 3 1 1 8 3 7 5 3 52 Little Egret 1 2 4 3 2 4 2 1 1 20 Grey Heron 14 6 2 1 2 1 3 1 1 4 35 Mute Swan 1 2 3 6 Greylag Goose 6 1 513 520 Canada Goose 178 72 26 276 DB Goose 5 28 497 62 193 80 314 1179 Shelduck 23 6 82 6 24 16 3 7 29 20 6 59 95 14 390 Wigeon 4 53 14 40 225 23 43 357 368 79 9 115 16 1346 Gadwall 25 35 60 Teal 6 15 786 305 1112 Mallard 28 2 3 27 132 59 251 Pintail 19 16 4 14 9 62 Shoveler 74 74 Pochard 13 22 35 Tufted Duck 13 53 66 Goldeneye 4 7 1 4 5 6 8 4 39 RB Merganser 1 4 7 10 8 3 33 Moorhen 3 2 6 3 14 Coot 2 9 2 38 86 137 Oystercatcher 4 5 2 6 34 6 6 5 30 7 7 3 200 803 260 39 1417 Avocet 4 38 19 35 96 Ringed Plover 8 1 20 82 111 Golden Plover 90 90 Grey Plover 7 12 27 4 3 1 48 52 43 197 Lapwing 155 47 84 4 33 522 201 1046 Knot 14 12 8 1 35 Dunlin 3 10 32 32 290 435 940 2630 1226 5598 Jack Snipe 1 1 Black-t Godwit 9 27 135 9 28 1 5 156 5 375 Bar-t Godwit 31 31 Curlew 3 9 12 7 10 42 20 8 4 10 18 47 72 2 166 39 9 478 Spotted Redshank 17 17 Redshank 6 62 32 500 115 33 28 72 16 53 39 1 78 84 112 46 1277 Turnstone 1 2 3 1 16 8 20 31 82 Kingfisher 1 1 1 3
39 Stour-Orwell SPA monitoring 2015/2016
18.1.2016 1 2 21 3 22 23 5 6 19 24 25 26 27 28 29 30 10 11 12 31 32 33 34 35 36 37 38 39 40 41 17 18 Total Great Northern Diver 1 1 Little Grebe 4 1 1 2 5 9 22 Great Crested Grebe 3 9 2 1 1 12 8 13 28 3 80 Cormorant 2 6 5 9 3 1 7 1 7 17 5 2 8 73 Little Egret 1 1 4 1 1 1 2 1 12 Grey Heron 1 2 10 1 1 1 1 17 Mute Swan 7 2 3 2 4 18 Greylag Goose 1 246 52 299 Canada Goose 26 5 36 50 117 Dark-bellied Brent Goose 375 82 632 16 106 1211 Shelduck 2 55 6 4 76 14 9 2 45 2 31 22 93 51 30 442 Wigeon 43 120 36 27 103 112 2 684 285 2 1 1415 Gadwall 11 29 40 Teal 13 129 183 2 648 173 1148 Mallard 24 4 9 96 3 43 179 Pintail 29 37 18 38 122 Shoveler 93 93 Pochard 17 42 59 Tufted Duck 23 29 52 Goldeneye 15 3 1 1 3 6 6 8 43 Red-breasted Merganser 10 3 1 2 2 18 Moorhen 6 7 4 17 Coot 5 9 36 28 78 Oystercatcher 4 2 4 51 7 6 14 29 3 5 1 151 738 345 55 1415 Avocet 48 10 6 8 30 24 126 Ringed Plover 14 53 10 1 12 10 100 Golden Plover 100 100 Grey Plover 3 1 10 26 2 6 1 20 98 26 193 Lapwing 6 227 1 1 1 9 104 3 17 273 60 190 8 1 1 4 906 Knot 20 5 1 30 13 5 74 Dunlin 4 117 4 290 2 404 950 4858 330 7 6966 Snipe 1 4 2 7 Black-tailed Godwit 1 2 2 14 19 Curlew 1 2 14 18 4 17 52 44 2 11 1 1 16 11 25 102 5 132 57 5 520 Redshank 1 34 51 441 63 31 8 52 28 38 98 10 4 60 20 135 62 148 1284 Greenshank 1 1 Turnstone 2 8 5 2 19 1 12 26 35 110 Kingfisher 1 1 1 1 4
40 Stour-Orwell SPA monitoring 2015/2016
16.2.2016 1 2 21 3 22 23 5 6 19 24 25 26 27 28 29 30 10 11 12 31 32 33 34 35 36 37 38 39 40 41 17 18 Total GN Diver 1 1 Little Grebe 6 1 5 1 7 2 14 36 GC Grebe 8 1 2 2 3 8 2 1 4 3 3 10 12 59 Cormorant 1 17 41 2 1 1 63 Little Egret 1 1 2 1 2 1 1 9 Grey Heron 2 1 3 2 1 4 2 1 16 Mute Swan 4 4 1 2 2 2 2 3 20 Greylag Goose 7 3 6 1 13 131 11 172 Canada Goose 17 37 12 12 10 34 3 8 13 146 DB Goose 465 380 349 1194 Shelduck 8 15 108 28 25 36 3 5 16 11 62 72 189 11 589 Wigeon 6 18 32 42 72 81 12 30 156 41 2 260 90 5 45 8 24 924 Gadwall 9 42 5 56 Teal 35 144 26 16 238 130 589 Mallard 16 1 11 48 42 118 Pintail 2 6 76 84 Shoveler 112 112 Pochard 10 18 2 30 Tufted Duck 36 37 73 Goldeneye 1 1 2 3 2 2 15 3 29 RB Merganser 5 5 3 2 2 3 1 24 45 Water Rail 2 1 3 Moorhen 3 2 4 3 12 Coot 5 31 56 92 Oystercatcher 4 5 9 9 69 9 14 5 18 1 5 2 206 225 355 61 997 Avocet 29 28 7 3 11 45 123 Ringed Plover 18 25 120 12 47 222 Golden Plover 70 200 270 Grey Plover 11 4 640 3 5 3 35 14 227 942 Lapwing 180 23 246 17 130 55 7 14 672 Knot 2 550 53 11 616 Dunlin 52 50 1280 10 499 1800 360 1371 5422 Snipe 5 23 28 Black-t Godwit 15 144 83 15 1 3 2 10 3 1 7 18 302 Bar-t Godwit 32 4 67 103 Curlew 1 3 4 8 16 4 16 16 1 58 1 8 3 1 20 26 175 2 185 41 12 601 Redshank 1 46 1 22 443 94 38 33 46 5 59 53 1 93 31 61 18 81 1126 Greenshank 1 1 Turnstone 3 7 19 1 7 1 5 43
41 Stour-Orwell SPA monitoring 2015/2016
Appendix 2: Stour data 2015/2016
20.11.2015 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Total Great N Diver 1 1 2 Little Grebe 3 20 2 25 Great C Grebe 2 4 1 2 1 8 2 6 3 1 7 1 1 25 22 4 24 27 3 8 2 12 11 1 1 2 181 Slavonian Grebe 1 1 Cormorant 2 1 2 3 2 1 5 8 1 2 3 2 1 2 35 Shag 1 1 Little Egret 2 2 1 2 2 3 3 1 3 4 1 1 2 6 2 2 4 1 3 1 1 2 10 1 1 2 2 1 1 67 Grey Heron 1 4 2 1 1 1 2 2 1 15 Mute Swan 16 2 3 5 5 104 15 17 29 196 Canada Goose 1 33 34 DB Brent Goose 215 11 24 4 38 19 28 44 44 59 25 33 119 9 11 76 5 9 62 74 75 10 94 31 42 40 40 16 91 74 350 49 1821 Shelduck 30 34 42 77 52 11 34 58 33 17 483 34 98 2 13 11 6 16 6 1057 Wigeon 7 18 3 6 65 145 30 84 1 79 21 3 28 26 146 139 125 72 95 10 24 141 560 47 18 235 226 73 31 2458 Teal 107 240 14 11 25 61 1 10 220 10 36 35 4 49 8 49 19 86 185 282 1452 Mallard 50 47 4 22 1 2 2 33 9 19 32 17 21 259 Pintail 117 5 12 11 1 116 49 311 Shoveler 1 1 Goldeneye 1 1 1 12 1 4 2 3 9 11 27 2 74 RB Merganser 2 5 8 4 3 2 6 15 3 5 11 9 10 83 Moorhen 6 6 Coot 3 3 Oystercatcher 4 2 2 40 19 17 11 2 3 40 4 13 14 6 4 36 92 25 2 18 7 44 2 2 4 11 39 33 41 34 8 34 20 33 15 681 Avocet 33 8 1 20 20 58 32 33 15 17 237 Ringed Plover 10 17 17 1 2 47 Golden Plover 302 140 895 1337 Grey Plover 40 10 33 5 8 40 121 27 15 9 7 6 12 16 14 2 12 3 41 29 6 32 2 10 3 16 65 79 7 6 3 4 25 7 9 724 Lapwing 11 35 14 327 24 155 5 336 293 27 10 150 50 120 192 1749 Knot ## 1 20 173 1473 20 301 7 321 700 49 320 180 1665 6080 12510 Sanderling 7 250 257 Dunlin 734 28 4 1 670 504 1010 2 5 491 563 1286 220 119 104 25 86 40 68 242 245 370 740 53 3 312 697 14 8636 Jack Snipe 2 2 Snipe 1 2 1 3 7 Black-t Godwit 4 13 2 15 2 13 26 15 6 365 1 2 24 132 7 81 2 14 77 2 1 4 18 2 15 5 1 849 Bar-t Godwit 6 11 2 7 76 8 110 Curlew 15 14 26 4 11 12 24 37 24 8 4 2 23 8 52 4 27 10 3 9 49 12 35 8 23 6 21 36 66 43 16 10 6 13 11 8 680 Redshank 86 21 41 1 3 4 22 56 10 12 9 10 1 26 14 12 33 9 79 5 40 26 10 52 20 60 7 13 26 25 91 86 16 28 9 20 16 19 12 1030 Greenshank 1 1 2 4 Green Sandpiper 1 1 Turnstone 5 3 1 3 16 4 1 7 11 4 10 3 1 2 56 6 27 21 7 7 22 35 10 262 Kingfisher 1 1 Black Swan 3 3
42 Stour-Orwell SPA monitoring 2015/2016
18.12.2015 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Total Black-throated Diver 1 1 Great N Diver 1 1 Little Grebe 12 8 4 24 Great C Grebe 3 2 2 2 1 2 2 4 6 14 9 8 3 1 1 7 10 4 15 3 10 7 8 3 5 5 5 142 Slavonian Grebe 2 2 Black-necked Grebe 1 1 Cormorant 1 1 2 2 2 4 1 2 6 2 3 2 2 2 2 4 6 9 1 1 5 2 2 2 1 67 Shag 1 1 2 Little Egret 1 1 1 1 2 1 2 1 1 2 4 4 1 4 1 1 1 1 1 2 4 1 3 2 1 44 Grey Heron 2 4 3 1 1 1 12 Mute Swan 26 4 155 1 4 190 Canada Goose 16 30 46 DB Brent Goose 1 2 1 2 2 1 35 9 47 20 6 131 9 34 4 5 323 176 24 53 167 34 5 40 103 6 2 22 377 760 2401 Egyptian Goose 2 2 Shelduck 125 2 2 32 78 56 66 11 15 9 136 70 99 37 7 19 2 224 5 126 74 15 14 28 4 28 69 1 1 8 1 1364 Wigeon 26 7 16 35 10 5 4 254 123 81 46 12 29 19 1 42 30 164 21 114 32 64 68 81 24 106 42 21 270 530 28 19 2324 Teal 64 217 1 20 34 120 12 26 94 149 134 69 4 4 79 7 186 299 129 1648 Mallard 58 8 18 28 35 4 12 20 2 2 13 28 49 277 Pintail 1 12 208 6 9 2 17 46 22 31 59 38 451 Shoveler 3 3 Eider 1 1 1 3 Goldeneye 1 1 1 1 2 1 7 2 2 12 3 3 3 41 4 10 1 2 4 11 3 115 RB Merganser 2 2 2 11 8 9 14 9 34 1 2 1 2 2 9 6 114 Moorhen 4 4 Coot 2 2 Oystercatcher 12 9 3 2 27 23 18 15 3 11 3 51 8 19 8 109 151 48 1 2 1 8 7 61 32 6 28 3 59 43 35 31 2 13 5 23 18 898 Avocet 32 103 78 213 Ringed Plover 25 12 4 1 18 60 Grey Plover 31 7 8 2 1 12 7 11 15 6 14 46 36 51 13 1 6 2 1 115 95 54 335 39 31 65 2 4 7 9 2 1028 Lapwing 2 90 89 94 2 348 198 148 10 422 235 219 48 170 137 98 138 80 2528 Knot ## 3217 315 137 89 105 121 17 85 230 920 3200 9696 Dunlin 521 111 38 354 730 800 330 1 116 1460 1084 873 300 9 61 40 10 12 220 1500 350 731 1441 159 1070 233 1048 3500 17102 Jack Snipe 2 4 6 Snipe 1 4 5 Black-t Godwit 7 10 1 32 1 4 1 8 15 11 160 300 663 48 174 71 60 1 57 9 23 2 1658 Bar-t Godwit 16 13 4 5 5 36 1 11 46 60 197 Curlew 28 10 28 4 9 16 21 37 24 9 3 3 12 53 46 68 33 51 6 1 5 10 34 12 33 25 83 28 11 59 41 17 5 9 11 67 13 12 937 Redshank 88 14 113 6 28 23 49 28 41 29 4 30 13 82 89 9 33 3 4 58 60 58 3 35 91 12 33 3 31 3 33 13 1119 Greenshank 1 1 1 3 3 23 55 18 105 Turnstone 2 1 10 1 23 2 5 3 12 4 46 64 5 15 10 203 Kingfisher 1 1 2 Black Swan 3 3
43 Stour-Orwell SPA monitoring 2015/2016
18.1.2016 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Total Great N Diver 1 1 Little Grebe 27 7 34 Great C Grebe 2 2 3 8 2 1 3 7 9 16 16 3 2 21 2 1 10 9 7 2 8 9 1 4 4 1 153 Slavonian Grebe 2 5 7 Cormorant 1 2 1 1 5 3 1 2 2 3 1 8 1 1 6 1 1 5 2 3 2 52 Little Egret 1 1 1 1 4 1 2 2 1 2 16 Grey Heron 1 1 Mute Swan 15 1 2 132 150 Greylag Goose 3 3 Canada Goose 122 122 DB Brent Goose 30 1 1 53 26 16 65 2 6 2 2 240 33 329 145 32 983 Egyptian Goose 2 1 3 Shelduck 202 2 7 8 73 80 30 28 3 3 31 3 37 22 43 57 2 19 477 17 156 43 75 49 110 126 27 27 5 1762 Wigeon 67 41 24 10 15 7 83 33 82 80 12 13 23 785 8 81 122 2 38 59 53 150 380 140 2308 Gadwall 2 2 Teal 156 112 19 42 43 321 95 145 35 34 135 397 27 149 6 2 10 4 46 14 119 480 190 2581 Mallard 71 4 4 35 7 22 2 4 3 32 35 9 228 Pintail 1 196 12 88 16 28 341 Scaup 1 1 Eider 1 1 Goldeneye 2 1 1 3 2 1 20 2 6 4 14 1 35 9 5 12 6 2 126 RB Merganser 1 2 5 17 15 3 3 9 4 3 2 1 3 2 14 21 8 1 114 Moorhen 6 5 11 Coot 9 9 Oystercatcher 21 2 3 1 21 21 19 14 2 1 14 6 41 27 10 73 16 5 20 2 105 23 12 43 11 35 57 11 34 4 7 4 2 16 683 Avocet 34 3 10 4 39 43 133 Ringed Plover 53 1 3 2 11 7 5 19 11 2 2 2 118 Golden Plover 1 25 82 108 Grey Plover 8 10 16 3 104 61 11 6 2 9 7 1 73 25 2 3 3 54 200 59 180 71 12 106 3 4 12 6 10 1061 Lapwing 11 2 8 5 15 2 3 1 57 5 1 110 Knot 3 485 106 1 890 3309 530 250 1195 85 3 3000 9857 Sanderling 11 11 Dunlin 685 83 147 57 54 440 106 8 20 14 3 126 1968 643 43 79 337 4 3 123 1000 650 510 1230 263 230 795 12 33 25 1635 454 11780 Snipe 1 1 1 1 5 9 Black-t Godwit 12 1 1 7 4 2 1 2530 2 47 33 1 2641 Bar-t Godwit 1 17 9 14 1 15 29 12 3 3 4 108 Curlew 27 15 26 2 7 15 22 37 17 26 9 3 8 18 61 40 10 9 2 9 16 11 10 76 82 23 35 34 42 33 12 7 8 8 11 15 786 Redshank 130 21 43 27 11 29 5 10 24 6 2 13 2 30 17 22 11 21 28 40 25 9 36 31 12 12 21 20 62 55 55 1 34 1 10 22 5 19 922 Greenshank 1 3 1 1 6 Turnstone 20 27 7 20 8 12 1 30 5 2 6 58 24 18 57 1 12 14 20 34 376 Black Swan 4 4
44 Stour-Orwell SPA monitoring 2015/2016
16.2.2016 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Total Little Grebe 12 3 21 6 42 Great C Grebe 1 2 1 1 3 4 1 4 9 11 2 1 4 2 4 19 24 7 3 3 2 1 5 1 115 Slavonian Grebe 1 4 5 Cormorant 1 1 1 1 1 5 3 1 4 1 1 1 2 1 1 1 26 Shag 1 1 Little Egret 1 2 1 1 1 1 2 9 Grey Heron 1 1 1 1 1 5 Mute Swan 16 4 1 114 135 Canada Goose 2 2 DB Brent Goose 4 2 2 4 2 4 34 152 6 3 3 140 255 2 3 530 32 4 130 1312 Shelduck 225 7 5 4 32 44 68 22 6 17 30 91 157 27 20 112 2 28 5 221 9 7 72 69 36 13 58 19 35 6 27 4 1478 Wigeon 86 30 163 7 4 13 2 4 4 91 105 38 117 3 40 12 28 2 611 10 5 63 14 108 71 27 108 12 70 62 50 94 15 2069 Gadwall 2 2 Teal 15 160 8 23 3 1 2 3 53 52 132 80 10 24 101 103 5 194 41 40 4 77 27 135 20 120 1433 Mallard 52 12 1 2 24 8 2 2 5 10 2 16 6 16 158 Pintail 1 3 88 24 311 19 18 68 2 118 22 52 28 3 757 Shoveler 2 2 Pochard 1 1 Eider 1 1 Goldeneye 1 1 10 7 4 3 7 6 16 4 46 6 8 5 13 6 5 148 RB Merganser 1 1 2 18 5 10 3 7 5 1 4 6 4 8 13 6 1 1 96 Moorhen 9 2 11 Oystercatcher 15 3 7 8 13 14 6 4 3 8 2 33 18 8 4 5 18 2 15 2 3 88 77 2 11 8 42 42 24 44 11 21 6 9 22 598 Avocet 27 3 8 8 4 126 97 273 Ringed Plover 55 2 4 20 1 1 1 6 90 Golden Plover 36 36 Grey Plover 9 15 57 23 63 40 14 9 3 1 18 59 64 32 1 2 76 28 20 48 68 56 41 14 8 8 9 27 813 Lapwing 9 113 2 74 89 168 253 97 145 1 20 971 Knot 1 22 1 8 2 1377 262 3000 1200 48 50 1500 240 850 8561 Sanderling 2 2 Dunlin 540 370 460 136 6 160 125 260 24 3 80 84 1783 958 32 3 156 19 2 3 15 46 790 93 387 726 800 540 265 108 138 360 1750 450 11672 Jack Snipe 1 1 Snipe 9 2 5 4 20 Black-t Godwit 6 4 16 3 2 3 36 19 258 19 9 10 9 3 29 289 40 134 33 86 41 1 1 1 4 1056 Bar-t Godwit 2 9 8 7 2 2 3 8 6 6 3 4 60 Curlew 31 10 22 7 11 13 22 17 32 25 3 2 25 4 41 51 16 16 8 1 6 16 6 10 96 87 21 10 57 39 41 13 16 6 32 10 9 832 Redshank 89 18 5 8 15 10 6 6 21 2 5 1 33 5 39 21 1 13 11 88 63 11 43 35 13 106 88 49 22 85 58 47 30 11 35 21 7 18 1139 Turnstone 2 2 1 19 15 1 23 6 18 4 1 3 3 57 21 17 23 6 25 26 273 Kingfisher 1 1 1 3 Black Swan 1 5 6
45
Changes in the distribution of birds at low water in the Stour and Orwell Estuaries SPA 1996-2015.
February 2016
Neil Ravenscroft Mike Meadows Jim Warner Wildside Ecology Natural England Harwich Haven Authority Bramley Cottage Dragonfly House Harbour House Blaxhall 2 Gilders Way The Quay Suffolk Norwich Harwich IP12 2DX NR3 1UB CO12 3HH
Summary 1. The Stour and Orwell estuaries are wintering grounds for an important assemblage of waders and wildfowl. Counts of the bird populations occurring at low tide started in the 1980s, and a programme of annual simultaneous low tide counts commenced in 1999 as part of a scheme to monitor the environment of the estuaries.
2. The populations of several species have changed since monitoring began and there is concern about altering estuarine conditions. To date, no assessment of patterns in bird distribution within the estuaries has been undertaken to identify where changes have occurred.
3. This study represents the first step towards pinpointing areas of concern within the estuaries and to determining the potential causes of any changes in the distribution of species. It undertakes a simple analysis of the numbers of 13 species occurring within 37 sections of the Stour and Orwell between 1996 and 2015.
4. Maps show where there are trends in bird populations within the estuaries and these are presented alongside maps of winter populations for each species. Data are provided as an information source for estuarine managers and for further development, and no attempt is made to interpret or explain any changes in the distributions of birds that are highlighted.
1 Contents
Summary 1
1 Introduction 3
2 Methods Count data 3 Consistency of data 4 Count sections 4 Analyses 5 Presentation 5 Interpretation 5
3 Results (hyperlinks) 1. Brent goose 7 2. Shelduck 8 3. Wigeon 9 4. Pintail 10 5. Oystercatcher 11 6. Ringed plover 12 7. Grey plover 13 8. Knot 14 9. Black-tailed godwit 15 10. Dunlin 16 11. Curlew 17 12. Redshank 18 13. Turnstone 19 14. All species: trends in winter section populations 1996-2015 20 15. All species: trends in section proportions of estuary populations 1996-2015 21 16. Cumulative trends 22
Appendices (hyperlinks) Appendix 1: Low water count sections of the Orwell and Stour estuaries 23 Appendix 2: Statistical analysis 24 Appendix 3: Expanded arrays of significant relationships 25 Appendix 4: Raw section data 28
2 1 Introduction The Stour and Orwell estuaries together support an assemblage of breeding and wintering birds that is internationally important. They are designated individually as Sites of Special Scientific Interest and together as both a Special Protection Area (under the European Birds Directive (2009/147EC)) and a wetland of international importance under the Ramsar Convention 1971, and form part of the network of Natura 2000 European Marine Sites. They are also a major component of the Suffolk Coast and Heaths Area of Outstanding Natural Beauty. Counts of birds at low water within the estuaries have been ongoing since the 1980s. Simultaneous low water winter counts of both estuaries were included in the Mitigation and Monitoring Package of Harwich Haven Authority (HHA) that was associated with the deepening of the approach channel to the harbour in 1998-2000. These counts have been conducted each winter since 1999/2000 in a programme that also includes surveys of sediment and the invertebrate faunas of the estuaries. Counts during the 1980s and 1990s were primarily of the Orwell and undertaken by Suffolk Wildlife Trust (SWT). Annual reports of the HHA bird monitoring programme in the SPA have summarised the low tide status of bird populations within each estuary and the SPA since 2000, and provide ongoing indications of overall population trends after each winter. To date, the mean winter numbers of seven species have declined and two species have increased in one or both estuaries since the first winter’s monitoring. The causes of all of these changes are unknown, but some reflect changes in the national populations of species. The annual reports also include maps of overall winter distribution for each species within each estuary. Comparisons of maps from different winters provide subjective assessments of altered distributions from year to year, but these do not permit confident evaluations of where changes in a particular species have taken place. Such assessments might provide initial indications of changing estuarine conditions, as there is concern over the potential impact from a number of sources, including disturbance. This study was commissioned by Harwich Haven Authority and Natural England to examine where changes have occurred in the distributions of 13 species within the SPA since the 1990s. A simple analysis of trends within the count sections of each estuary was undertaken for the period 1996-2015. Two aspects of the data were examined: 1) trends in the absolute numbers of birds using each section; and 2) trends in the proportion of the whole estuary population using each section. This study is the first step towards determining the potential causes of any altered distributions of species at low tide within the estuaries. Maps are presented showing the distribution of trends in each estuary for each species. Results are provided as information for users, managers and as a basis for further investigation and no attempt is made to interpret or explain highlighted trends. Factors affecting the distribution of birds within an estuary are extremely complex.
2 Methods Count data Low water data for both estuaries was available for all winters between and including 1999/2000 and 2014/15 via the programme of counts that were commissioned by HHA. Earlier data exists from counts by SWT of the Orwell (all winters since 1984 bar 1986/87, 1987/88 and 1993/94) but only sporadic low water counts of the Stour have been undertaken since 1984 (between 1988/89 and 1992/93 and in 1996/97). Only count data starting from 1994 were available to this study through the Wetland Bird Survey (WeBS) database of the British Trust for Ornithology (BTO). Owing to the availability of data, a simultaneous start date for analyses was set to 1996/97. Therefore, data was composed of a continuous sequence of 19 winters for the Orwell (1996/97 to 2014/15) and a broken sequence including 17 winters for the Stour (1996/97 and 1999/2000 to 2014/15).
3 Consistency of data Four counts were undertaken in each winter during the period of the HHA programme (1999-2015), composed of one per month from November to February. Counts before 1999 spanned a broader winter period, some starting as early as September and ending in March. Two counts per month were also undertaken in some winters. To be consistent with the HHA Table 1: Number of complete counts available in the winter counts that form the months November-February. majority of the dataset,
Winter Estuary5B No.6B Months Estuary7B No.8B Months only individual counts 1996/97 Orwell 3 DJF Stour 2 DF undertaken within the four 1997/98 Orwell 5 NDJJF month period of November 1998/99 Orwell 3 DJF 1999/00 Orwell 4 NDJF Stour 3 NJF to February were 2000/01 Orwell 4 NDJF Stour 3 DJF extracted 2001/02 Orwell 4 NDFF Stour 4 NDFF from the data for earlier 2002/03 Orwell 4 NDJF Stour 4 NDJF winters. 2003/04 Orwell 4 NDJF Stour 4 NDJF 2004/05 Orwell 2 DF Stour 4 NDJF Furthermore, only 2005/06 Orwell 3 NDJ Stour 4 NDJF complete counts occurring 2006/07 Orwell 4 NDJF Stour 4 NDJF in November to February 2007/08 Orwell 3 NDF Stour 2 DF were used in analyses 2008/09 Orwell 4 NDJF Stour 3 NDJ 2009/10 Orwell 3 NFF Stour 4 NDFF (Table 1). It was 2010/11 Orwell 3 NDJ Stour 4 NDJF necessary to exclude 2011/12 Orwell 3 NDF Stour 4 NDJF counts with missing 2012/13 Orwell 3 NDF Stour 2 NJ sections as analyses 2013/14 Orwell 4 NDJF Stour 3 NDF required an accurate total 2014/15 Orwell 3 NDJ Stour 3 DJF of the estuary population for each species.
Count sections Orwell. Counts were performed in 18 sections of the Orwell until 1999, when there was a change to their nomenclature and a further 14 sections were added to bring the total to 32 (see appendix 1). These additional sections were effectively sub- divisions of eight of the Fig. 1: original sections to Current formalise the counting of count hinterland. sections of the Stour For this study, count data and Orwell from these additional (top) and sections were combined after with their original parent
consolidation sections for all Orwell for the counts from 1999 onwards analyses (fig. 1). This made them (bottom). compatible with earlier For detail of counts that used only 18 count sections, as the reverse sections see could not be effected. In appendix 1. practice, there are usually few birds in these
hinterland sections, with the occasional exception of ducks and geese.
4 Furthermore, one count section (section A1 or 1, comprising open water at the docks in Ipswich, see appendix 1) was not always counted in early winters and this section was removed from the dataset. This will not have compromised the dataset as this section usually contained no bird species of interest to this study – any present were waterborne species. A further section (D3 or 12, Trimley Lake) that usually contained small numbers of wildfowl, was combined with the neighbouring intertidal section (D2 or 11, Thorpe Bay). Therefore, analyses of changes in distribution within the Orwell were undertaken for 16 divisions of the estuary. Stour. Winter counts on the Stour have been conducted in the same 40 sections in all winters (fig. 1). Many sections are small and contain relatively few birds (particularly those along the southern shore). Adjacent sections were merged in these areas, primarily to provide sufficient data for analyses, but also to provide sections of similar size throughout the estuary and because these sections formed obvious geographic features. This process produced 21 sections for analyses from the original 40 (fig. 1). Analyses Analyses examined the populations of 13 species – brent goose, shelduck, wigeon, pintail, oystercatcher, ringed plover, grey plover, knot, dunlin, black-tailed godwit, curlew, redshank and turnstone. Two aspects of population data were examined for each of these in the 37 sections of the two estuaries between 1996 and 2015 (19 winters for the Orwell and 17 for the Stour): A. The trend (increasing, decreasing or no change) in the mean winter population in each section between 1996/97 and 2014/15, i.e. the absolute numbers of birds using each section in isolation. B. The trend (increasing, decreasing or no change) in the proportion of the whole estuary population using each section between 1996/97 and 2014/15. Estuary populations have not remained stable for most species and may be changing for reasons not attributable to the environments of the estuaries, such as summer breeding success and weather. This analysis shows trends in section use with variations in overall estuary population moderated (although changes in whole populations may in themselves affect the distribution of birds owing to subsequent behavioural factors). To obtain these data, the proportion of the estuary population present in a section was calculated for each count and averaged for each winter (hence the requirement for complete counts). Detail of methods and analyses is provided in appendix 2, and expanded interpretations of trends are shown in appendix 3. Presentation The results are presented in a series of maps for each species. To provide context to highlighted trends, two maps are also included that show the mean populations of each species within each section of the estuaries at the start and end of the period analysed: 1) in the first five winters (1996/97 to 2000/01) (three for the Stour); and 2) in the last five winters (2010/11 to 2014/15). Interpretation Trends usually indicate where populations within sections have altered consistently. Therefore, population trends may involve small numbers of birds and none may show despite apparently large changes if populations have fluctuated. A trend in analysis A shows whether a section’s population has altered and a trend in analysis B shows whether it has altered relative to the whole estuary. Therefore, the population of a species within a section may show a trend in A but none in B. Sections may show trends in analysis B even if numbers have remained stable within them, depending on patterns in the whole estuary population. The raw population data for each section between 1996-2015 are shown in appendix 4, and it is recommended that these be consulted and used in conjunction with the maps of populations and trends where further detail is required.
5 3 Results (hyperlinks) 1. Brent goose 2. Shelduck 3. Wigeon 4. Pintail 5. Oystercatcher 6. Ringed plover 7. Grey plover 8. Knot 9. Black-tailed godwit 10. Dunlin 11. Curlew 12. Redshank 13. Turnstone 14. All species: trends in winter section populations 1996-2015 15. All species: trends in section proportions of estuary populations 1996-2015 16. Cumulative trends
6 1. Brent goose
Mean winter section populations 1996-2001 Mean9B winter section populations 2010-2015
A.10B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
7 2. Shelduck
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.11B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
8 3. Wigeon
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.12B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
9 4. Pintail
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.13B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
10 5. Oystercatcher
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.14B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
11 6. Ringed plover
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.15B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
12 7. Grey plover
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.16B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
13 8. Knot
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.17B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
14 9. Dunlin
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.18B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
15 10. Black-tailed godwit
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.19B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
16 11. Curlew
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.20B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
17 12. Redshank
Mean winter section populations 1996-2001 Mean21B winter section populations 2010-2015
A.22B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
18 13. Turnstone
Mean winter section populations 1996-2001 Mean winter section populations 2010-2015
A.23B Trends in winter section populations 1996-2015 B. Trends in section proportions of winter estuary populations 1996-2015
19 14. All species: trends in winter section populations 1996-2015
20 15. All species: trends in section proportions of winter estuary populations 1996-2015
21 16. Cumulative trends
Decreasing population Decreasing proportion of estuary population
Increasing24B population Increasing proportion of estuary population
22
Appendix 1: Count sections of the Orwell (blue numbers) and Stour (red numbers). The Orwell was counted originally in 18 sections (A1-F3 in black) and re-numbered when sections of hinterland were added (green). Section D4 was sub-divided at this time.
23 Appendix 2: Statistical analysis.
All raw data are in appendix 4. The statistical test used was non-parametric correlation (Spearman’s r). A non-parametric test was used in preference to the parametric equivalent (Pearson’s) in order to reduce the effect of large annual variations in section populations that may have been caused by external factors such as weather or summer breeding success. A non-parametric test also permits the analyses of the proportional data that were used to assess trends in the relative importance of each section. Non-parametric tests rank data – in this case, the populations or proportions of birds in a section in the 19 winters between 1996/97 and 2014/15 are ranked and compared with the rank of their winter. The test produces a test statistic to which is attached a probability that a relationship exists (in this case between bird population size or proportion and winter). It is standard practice to show probabilities in a series of levels that represent the degree of confidence in the relationship. Generally, a probability of greater than 95% is evidence that a relationship exists (usually shown as P<0.05, indicating a chance of less than 5% chance that it doesn’t), and the higher the probability the greater the confidence in the relationship. For this study, owing to the large number of tests that have been conducted and the importance of identifying unequivocal trends, the threshold of confidence for the existence of a trend has been set to P<0.01 i.e. there is a probability of >99% that the trends shown in the species maps exist. Appendix 3 shows these maps with the additional relationships that result from a standard threshold of 95%, and separates trends into three levels of confidence: >95% (or P<0.05, low); >99% (or P<0.01, high); and >99.9% (or P<0.001, very high).
24 Appendix 3A: Expanded array of relationships showing three levels of confidence (see appendix 2): changes in winter section populations 1996-2015.
25 Appendix 3B: Expanded array of relationships showing three levels of confidence (see appendix 2): changes in winter section proportions 1996-2015.
26 Appendix 3C: Cumulative trends from the expanded array of relationships.
Decreasing population Decreasing proportion of estuary population
Increasing25B population Increasing proportion of estuary population
27 Appendix 4: Raw section data Brent goose: mean numbers
STOUR Section
Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total0B 1996/97 1 42.50 15.00 64.50 43.50 21.50 124.00 62.00 156.50 0.00 0.00 0.00 80.00 67.50 2.00 0.00 25.50 10.00 96.00 341.50 76.00 109.00 1337.00 1999/00 2 25.33 14.33 118.33 71.67 12.00 30.00 4.00 0.00 0.00 0.00 0.00 0.00 40.00 215.00 20.00 41.67 96.00 94.00 250.00 0.00 107.00 1139.33 2000/01 3 21.33 12.33 98.33 63.00 6.67 26.67 52.00 25.33 0.00 0.00 0.00 0.00 2.00 147.00 14.33 20.00 14.67 70.00 334.00 22.67 83.67 1014.00 2001/02 4 35.75 22.75 62.25 19.00 17.50 61.50 53.00 60.25 0.00 6.25 0.00 40.25 10.25 29.50 164.50 5.75 286.50 3.25 263.25 12.75 51.50 1205.75 2002/03 5 22.50 14.00 12.00 51.75 3.50 53.00 123.25 141.50 0.00 0.00 0.00 3.00 0.00 150.25 1.25 14.75 31.75 25.25 256.75 7.50 69.50 981.50 2003/04 6 7.25 10.00 38.00 62.00 15.50 57.00 57.25 249.50 0.00 6.50 0.00 17.50 0.00 101.75 9.75 21.00 60.75 157.75 176.75 12.50 82.50 1143.25 2004/05 7 15.25 21.50 26.25 30.75 14.25 48.25 32.75 56.25 0.00 3.25 0.00 2.75 2.25 0.00 8.25 32.00 11.00 36.50 250.75 106.50 161.25 859.75 2005/06 8 1.00 2.00 15.50 92.25 26.00 76.50 30.25 82.75 0.00 2.25 1.00 11.00 0.75 3.25 73.00 34.25 14.25 30.25 151.00 43.75 130.25 821.25 2006/07 9 18.00 4.25 46.00 50.75 5.25 64.75 136.75 187.25 0.00 0.25 0.25 19.75 12.75 0.25 21.25 28.25 13.00 65.00 320.75 105.75 24.75 1125.00 2007/08 10 0.00 0.00 30.00 73.50 5.00 250.00 65.00 48.00 0.00 0.00 0.00 1.00 1.00 93.00 26.50 39.00 68.00 516.00 306.50 0.00 74.00 1596.50 2008/09 11 40.00 2.67 46.67 64.00 21.67 82.67 203.33 10.00 0.00 11.00 0.00 4.00 129.00 28.33 33.00 145.33 100.00 129.33 132.00 35.00 127.67 1345.67 2009/10 12 12.00 0.75 39.25 199.25 61.75 113.25 92.00 243.25 0.00 1.25 0.00 15.50 4.25 5.50 65.25 93.50 28.50 120.75 314.50 89.75 89.50 1589.75 2010/11 13 47.50 1.25 163.00 68.25 71.50 173.25 119.50 55.50 0.00 0.00 0.00 5.25 0.25 32.75 100.00 85.75 32.25 275.50 92.50 105.50 39.50 1469.00 2011/12 14 16.00 4.00 10.50 113.75 21.00 27.75 6.25 3.75 0.00 0.25 37.50 1.00 5.00 0.00 40.75 299.75 704.25 329.00 32.50 30.00 16.75 1699.75 2012/13 15 43.00 21.50 118.50 248.50 75.50 19.50 3.50 3.50 0.00 0.00 37.50 129.00 25.50 79.50 101.50 247.50 182.50 185.50 230.00 73.00 55.00 1880.00 2013/14 16 52.00 2.67 26.00 26.00 54.67 19.00 5.33 172.67 0.00 0.00 0.00 0.67 6.33 225.00 10.33 27.33 129.33 63.33 244.33 181.33 122.67 1369.00 2014/15 17 0.00 0.67 2.67 54.67 84.00 7.33 38.33 469.00 0.00 0.00 0.00 43.33 62.67 0.00 169.67 26.67 74.00 136.67 236.67 0.00 241.33 1647.67
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 0.00 0.00 0.00 5.33 9.67 29.67 623.33 0.00 41.33 0.00 0.33 0.00 0.00 0.00 0.00 709.67 1997/98 2 0.00 0.00 0.00 0.00 0.00 1.40 252.80 226.00 8.40 40.20 32.20 72.00 28.80 3.80 0.00 0.00 665.60 1998/99 3 0.00 0.00 0.00 0.00 3.67 0.00 532.33 183.33 0.67 12.00 129.67 56.00 11.33 2.33 9.00 0.00 940.33 1999/00 4 0.00 0.00 0.00 0.00 0.00 1.50 266.25 631.75 10.75 24.50 209.25 32.00 1.25 3.25 0.00 0.00 1180.50 2000/01 5 0.00 0.00 0.00 0.25 0.00 0.50 23.00 468.75 21.50 2.00 296.75 5.50 0.00 0.00 1.25 0.00 819.50 2001/02 6 0.00 0.00 0.00 0.00 0.00 0.00 6.00 219.75 26.50 0.75 291.25 180.00 0.00 1.50 3.25 0.00 729.00 2002/03 7 0.00 0.00 0.00 0.75 0.00 1.00 12.75 474.75 0.00 2.25 342.25 12.75 26.00 8.25 7.75 0.00 888.50 2003/04 8 0.00 0.00 0.00 0.00 0.00 0.25 18.00 490.00 0.00 44.00 85.00 41.50 0.00 62.50 0.00 0.00 741.25 2004/05 9 0.00 0.00 0.00 0.00 0.00 0.00 1080.50 714.00 0.00 4.00 16.00 56.50 0.00 115.00 0.00 0.00 1986.00 2005/06 10 0.00 0.00 0.00 0.00 0.00 0.00 88.67 466.33 0.00 171.00 57.67 54.00 0.00 6.67 2.67 0.00 847.00 2006/07 11 0.00 0.00 0.00 0.00 0.00 0.00 48.75 537.25 0.00 34.75 209.50 25.75 0.00 1.75 0.00 0.00 857.75 2007/08 12 0.00 0.00 0.00 0.00 0.00 0.00 472.33 404.00 3.00 182.33 38.33 1.67 0.00 0.00 2.33 0.00 1104.00 2008/09 13 0.00 0.00 0.00 0.00 0.00 0.00 58.75 467.00 9.50 25.75 45.00 19.00 56.00 1.00 0.00 0.00 682.00 2009/10 14 0.00 0.00 49.00 0.00 1.67 0.00 183.67 928.00 7.00 3.00 25.33 20.00 14.67 9.33 3.00 0.00 1244.67 2010/11 15 0.00 0.00 0.00 0.00 1.33 0.00 246.67 473.33 0.00 1.00 287.33 1.00 0.00 38.00 2.33 0.00 1051.00 2011/12 16 0.00 0.00 0.00 0.00 0.00 0.00 63.00 569.67 16.00 0.67 3.00 184.33 0.00 120.67 0.00 0.00 957.33 2012/13 17 0.00 0.00 0.00 0.00 0.00 0.00 147.00 595.67 8.00 3.33 3.00 109.33 22.33 6.00 4.00 0.00 898.67 2013/14 18 0.00 0.00 0.00 0.00 0.00 31.50 446.75 747.75 0.25 0.00 3.00 8.75 2.75 16.00 1.50 0.00 1258.25 2014/15 19 0.00 1.67 0.00 0.00 0.00 0.33 84.00 748.33 4.00 159.33 120.33 98.33 12.00 51.67 0.00 0.00 1280.00 28 Brent goose: mean proportions of winter estuary population
STOUR Section30B Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 3.18 1.12 4.82 3.25 1.61 9.27 4.64 11.71 0.00 0.00 0.00 5.98 5.05 0.15 0.00 1.91 0.75 7.18 25.54 5.68 8.15 1999/00 2 2.22 1.26 10.39 6.29 1.05 2.63 0.35 0.00 0.00 0.00 0.00 0.00 3.51 18.87 1.76 3.66 8.43 8.25 21.94 0.00 9.39 2000/01 3 2.10 1.22 9.70 6.21 0.66 2.63 5.13 2.50 0.00 0.00 0.00 0.00 0.20 14.50 1.41 1.97 1.45 6.90 32.94 2.24 8.25 2001/02 4 2.96 1.89 5.16 1.58 1.45 5.10 4.40 5.00 0.00 0.52 0.00 3.34 0.85 2.45 13.64 0.48 23.76 0.27 21.83 1.06 4.27 2002/03 5 2.29 1.43 1.22 5.27 0.36 5.40 12.56 14.42 0.00 0.00 0.00 0.31 0.00 15.31 0.13 1.50 3.23 2.57 26.16 0.76 7.08 2003/04 6 0.63 0.87 3.32 5.42 1.36 4.99 5.01 21.82 0.00 0.57 0.00 1.53 0.00 8.90 0.85 1.84 5.31 13.80 15.46 1.09 7.22 2004/05 7 1.77 2.50 3.05 3.58 1.66 5.61 3.81 6.54 0.00 0.38 0.00 0.32 0.26 0.00 0.96 3.72 1.28 4.25 29.17 12.39 18.76 2005/06 8 0.12 0.24 1.89 11.23 3.17 9.32 3.68 10.08 0.00 0.27 0.12 1.34 0.09 0.40 8.89 4.17 1.74 3.68 18.39 5.33 15.86 2006/07 9 1.60 0.38 4.09 4.51 0.47 5.76 12.16 16.64 0.00 0.02 0.02 1.76 1.13 0.02 1.89 2.51 1.16 5.78 28.51 9.40 2.20 2007/08 10 0.00 0.00 1.88 4.60 0.31 15.66 4.07 3.01 0.00 0.00 0.00 0.06 0.06 5.83 1.66 2.44 4.26 32.32 19.20 0.00 4.64 2008/09 11 2.97 0.20 3.47 4.76 1.61 6.14 15.11 0.74 0.00 0.82 0.00 0.30 9.59 2.11 2.45 10.80 7.43 9.61 9.81 2.60 9.49 2009/10 12 0.75 0.05 2.47 12.53 3.88 7.12 5.79 15.30 0.00 0.08 0.00 0.97 0.27 0.35 4.10 5.88 1.79 7.60 19.78 5.65 5.63 2010/11 13 3.23 0.09 11.10 4.65 4.87 11.79 8.13 3.78 0.00 0.00 0.00 0.36 0.02 2.23 6.81 5.84 2.20 18.75 6.30 7.18 2.69 2011/12 14 0.94 0.24 0.62 6.69 1.24 1.63 0.37 0.22 0.00 0.01 2.21 0.06 0.29 0.00 2.40 17.63 41.43 19.36 1.91 1.76 0.99 2012/13 15 2.29 1.14 6.30 13.22 4.02 1.04 0.19 0.19 0.00 0.00 1.99 6.86 1.36 4.23 5.40 13.16 9.71 9.87 12.23 3.88 2.93 2013/14 16 3.80 0.19 1.90 1.90 3.99 1.39 0.39 12.61 0.00 0.00 0.00 0.05 0.46 16.44 0.75 2.00 9.45 4.63 17.85 13.25 8.96 2014/15 17 0.00 0.04 0.16 3.32 5.10 0.45 2.33 28.46 0.00 0.00 0.00 2.63 3.80 0.00 10.30 1.62 4.49 8.29 14.36 0.00 14.65
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.00 0.00 0.00 0.75 1.36 4.18 87.83 0.00 5.82 0.00 0.05 0.00 0.00 0.00 0.00 1997/98 2 0.00 0.00 0.00 0.00 0.00 0.21 37.98 33.95 1.26 6.04 4.84 10.82 4.33 0.57 0.00 0.00 1998/99 3 0.00 0.00 0.00 0.00 0.39 0.00 56.61 19.50 0.07 1.28 13.79 5.96 1.21 0.25 0.96 0.00 1999/00 4 0.00 0.00 0.00 0.00 0.00 0.13 22.55 53.52 0.91 2.08 17.73 2.71 0.11 0.28 0.00 0.00 2000/01 5 0.00 0.00 0.00 0.03 0.00 0.06 2.81 57.20 2.62 0.24 36.21 0.67 0.00 0.00 0.15 0.00 2001/02 6 0.00 0.00 0.00 0.00 0.00 0.00 0.82 30.14 3.64 0.10 39.95 24.69 0.00 0.21 0.45 0.00 2002/03 7 0.00 0.00 0.00 0.08 0.00 0.11 1.44 53.43 0.00 0.25 38.52 1.44 2.93 0.93 0.87 0.00 2003/04 8 0.00 0.00 0.00 0.00 0.00 0.03 2.43 66.10 0.00 5.94 11.47 5.60 0.00 8.43 0.00 0.00 2004/05 9 0.00 0.00 0.00 0.00 0.00 0.00 54.41 35.95 0.00 0.20 0.81 2.84 0.00 5.79 0.00 0.00 2005/06 10 0.00 0.00 0.00 0.00 0.00 0.00 10.47 55.06 0.00 20.19 6.81 6.38 0.00 0.79 0.31 0.00 2006/07 11 0.00 0.00 0.00 0.00 0.00 0.00 5.68 62.63 0.00 4.05 24.42 3.00 0.00 0.20 0.00 0.00 2007/08 12 0.00 0.00 0.00 0.00 0.00 0.00 42.78 36.59 0.27 16.52 3.47 0.15 0.00 0.00 0.21 0.00 2008/09 13 0.00 0.00 0.00 0.00 0.00 0.00 8.61 68.48 1.39 3.78 6.60 2.79 8.21 0.15 0.00 0.00 2009/10 14 0.00 0.00 3.94 0.00 0.13 0.00 14.76 74.56 0.56 0.24 2.04 1.61 1.18 0.75 0.24 0.00 2010/11 15 0.00 0.00 0.00 0.00 0.13 0.00 23.47 45.04 0.00 0.10 27.34 0.10 0.00 3.62 0.22 0.00 2011/12 16 0.00 0.00 0.00 0.00 0.00 0.00 6.58 59.51 1.67 0.07 0.31 19.25 0.00 12.60 0.00 0.00 2012/13 17 0.00 0.00 0.00 0.00 0.00 0.00 16.36 66.28 0.89 0.37 0.33 12.17 2.49 0.67 0.45 0.00 2013/14 18 0.00 0.00 0.00 0.00 0.00 2.50 35.51 59.43 0.02 0.00 0.24 0.70 0.22 1.27 0.12 0.00 2014/15 19 0.00 0.13 0.00 0.00 0.00 0.03 6.56 58.46 0.31 12.45 9.40 7.68 0.94 4.04 0.00 0.00
29 Shelduck: mean numbers
STOUR Section31B Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 121.00 112.00 53.50 35.00 0.00 20.00 105.00 171.50 11.50 21.00 0.00 409.50 424.50 59.00 53.00 73.50 49.00 29.50 17.00 4.00 68.00 1837.50 1999/00 2 142.67 81.67 68.00 115.00 1.00 24.00 137.33 146.00 24.00 81.67 4.00 291.00 372.33 101.33 24.67 86.33 36.67 53.33 55.33 21.33 39.33 1907.00 2000/01 3 139.00 29.00 208.00 131.67 5.67 255.00 203.33 108.00 0.67 33.67 2.00 90.00 38.33 75.67 97.33 156.33 45.00 82.00 53.00 21.33 77.67 1852.67 2001/02 4 160.50 41.75 119.00 75.25 9.75 84.00 155.75 55.00 5.75 29.75 1.00 96.75 41.25 30.50 25.00 58.25 65.00 49.75 28.00 36.50 17.50 1186.00 2002/03 5 229.00 143.50 122.50 93.00 2.25 66.75 138.75 81.75 0.25 12.50 1.75 190.75 62.00 124.25 82.50 105.75 46.50 54.50 18.00 12.25 22.00 1610.50 2003/04 6 157.00 62.75 76.25 80.50 1.25 77.25 90.75 85.50 17.75 11.50 1.75 111.00 37.75 59.50 41.00 213.75 41.25 38.00 8.50 113.50 44.25 1370.75 2004/05 7 150.75 9.75 134.00 119.25 6.75 67.25 68.25 59.00 4.75 12.75 1.50 323.50 141.00 75.25 84.00 158.25 18.50 58.75 13.00 4.75 35.50 1546.50 2005/06 8 112.25 9.25 100.25 89.25 0.75 19.50 51.50 81.00 6.75 6.25 0.50 137.25 79.50 95.00 154.00 67.25 27.25 43.00 4.25 27.25 55.75 1167.75 2006/07 9 141.50 11.50 196.25 153.25 0.50 9.50 86.50 178.00 1.25 40.25 0.25 210.25 73.00 245.50 77.75 61.50 29.00 23.75 2.75 3.75 31.50 1577.50 2007/08 10 205.50 6.00 179.50 67.50 15.00 82.50 175.00 240.00 29.50 43.00 12.50 78.50 143.00 181.00 260.00 185.00 21.00 58.00 19.50 11.00 22.50 2035.50 2008/09 11 79.33 0.67 199.33 57.00 4.00 101.00 291.67 381.00 4.00 137.00 0.00 160.00 147.00 184.33 182.33 200.33 29.33 49.00 3.67 0.33 17.33 2228.67 2009/10 12 68.25 14.25 109.75 89.50 0.75 27.75 127.00 353.75 6.50 52.75 1.25 301.25 70.75 219.25 109.00 175.75 23.75 74.75 15.50 27.50 23.75 1892.75 2010/11 13 97.00 20.75 120.25 29.50 2.00 30.00 71.75 345.75 9.25 102.25 5.75 113.50 52.25 72.75 170.75 160.50 22.50 83.50 18.00 11.50 17.25 1556.75 2011/12 14 67.00 23.50 40.50 43.75 1.00 41.75 122.25 273.25 30.00 99.25 0.50 79.75 41.75 34.50 206.00 129.25 28.50 41.25 11.25 10.50 28.50 1354.00 2012/13 15 56.50 23.50 30.00 8.00 2.50 33.50 137.00 76.50 20.00 71.50 0.00 115.50 104.00 34.50 105.50 43.00 12.50 33.00 18.00 1.00 4.00 930.00 2013/14 16 45.00 39.67 101.67 34.33 5.33 59.67 154.33 222.00 0.67 24.00 0.33 285.00 178.33 33.00 32.00 41.67 70.00 21.00 6.67 0.00 1.00 1355.67 2014/15 17 93.00 7.67 107.67 21.67 5.33 86.67 162.33 542.67 1.33 6.33 1.33 285.67 43.00 78.00 362.67 311.67 21.67 59.67 17.33 3.33 0.67 2219.67
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 36.67 51.00 18.00 58.67 68.67 24.33 33.00 17.67 0.00 20.33 11.67 65.00 142.33 174.67 69.00 11.33 802.33 1997/98 2 57.00 57.20 14.60 57.40 44.60 20.20 32.80 17.40 0.60 57.80 10.00 20.40 120.80 160.00 86.40 22.60 779.80 1998/99 3 39.33 31.00 11.33 51.33 51.00 33.67 9.67 16.67 0.67 7.67 11.67 42.67 54.67 73.00 41.00 32.67 508.00 1999/00 4 40.50 31.00 8.50 37.75 20.25 6.00 11.25 34.75 0.75 5.75 14.75 41.75 83.50 135.25 28.25 14.25 514.25 2000/01 5 7.75 42.00 16.25 38.75 23.50 11.25 22.75 16.25 2.75 15.50 10.25 42.50 20.25 90.25 95.50 1.25 456.75 2001/02 6 7.75 25.75 2.00 46.75 18.50 9.25 43.50 14.00 1.00 13.50 38.25 31.00 67.50 117.25 37.50 45.00 518.50 2002/03 7 2.50 62.75 3.25 19.25 28.00 16.00 35.00 16.25 2.00 40.25 23.00 23.25 91.50 68.00 97.25 21.25 549.50 2003/04 8 7.75 46.50 11.50 44.25 19.25 9.25 28.50 30.25 0.00 8.50 54.50 45.25 72.75 56.25 63.00 19.00 516.50 2004/05 9 3.00 54.50 2.50 69.50 51.00 0.50 6.00 28.00 0.00 16.50 34.50 54.50 29.00 35.00 82.50 13.50 480.50 2005/06 10 0.00 29.00 0.00 54.33 12.33 0.67 2.00 4.67 0.00 19.00 25.00 35.00 74.67 53.33 60.33 6.00 376.33 2006/07 11 5.25 18.25 2.00 62.50 66.50 3.00 3.50 12.25 1.00 29.25 77.75 29.25 126.25 27.75 73.50 22.00 560.00 2007/08 12 3.33 34.00 0.67 5.33 21.33 1.67 7.00 6.00 8.67 44.33 42.00 41.33 113.33 100.67 93.67 14.67 538.00 2008/09 13 0.75 62.75 8.50 21.50 8.00 6.00 9.50 4.75 3.50 39.75 15.50 21.75 101.00 159.75 96.25 1.75 561.00 2009/10 14 0.00 88.33 0.00 60.67 61.33 3.00 32.00 6.00 5.67 57.00 63.33 25.67 114.67 61.67 68.67 17.33 665.33 2010/11 15 1.67 40.00 20.67 60.67 12.67 1.00 0.00 36.67 13.33 35.33 7.67 28.00 178.67 170.33 82.33 28.33 717.33 2011/12 16 4.67 46.67 22.00 112.00 26.00 5.67 0.33 11.33 19.67 61.67 24.67 13.67 111.33 104.67 59.33 4.33 628.00 2012/13 17 0.67 39.00 15.33 43.67 24.67 8.33 6.00 9.67 30.67 28.67 39.33 11.33 56.67 36.67 70.33 9.00 430.00 2013/14 18 0.50 14.50 8.00 94.75 47.25 12.50 34.75 7.00 6.00 4.00 29.75 10.50 22.25 46.75 26.50 13.00 378.00 2014/15 19 6.00 2.33 0.00 91.00 46.67 24.67 3.33 7.00 14.00 11.00 15.00 9.33 45.33 32.33 38.33 0.00 346.33
30 Shelduck: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 6.59 6.10 2.91 1.90 0.00 1.09 5.71 9.33 0.63 1.14 0.00 22.29 23.10 3.21 2.88 4.00 2.67 1.61 0.93 0.22 3.70 1999/00 2 7.48 4.28 3.57 6.03 0.05 1.26 7.20 7.66 1.26 4.28 0.21 15.26 19.52 5.31 1.29 4.53 1.92 2.80 2.90 1.12 2.06 2000/01 3 7.50 1.57 11.23 7.11 0.31 13.76 10.98 5.83 0.04 1.82 0.11 4.86 2.07 4.08 5.25 8.44 2.43 4.43 2.86 1.15 4.19 2001/02 4 13.53 3.52 10.03 6.34 0.82 7.08 13.13 4.64 0.48 2.51 0.08 8.16 3.48 2.57 2.11 4.91 5.48 4.19 2.36 3.08 1.48 2002/03 5 14.22 8.91 7.61 5.77 0.14 4.14 8.62 5.08 0.02 0.78 0.11 11.84 3.85 7.71 5.12 6.57 2.89 3.38 1.12 0.76 1.37 2003/04 6 11.45 4.58 5.56 5.87 0.09 5.64 6.62 6.24 1.29 0.84 0.13 8.10 2.75 4.34 2.99 15.59 3.01 2.77 0.62 8.28 3.23 2004/05 7 9.75 0.63 8.66 7.71 0.44 4.35 4.41 3.82 0.31 0.82 0.10 20.92 9.12 4.87 5.43 10.23 1.20 3.80 0.84 0.31 2.30 2005/06 8 9.61 0.79 8.58 7.64 0.06 1.67 4.41 6.94 0.58 0.54 0.04 11.75 6.81 8.14 13.19 5.76 2.33 3.68 0.36 2.33 4.77 2006/07 9 8.97 0.73 12.44 9.71 0.03 0.60 5.48 11.28 0.08 2.55 0.02 13.33 4.63 15.56 4.93 3.90 1.84 1.51 0.17 0.24 2.00 2007/08 10 10.10 0.29 8.82 3.32 0.74 4.05 8.60 11.79 1.45 2.11 0.61 3.86 7.03 8.89 12.77 9.09 1.03 2.85 0.96 0.54 1.11 2008/09 11 3.56 0.03 8.94 2.56 0.18 4.53 13.09 17.10 0.18 6.15 0.00 7.18 6.60 8.27 8.18 8.99 1.32 2.20 0.16 0.01 0.78 2009/10 12 3.61 0.75 5.80 4.73 0.04 1.47 6.71 18.69 0.34 2.79 0.07 15.92 3.74 11.58 5.76 9.29 1.25 3.95 0.82 1.45 1.25 2010/11 13 6.23 1.33 7.72 1.89 0.13 1.93 4.61 22.21 0.59 6.57 0.37 7.29 3.36 4.67 10.97 10.31 1.45 5.36 1.16 0.74 1.11 2011/12 14 4.95 1.74 2.99 3.23 0.07 3.08 9.03 20.18 2.22 7.33 0.04 5.89 3.08 2.55 15.21 9.55 2.10 3.05 0.83 0.78 2.10 2012/13 15 6.08 2.53 3.23 0.86 0.27 3.60 14.73 8.23 2.15 7.69 0.00 12.42 11.18 3.71 11.34 4.62 1.34 3.55 1.94 0.11 0.43 2013/14 16 3.32 2.93 7.50 2.53 0.39 4.40 11.38 16.38 0.05 1.77 0.02 21.02 13.15 2.43 2.36 3.07 5.16 1.55 0.49 0.00 0.07 2014/15 17 4.19 0.35 4.85 0.98 0.24 3.90 7.31 24.45 0.06 0.29 0.06 12.87 1.94 3.51 16.34 14.04 0.98 2.69 0.78 0.15 0.03
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 4.57 6.36 2.24 7.31 8.56 3.03 4.11 2.20 0.00 2.53 1.45 8.10 17.74 21.77 8.60 1.41 1997/98 2 7.31 7.34 1.87 7.36 5.72 2.59 4.21 2.23 0.08 7.41 1.28 2.62 15.49 20.52 11.08 2.90 1998/99 3 7.74 6.10 2.23 10.10 10.04 6.63 1.90 3.28 0.13 1.51 2.30 8.40 10.76 14.37 8.07 6.43 1999/00 4 7.88 6.03 1.65 7.34 3.94 1.17 2.19 6.76 0.15 1.12 2.87 8.12 16.24 26.30 5.49 2.77 2000/01 5 1.70 9.20 3.56 8.48 5.15 2.46 4.98 3.56 0.60 3.39 2.24 9.30 4.43 19.76 20.91 0.27 2001/02 6 1.49 4.97 0.39 9.02 3.57 1.78 8.39 2.70 0.19 2.60 7.38 5.98 13.02 22.61 7.23 8.68 2002/03 7 0.45 11.42 0.59 3.50 5.10 2.91 6.37 2.96 0.36 7.32 4.19 4.23 16.65 12.37 17.70 3.87 2003/04 8 1.50 9.00 2.23 8.57 3.73 1.79 5.52 5.86 0.00 1.65 10.55 8.76 14.09 10.89 12.20 3.68 2004/05 9 0.62 11.34 0.52 14.46 10.61 0.10 1.25 5.83 0.00 3.43 7.18 11.34 6.04 7.28 17.17 2.81 2005/06 10 0.00 7.71 0.00 14.44 3.28 0.18 0.53 1.24 0.00 5.05 6.64 9.30 19.84 14.17 16.03 1.59 2006/07 11 0.94 3.26 0.36 11.16 11.88 0.54 0.63 2.19 0.18 5.22 13.88 5.22 22.54 4.96 13.13 3.93 2007/08 12 0.62 6.32 0.12 0.99 3.97 0.31 1.30 1.12 1.61 8.24 7.81 7.68 21.07 18.71 17.41 2.73 2008/09 13 0.13 11.19 1.52 3.83 1.43 1.07 1.69 0.85 0.62 7.09 2.76 3.88 18.00 28.48 17.16 0.31 2009/10 14 0.00 13.28 0.00 9.12 9.22 0.45 4.81 0.90 0.85 8.57 9.52 3.86 17.23 9.27 10.32 2.61 2010/11 15 0.23 5.58 2.88 8.46 1.77 0.14 0.00 5.11 1.86 4.93 1.07 3.90 24.91 23.75 11.48 3.95 2011/12 16 0.74 7.43 3.50 17.83 4.14 0.90 0.05 1.80 3.13 9.82 3.93 2.18 17.73 16.67 9.45 0.69 2012/13 17 0.16 9.07 3.57 10.16 5.74 1.94 1.40 2.25 7.13 6.67 9.15 2.64 13.18 8.53 16.36 2.09 2013/14 18 0.13 3.84 2.12 25.07 12.50 3.31 9.19 1.85 1.59 1.06 7.87 2.78 5.89 12.37 7.01 3.44 2014/15 19 1.73 0.67 0.00 26.28 13.47 7.12 0.96 2.02 4.04 3.18 4.33 2.69 13.09 9.34 11.07 0.00
31 Wigeon: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 0.00 98.50 243.00 155.50 42.00 220.00 157.00 242.00 16.50 355.00 48.50 102.00 204.50 69.50 253.00 407.50 220.00 155.00 89.00 36.00 161.50 3276.00 1999/00 2 0.00 62.67 29.00 93.00 64.00 180.33 185.00 147.00 12.33 13.00 2.33 27.67 194.67 71.33 172.00 79.00 83.00 79.67 112.00 220.33 156.33 1984.67 2000/01 3 0.00 168.00 212.00 95.67 89.33 413.67 806.33 103.33 76.33 53.00 0.33 58.33 103.33 61.33 505.33 162.67 109.33 73.33 49.33 272.67 162.00 3575.67 2001/02 4 0.00 149.00 16.75 18.25 63.75 165.75 338.75 135.75 57.00 11.50 98.00 68.00 120.25 59.25 177.50 128.50 116.75 33.25 48.50 340.00 94.75 2241.25 2002/03 5 0.25 101.00 85.50 30.25 65.25 123.50 237.00 157.75 76.75 3.00 7.50 168.00 121.25 332.75 130.00 107.75 210.75 69.75 170.00 198.50 139.75 2536.25 2003/04 6 0.00 96.25 79.75 8.00 68.75 192.50 237.75 190.50 45.00 10.25 52.00 45.25 98.25 115.25 238.75 142.50 139.50 73.25 191.25 472.00 110.00 2606.75 2004/05 7 0.00 196.00 61.00 8.75 105.00 178.00 167.00 210.00 60.50 84.25 123.25 103.25 244.75 85.25 244.75 212.75 44.25 102.50 194.50 290.25 263.50 2979.50 2005/06 8 0.00 169.50 77.75 10.25 110.75 367.50 228.50 229.50 56.25 14.75 63.25 207.75 281.00 291.75 232.50 384.50 173.00 132.75 102.25 203.25 217.00 3553.75 2006/07 9 0.00 208.00 236.50 18.25 173.00 179.75 114.25 334.25 29.75 11.25 56.25 78.00 267.25 120.50 456.25 129.25 104.75 118.75 187.00 205.00 150.50 3178.50 2007/08 10 0.00 160.00 4.00 0.50 84.50 369.00 190.50 554.50 52.00 112.50 38.00 38.50 156.00 215.00 382.00 150.50 175.50 192.50 353.00 327.00 165.00 3720.50 2008/09 11 0.00 99.67 75.67 1.33 59.33 175.67 178.33 285.33 30.67 407.67 155.67 258.67 412.00 215.33 244.67 308.33 186.00 42.00 281.67 211.00 134.00 3763.00 2009/10 12 0.00 148.75 15.00 2.25 129.50 183.00 103.75 241.50 42.50 20.75 78.00 190.75 167.00 108.00 210.25 241.25 108.00 90.75 217.75 278.25 92.25 2669.25 2010/11 13 0.00 142.25 58.00 37.00 90.25 84.25 216.75 339.50 28.75 65.25 122.00 12.75 31.25 38.25 189.50 237.50 40.00 76.25 128.25 318.75 97.00 2353.50 2011/12 14 0.00 171.75 49.50 5.25 45.50 65.50 36.50 72.75 32.00 21.50 255.25 6.00 163.75 42.75 193.25 268.50 178.50 159.00 313.00 310.75 134.75 2525.75 2012/13 15 0.00 65.00 34.00 23.50 114.00 83.50 36.00 63.00 25.00 40.50 86.00 30.00 264.50 100.50 486.50 84.50 269.50 43.00 294.50 296.00 185.50 2625.00 2013/14 16 0.00 25.00 37.33 12.00 116.00 38.33 35.67 62.33 26.67 6.00 152.33 10.67 27.00 38.33 214.33 58.00 87.33 22.67 75.67 465.67 82.00 1593.33 2014/15 17 0.00 166.33 63.67 45.00 167.00 112.00 40.33 57.67 20.33 9.33 327.00 2.00 105.00 17.00 71.67 205.67 116.00 19.00 232.33 327.00 105.67 2210.00
ORWELL Section
Winter No. A21B A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 4.67 50.00 59.33 57.67 160.67 296.00 199.33 78.00 134.00 580.00 250.33 30.33 47.67 43.33 0.00 1991.33 1997/98 2 0.00 0.80 40.00 66.80 80.00 145.60 116.80 52.20 13.60 80.40 306.00 135.80 17.40 64.60 75.00 19.40 1214.40 1998/99 3 0.00 10.33 22.00 25.33 31.33 82.00 267.67 80.00 24.33 68.33 422.00 88.33 4.00 63.00 73.00 17.67 1279.33 1999/00 4 0.00 11.75 4.50 28.25 21.75 22.75 204.25 63.75 2.50 70.25 584.25 113.75 3.00 64.00 91.00 32.00 1317.75 2000/01 5 0.00 0.00 7.00 25.75 22.25 4.75 304.25 165.00 32.75 50.75 575.00 137.25 59.50 47.25 50.50 24.00 1506.00 2001/02 6 0.50 8.25 4.25 53.75 46.25 24.00 304.25 153.00 17.00 57.50 929.00 96.50 24.50 51.50 42.00 24.75 1837.00 2002/03 7 0.50 16.50 30.75 9.00 55.00 39.75 410.00 176.75 83.50 99.25 1038.25 184.25 36.25 157.50 76.25 43.25 2456.75 2003/04 8 1.00 27.25 11.25 50.00 45.75 44.50 412.00 134.25 0.50 82.75 446.25 199.00 36.00 153.00 156.75 25.25 1825.50 2004/05 9 0.00 23.00 7.00 101.50 54.00 48.50 153.00 215.00 0.00 60.50 390.50 165.50 126.00 277.50 117.00 19.00 1758.00 2005/06 10 0.00 15.00 27.00 99.33 21.00 44.67 261.33 49.00 0.00 100.67 406.33 132.33 63.67 169.33 58.67 6.00 1454.33 2006/07 11 0.25 16.25 2.25 13.00 13.25 31.25 218.75 39.50 2.50 136.75 535.75 81.00 22.75 78.75 134.75 23.00 1349.75 2007/08 12 2.67 82.67 6.00 7.67 16.00 68.67 255.00 39.33 0.00 73.00 532.67 122.00 31.33 111.00 121.33 18.33 1487.67 2008/09 13 2.00 23.75 17.75 17.50 6.25 10.75 220.25 59.50 14.50 271.25 106.00 248.50 91.75 58.50 52.00 2.50 1202.75 2009/10 14 3.00 7.00 16.33 22.00 8.00 29.33 202.00 43.00 7.67 64.33 399.33 154.00 43.00 69.33 52.00 11.67 1132.00 2010/11 15 0.00 7.33 16.33 8.67 5.33 2.67 273.33 51.00 5.33 26.00 414.33 263.33 90.67 144.00 122.33 13.00 1443.67 2011/12 16 0.00 7.33 78.67 25.33 14.00 33.33 238.00 76.00 62.67 54.00 135.67 250.33 95.00 71.00 71.00 4.67 1217.00 2012/13 17 0.67 24.67 19.33 39.00 16.67 47.00 95.33 17.67 0.00 41.00 477.33 275.33 14.67 31.00 100.33 0.00 1200.00 2013/14 18 0.00 0.00 21.00 47.50 20.25 73.00 75.75 25.75 5.00 22.25 501.00 87.25 23.00 21.75 54.50 11.00 989.00 2014/15 19 0.00 0.00 15.67 107.00 20.00 41.67 248.33 9.33 11.33 46.33 335.33 145.67 21.33 53.67 41.33 0.67 1097.67
32 Wigeon: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 0.00 3.01 7.42 4.75 1.28 6.72 4.79 7.39 0.50 10.84 1.48 3.11 6.24 2.12 7.72 12.44 6.72 4.73 2.72 1.10 4.93 1999/00 2 0.00 3.16 1.46 4.69 3.22 9.09 9.32 7.41 0.62 0.66 0.12 1.39 9.81 3.59 8.67 3.98 4.18 4.01 5.64 11.10 7.88 2000/01 3 0.00 4.70 5.93 2.68 2.50 11.57 22.55 2.89 2.13 1.48 0.01 1.63 2.89 1.72 14.13 4.55 3.06 2.05 1.38 7.63 4.53 2001/02 4 0.00 6.65 0.75 0.81 2.84 7.40 15.11 6.06 2.54 0.51 4.37 3.03 5.37 2.64 7.92 5.73 5.21 1.48 2.16 15.17 4.23 2002/03 5 0.01 3.98 3.37 1.19 2.57 4.87 9.34 6.22 3.03 0.12 0.30 6.62 4.78 13.12 5.13 4.25 8.31 2.75 6.70 7.83 5.51 2003/04 6 0.00 3.69 3.06 0.31 2.64 7.38 9.12 7.31 1.73 0.39 1.99 1.74 3.77 4.42 9.16 5.47 5.35 2.81 7.34 18.11 4.22 2004/05 7 0.00 6.58 2.05 0.29 3.52 5.97 5.60 7.05 2.03 2.83 4.14 3.47 8.21 2.86 8.21 7.14 1.49 3.44 6.53 9.74 8.84 2005/06 8 0.00 4.77 2.19 0.29 3.12 10.34 6.43 6.46 1.58 0.42 1.78 5.85 7.91 8.21 6.54 10.82 4.87 3.74 2.88 5.72 6.11 2006/07 9 0.00 6.54 7.44 0.57 5.44 5.66 3.59 10.52 0.94 0.35 1.77 2.45 8.41 3.79 14.35 4.07 3.30 3.74 5.88 6.45 4.73 2007/08 10 0.00 4.30 0.11 0.01 2.27 9.92 5.12 14.90 1.40 3.02 1.02 1.03 4.19 5.78 10.27 4.05 4.72 5.17 9.49 8.79 4.43 2008/09 11 0.00 2.65 2.01 0.04 1.58 4.67 4.74 7.58 0.81 10.83 4.14 6.87 10.95 5.72 6.50 8.19 4.94 1.12 7.49 5.61 3.56 2009/10 12 0.00 5.57 0.56 0.08 4.85 6.86 3.89 9.05 1.59 0.78 2.92 7.15 6.26 4.05 7.88 9.04 4.05 3.40 8.16 10.42 3.46 2010/11 13 0.00 6.04 2.46 1.57 3.83 3.58 9.21 14.43 1.22 2.77 5.18 0.54 1.33 1.63 8.05 10.09 1.70 3.24 5.45 13.54 4.12 2011/12 14 0.00 6.80 1.96 0.21 1.80 2.59 1.45 2.88 1.27 0.85 10.11 0.24 6.48 1.69 7.65 10.63 7.07 6.30 12.39 12.30 5.34 2012/13 15 0.00 2.48 1.30 0.90 4.34 3.18 1.37 2.40 0.95 1.54 3.28 1.14 10.08 3.83 18.53 3.22 10.27 1.64 11.22 11.28 7.07 2013/14 16 0.00 1.57 2.34 0.75 7.28 2.41 2.24 3.91 1.67 0.38 9.56 0.67 1.69 2.41 13.45 3.64 5.48 1.42 4.75 29.23 5.15 2014/15 17 0.00 7.53 2.88 2.04 7.56 5.07 1.83 2.61 0.92 0.42 14.80 0.09 4.75 0.77 3.24 9.31 5.25 0.86 10.51 14.80 4.78
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.23 2.51 2.98 2.90 8.07 14.86 10.01 3.92 6.73 29.13 12.57 1.52 2.39 2.18 0.00 1997/98 2 0.00 0.07 3.29 5.50 6.59 11.99 9.62 4.30 1.12 6.62 25.20 11.18 1.43 5.32 6.18 1.60 1998/99 3 0.00 0.81 1.72 1.98 2.45 6.41 20.92 6.25 1.90 5.34 32.99 6.90 0.31 4.92 5.71 1.38 1999/00 4 0.00 0.89 0.34 2.14 1.65 1.73 15.50 4.84 0.19 5.33 44.34 8.63 0.23 4.86 6.91 2.43 2000/01 5 0.00 0.00 0.46 1.71 1.48 0.32 20.20 10.96 2.17 3.37 38.18 9.11 3.95 3.14 3.35 1.59 2001/02 6 0.03 0.45 0.23 2.93 2.52 1.31 16.56 8.33 0.93 3.13 50.57 5.25 1.33 2.80 2.29 1.35 2002/03 7 0.02 0.67 1.25 0.37 2.24 1.62 16.69 7.19 3.40 4.04 42.26 7.50 1.48 6.41 3.10 1.76 2003/04 8 0.05 1.49 0.62 2.74 2.51 2.44 22.57 7.35 0.03 4.53 24.45 10.90 1.97 8.38 8.59 1.38 2004/05 9 0.00 1.31 0.40 5.77 3.07 2.76 8.70 12.23 0.00 3.44 22.21 9.41 7.17 15.78 6.66 1.08 2005/06 10 0.00 1.03 1.86 6.83 1.44 3.07 17.97 3.37 0.00 6.92 27.94 9.10 4.38 11.64 4.03 0.41 2006/07 11 0.02 1.20 0.17 0.96 0.98 2.32 16.21 2.93 0.19 10.13 39.69 6.00 1.69 5.83 9.98 1.70 2007/08 12 0.18 5.56 0.40 0.52 1.08 4.62 17.14 2.64 0.00 4.91 35.81 8.20 2.11 7.46 8.16 1.23 2008/09 13 0.17 1.97 1.48 1.45 0.52 0.89 18.31 4.95 1.21 22.55 8.81 20.66 7.63 4.86 4.32 0.21 2009/10 14 0.27 0.62 1.44 1.94 0.71 2.59 17.84 3.80 0.68 5.68 35.28 13.60 3.80 6.12 4.59 1.03 2010/11 15 0.00 0.51 1.13 0.60 0.37 0.18 18.93 3.53 0.37 1.80 28.70 18.24 6.28 9.97 8.47 0.90 2011/12 16 0.00 0.60 6.46 2.08 1.15 2.74 19.56 6.24 5.15 4.44 11.15 20.57 7.81 5.83 5.83 0.38 2012/13 17 0.06 2.06 1.61 3.25 1.39 3.92 7.94 1.47 0.00 3.42 39.78 22.94 1.22 2.58 8.36 0.00 2013/14 18 0.00 0.00 2.12 4.80 2.05 7.38 7.66 2.60 0.51 2.25 50.66 8.82 2.33 2.20 5.51 1.11 2014/15 19 0.00 0.00 1.43 9.75 1.82 3.80 22.62 0.85 1.03 4.22 30.55 13.27 1.94 4.89 3.77 0.06
33 Pintail: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 0.00 37.50 147.00 16.50 0.00 6.00 0.00 81.00 1.50 185.00 0.00 87.50 28.50 0.00 0.00 2.50 2.00 2.50 0.00 0.00 2.00 599.50 1999/00 2 0.00 1.33 61.00 71.67 0.00 0.00 3.33 23.67 38.67 20.67 0.00 6.67 27.33 51.67 3.33 0.00 0.00 0.00 8.00 0.67 1.33 319.33 2000/01 3 0.00 0.00 98.33 80.00 0.00 16.67 48.33 116.00 45.00 12.00 0.00 23.33 16.00 24.00 0.00 0.00 20.00 2.33 0.00 0.00 0.00 502.00 2001/02 4 0.00 1.50 74.50 11.00 0.00 3.75 5.50 105.25 8.75 14.00 0.00 5.25 11.75 17.00 2.25 25.75 38.50 6.75 1.00 0.00 2.00 334.50 2002/03 5 0.00 0.75 163.50 58.50 0.00 0.00 3.25 127.75 2.75 2.75 0.00 33.25 5.25 7.00 1.00 7.75 48.00 1.75 0.00 0.50 7.50 471.25 2003/04 6 0.00 2.50 82.25 5.75 0.00 0.00 1.25 40.00 9.00 42.25 0.00 4.75 14.50 2.75 0.00 1.50 23.25 0.00 1.25 0.00 1.50 232.50 2004/05 7 0.00 5.75 88.75 31.50 0.00 0.00 6.25 55.00 55.75 19.75 0.00 5.50 24.00 0.50 0.50 2.75 27.75 1.50 5.00 0.00 1.75 332.00 2005/06 8 0.00 0.75 59.50 13.75 0.00 0.00 0.00 65.00 0.50 27.25 0.00 14.00 8.00 4.25 0.00 6.75 23.50 2.00 0.75 1.00 0.50 227.50 2006/07 9 0.00 0.00 45.25 1.50 0.00 0.00 0.00 109.25 0.00 0.75 0.00 36.00 3.00 3.50 2.00 1.50 26.50 5.75 0.00 0.00 0.00 235.00 2007/08 10 0.00 0.00 80.00 0.00 0.00 0.00 1.00 71.00 0.00 0.00 0.00 19.50 1.00 1.00 0.00 18.50 8.00 2.50 0.00 0.00 0.00 202.50 2008/09 11 0.00 0.00 54.67 7.33 0.00 0.67 0.00 45.67 1.33 59.33 0.00 24.67 3.00 2.67 0.00 6.00 13.00 6.67 0.00 0.00 2.67 227.67 2009/10 12 0.00 1.75 20.25 4.00 0.00 0.00 5.75 63.50 0.00 39.75 0.00 65.50 6.25 1.25 0.00 5.00 8.75 5.50 1.50 0.50 0.25 229.50 2010/11 13 0.00 0.00 43.75 15.75 0.00 0.00 0.00 67.00 1.25 51.00 0.00 35.25 2.50 1.00 0.00 2.00 19.50 3.50 1.00 0.00 0.00 243.50 2011/12 14 0.00 0.00 50.50 0.75 0.00 0.25 0.00 57.25 0.00 73.50 1.25 26.50 10.75 4.50 5.50 12.00 12.25 0.50 0.25 0.00 0.00 255.75 2012/13 15 0.00 0.00 64.50 1.00 0.50 0.00 0.00 35.00 0.00 16.00 0.00 50.00 19.00 1.00 21.00 3.00 20.00 0.00 0.00 0.00 0.00 231.00 2013/14 16 0.00 0.00 62.33 0.00 0.00 0.00 0.00 92.33 0.00 37.00 0.00 22.00 17.67 7.00 11.00 0.00 22.00 0.00 0.00 0.00 0.00 271.33 2014/15 17 0.00 0.00 144.00 95.00 0.00 0.00 0.00 24.67 0.00 19.33 0.67 26.33 17.33 0.67 0.00 9.00 30.67 2.67 0.00 0.00 0.00 370.33
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 0.00 4.67 34.00 6.00 2.33 2.67 0.67 0.00 0.00 23.33 4.33 0.67 93.67 5.00 0.00 177.33 1997/98 2 0.00 0.00 5.00 50.80 0.60 0.00 0.00 0.00 0.00 17.60 46.40 16.80 0.20 127.40 4.20 0.00 269.00 1998/99 3 0.00 0.00 9.33 19.33 0.67 0.00 1.00 0.00 0.00 0.00 1.33 6.33 0.00 19.33 8.33 0.00 65.67 1999/00 4 0.00 0.00 0.00 9.25 0.00 0.00 0.00 0.00 0.00 0.00 7.00 12.00 0.00 50.25 0.00 0.00 78.50 2000/01 5 0.00 0.00 0.00 19.25 0.00 0.00 0.00 0.00 0.00 0.00 25.50 23.00 0.00 7.50 2.00 0.00 77.25 2001/02 6 0.00 0.00 0.00 4.25 0.00 0.00 0.00 0.50 0.00 0.00 153.50 0.75 0.25 41.75 0.00 0.00 201.00 2002/03 7 0.00 0.00 0.00 2.25 0.00 0.00 0.00 1.00 0.00 0.00 144.75 5.25 0.00 56.50 7.75 0.00 217.50 2003/04 8 0.00 0.00 0.00 1.75 0.00 0.00 0.00 0.00 0.00 0.00 181.75 4.00 0.00 36.75 8.25 0.00 232.50 2004/05 9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.50 61.00 1.00 0.00 77.00 10.50 0.00 150.00 2005/06 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.67 114.00 50.00 0.00 73.00 2.33 0.00 240.00 2006/07 11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 247.75 23.25 0.00 42.25 9.75 0.00 323.00 2007/08 12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 91.00 0.67 0.00 24.33 21.00 0.00 137.00 2008/09 13 0.00 0.00 0.00 10.25 0.00 0.00 0.00 0.00 0.25 3.00 25.25 6.75 0.00 31.50 10.75 0.00 87.75 2009/10 14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.33 0.00 0.00 11.33 48.67 3.67 163.00 2010/11 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 108.00 4.67 0.00 44.00 14.67 0.00 171.33 2011/12 16 0.00 0.00 0.00 3.33 0.00 0.00 0.00 0.00 0.00 0.00 43.67 16.33 0.33 79.67 20.00 9.67 173.00 2012/13 17 0.00 0.00 0.00 2.33 0.00 0.00 0.00 0.00 0.00 0.00 44.67 0.67 0.00 11.00 22.33 0.00 81.00 2013/14 18 0.00 0.00 6.75 28.25 0.00 0.00 0.00 0.00 0.00 0.00 46.00 1.00 1.25 12.00 24.75 0.00 120.00 2014/15 19 0.00 0.00 0.00 3.33 0.00 0.00 0.00 0.00 0.00 0.00 17.67 5.33 2.00 44.33 12.00 17.00 101.67
34 Pintail: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 0.00 6.26 24.52 2.75 0.00 1.00 0.00 13.51 0.25 30.86 0.00 14.60 4.75 0.00 0.00 0.42 0.33 0.42 0.00 0.00 0.33 1999/00 2 0.00 0.42 19.10 22.44 0.00 0.00 1.04 7.41 12.11 6.47 0.00 2.09 8.56 16.18 1.04 0.00 0.00 0.00 2.51 0.21 0.42 2000/01 3 0.00 0.00 19.59 15.94 0.00 3.32 9.63 23.11 8.96 2.39 0.00 4.65 3.19 4.78 0.00 0.00 3.98 0.46 0.00 0.00 0.00 2001/02 4 0.00 0.45 22.27 3.29 0.00 1.12 1.64 31.46 2.62 4.19 0.00 1.57 3.51 5.08 0.67 7.70 11.51 2.02 0.30 0.00 0.60 2002/03 5 0.00 0.16 34.69 12.41 0.00 0.00 0.69 27.11 0.58 0.58 0.00 7.06 1.11 1.49 0.21 1.64 10.19 0.37 0.00 0.11 1.59 2003/04 6 0.00 1.08 35.38 2.47 0.00 0.00 0.54 17.20 3.87 18.17 0.00 2.04 6.24 1.18 0.00 0.65 10.00 0.00 0.54 0.00 0.65 2004/05 7 0.00 1.73 26.73 9.49 0.00 0.00 1.88 16.57 16.79 5.95 0.00 1.66 7.23 0.15 0.15 0.83 8.36 0.45 1.51 0.00 0.53 2005/06 8 0.00 0.33 26.15 6.04 0.00 0.00 0.00 28.57 0.22 11.98 0.00 6.15 3.52 1.87 0.00 2.97 10.33 0.88 0.33 0.44 0.22 2006/07 9 0.00 0.00 19.26 0.64 0.00 0.00 0.00 46.49 0.00 0.32 0.00 15.32 1.28 1.49 0.85 0.64 11.28 2.45 0.00 0.00 0.00 2007/08 10 0.00 0.00 39.51 0.00 0.00 0.00 0.49 35.06 0.00 0.00 0.00 9.63 0.49 0.49 0.00 9.14 3.95 1.23 0.00 0.00 0.00 2008/09 11 0.00 0.00 24.01 3.22 0.00 0.29 0.00 20.06 0.59 26.06 0.00 10.83 1.32 1.17 0.00 2.64 5.71 2.93 0.00 0.00 1.17 2009/10 12 0.00 0.76 8.82 1.74 0.00 0.00 2.51 27.67 0.00 17.32 0.00 28.54 2.72 0.54 0.00 2.18 3.81 2.40 0.65 0.22 0.11 2010/11 13 0.00 0.00 17.97 6.47 0.00 0.00 0.00 27.52 0.51 20.94 0.00 14.48 1.03 0.41 0.00 0.82 8.01 1.44 0.41 0.00 0.00 2011/12 14 0.00 0.00 19.75 0.29 0.00 0.10 0.00 22.39 0.00 28.74 0.49 10.36 4.20 1.76 2.15 4.69 4.79 0.20 0.10 0.00 0.00 2012/13 15 0.00 0.00 27.92 0.43 0.22 0.00 0.00 15.15 0.00 6.93 0.00 21.65 8.23 0.43 9.09 1.30 8.66 0.00 0.00 0.00 0.00 2013/14 16 0.00 0.00 22.97 0.00 0.00 0.00 0.00 34.03 0.00 13.64 0.00 8.11 6.51 2.58 4.05 0.00 8.11 0.00 0.00 0.00 0.00 2014/15 17 0.00 0.00 38.88 25.65 0.00 0.00 0.00 6.66 0.00 5.22 0.18 7.11 4.68 0.18 0.00 2.43 8.28 0.72 0.00 0.00 0.00
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.00 2.63 19.17 3.38 1.32 1.50 0.38 0.00 0.00 13.16 2.44 0.38 52.82 2.82 0.00 1997/98 2 0.00 0.00 1.86 18.88 0.22 0.00 0.00 0.00 0.00 6.54 17.25 6.25 0.07 47.36 1.56 0.00 1998/99 3 0.00 0.00 14.21 29.44 1.02 0.00 1.52 0.00 0.00 0.00 2.03 9.64 0.00 29.44 12.69 0.00 1999/00 4 0.00 0.00 0.00 11.78 0.00 0.00 0.00 0.00 0.00 0.00 8.92 15.29 0.00 64.01 0.00 0.00 2000/01 5 0.00 0.00 0.00 24.92 0.00 0.00 0.00 0.00 0.00 0.00 33.01 29.77 0.00 9.71 2.59 0.00 2001/02 6 0.00 0.00 0.00 2.11 0.00 0.00 0.00 0.25 0.00 0.00 76.37 0.37 0.12 20.77 0.00 0.00 2002/03 7 0.00 0.00 0.00 1.03 0.00 0.00 0.00 0.46 0.00 0.00 66.55 2.41 0.00 25.98 3.56 0.00 2003/04 8 0.00 0.00 0.00 0.75 0.00 0.00 0.00 0.00 0.00 0.00 78.17 1.72 0.00 15.81 3.55 0.00 2004/05 9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.33 40.67 0.67 0.00 51.33 7.00 0.00 2005/06 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.28 47.50 20.83 0.00 30.42 0.97 0.00 2006/07 11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 76.70 7.20 0.00 13.08 3.02 0.00 2007/08 12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 66.42 0.49 0.00 17.76 15.33 0.00 2008/09 13 0.00 0.00 0.00 11.68 0.00 0.00 0.00 0.00 0.28 3.42 28.77 7.69 0.00 35.90 12.25 0.00 2009/10 14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 60.94 0.00 0.00 6.95 29.86 2.25 2010/11 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 63.04 2.72 0.00 25.68 8.56 0.00 2011/12 16 0.00 0.00 0.00 1.93 0.00 0.00 0.00 0.00 0.00 0.00 25.24 9.44 0.19 46.05 11.56 5.59 2012/13 17 0.00 0.00 0.00 2.88 0.00 0.00 0.00 0.00 0.00 0.00 55.14 0.82 0.00 13.58 27.57 0.00 2013/14 18 0.00 0.00 5.63 23.54 0.00 0.00 0.00 0.00 0.00 0.00 38.33 0.83 1.04 10.00 20.63 0.00 2014/15 19 0.00 0.00 0.00 3.28 0.00 0.00 0.00 0.00 0.00 0.00 17.38 5.25 1.97 43.61 11.80 16.72
35 Oystercatcher: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 85.50 9.00 110.50 26.00 18.00 8.50 13.00 206.00 3.00 2.00 0.50 0.00 42.00 21.00 31.50 123.50 53.00 39.00 11.00 97.50 164.00 1064.50 1999/00 2 14.00 7.67 83.67 51.33 83.00 71.67 161.33 137.00 0.33 0.00 0.00 10.67 36.00 20.33 17.67 41.33 78.33 140.33 16.33 68.33 69.67 1109.00 2000/01 3 16.67 8.00 53.67 31.67 67.33 27.33 9.00 18.00 0.00 0.00 0.00 62.33 0.33 162.00 45.00 51.33 110.67 171.00 18.33 29.67 81.67 964.00 2001/02 4 21.75 12.00 60.25 61.50 33.25 46.75 23.00 58.75 0.50 2.50 0.00 98.75 20.50 228.00 37.00 171.25 136.50 108.75 36.00 82.25 90.75 1330.00 2002/03 5 18.75 15.25 75.75 58.25 44.50 32.25 147.00 210.75 0.00 0.50 0.00 90.25 22.25 303.75 41.50 67.25 66.25 86.25 14.00 24.75 74.25 1393.50 2003/04 6 5.50 19.00 57.50 54.25 22.75 44.00 159.75 142.50 1.00 3.50 1.00 45.50 0.75 139.50 26.50 118.00 126.00 90.75 18.50 25.25 49.25 1150.75 2004/05 7 6.25 13.75 36.50 28.75 46.25 36.75 31.75 230.25 1.25 1.75 0.00 101.75 16.75 327.00 10.25 97.25 73.00 88.50 29.00 48.00 53.00 1277.75 2005/06 8 4.75 19.25 98.50 46.00 49.75 44.25 69.75 204.75 0.00 1.25 0.00 2.25 7.75 317.50 40.75 30.00 42.00 82.50 19.50 17.50 64.00 1162.00 2006/07 9 3.75 7.50 123.75 83.50 36.75 37.75 46.00 93.75 0.50 2.50 0.00 16.75 43.50 138.25 50.50 49.25 85.75 98.50 37.75 17.25 77.25 1050.50 2007/08 10 1.50 13.00 98.50 40.50 35.00 107.50 40.50 81.50 4.00 4.00 0.00 9.50 54.00 82.50 96.50 113.00 94.00 136.50 17.00 9.00 53.00 1091.00 2008/09 11 3.33 17.33 130.67 66.00 54.33 142.33 54.67 71.33 0.00 0.33 0.00 75.00 24.00 115.00 30.33 74.67 58.33 74.67 9.33 8.00 43.00 1052.67 2009/10 12 1.75 6.50 87.50 42.75 73.75 124.75 39.50 72.00 0.75 11.50 0.00 36.25 5.75 25.00 95.00 70.00 69.50 110.75 15.00 15.00 68.75 971.75 2010/11 13 5.50 9.50 58.75 60.75 59.25 27.00 93.75 91.00 1.25 3.25 0.25 20.50 24.75 43.75 68.75 256.25 99.00 71.25 14.00 12.25 34.00 1054.75 2011/12 14 2.25 18.75 62.00 42.75 41.75 18.50 54.00 83.00 1.50 12.50 0.25 25.25 27.75 30.00 54.25 96.75 50.50 85.50 35.25 3.50 25.25 771.25 2012/13 15 4.00 5.50 35.50 21.00 46.50 34.50 135.00 84.00 0.00 7.00 0.00 15.00 7.50 60.50 75.50 86.00 62.00 79.00 11.50 5.50 24.00 799.50 2013/14 16 17.00 4.33 43.33 27.67 42.67 32.33 49.33 145.33 1.67 4.00 0.67 28.67 11.00 62.33 114.00 97.33 40.33 57.67 21.00 9.00 31.33 841.00 2014/15 17 19.67 3.00 48.00 64.67 56.33 39.00 18.67 103.33 1.00 10.67 0.33 11.00 13.67 7.33 64.00 78.33 71.00 54.33 35.33 6.67 37.33 743.67
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 5.33 80.33 26.67 44.67 6.00 3.33 3.67 13.67 4.67 104.67 0.33 51.33 352.33 33.33 34.33 8.33 773.00 1997/98 2 15.00 161.80 18.00 32.00 7.20 7.60 1.00 3.20 3.60 17.40 0.00 22.20 166.60 485.80 71.00 68.20 1080.60 1998/99 3 8.00 76.67 10.33 12.67 36.67 2.33 3.33 4.33 0.67 16.33 0.00 32.33 119.00 443.33 85.33 51.00 902.33 1999/00 4 8.50 20.75 4.50 4.75 12.25 1.75 2.00 4.00 3.75 10.50 0.00 134.25 233.50 696.50 64.25 21.25 1222.50 2000/01 5 1.50 24.25 3.50 10.75 22.75 3.50 1.00 6.25 3.50 6.25 0.00 88.50 296.25 629.00 53.75 59.50 1210.25 2001/02 6 1.00 13.75 11.50 145.00 37.50 2.75 1.25 6.50 5.25 10.25 0.00 77.50 369.25 448.25 71.50 31.00 1232.25 2002/03 7 1.00 38.25 12.25 66.25 1.75 4.25 2.50 3.75 1.50 6.50 0.00 26.50 242.00 777.25 152.50 65.25 1401.50 2003/04 8 1.75 19.75 3.25 221.50 5.50 7.75 4.25 7.00 1.50 5.25 0.75 32.50 130.25 861.75 226.75 69.25 1598.75 2004/05 9 4.50 43.50 10.50 103.50 0.50 1.00 4.50 6.00 1.50 10.00 0.00 54.50 155.00 822.00 269.50 55.50 1542.00 2005/06 10 0.33 22.00 11.33 75.67 4.00 4.33 5.33 7.00 2.33 13.67 0.00 31.00 141.00 861.00 105.67 73.00 1357.67 2006/07 11 2.00 58.25 12.25 79.00 28.00 6.00 2.75 9.50 0.25 5.25 0.75 65.50 202.50 780.25 238.75 66.00 1557.00 2007/08 12 0.33 54.00 12.33 103.00 5.00 1.67 2.67 11.00 4.00 5.33 0.00 71.00 165.67 768.00 141.00 93.67 1438.67 2008/09 13 1.25 38.00 7.25 83.50 4.25 1.50 3.50 9.50 2.25 4.50 1.75 44.00 168.75 578.00 117.00 57.25 1122.25 2009/10 14 0.33 47.33 5.33 43.33 2.67 6.00 4.00 6.33 2.00 5.00 1.67 70.00 330.00 487.33 216.67 84.67 1312.67 2010/11 15 0.67 5.00 4.33 132.00 6.00 0.67 3.00 3.67 3.00 4.33 1.00 67.33 226.00 667.33 345.33 131.33 1601.00 2011/12 16 3.00 26.33 35.67 354.67 7.00 1.00 2.67 7.67 1.67 6.67 0.00 7.00 155.67 550.00 330.67 100.00 1589.67 2012/13 17 9.67 22.00 6.00 110.67 6.67 1.67 1.67 13.67 0.33 1.00 0.33 4.33 137.00 634.00 349.00 70.00 1368.00 2013/14 18 1.00 9.50 7.25 177.50 7.50 2.25 1.25 10.25 3.75 2.50 0.00 9.50 173.75 742.50 418.50 63.00 1630.00 2014/15 19 0.67 3.67 48.67 281.67 6.33 3.00 3.67 16.67 7.00 6.67 2.00 7.67 236.00 407.67 380.33 141.67 1553.33
36 Oystercatcher: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 8.03 0.85 10.38 2.44 1.69 0.80 1.22 19.35 0.28 0.19 0.05 0.00 3.95 1.97 2.96 11.60 4.98 3.66 1.03 9.16 15.41 1999/00 2 1.26 0.69 7.54 4.63 7.48 6.46 14.55 12.35 0.03 0.00 0.00 0.96 3.25 1.83 1.59 3.73 7.06 12.65 1.47 6.16 6.28 2000/01 3 1.73 0.83 5.57 3.28 6.98 2.84 0.93 1.87 0.00 0.00 0.00 6.47 0.03 16.80 4.67 5.33 11.48 17.74 1.90 3.08 8.47 2001/02 4 1.64 0.90 4.53 4.62 2.50 3.52 1.73 4.42 0.04 0.19 0.00 7.42 1.54 17.14 2.78 12.88 10.26 8.18 2.71 6.18 6.82 2002/03 5 1.35 1.09 5.44 4.18 3.19 2.31 10.55 15.12 0.00 0.04 0.00 6.48 1.60 21.80 2.98 4.83 4.75 6.19 1.00 1.78 5.33 2003/04 6 0.48 1.65 5.00 4.71 1.98 3.82 13.88 12.38 0.09 0.30 0.09 3.95 0.07 12.12 2.30 10.25 10.95 7.89 1.61 2.19 4.28 2004/05 7 0.49 1.08 2.86 2.25 3.62 2.88 2.48 18.02 0.10 0.14 0.00 7.96 1.31 25.59 0.80 7.61 5.71 6.93 2.27 3.76 4.15 2005/06 8 0.41 1.66 8.48 3.96 4.28 3.81 6.00 17.62 0.00 0.11 0.00 0.19 0.67 27.32 3.51 2.58 3.61 7.10 1.68 1.51 5.51 2006/07 9 0.36 0.71 11.78 7.95 3.50 3.59 4.38 8.92 0.05 0.24 0.00 1.59 4.14 13.16 4.81 4.69 8.16 9.38 3.59 1.64 7.35 2007/08 10 0.14 1.19 9.03 3.71 3.21 9.85 3.71 7.47 0.37 0.37 0.00 0.87 4.95 7.56 8.85 10.36 8.62 12.51 1.56 0.82 4.86 2008/09 11 0.32 1.65 12.41 6.27 5.16 13.52 5.19 6.78 0.00 0.03 0.00 7.12 2.28 10.92 2.88 7.09 5.54 7.09 0.89 0.76 4.08 2009/10 12 0.18 0.67 9.00 4.40 7.59 12.84 4.06 7.41 0.08 1.18 0.00 3.73 0.59 2.57 9.78 7.20 7.15 11.40 1.54 1.54 7.07 2010/11 13 0.52 0.90 5.57 5.76 5.62 2.56 8.89 8.63 0.12 0.31 0.02 1.94 2.35 4.15 6.52 24.29 9.39 6.76 1.33 1.16 3.22 2011/12 14 0.29 2.43 8.04 5.54 5.41 2.40 7.00 10.76 0.19 1.62 0.03 3.27 3.60 3.89 7.03 12.54 6.55 11.09 4.57 0.45 3.27 2012/13 15 0.50 0.69 4.44 2.63 5.82 4.32 16.89 10.51 0.00 0.88 0.00 1.88 0.94 7.57 9.44 10.76 7.75 9.88 1.44 0.69 3.00 2013/14 16 2.02 0.52 5.15 3.29 5.07 3.84 5.87 17.28 0.20 0.48 0.08 3.41 1.31 7.41 13.56 11.57 4.80 6.86 2.50 1.07 3.73 2014/15 17 2.64 0.40 6.45 8.70 7.58 5.24 2.51 13.90 0.13 1.43 0.04 1.48 1.84 0.99 8.61 10.53 9.55 7.31 4.75 0.90 5.02
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.69 10.39 3.45 5.78 0.78 0.43 0.47 1.77 0.60 13.54 0.04 6.64 45.58 4.31 4.44 1.08 1997/98 2 1.39 14.97 1.67 2.96 0.67 0.70 0.09 0.30 0.33 1.61 0.00 2.05 15.42 44.96 6.57 6.31 1998/99 3 0.89 8.50 1.15 1.40 4.06 0.26 0.37 0.48 0.07 1.81 0.00 3.58 13.19 49.13 9.46 5.65 1999/00 4 0.70 1.70 0.37 0.39 1.00 0.14 0.16 0.33 0.31 0.86 0.00 10.98 19.10 56.97 5.26 1.74 2000/01 5 0.12 2.00 0.29 0.89 1.88 0.29 0.08 0.52 0.29 0.52 0.00 7.31 24.48 51.97 4.44 4.92 2001/02 6 0.08 1.12 0.93 11.77 3.04 0.22 0.10 0.53 0.43 0.83 0.00 6.29 29.97 36.38 5.80 2.52 2002/03 7 0.07 2.73 0.87 4.73 0.12 0.30 0.18 0.27 0.11 0.46 0.00 1.89 17.27 55.46 10.88 4.66 2003/04 8 0.11 1.24 0.20 13.85 0.34 0.48 0.27 0.44 0.09 0.33 0.05 2.03 8.15 53.90 14.18 4.33 2004/05 9 0.29 2.82 0.68 6.71 0.03 0.06 0.29 0.39 0.10 0.65 0.00 3.53 10.05 53.31 17.48 3.60 2005/06 10 0.02 1.62 0.83 5.57 0.29 0.32 0.39 0.52 0.17 1.01 0.00 2.28 10.39 63.42 7.78 5.38 2006/07 11 0.13 3.74 0.79 5.07 1.80 0.39 0.18 0.61 0.02 0.34 0.05 4.21 13.01 50.11 15.33 4.24 2007/08 12 0.02 3.75 0.86 7.16 0.35 0.12 0.19 0.76 0.28 0.37 0.00 4.94 11.52 53.38 9.80 6.51 2008/09 13 0.11 3.39 0.65 7.44 0.38 0.13 0.31 0.85 0.20 0.40 0.16 3.92 15.04 51.50 10.43 5.10 2009/10 14 0.03 3.61 0.41 3.30 0.20 0.46 0.30 0.48 0.15 0.38 0.13 5.33 25.14 37.13 16.51 6.45 2010/11 15 0.04 0.31 0.27 8.24 0.37 0.04 0.19 0.23 0.19 0.27 0.06 4.21 14.12 41.68 21.57 8.20 2011/12 16 0.19 1.66 2.24 22.31 0.44 0.06 0.17 0.48 0.10 0.42 0.00 0.44 9.79 34.60 20.80 6.29 2012/13 17 0.71 1.61 0.44 8.09 0.49 0.12 0.12 1.00 0.02 0.07 0.02 0.32 10.01 46.35 25.51 5.12 2013/14 18 0.06 0.58 0.44 10.89 0.46 0.14 0.08 0.63 0.23 0.15 0.00 0.58 10.66 45.55 25.67 3.87 2014/15 19 0.04 0.24 3.13 18.13 0.41 0.19 0.24 1.07 0.45 0.43 0.13 0.49 15.19 26.24 24.48 9.12
37 Ringed plover: mean populations
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 5.00 6.00 1.50 0.00 0.00 0.50 0.00 2.50 2.00 16.50 0.00 0.50 1.00 0.00 0.00 15.00 1.00 0.00 6.50 0.00 15.00 73.00 1999/00 2 35.33 13.33 1.67 4.33 2.67 2.33 0.67 5.33 0.00 0.00 0.00 8.00 10.33 14.33 0.00 0.00 7.67 23.67 4.00 0.33 5.67 139.67 2000/01 3 35.67 4.00 5.33 4.00 5.33 2.67 0.00 0.00 1.00 9.00 0.00 8.00 0.33 4.00 7.67 0.33 1.33 8.33 13.67 129.67 15.00 255.33 2001/02 4 36.50 1.50 3.75 18.75 12.50 2.50 3.25 1.00 3.75 2.75 0.00 1.25 0.25 3.75 0.00 4.00 0.25 15.50 8.25 2.25 9.50 131.25 2002/03 5 41.25 1.75 1.75 2.75 2.00 1.50 0.00 1.25 1.00 3.00 0.00 0.00 0.50 0.50 1.00 1.50 1.00 24.25 18.50 0.00 3.75 107.25 2003/04 6 46.50 0.75 0.75 3.00 6.00 0.00 0.00 0.25 3.25 3.00 0.00 0.25 0.00 0.50 0.00 2.00 0.00 24.50 16.50 1.00 2.75 111.00 2004/05 7 67.75 2.50 1.00 4.25 5.25 0.25 0.25 0.00 8.50 16.00 0.00 0.00 0.00 0.75 0.00 6.50 0.00 13.75 31.75 10.25 6.00 174.75 2005/06 8 89.00 3.50 0.00 7.50 1.75 0.75 1.00 1.50 3.50 12.00 0.00 0.00 31.25 0.50 1.50 3.00 0.00 21.25 42.50 13.75 0.75 235.00 2006/07 9 115.25 3.25 0.50 3.75 0.25 8.25 0.00 0.25 10.25 3.25 0.00 0.00 4.00 0.00 0.00 1.75 2.50 15.50 9.50 4.25 0.50 183.00 2007/08 10 89.00 0.00 0.00 3.50 1.00 0.50 0.00 0.00 3.50 0.00 4.00 0.00 0.50 0.00 0.50 1.00 0.00 26.50 24.50 3.50 1.00 159.00 2008/09 11 96.67 0.67 0.00 5.33 3.33 7.33 3.33 0.00 15.33 4.33 0.33 3.67 0.67 0.00 2.00 0.33 0.00 22.67 5.33 3.00 1.00 175.33 2009/10 12 27.00 1.25 0.00 8.00 4.25 11.75 0.25 0.25 11.00 2.25 0.00 1.25 1.75 2.50 0.00 0.75 10.00 18.25 2.25 1.00 3.75 107.50 2010/11 13 31.25 1.25 0.00 5.75 2.50 7.00 1.00 0.25 9.00 9.00 0.50 0.00 0.00 0.00 0.00 1.75 0.50 23.00 3.25 0.25 4.75 101.00 2011/12 14 24.75 0.75 0.00 4.50 0.50 6.50 1.25 0.25 11.00 3.75 0.50 0.00 0.00 0.00 0.00 0.25 0.75 30.00 2.75 0.00 0.00 87.50 2012/13 15 25.50 0.00 0.00 7.00 7.00 0.00 0.00 0.00 0.50 1.00 0.00 0.00 9.50 0.00 1.00 0.00 4.50 28.00 2.50 0.00 1.50 88.00 2013/14 16 25.67 0.00 0.00 12.33 6.33 1.33 0.00 0.67 2.00 0.00 0.00 0.00 0.67 0.33 0.00 0.00 2.00 15.00 0.00 0.00 0.33 66.67 2014/15 17 17.33 0.67 0.00 2.67 7.00 0.00 0.00 0.00 10.00 5.67 0.00 0.00 0.67 0.00 0.00 0.00 1.67 26.67 0.67 3.00 0.00 76.00
ORWELL Section
Winter No. A22B A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 1.00 0.00 0.67 0.33 6.33 25.33 1.67 25.00 1.00 8.67 0.00 8.67 0.33 3.33 55.33 7.33 145.00 1997/98 2 0.00 0.40 0.80 57.00 1.80 0.80 11.20 19.40 1.00 6.40 0.00 32.40 0.00 0.20 12.40 1.20 145.00 1998/99 3 0.00 1.00 4.67 23.00 11.00 36.00 13.00 6.67 1.00 4.33 0.00 9.33 0.67 0.67 14.67 1.33 127.33 1999/00 4 0.00 0.00 1.00 14.25 2.00 0.50 21.25 18.75 4.25 32.25 0.00 20.25 13.00 0.50 61.50 2.50 192.00 2000/01 5 0.00 0.25 1.25 7.25 1.25 3.75 7.00 18.25 4.50 9.25 0.00 8.00 7.00 0.00 16.25 31.25 115.25 2001/02 6 0.00 5.00 5.00 7.50 2.50 2.75 9.25 28.00 4.00 8.75 0.25 18.00 0.50 0.75 21.75 9.50 123.50 2002/03 7 0.00 2.50 12.25 20.00 10.25 12.50 1.50 26.50 4.75 12.50 7.25 33.75 15.25 0.00 7.00 4.75 170.75 2003/04 8 0.00 0.00 27.25 8.00 2.75 2.00 3.50 34.25 1.00 2.25 6.75 28.75 3.50 0.00 59.25 8.50 187.75 2004/05 9 0.00 0.00 1.50 8.50 2.50 1.50 0.00 6.00 0.00 1.00 24.50 21.50 2.50 0.00 43.50 6.50 119.50 2005/06 10 0.00 0.00 5.33 0.00 4.67 1.00 1.33 24.33 0.00 20.67 16.33 7.67 0.67 0.00 13.67 0.00 95.67 2006/07 11 0.00 1.00 10.00 0.00 19.50 0.25 11.50 17.25 0.00 17.00 5.00 0.25 1.00 0.00 4.75 0.00 87.50 2007/08 12 0.00 0.67 3.33 0.00 17.67 0.00 0.00 16.33 0.00 5.00 1.67 5.33 0.33 1.33 0.00 0.00 51.67 2008/09 13 0.00 0.00 0.00 0.50 52.50 0.00 2.25 14.25 0.00 35.00 0.00 7.00 19.00 2.25 2.00 0.00 134.75 2009/10 14 0.00 0.00 0.00 0.00 39.67 0.00 0.00 6.00 0.67 22.33 2.67 2.00 1.67 0.33 1.67 0.00 77.00 2010/11 15 0.00 0.00 0.00 0.00 47.67 0.00 4.33 4.00 0.67 7.00 0.67 0.67 14.00 1.33 10.00 0.00 90.33 2011/12 16 0.00 0.00 0.00 0.00 30.00 0.00 0.33 19.00 1.00 6.00 0.00 2.00 0.00 0.00 9.00 0.00 67.33 2012/13 17 0.00 0.00 0.00 0.00 28.00 0.33 0.00 0.00 0.67 4.33 0.00 1.33 0.00 0.00 3.33 0.00 38.00 2013/14 18 0.00 0.00 0.00 0.00 23.75 1.00 0.00 95.50 0.00 1.25 0.00 15.50 0.00 0.00 0.00 0.00 137.00 2014/15 19 0.00 0.00 0.00 0.00 23.00 0.33 3.00 36.33 0.00 5.67 2.33 7.00 1.67 0.00 0.00 0.00 79.33
38 Ringed plover: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 6.85 8.22 2.05 0.00 0.00 0.68 0.00 3.42 2.74 22.60 0.00 0.68 1.37 0.00 0.00 20.55 1.37 0.00 8.90 0.00 20.55 1999/00 2 25.30 9.55 1.19 3.10 1.91 1.67 0.48 3.82 0.00 0.00 0.00 5.73 7.40 10.26 0.00 0.00 5.49 16.95 2.86 0.24 4.06 2000/01 3 13.97 1.57 2.09 1.57 2.09 1.04 0.00 0.00 0.39 3.52 0.00 3.13 0.13 1.57 3.00 0.13 0.52 3.26 5.35 50.78 5.87 2001/02 4 27.81 1.14 2.86 14.29 9.52 1.90 2.48 0.76 2.86 2.10 0.00 0.95 0.19 2.86 0.00 3.05 0.19 11.81 6.29 1.71 7.24 2002/03 5 38.46 1.63 1.63 2.56 1.86 1.40 0.00 1.17 0.93 2.80 0.00 0.00 0.47 0.47 0.93 1.40 0.93 22.61 17.25 0.00 3.50 2003/04 6 41.89 0.68 0.68 2.70 5.41 0.00 0.00 0.23 2.93 2.70 0.00 0.23 0.00 0.45 0.00 1.80 0.00 22.07 14.86 0.90 2.48 2004/05 7 38.77 1.43 0.57 2.43 3.00 0.14 0.14 0.00 4.86 9.16 0.00 0.00 0.00 0.43 0.00 3.72 0.00 7.87 18.17 5.87 3.43 2005/06 8 37.87 1.49 0.00 3.19 0.74 0.32 0.43 0.64 1.49 5.11 0.00 0.00 13.30 0.21 0.64 1.28 0.00 9.04 18.09 5.85 0.32 2006/07 9 62.98 1.78 0.27 2.05 0.14 4.51 0.00 0.14 5.60 1.78 0.00 0.00 2.19 0.00 0.00 0.96 1.37 8.47 5.19 2.32 0.27 2007/08 10 55.97 0.00 0.00 2.20 0.63 0.31 0.00 0.00 2.20 0.00 2.52 0.00 0.31 0.00 0.31 0.63 0.00 16.67 15.41 2.20 0.63 2008/09 11 55.13 0.38 0.00 3.04 1.90 4.18 1.90 0.00 8.75 2.47 0.19 2.09 0.38 0.00 1.14 0.19 0.00 12.93 3.04 1.71 0.57 2009/10 12 25.12 1.16 0.00 7.44 3.95 10.93 0.23 0.23 10.23 2.09 0.00 1.16 1.63 2.33 0.00 0.70 9.30 16.98 2.09 0.93 3.49 2010/11 13 30.94 1.24 0.00 5.69 2.48 6.93 0.99 0.25 8.91 8.91 0.50 0.00 0.00 0.00 0.00 1.73 0.50 22.77 3.22 0.25 4.70 2011/12 14 28.29 0.86 0.00 5.14 0.57 7.43 1.43 0.29 12.57 4.29 0.57 0.00 0.00 0.00 0.00 0.29 0.86 34.29 3.14 0.00 0.00 2012/13 15 28.98 0.00 0.00 7.95 7.95 0.00 0.00 0.00 0.57 1.14 0.00 0.00 10.80 0.00 1.14 0.00 5.11 31.82 2.84 0.00 1.70 2013/14 16 38.50 0.00 0.00 18.50 9.50 2.00 0.00 1.00 3.00 0.00 0.00 0.00 1.00 0.50 0.00 0.00 3.00 22.50 0.00 0.00 0.50 2014/15 17 22.81 0.88 0.00 3.51 9.21 0.00 0.00 0.00 13.16 7.46 0.00 0.00 0.88 0.00 0.00 0.00 2.19 35.09 0.88 3.95 0.00
ORWELL Section
Winter No. A23B A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.69 0.00 0.46 0.23 4.37 17.47 1.15 17.24 0.69 5.98 0.00 5.98 0.23 2.30 38.16 5.06 1997/98 2 0.00 0.28 0.55 39.31 1.24 0.55 7.72 13.38 0.69 4.41 0.00 22.34 0.00 0.14 8.55 0.83 1998/99 3 0.00 0.79 3.66 18.06 8.64 28.27 10.21 5.24 0.79 3.40 0.00 7.33 0.52 0.52 11.52 1.05 1999/00 4 0.00 0.00 0.52 7.42 1.04 0.26 11.07 9.77 2.21 16.80 0.00 10.55 6.77 0.26 32.03 1.30 2000/01 5 0.00 0.22 1.08 6.29 1.08 3.25 6.07 15.84 3.90 8.03 0.00 6.94 6.07 0.00 14.10 27.11 2001/02 6 0.00 4.05 4.05 6.07 2.02 2.23 7.49 22.67 3.24 7.09 0.20 14.57 0.40 0.61 17.61 7.69 2002/03 7 0.00 1.46 7.17 11.71 6.00 7.32 0.88 15.52 2.78 7.32 4.25 19.77 8.93 0.00 4.10 2.78 2003/04 8 0.00 0.00 14.51 4.26 1.46 1.07 1.86 18.24 0.53 1.20 3.60 15.31 1.86 0.00 31.56 4.53 2004/05 9 0.00 0.00 1.26 7.11 2.09 1.26 0.00 5.02 0.00 0.84 20.50 17.99 2.09 0.00 36.40 5.44 2005/06 10 0.00 0.00 5.57 0.00 4.88 1.05 1.39 25.44 0.00 21.60 17.07 8.01 0.70 0.00 14.29 0.00 2006/07 11 0.00 1.14 11.43 0.00 22.29 0.29 13.14 19.71 0.00 19.43 5.71 0.29 1.14 0.00 5.43 0.00 2007/08 12 0.00 1.29 6.45 0.00 34.19 0.00 0.00 31.61 0.00 9.68 3.23 10.32 0.65 2.58 0.00 0.00 2008/09 13 0.00 0.00 0.00 0.37 38.96 0.00 1.67 10.58 0.00 25.97 0.00 5.19 14.10 1.67 1.48 0.00 2009/10 14 0.00 0.00 0.00 0.00 51.52 0.00 0.00 7.79 0.87 29.00 3.46 2.60 2.16 0.43 2.16 0.00 2010/11 15 0.00 0.00 0.00 0.00 52.77 0.00 4.80 4.43 0.74 7.75 0.74 0.74 15.50 1.48 11.07 0.00 2011/12 16 0.00 0.00 0.00 0.00 44.55 0.00 0.50 28.22 1.49 8.91 0.00 2.97 0.00 0.00 13.37 0.00 2012/13 17 0.00 0.00 0.00 0.00 73.68 0.88 0.00 0.00 1.75 11.40 0.00 3.51 0.00 0.00 8.77 0.00 2013/14 18 0.00 0.00 0.00 0.00 17.34 0.73 0.00 69.71 0.00 0.91 0.00 11.31 0.00 0.00 0.00 0.00 2014/15 19 0.00 0.00 0.00 0.00 28.99 0.42 3.78 45.80 0.00 7.14 2.94 8.82 2.10 0.00 0.00 0.00
39 Grey plover: mean populations
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 10.50 7.00 109.00 10.50 4.00 247.00 30.00 36.00 195.00 122.50 0.00 100.00 3.50 26.00 106.50 675.00 80.00 177.00 4.50 21.50 17.00 1982.50 1999/00 2 12.00 28.00 46.67 48.33 61.00 365.33 127.67 35.33 0.00 10.67 0.00 38.00 17.33 13.67 82.00 126.33 206.67 182.67 23.67 38.67 43.33 1507.33 2000/01 3 8.00 25.67 155.67 83.67 48.67 411.00 175.00 21.33 1.33 3.67 0.00 10.33 7.33 27.00 90.33 145.00 301.00 191.67 18.67 48.67 44.67 1818.67 2001/02 4 53.50 38.00 135.25 61.25 18.00 69.25 33.00 36.50 7.75 64.00 0.50 48.25 5.00 5.75 49.75 108.25 340.50 142.75 28.25 110.50 104.00 1460.00 2002/03 5 34.00 38.25 188.75 118.25 30.25 117.50 161.25 33.75 1.25 13.00 0.25 34.00 4.75 12.25 61.25 195.50 457.75 133.75 25.00 23.75 30.50 1715.00 2003/04 6 30.00 29.25 133.00 107.50 59.50 88.25 38.00 35.25 4.75 12.00 0.50 53.25 24.00 24.50 32.00 195.75 376.50 190.50 15.75 9.00 32.50 1491.75 2004/05 7 42.50 51.25 45.00 96.50 75.00 71.50 69.00 22.25 0.25 19.25 0.00 32.00 7.00 16.25 17.00 214.00 457.50 293.75 42.00 12.75 44.00 1628.75 2005/06 8 23.75 26.75 81.25 60.00 125.25 123.50 44.75 28.00 0.75 20.25 0.00 42.00 8.00 21.25 99.75 262.00 304.50 230.25 36.25 15.50 50.25 1604.00 2006/07 9 62.00 92.00 102.25 113.75 39.00 55.00 80.25 62.00 2.00 7.75 0.00 29.00 9.50 23.75 36.75 108.50 243.50 282.75 19.00 13.75 44.00 1426.50 2007/08 10 8.00 16.50 70.00 41.50 73.50 413.00 62.50 31.00 0.00 1.50 1.00 1.50 1.00 2.00 224.50 272.00 655.00 132.00 16.00 9.50 45.00 2077.00 2008/09 11 105.67 28.33 32.00 30.00 76.67 196.33 207.00 15.67 0.00 0.33 0.33 1.33 1.00 14.67 54.67 344.33 187.33 16.33 13.33 35.67 56.67 1417.67 2009/10 12 30.50 56.75 78.75 81.25 67.00 159.00 34.00 35.75 0.25 11.75 0.00 6.50 13.25 64.75 11.75 316.50 79.25 55.00 13.50 28.50 39.00 1183.00 2010/11 13 39.50 87.00 91.25 69.75 36.75 72.50 28.50 21.75 0.75 8.50 0.50 9.00 4.00 18.00 59.00 69.75 66.00 90.50 28.75 13.00 43.00 857.75 2011/12 14 16.25 31.75 38.50 30.25 22.50 68.00 10.75 13.25 0.25 10.25 1.00 20.25 17.50 11.25 77.50 293.50 36.75 91.75 12.50 19.25 35.00 858.00 2012/13 15 15.50 29.00 61.50 45.00 67.00 72.50 12.50 4.50 0.00 61.50 0.00 11.00 4.00 3.50 13.00 398.00 63.00 238.00 8.50 52.00 67.50 1227.50 2013/14 16 14.33 17.00 58.67 38.33 40.33 44.00 20.33 3.33 1.00 5.67 0.00 4.00 14.33 7.33 28.33 222.67 46.00 93.67 20.00 9.00 33.00 721.33 2014/15 17 63.67 54.67 136.00 228.67 33.67 64.67 77.33 18.00 2.00 10.00 0.00 3.33 5.33 0.67 39.33 55.67 51.33 38.67 14.67 56.67 22.67 977.00
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 1.33 0.33 1.00 3.33 14.33 13.00 7.33 4.67 11.00 0.00 8.67 29.67 27.00 38.67 2.33 162.67 1997/98 2 0.00 1.60 2.20 0.40 5.80 6.60 10.20 10.80 7.80 8.80 0.00 19.20 39.60 81.60 46.80 0.60 242.00 1998/99 3 0.00 0.33 1.00 3.33 8.67 8.67 7.00 8.33 7.33 11.67 0.00 15.67 32.00 36.67 28.00 1.33 170.00 1999/00 4 0.00 0.75 1.00 3.00 5.50 1.75 11.00 16.50 16.00 11.50 0.00 24.50 83.25 49.75 19.50 0.50 244.50 2000/01 5 0.00 0.00 1.00 0.50 2.75 1.25 14.00 19.00 9.75 8.50 1.25 23.50 64.50 71.00 16.00 1.75 234.75 2001/02 6 0.00 0.00 0.00 22.25 5.25 2.50 9.25 17.50 5.25 6.75 12.75 20.00 35.00 48.75 17.75 2.00 205.00 2002/03 7 0.00 0.50 1.50 5.75 6.50 1.50 8.50 23.00 9.75 10.25 10.00 14.50 79.00 86.25 32.00 3.50 292.50 2003/04 8 0.00 0.00 0.00 4.50 3.50 2.25 13.75 26.00 3.25 10.00 8.25 25.50 66.75 80.00 20.50 2.75 267.00 2004/05 9 0.00 0.00 0.00 0.00 3.00 0.00 13.00 15.50 3.00 3.00 2.00 29.00 145.50 34.50 6.50 0.00 255.00 2005/06 10 0.00 0.00 0.00 2.00 12.67 3.00 17.33 16.33 1.00 10.33 7.33 26.00 85.33 31.33 6.33 1.33 220.33 2006/07 11 0.00 0.00 0.00 0.00 6.25 1.50 11.00 13.25 0.00 3.25 1.75 32.25 60.00 37.75 2.50 0.00 169.50 2007/08 12 0.00 0.00 0.00 0.00 3.33 0.67 18.33 17.00 1.67 9.00 2.00 17.33 109.00 17.00 2.00 0.00 197.33 2008/09 13 0.00 0.00 0.00 4.00 11.25 1.00 5.00 16.00 2.00 15.75 1.75 43.50 74.75 49.25 0.75 0.00 225.00 2009/10 14 0.00 0.00 0.00 0.33 8.33 0.33 6.00 16.67 2.33 11.00 14.33 9.33 126.33 92.00 7.33 0.00 294.33 2010/11 15 0.00 7.00 0.00 0.00 8.00 0.33 5.67 14.67 2.00 4.33 0.33 10.67 86.33 45.00 9.00 0.67 194.00 2011/12 16 0.00 2.33 2.67 0.00 6.67 0.67 2.67 12.67 3.67 5.33 1.00 8.33 54.00 88.67 13.33 1.67 203.67 2012/13 17 0.00 0.00 0.00 0.00 10.00 0.33 2.33 49.67 1.67 6.67 1.00 11.00 35.33 57.33 7.00 1.33 183.67 2013/14 18 0.00 0.00 0.00 1.00 8.25 1.75 6.50 28.00 1.25 4.50 0.00 25.25 53.50 54.50 2.75 1.00 188.25 2014/15 19 0.00 0.00 0.67 0.00 6.00 0.33 3.67 19.33 1.33 7.33 1.67 10.00 119.00 82.33 1.33 0.00 253.00
40 Grey plover: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 0.53 0.35 5.50 0.53 0.20 12.46 1.51 1.82 9.84 6.18 0.00 5.04 0.18 1.31 5.37 34.05 4.04 8.93 0.23 1.08 0.86 1999/00 2 0.80 1.86 3.10 3.21 4.05 24.24 8.47 2.34 0.00 0.71 0.00 2.52 1.15 0.91 5.44 8.38 13.71 12.12 1.57 2.57 2.87 2000/01 3 0.44 1.41 8.56 4.60 2.68 22.60 9.62 1.17 0.07 0.20 0.00 0.57 0.40 1.48 4.97 7.97 16.55 10.54 1.03 2.68 2.46 2001/02 4 3.66 2.60 9.26 4.20 1.23 4.74 2.26 2.50 0.53 4.38 0.03 3.30 0.34 0.39 3.41 7.41 23.32 9.78 1.93 7.57 7.12 2002/03 5 1.98 2.23 11.01 6.90 1.76 6.85 9.40 1.97 0.07 0.76 0.01 1.98 0.28 0.71 3.57 11.40 26.69 7.80 1.46 1.38 1.78 2003/04 6 2.01 1.96 8.92 7.21 3.99 5.92 2.55 2.36 0.32 0.80 0.03 3.57 1.61 1.64 2.15 13.12 25.24 12.77 1.06 0.60 2.18 2004/05 7 2.61 3.15 2.76 5.92 4.60 4.39 4.24 1.37 0.02 1.18 0.00 1.96 0.43 1.00 1.04 13.14 28.09 18.04 2.58 0.78 2.70 2005/06 8 1.48 1.67 5.07 3.74 7.81 7.70 2.79 1.75 0.05 1.26 0.00 2.62 0.50 1.32 6.22 16.33 18.98 14.35 2.26 0.97 3.13 2006/07 9 4.35 6.45 7.17 7.97 2.73 3.86 5.63 4.35 0.14 0.54 0.00 2.03 0.67 1.66 2.58 7.61 17.07 19.82 1.33 0.96 3.08 2007/08 10 0.39 0.79 3.37 2.00 3.54 19.88 3.01 1.49 0.00 0.07 0.05 0.07 0.05 0.10 10.81 13.10 31.54 6.36 0.77 0.46 2.17 2008/09 11 7.45 2.00 2.26 2.12 5.41 13.85 14.60 1.11 0.00 0.02 0.02 0.09 0.07 1.03 3.86 24.29 13.21 1.15 0.94 2.52 4.00 2009/10 12 2.58 4.80 6.66 6.87 5.66 13.44 2.87 3.02 0.02 0.99 0.00 0.55 1.12 5.47 0.99 26.75 6.70 4.65 1.14 2.41 3.30 2010/11 13 4.61 10.14 10.64 8.13 4.28 8.45 3.32 2.54 0.09 0.99 0.06 1.05 0.47 2.10 6.88 8.13 7.69 10.55 3.35 1.52 5.01 2011/12 14 1.89 3.70 4.49 3.53 2.62 7.93 1.25 1.54 0.03 1.19 0.12 2.36 2.04 1.31 9.03 34.21 4.28 10.69 1.46 2.24 4.08 2012/13 15 1.26 2.36 5.01 3.67 5.46 5.91 1.02 0.37 0.00 5.01 0.00 0.90 0.33 0.29 1.06 32.42 5.13 19.39 0.69 4.24 5.50 2013/14 16 1.99 2.36 8.13 5.31 5.59 6.10 2.82 0.46 0.14 0.79 0.00 0.55 1.99 1.02 3.93 30.87 6.38 12.99 2.77 1.25 4.57 2014/15 17 6.52 5.60 13.92 23.40 3.45 6.62 7.92 1.84 0.20 1.02 0.00 0.34 0.55 0.07 4.03 5.70 5.25 3.96 1.50 5.80 2.32
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.82 0.20 0.61 2.05 8.81 7.99 4.51 2.87 6.76 0.00 5.33 18.24 16.60 23.77 1.43 1997/98 2 0.00 0.66 0.91 0.17 2.40 2.73 4.21 4.46 3.22 3.64 0.00 7.93 16.36 33.72 19.34 0.25 1998/99 3 0.00 0.20 0.59 1.96 5.10 5.10 4.12 4.90 4.31 6.86 0.00 9.22 18.82 21.57 16.47 0.78 1999/00 4 0.00 0.31 0.41 1.23 2.25 0.72 4.50 6.75 6.54 4.70 0.00 10.02 34.05 20.35 7.98 0.20 2000/01 5 0.00 0.00 0.43 0.21 1.17 0.53 5.96 8.09 4.15 3.62 0.53 10.01 27.48 30.24 6.82 0.75 2001/02 6 0.00 0.00 0.00 10.85 2.56 1.22 4.51 8.54 2.56 3.29 6.22 9.76 17.07 23.78 8.66 0.98 2002/03 7 0.00 0.17 0.51 1.97 2.22 0.51 2.91 7.86 3.33 3.50 3.42 4.96 27.01 29.49 10.94 1.20 2003/04 8 0.00 0.00 0.00 1.69 1.31 0.84 5.15 9.74 1.22 3.75 3.09 9.55 25.00 29.96 7.68 1.03 2004/05 9 0.00 0.00 0.00 0.00 1.18 0.00 5.10 6.08 1.18 1.18 0.78 11.37 57.06 13.53 2.55 0.00 2005/06 10 0.00 0.00 0.00 0.91 5.75 1.36 7.87 7.41 0.45 4.69 3.33 11.80 38.73 14.22 2.87 0.61 2006/07 11 0.00 0.00 0.00 0.00 3.69 0.88 6.49 7.82 0.00 1.92 1.03 19.03 35.40 22.27 1.47 0.00 2007/08 12 0.00 0.00 0.00 0.00 1.69 0.34 9.29 8.61 0.84 4.56 1.01 8.78 55.24 8.61 1.01 0.00 2008/09 13 0.00 0.00 0.00 1.78 5.00 0.44 2.22 7.11 0.89 7.00 0.78 19.33 33.22 21.89 0.33 0.00 2009/10 14 0.00 0.00 0.00 0.11 2.83 0.11 2.04 5.66 0.79 3.74 4.87 3.17 42.92 31.26 2.49 0.00 2010/11 15 0.00 3.61 0.00 0.00 4.12 0.17 2.92 7.56 1.03 2.23 0.17 5.50 44.50 23.20 4.64 0.34 2011/12 16 0.00 1.15 1.31 0.00 3.27 0.33 1.31 6.22 1.80 2.62 0.49 4.09 26.51 43.54 6.55 0.82 2012/13 17 0.00 0.00 0.00 0.00 5.44 0.18 1.27 27.04 0.91 3.63 0.54 5.99 19.24 31.22 3.81 0.73 2013/14 18 0.00 0.00 0.00 0.53 4.38 0.93 3.45 14.87 0.66 2.39 0.00 13.41 28.42 28.95 1.46 0.53 2014/15 19 0.00 0.00 0.26 0.00 2.37 0.13 1.45 7.64 0.53 2.90 0.66 3.95 47.04 32.54 0.53 0.00
41 Knot: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 536.00 52.50 23.50 87.50 0.00 45.00 482.00 0.00 0.00 37.50 0.00 1000.00 661.00 400.00 21.50 145.00 0.00 91.00 0.00 62.50 289.00 3934.00 1999/00 2 140.67 8.00 185.33 0.00 0.00 65.33 31.00 111.33 0.00 97.67 0.00 492.00 237.33 52.67 66.00 8.00 351.00 307.33 0.00 145.67 0.00 2299.33 2000/01 3 83.33 7.67 150.67 35.67 0.00 513.67 2.67 506.33 1.00 417.67 0.00 1710.00 269.33 524.00 0.00 15.33 288.33 216.67 0.00 44.00 280.33 5066.67 2001/02 4 164.00 0.00 47.75 10.00 0.00 896.25 183.00 292.25 0.00 102.50 0.00 715.00 322.00 466.50 152.50 109.00 160.75 376.25 0.00 48.50 312.50 4358.75 2002/03 5 407.50 3.50 131.75 360.50 0.00 199.25 166.25 905.75 0.00 86.00 0.00 1232.75 105.75 148.25 0.00 32.50 15.00 266.25 0.50 13.00 309.25 4383.75 2003/04 6 279.50 0.00 2.00 39.75 0.00 388.75 70.50 1352.25 0.25 213.00 0.00 1025.00 282.50 251.75 32.50 170.75 191.75 416.50 0.00 41.00 185.25 4943.00 2004/05 7 130.75 14.00 39.00 109.25 0.00 367.25 396.75 20.25 0.50 185.50 0.00 520.00 328.25 149.25 29.25 148.00 1628.75 1258.25 3.50 12.50 57.75 5398.75 2005/06 8 6.00 0.75 21.25 23.25 0.00 1053.00 170.25 1368.50 10.50 31.75 0.00 69.25 549.75 1227.25 0.00 268.25 1137.50 712.00 12.75 30.00 307.00 6999.00 2006/07 9 156.25 182.50 551.25 669.00 0.00 290.75 346.25 1575.25 15.25 70.00 0.00 910.25 1855.00 649.00 0.00 184.50 1317.50 1305.50 0.00 15.00 847.00 10940.25 2007/08 10 57.00 0.00 113.00 4.00 0.00 594.00 390.00 370.50 5.50 465.00 0.00 52.50 29.50 31.00 51.00 228.50 330.00 661.00 0.00 11.00 572.50 3966.00 2008/09 11 254.67 3.33 20.33 213.33 200.00 2215.67 257.33 218.00 4.00 189.00 0.00 188.67 222.33 182.00 0.00 67.00 114.00 707.67 0.00 0.33 99.00 5156.67 2009/10 12 153.25 188.75 72.25 180.25 0.00 755.50 83.75 297.50 49.00 31.75 0.00 856.25 729.50 372.75 0.00 50.25 85.25 273.50 0.00 197.25 232.50 4609.25 2010/11 13 898.00 16.00 116.00 212.25 1.25 492.25 324.50 609.25 3.50 2.00 0.00 420.25 245.00 400.00 375.00 44.50 108.50 752.00 1.75 51.25 969.75 6043.00 2011/12 14 74.00 1.00 82.00 108.75 123.50 1018.00 91.25 80.25 1.75 325.50 0.00 633.75 125.00 1004.50 40.25 296.75 205.00 365.50 0.00 201.00 91.00 4868.75 2012/13 15 220.00 0.00 8.50 158.00 12.00 1933.00 42.50 199.50 0.00 45.50 0.00 458.50 117.50 1356.50 8.00 197.00 240.00 353.00 0.00 125.00 1422.00 6896.50 2013/14 16 99.33 5.33 22.33 48.00 103.67 2612.67 692.67 720.33 0.00 30.33 0.00 231.00 890.33 5.33 667.33 575.67 67.33 75.67 0.00 528.33 502.00 7877.67 2014/15 17 248.67 0.00 94.67 0.00 0.00 146.67 515.00 582.67 31.33 1188.67 0.00 4.33 990.67 233.33 0.67 156.33 50.33 226.00 0.00 406.67 866.67 5742.67
ORWELL Section32B
Winter No. 4BA2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 0.00 0.00 0.00 0.00 0.00 2.33 0.00 0.00 0.00 0.00 0.00 316.67 275.33 24.00 6.00 624.33 1997/98 2 0.00 89.80 8.80 43.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 200.00 290.00 696.00 229.20 51.40 1608.20 1998/99 3 0.00 0.00 0.00 34.67 12.33 0.00 2.67 0.00 0.00 0.00 0.00 200.00 256.67 165.00 105.00 221.67 998.00 1999/00 4 0.50 107.00 6.00 267.00 1.75 0.00 0.00 0.00 0.00 1.75 0.00 75.00 340.00 0.50 150.00 6.75 956.25 2000/01 5 0.00 55.50 0.00 60.00 6.50 0.00 0.00 0.50 0.00 0.00 0.00 7.75 285.75 27.00 317.25 39.75 800.00 2001/02 6 0.00 0.00 0.00 22.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 30.75 286.75 3.75 204.25 0.00 548.00 2002/03 7 0.00 8.00 32.00 570.00 24.75 9.50 0.00 0.00 0.00 6.75 33.50 52.00 339.75 189.25 540.00 303.75 2109.25 2003/04 8 0.00 0.00 30.25 109.50 140.75 0.25 40.25 0.00 0.00 6.75 5.50 3.25 420.50 90.75 875.00 90.00 1812.75 2004/05 9 0.00 0.00 0.00 34.00 26.00 0.00 0.00 0.00 0.00 0.00 25.50 2.00 1300.00 301.50 186.50 237.50 2113.00 2005/06 10 0.00 0.00 0.00 42.33 0.67 16.00 333.33 0.00 0.00 0.00 0.00 7.00 535.33 86.33 40.00 1.67 1062.67 2006/07 11 0.00 0.00 0.00 172.75 4.75 52.00 21.00 0.50 0.00 0.00 0.00 10.00 60.50 392.25 1.00 0.00 714.75 2007/08 12 0.00 0.00 5.33 111.33 17.67 16.67 13.67 0.00 0.00 0.33 330.00 393.33 530.67 0.33 29.67 9.00 1458.00 2008/09 13 0.00 2.50 0.50 113.25 1.75 8.00 2.50 0.25 0.00 49.50 23.50 2.00 783.50 193.25 750.00 0.50 1931.00 2009/10 14 0.00 0.00 0.00 31.33 24.33 10.33 0.00 1.33 0.00 52.67 64.00 80.67 843.33 1204.00 543.33 0.00 2855.33 2010/11 15 0.00 10.33 10.00 48.33 141.33 0.00 2.33 0.00 0.00 15.00 0.67 5.67 543.33 254.67 18.00 23.67 1073.33 2011/12 16 0.00 14.67 0.00 137.00 2.67 10.00 0.00 14.67 0.00 0.00 18.33 5.67 729.00 699.33 214.00 0.00 1845.33 2012/13 17 0.00 2.67 0.00 13.00 16.33 53.67 0.00 0.00 0.00 0.33 1.00 7.00 141.00 350.00 933.33 0.00 1518.33 2013/14 18 0.00 0.00 30.00 8.00 132.50 13.25 4.75 0.75 0.00 0.00 0.00 3.75 19.50 649.75 1.50 0.00 863.75 2014/15 19 0.00 20.00 30.00 11.00 0.00 11.67 0.00 0.00 0.00 0.00 0.33 0.00 64.00 252.00 0.67 0.00 389.67
42 Knot: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 13.62 1.33 0.60 2.22 0.00 1.14 12.25 0.00 0.00 0.95 0.00 25.42 16.80 10.17 0.55 3.69 0.00 2.31 0.00 1.59 7.35 1999/00 2 6.12 0.35 8.06 0.00 0.00 2.84 1.35 4.84 0.00 4.25 0.00 21.40 10.32 2.29 2.87 0.35 15.27 13.37 0.00 6.34 0.00 2000/01 3 1.64 0.15 2.97 0.70 0.00 10.14 0.05 9.99 0.02 8.24 0.00 33.75 5.32 10.34 0.00 0.30 5.69 4.28 0.00 0.87 5.53 2001/02 4 3.76 0.00 1.10 0.23 0.00 20.56 4.20 6.70 0.00 2.35 0.00 16.40 7.39 10.70 3.50 2.50 3.69 8.63 0.00 1.11 7.17 2002/03 5 9.30 0.08 3.01 8.22 0.00 4.55 3.79 20.66 0.00 1.96 0.00 28.12 2.41 3.38 0.00 0.74 0.34 6.07 0.01 0.30 7.05 2003/04 6 5.65 0.00 0.04 0.80 0.00 7.86 1.43 27.36 0.01 4.31 0.00 20.74 5.72 5.09 0.66 3.45 3.88 8.43 0.00 0.83 3.75 2004/05 7 2.42 0.26 0.72 2.02 0.00 6.80 7.35 0.38 0.01 3.44 0.00 9.63 6.08 2.76 0.54 2.74 30.17 23.31 0.06 0.23 1.07 2005/06 8 0.09 0.01 0.30 0.33 0.00 15.05 2.43 19.55 0.15 0.45 0.00 0.99 7.85 17.53 0.00 3.83 16.25 10.17 0.18 0.43 4.39 2006/07 9 1.43 1.67 5.04 6.12 0.00 2.66 3.16 14.40 0.14 0.64 0.00 8.32 16.96 5.93 0.00 1.69 12.04 11.93 0.00 0.14 7.74 2007/08 10 1.44 0.00 2.85 0.10 0.00 14.98 9.83 9.34 0.14 11.72 0.00 1.32 0.74 0.78 1.29 5.76 8.32 16.67 0.00 0.28 14.44 2008/09 11 4.94 0.06 0.39 4.14 3.88 42.97 4.99 4.23 0.08 3.67 0.00 3.66 4.31 3.53 0.00 1.30 2.21 13.72 0.00 0.01 1.92 2009/10 12 3.32 4.10 1.57 3.91 0.00 16.39 1.82 6.45 1.06 0.69 0.00 18.58 15.83 8.09 0.00 1.09 1.85 5.93 0.00 4.28 5.04 2010/11 13 14.86 0.26 1.92 3.51 0.02 8.15 5.37 10.08 0.06 0.03 0.00 6.95 4.05 6.62 6.21 0.74 1.80 12.44 0.03 0.85 16.05 2011/12 14 1.52 0.02 1.68 2.23 2.54 20.91 1.87 1.65 0.04 6.69 0.00 13.02 2.57 20.63 0.83 6.09 4.21 7.51 0.00 4.13 1.87 2012/13 15 3.19 0.00 0.12 2.29 0.17 28.03 0.62 2.89 0.00 0.66 0.00 6.65 1.70 19.67 0.12 2.86 3.48 5.12 0.00 1.81 20.62 2013/14 16 1.26 0.07 0.28 0.61 1.32 33.17 8.79 9.14 0.00 0.39 0.00 2.93 11.30 0.07 8.47 7.31 0.85 0.96 0.00 6.71 6.37 2014/15 17 4.33 0.00 1.65 0.00 0.00 2.55 8.97 10.15 0.55 20.70 0.00 0.08 17.25 4.06 0.01 2.72 0.88 3.94 0.00 7.08 15.09
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.00 0.00 0.00 0.00 0.00 0.37 0.00 0.00 0.00 0.00 0.00 50.72 44.10 3.84 0.96 1997/98 2 0.00 5.58 0.55 2.67 0.00 0.00 0.00 0.00 0.00 0.00 0.00 12.44 18.03 43.28 14.25 3.20 1998/99 3 0.00 0.00 0.00 3.47 1.24 0.00 0.27 0.00 0.00 0.00 0.00 20.04 25.72 16.53 10.52 22.21 1999/00 4 0.05 11.19 0.63 27.92 0.18 0.00 0.00 0.00 0.00 0.18 0.00 7.84 35.56 0.05 15.69 0.71 2000/01 5 0.00 6.94 0.00 7.50 0.81 0.00 0.00 0.06 0.00 0.00 0.00 0.97 35.72 3.38 39.66 4.97 2001/02 6 0.00 0.00 0.00 4.11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.61 52.33 0.68 37.27 0.00 2002/03 7 0.00 0.38 1.52 27.02 1.17 0.45 0.00 0.00 0.00 0.32 1.59 2.47 16.11 8.97 25.60 14.40 2003/04 8 0.00 0.00 1.67 6.04 7.76 0.01 2.22 0.00 0.00 0.37 0.30 0.18 23.20 5.01 48.27 4.96 2004/05 9 0.00 0.00 0.00 1.61 1.23 0.00 0.00 0.00 0.00 0.00 1.21 0.09 61.52 14.27 8.83 11.24 2005/06 10 0.00 0.00 0.00 3.98 0.06 1.51 31.37 0.00 0.00 0.00 0.00 0.66 50.38 8.12 3.76 0.16 2006/07 11 0.00 0.00 0.00 24.17 0.66 7.28 2.94 0.07 0.00 0.00 0.00 1.40 8.46 54.88 0.14 0.00 2007/08 12 0.00 0.00 0.37 7.64 1.21 1.14 0.94 0.00 0.00 0.02 22.63 26.98 36.40 0.02 2.03 0.62 2008/09 13 0.00 0.13 0.03 5.86 0.09 0.41 0.13 0.01 0.00 2.56 1.22 0.10 40.57 10.01 38.84 0.03 2009/10 14 0.00 0.00 0.00 1.10 0.85 0.36 0.00 0.05 0.00 1.84 2.24 2.83 29.54 42.17 19.03 0.00 2010/11 15 0.00 0.96 0.93 4.50 13.17 0.00 0.22 0.00 0.00 1.40 0.06 0.53 50.62 23.73 1.68 2.20 2011/12 16 0.00 0.79 0.00 7.42 0.14 0.54 0.00 0.79 0.00 0.00 0.99 0.31 39.51 37.90 11.60 0.00 2012/13 17 0.00 0.18 0.00 0.86 1.08 3.53 0.00 0.00 0.00 0.02 0.07 0.46 9.29 23.05 61.47 0.00 2013/14 18 0.00 0.00 3.47 0.93 15.34 1.53 0.55 0.09 0.00 0.00 0.00 0.43 2.26 75.22 0.17 0.00 2014/15 19 0.00 5.13 7.70 2.82 0.00 2.99 0.00 0.00 0.00 0.00 0.09 0.00 16.42 64.67 0.17 0.00
43 Dunlin: mean numbers
STOUR Section26B Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 263.00 130.50 295.50 48.00 75.00 994.50 925.00 912.00 237.50 710.50 0.50 1060.00 137.00 55.00 1279.50 4090.00 115.00 273.00 5.50 150.50 664.00 12421.50 1999/00 2 235.00 202.00 1007.67 383.33 43.33 1104.00 968.67 1168.67 69.00 540.00 1.00 1410.00 385.67 75.67 260.00 394.33 330.00 631.67 71.00 253.00 771.67 10305.67 2000/01 3 522.33 361.00 1115.67 342.33 78.67 1034.67 846.00 1589.67 11.67 122.00 0.00 1048.67 238.00 1383.00 753.00 667.33 341.67 603.00 65.67 207.33 782.67 12114.33 2001/02 4 660.75 127.50 1038.75 728.00 51.25 1246.50 944.00 868.25 24.50 230.50 0.75 1905.00 882.25 1332.25 439.25 770.50 285.50 526.75 151.75 406.00 639.50 13259.50 2002/03 5 561.50 107.50 1132.00 518.25 41.00 829.75 824.50 977.50 255.50 334.00 2.50 1190.00 167.50 302.75 286.00 778.50 277.75 669.50 86.25 332.25 669.00 10343.50 2003/04 6 271.75 42.75 667.00 720.00 111.00 502.25 474.50 566.50 14.00 248.00 0.25 751.25 497.75 581.00 614.25 1531.00 164.00 701.50 68.00 176.00 941.50 9644.25 2004/05 7 458.75 55.00 1234.50 809.50 90.25 908.75 705.75 360.00 2.50 228.00 0.00 827.75 544.25 839.25 449.50 1918.50 390.00 1142.00 153.25 138.50 297.75 11553.75 2005/06 8 292.50 61.50 658.00 384.25 161.25 1237.00 1412.75 1049.50 11.25 63.50 0.00 195.50 957.25 658.25 904.75 1706.50 153.75 1645.00 203.00 187.25 524.50 12467.25 2006/07 9 531.75 102.00 1009.75 802.50 80.25 698.50 642.75 1663.75 7.75 129.25 0.00 640.00 1261.50 398.00 798.50 1692.75 597.50 1168.75 17.75 73.50 894.75 13211.25 2007/08 10 445.00 61.00 1003.50 367.50 80.00 1730.00 2265.00 1120.00 111.50 76.00 1.50 40.50 62.00 28.50 1274.00 2016.00 200.00 2237.50 64.00 83.50 641.00 13908.00 2008/09 11 535.33 136.33 650.67 279.33 110.00 1386.33 1803.00 340.00 57.67 18.00 6.33 97.00 406.33 916.00 1006.67 3018.67 335.00 1270.67 72.00 160.67 596.67 13202.67 2009/10 12 275.00 85.50 521.50 1654.00 113.25 1165.50 1075.00 3191.75 112.25 31.00 2.75 164.25 810.50 1163.00 554.50 1990.50 347.50 934.00 385.50 276.75 516.25 15370.25 2010/11 13 808.50 123.00 446.75 888.25 102.75 1155.75 829.75 2096.25 57.75 85.75 11.50 617.00 209.00 364.25 423.25 1773.75 210.25 1394.75 91.50 335.00 1282.75 13307.50 2011/12 14 399.75 285.75 368.00 826.25 71.75 2052.75 855.75 888.75 179.25 446.75 13.75 955.75 423.00 300.00 491.00 3025.25 138.25 1421.25 64.75 133.00 241.50 13582.25 2012/13 15 281.50 91.50 683.50 414.50 78.50 1543.50 407.50 264.50 17.00 190.00 2.00 256.50 100.00 43.50 731.00 2923.00 136.00 1544.00 86.50 175.00 1176.50 11146.00 2013/14 16 581.00 114.00 637.67 178.67 164.00 970.33 1534.00 29.33 48.33 243.33 0.00 335.00 116.33 153.00 775.67 955.33 63.33 681.67 67.00 209.67 328.00 8185.67 2014/15 17 620.33 112.67 1653.00 3245.67 180.00 577.33 984.67 610.00 17.67 132.00 0.00 120.33 164.33 106.67 181.00 1207.67 127.67 1338.67 46.00 173.33 934.67 12533.67
ORWELL Section
Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total27B 1996/97 1 2.67 91.67 21.33 955.33 210.00 355.00 437.00 246.00 8.33 987.67 0.00 228.33 790.00 1553.00 651.33 69.00 6606.67 1997/98 2 0.00 170.60 9.20 392.40 156.00 81.00 67.80 94.60 14.60 733.40 0.40 215.60 470.00 1212.60 670.60 562.00 4850.80 1998/99 3 1.00 55.33 11.00 487.00 177.33 111.67 90.33 96.67 691.67 391.33 0.00 406.00 233.33 669.00 932.00 646.67 5000.33 1999/00 4 0.25 23.50 10.25 169.25 44.50 5.75 112.75 111.75 50.25 441.25 0.00 299.00 435.75 660.25 525.75 133.00 3023.25 2000/01 5 0.00 9.00 27.25 189.25 31.75 5.50 38.50 55.50 14.00 276.00 0.00 178.25 295.25 461.25 460.00 183.50 2225.00 2001/02 6 0.00 1.75 42.50 424.75 154.50 4.25 56.25 61.75 8.75 237.50 40.75 306.00 554.25 742.75 819.50 239.50 3694.75 2002/03 7 0.00 45.50 214.50 567.50 133.75 19.75 50.75 109.75 12.50 563.50 18.25 194.25 370.50 513.50 791.75 535.00 4140.75 2003/04 8 0.00 10.50 75.50 457.50 64.00 6.50 69.75 287.75 1.00 296.75 7.25 194.75 550.00 656.25 505.00 463.75 3646.25 2004/05 9 0.00 0.00 13.50 214.00 16.50 3.50 75.00 91.00 0.00 653.00 5.50 150.50 414.00 1110.50 406.00 158.50 3311.50 2005/06 10 0.00 0.00 92.33 434.00 13.00 0.67 122.00 260.00 0.33 318.00 0.67 136.33 681.67 315.67 314.67 2.33 2691.67 2006/07 11 0.00 0.00 171.75 292.75 75.25 0.00 650.00 149.00 4.00 291.00 2.25 87.25 614.75 406.50 22.75 15.75 2783.00 2007/08 12 0.00 0.67 2.33 18.33 48.33 45.67 132.00 288.33 0.33 587.67 1.33 385.00 574.33 754.00 5.67 0.00 2844.00 2008/09 13 0.00 0.00 0.50 132.25 72.50 11.25 27.50 76.75 0.00 356.75 0.00 231.25 321.50 501.00 262.25 7.75 2001.25 2009/10 14 0.00 2.33 0.00 1.00 24.67 0.00 2.33 187.33 3.00 223.33 1.67 236.33 611.33 428.00 256.00 0.00 1977.33 2010/11 15 0.00 15.33 12.33 84.33 279.67 0.00 19.33 94.67 12.00 230.33 1.00 137.67 220.00 1028.33 555.00 16.00 2706.00 2011/12 16 0.00 3.67 2.67 392.67 158.33 6.67 9.00 295.33 38.00 95.00 38.67 153.33 190.00 1169.00 648.33 11.33 3212.00 2012/13 17 0.00 2.67 0.00 26.67 180.00 20.67 156.33 541.67 14.33 109.33 3.67 188.67 223.00 721.00 391.00 15.00 2594.00 2013/14 18 0.00 2.25 1.25 160.00 177.00 10.75 43.00 456.50 9.75 60.50 0.75 300.00 129.25 600.50 2.25 0.00 1953.75 2014/15 19 0.00 0.00 1.67 7.67 186.00 0.00 3.33 225.33 33.00 120.67 8.67 326.33 921.67 1151.33 3.00 0.00 2988.67
44 Dunlin: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 2.12 1.05 2.38 0.39 0.60 8.01 7.45 7.34 1.91 5.72 0.00 8.53 1.10 0.44 10.30 32.93 0.93 2.20 0.04 1.21 5.35 1999/00 2 2.28 1.96 9.78 3.72 0.42 10.71 9.40 11.34 0.67 5.24 0.01 13.68 3.74 0.73 2.52 3.83 3.20 6.13 0.69 2.45 7.49 2000/01 3 4.31 2.98 9.21 2.83 0.65 8.54 6.98 13.12 0.10 1.01 0.00 8.66 1.96 11.42 6.22 5.51 2.82 4.98 0.54 1.71 6.46 2001/02 4 4.98 0.96 7.83 5.49 0.39 9.40 7.12 6.55 0.18 1.74 0.01 14.37 6.65 10.05 3.31 5.81 2.15 3.97 1.14 3.06 4.82 2002/03 5 5.43 1.04 10.94 5.01 0.40 8.02 7.97 9.45 2.47 3.23 0.02 11.50 1.62 2.93 2.77 7.53 2.69 6.47 0.83 3.21 6.47 2003/04 6 2.82 0.44 6.92 7.47 1.15 5.21 4.92 5.87 0.15 2.57 0.00 7.79 5.16 6.02 6.37 15.87 1.70 7.27 0.71 1.82 9.76 2004/05 7 3.97 0.48 10.68 7.01 0.78 7.87 6.11 3.12 0.02 1.97 0.00 7.16 4.71 7.26 3.89 16.60 3.38 9.88 1.33 1.20 2.58 2005/06 8 2.35 0.49 5.28 3.08 1.29 9.92 11.33 8.42 0.09 0.51 0.00 1.57 7.68 5.28 7.26 13.69 1.23 13.19 1.63 1.50 4.21 2006/07 9 4.02 0.77 7.64 6.07 0.61 5.29 4.87 12.59 0.06 0.98 0.00 4.84 9.55 3.01 6.04 12.81 4.52 8.85 0.13 0.56 6.77 2007/08 10 3.20 0.44 7.22 2.64 0.58 12.44 16.29 8.05 0.80 0.55 0.01 0.29 0.45 0.20 9.16 14.50 1.44 16.09 0.46 0.60 4.61 2008/09 11 4.05 1.03 4.93 2.12 0.83 10.50 13.66 2.58 0.44 0.14 0.05 0.73 3.08 6.94 7.62 22.86 2.54 9.62 0.55 1.22 4.52 2009/10 12 1.79 0.56 3.39 10.76 0.74 7.58 6.99 20.77 0.73 0.20 0.02 1.07 5.27 7.57 3.61 12.95 2.26 6.08 2.51 1.80 3.36 2010/11 13 6.08 0.92 3.36 6.67 0.77 8.68 6.24 15.75 0.43 0.64 0.09 4.64 1.57 2.74 3.18 13.33 1.58 10.48 0.69 2.52 9.64 2011/12 14 2.94 2.10 2.71 6.08 0.53 15.11 6.30 6.54 1.32 3.29 0.10 7.04 3.11 2.21 3.62 22.27 1.02 10.46 0.48 0.98 1.78 2012/13 15 2.53 0.82 6.13 3.72 0.70 13.85 3.66 2.37 0.15 1.70 0.02 2.30 0.90 0.39 6.56 26.22 1.22 13.85 0.78 1.57 10.56 2013/14 16 7.10 1.39 7.79 2.18 2.00 11.85 18.74 0.36 0.59 2.97 0.00 4.09 1.42 1.87 9.48 11.67 0.77 8.33 0.82 2.56 4.01 2014/15 17 4.95 0.90 13.19 25.90 1.44 4.61 7.86 4.87 0.14 1.05 0.00 0.96 1.31 0.85 1.44 9.64 1.02 10.68 0.37 1.38 7.46
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.04 1.39 0.32 14.46 3.18 5.37 6.61 3.72 0.13 14.95 0.00 3.46 11.96 23.51 9.86 1.04 1997/98 2 0.00 3.52 0.19 8.09 3.22 1.67 1.40 1.95 0.30 15.12 0.01 4.44 9.69 25.00 13.82 11.59 1998/99 3 0.02 1.11 0.22 9.74 3.55 2.23 1.81 1.93 13.83 7.83 0.00 8.12 4.67 13.38 18.64 12.93 1999/00 4 0.01 0.78 0.34 5.60 1.47 0.19 3.73 3.70 1.66 14.60 0.00 9.89 14.41 21.84 17.39 4.40 2000/01 5 0.00 0.40 1.22 8.51 1.43 0.25 1.73 2.49 0.63 12.40 0.00 8.01 13.27 20.73 20.67 8.25 2001/02 6 0.00 0.05 1.15 11.50 4.18 0.12 1.52 1.67 0.24 6.43 1.10 8.28 15.00 20.10 22.18 6.48 2002/03 7 0.00 1.10 5.18 13.71 3.23 0.48 1.23 2.65 0.30 13.61 0.44 4.69 8.95 12.40 19.12 12.92 2003/04 8 0.00 0.29 2.07 12.55 1.76 0.18 1.91 7.89 0.03 8.14 0.20 5.34 15.08 18.00 13.85 12.72 2004/05 9 0.00 0.00 0.41 6.46 0.50 0.11 2.26 2.75 0.00 19.72 0.17 4.54 12.50 33.53 12.26 4.79 2005/06 10 0.00 0.00 3.43 16.12 0.48 0.02 4.53 9.66 0.01 11.81 0.02 5.07 25.33 11.73 11.69 0.09 2006/07 11 0.00 0.00 6.17 10.52 2.70 0.00 23.36 5.35 0.14 10.46 0.08 3.14 22.09 14.61 0.82 0.57 2007/08 12 0.00 0.02 0.08 0.64 1.70 1.61 4.64 10.14 0.01 20.66 0.05 13.54 20.19 26.51 0.20 0.00 2008/09 13 0.00 0.00 0.02 6.61 3.62 0.56 1.37 3.84 0.00 17.83 0.00 11.56 16.06 25.03 13.10 0.39 2009/10 14 0.00 0.12 0.00 0.05 1.25 0.00 0.12 9.47 0.15 11.29 0.08 11.95 30.92 21.65 12.95 0.00 2010/11 15 0.00 0.57 0.46 3.12 10.34 0.00 0.71 3.50 0.44 8.51 0.04 5.09 8.13 38.00 20.51 0.59 2011/12 16 0.00 0.11 0.08 12.22 4.93 0.21 0.28 9.19 1.18 2.96 1.20 4.77 5.92 36.39 20.18 0.35 2012/13 17 0.00 0.10 0.00 1.03 6.94 0.80 6.03 20.88 0.55 4.21 0.14 7.27 8.60 27.79 15.07 0.58 2013/14 18 0.00 0.12 0.06 8.19 9.06 0.55 2.20 23.37 0.50 3.10 0.04 15.36 6.62 30.74 0.12 0.00 2014/15 19 0.00 0.00 0.06 0.26 6.22 0.00 0.11 7.54 1.10 4.04 0.29 10.92 30.84 38.52 0.10 0.00
45 Black-tailed godwit: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 4.00 0.00 29.50 6.50 0.00 251.00 159.50 118.50 32.50 261.00 0.00 764.50 3.00 11.50 418.00 164.50 9.00 9.50 0.50 2.50 8.00 2253.50 1999/00 2 8.67 6.67 48.33 8.33 11.67 43.67 53.00 225.67 37.00 35.33 0.00 168.00 7.33 20.00 14.67 38.33 39.00 25.67 3.33 6.67 4.67 806.00 2000/01 3 2.00 0.67 42.00 22.00 8.33 339.67 471.33 421.33 1.00 9.67 0.00 13.33 190.00 140.33 16.67 29.67 13.33 3.67 1.67 19.67 1.67 1748.00 2001/02 4 2.00 1.00 19.50 5.00 1.50 41.25 165.75 527.25 4.75 22.50 0.00 106.50 16.50 72.00 93.75 48.25 27.75 12.75 0.75 7.75 5.00 1181.50 2002/03 5 4.00 4.75 42.75 7.25 1.75 143.25 179.25 173.50 1.00 18.00 0.00 281.00 62.25 107.75 27.00 46.50 25.00 0.75 8.00 9.00 48.75 1191.50 2003/04 6 7.00 1.75 56.50 20.75 1.00 112.75 182.50 261.50 17.75 28.25 0.25 35.50 30.50 33.75 26.25 149.50 17.00 11.25 2.25 13.00 1.50 1010.50 2004/05 7 5.75 0.00 95.75 22.50 2.25 76.75 52.25 298.50 11.00 134.25 1.00 159.75 34.25 30.00 14.00 88.75 12.75 2.50 0.50 0.00 3.50 1046.00 2005/06 8 19.75 3.25 37.25 3.25 1.00 142.75 111.25 150.25 19.50 26.75 0.50 28.50 3.25 3.50 39.75 105.00 6.25 25.25 15.25 9.00 14.00 765.25 2006/07 9 13.50 1.25 6.25 2.25 0.00 6.75 8.25 198.00 16.25 22.00 0.00 187.25 3.50 4.50 0.00 3.25 0.75 3.25 0.00 5.25 0.00 482.25 2007/08 10 0.00 2.00 30.00 3.50 4.00 37.00 7.00 76.50 32.50 82.50 1.00 2.50 3.00 0.50 218.50 53.00 2.50 29.00 0.00 0.50 0.50 586.00 2008/09 11 7.67 0.00 66.33 3.00 3.67 19.67 14.00 221.33 13.33 201.67 4.33 56.33 16.00 12.67 20.00 32.33 17.00 9.00 4.00 6.00 0.33 728.67 2009/10 12 1.25 4.50 22.50 12.25 2.00 7.50 10.50 161.75 9.50 84.50 1.25 89.50 0.00 0.00 21.75 52.25 16.75 61.00 0.50 5.50 2.50 567.25 2010/11 13 4.00 1.50 8.25 1.25 1.50 37.00 65.75 225.75 18.25 152.75 1.00 1.25 0.00 1.00 175.00 136.75 6.50 6.75 1.75 1.75 3.25 851.00 2011/12 14 0.50 5.00 9.75 7.00 2.75 0.00 5.25 13.75 19.00 155.25 11.75 9.50 2.00 2.25 29.25 91.50 40.00 10.75 0.00 1.50 4.00 420.75 2012/13 15 0.00 7.00 14.50 3.00 3.50 2.00 1.00 36.00 4.50 157.00 0.50 114.50 61.50 1.50 278.50 118.50 23.00 5.50 0.50 0.50 1.00 834.00 2013/14 16 2.33 0.00 18.33 4.00 34.67 84.33 47.67 276.00 41.00 144.67 1.67 120.33 0.00 0.00 728.33 45.00 22.67 1.00 0.00 3.00 9.67 1584.67 2014/15 17 0.00 0.00 31.00 27.33 3.33 64.33 56.33 420.33 14.33 128.33 0.00 1.33 2.67 0.00 198.00 171.33 14.00 6.67 0.00 0.00 0.00 1139.33
ORWELL Section
Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total28B 1996/97 1 0.00 17.67 6.33 77.67 12.67 33.00 12.00 0.33 0.00 0.67 1.00 0.00 0.00 2.33 16.00 2.67 182.33 1997/98 2 0.60 54.60 7.80 102.40 11.60 9.60 14.60 0.00 0.00 0.40 0.00 0.80 6.80 49.00 42.40 25.00 325.60 1998/99 3 0.00 11.67 5.00 78.67 29.67 11.33 3.33 0.00 0.00 0.00 0.00 1.33 3.00 3.00 51.00 10.67 208.67 1999/00 4 0.00 6.25 3.00 89.75 18.50 4.25 26.25 29.75 0.25 8.00 3.25 2.00 2.25 3.75 59.50 37.75 294.50 2000/01 5 0.00 0.00 1.00 17.75 4.50 0.25 4.25 3.25 0.00 1.25 0.50 8.50 0.00 2.50 4.50 6.50 54.75 2001/02 6 0.00 0.00 0.00 68.75 3.75 1.75 0.75 0.00 0.00 1.25 47.00 2.25 0.00 23.00 25.00 9.00 182.50 2002/03 7 0.00 0.00 0.00 53.50 6.50 1.75 5.50 0.75 0.00 2.00 1.00 11.50 0.25 13.50 77.00 72.25 245.50 2003/04 8 0.00 2.25 1.00 78.00 6.00 5.25 10.00 3.00 0.00 18.00 4.50 5.00 0.75 14.00 83.50 32.50 263.75 2004/05 9 0.00 2.50 0.00 25.00 13.00 10.00 27.00 0.50 0.50 25.00 4.00 9.00 1.00 44.00 21.50 44.00 227.00 2005/06 10 0.00 1.00 0.00 96.67 19.33 18.00 9.33 2.00 1.00 18.67 0.33 223.33 10.33 124.67 21.00 5.00 550.67 2006/07 11 0.00 0.25 0.50 35.25 29.00 10.00 4.25 0.25 0.25 0.00 1.00 12.25 0.00 45.75 81.75 13.50 234.00 2007/08 12 0.00 0.00 2.33 128.67 29.67 36.33 36.00 1.67 0.67 47.67 2.67 76.67 3.67 139.00 59.67 6.67 571.33 2008/09 13 0.00 7.50 1.00 145.75 43.25 24.25 33.25 15.25 3.00 24.25 3.75 26.25 13.00 55.50 28.00 29.25 453.25 2009/10 14 0.00 0.67 0.00 52.00 13.00 5.33 21.33 23.67 12.00 26.00 1.67 13.67 8.00 12.33 161.33 44.33 395.33 2010/11 15 0.00 0.00 1.33 100.67 7.00 1.00 53.00 3.00 3.00 35.00 20.00 33.33 5.00 38.67 98.67 28.00 427.67 2011/12 16 0.00 23.67 12.00 185.33 9.67 3.33 7.00 10.67 3.33 6.67 1.00 2.33 0.67 26.00 131.67 28.00 451.33 2012/13 17 0.00 0.00 1.00 57.33 5.33 3.67 4.00 5.00 0.00 1.67 6.67 5.00 0.00 1.33 8.67 4.67 104.33 2013/14 18 0.00 1.25 11.75 212.25 36.00 13.75 14.25 6.00 0.25 0.50 3.50 5.00 0.25 10.25 33.00 2.00 350.00 2014/15 19 0.00 0.00 13.67 410.00 3.67 38.67 1.00 0.00 0.00 1.33 3.33 2.67 0.00 3.33 84.33 4.67 566.67
46 Black-tailed godwit: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 0.18 0.00 1.31 0.29 0.00 11.14 7.08 5.26 1.44 11.58 0.00 33.93 0.13 0.51 18.55 7.30 0.40 0.42 0.02 0.11 0.36 1999/00 2 1.08 0.83 6.00 1.03 1.45 5.42 6.58 28.00 4.59 4.38 0.00 20.84 0.91 2.48 1.82 4.76 4.84 3.18 0.41 0.83 0.58 2000/01 3 0.11 0.04 2.40 1.26 0.48 19.43 26.96 24.10 0.06 0.55 0.00 0.76 10.87 8.03 0.95 1.70 0.76 0.21 0.10 1.13 0.10 2001/02 4 0.17 0.08 1.65 0.42 0.13 3.49 14.03 44.63 0.40 1.90 0.00 9.01 1.40 6.09 7.93 4.08 2.35 1.08 0.06 0.66 0.42 2002/03 5 0.34 0.40 3.59 0.61 0.15 12.02 15.04 14.56 0.08 1.51 0.00 23.58 5.22 9.04 2.27 3.90 2.10 0.06 0.67 0.76 4.09 2003/04 6 0.69 0.17 5.59 2.05 0.10 11.16 18.06 25.88 1.76 2.80 0.02 3.51 3.02 3.34 2.60 14.79 1.68 1.11 0.22 1.29 0.15 2004/05 7 0.55 0.00 9.15 2.15 0.22 7.34 5.00 28.54 1.05 12.83 0.10 15.27 3.27 2.87 1.34 8.48 1.22 0.24 0.05 0.00 0.33 2005/06 8 2.58 0.42 4.87 0.42 0.13 18.65 14.54 19.63 2.55 3.50 0.07 3.72 0.42 0.46 5.19 13.72 0.82 3.30 1.99 1.18 1.83 2006/07 9 2.80 0.26 1.30 0.47 0.00 1.40 1.71 41.06 3.37 4.56 0.00 38.83 0.73 0.93 0.00 0.67 0.16 0.67 0.00 1.09 0.00 2007/08 10 0.00 0.34 5.12 0.60 0.68 6.31 1.19 13.05 5.55 14.08 0.17 0.43 0.51 0.09 37.29 9.04 0.43 4.95 0.00 0.09 0.09 2008/09 11 1.05 0.00 9.10 0.41 0.50 2.70 1.92 30.38 1.83 27.68 0.59 7.73 2.20 1.74 2.74 4.44 2.33 1.24 0.55 0.82 0.05 2009/10 12 0.22 0.79 3.97 2.16 0.35 1.32 1.85 28.51 1.67 14.90 0.22 15.78 0.00 0.00 3.83 9.21 2.95 10.75 0.09 0.97 0.44 2010/11 13 0.47 0.18 0.97 0.15 0.18 4.35 7.73 26.53 2.14 17.95 0.12 0.15 0.00 0.12 20.56 16.07 0.76 0.79 0.21 0.21 0.38 2011/12 14 0.12 1.19 2.32 1.66 0.65 0.00 1.25 3.27 4.52 36.90 2.79 2.26 0.48 0.53 6.95 21.75 9.51 2.55 0.00 0.36 0.95 2012/13 15 0.00 0.84 1.74 0.36 0.42 0.24 0.12 4.32 0.54 18.82 0.06 13.73 7.37 0.18 33.39 14.21 2.76 0.66 0.06 0.06 0.12 2013/14 16 0.15 0.00 1.16 0.25 2.19 5.32 3.01 17.42 2.59 9.13 0.11 7.59 0.00 0.00 45.96 2.84 1.43 0.06 0.00 0.19 0.61 2014/15 17 0.00 0.00 2.72 2.40 0.29 5.65 4.94 36.89 1.26 11.26 0.00 0.12 0.23 0.00 17.38 15.04 1.23 0.59 0.00 0.00 0.00
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 9.69 3.47 42.60 6.95 18.10 6.58 0.18 0.00 0.37 0.55 0.00 0.00 1.28 8.78 1.46 1997/98 2 0.18 16.77 2.40 31.45 3.56 2.95 4.48 0.00 0.00 0.12 0.00 0.25 2.09 15.05 13.02 7.68 1998/99 3 0.00 5.59 2.40 37.70 14.22 5.43 1.60 0.00 0.00 0.00 0.00 0.64 1.44 1.44 24.44 5.11 1999/00 4 0.00 2.12 1.02 30.48 6.28 1.44 8.91 10.10 0.08 2.72 1.10 0.68 0.76 1.27 20.20 12.82 2000/01 5 0.00 0.00 1.83 32.42 8.22 0.46 7.76 5.94 0.00 2.28 0.91 15.53 0.00 4.57 8.22 11.87 2001/02 6 0.00 0.00 0.00 37.67 2.05 0.96 0.41 0.00 0.00 0.68 25.75 1.23 0.00 12.60 13.70 4.93 2002/03 7 0.00 0.00 0.00 21.79 2.65 0.71 2.24 0.31 0.00 0.81 0.41 4.68 0.10 5.50 31.36 29.43 2003/04 8 0.00 0.85 0.38 29.57 2.27 1.99 3.79 1.14 0.00 6.82 1.71 1.90 0.28 5.31 31.66 12.32 2004/05 9 0.00 1.10 0.00 11.01 5.73 4.41 11.89 0.22 0.22 11.01 1.76 3.96 0.44 19.38 9.47 19.38 2005/06 10 0.00 0.18 0.00 17.55 3.51 3.27 1.69 0.36 0.18 3.39 0.06 40.56 1.88 22.64 3.81 0.91 2006/07 11 0.00 0.11 0.21 15.06 12.39 4.27 1.82 0.11 0.11 0.00 0.43 5.24 0.00 19.55 34.94 5.77 2007/08 12 0.00 0.00 0.41 22.52 5.19 6.36 6.30 0.29 0.12 8.34 0.47 13.42 0.64 24.33 10.44 1.17 2008/09 13 0.00 1.65 0.22 32.16 9.54 5.35 7.34 3.36 0.66 5.35 0.83 5.79 2.87 12.24 6.18 6.45 2009/10 14 0.00 0.17 0.00 13.15 3.29 1.35 5.40 5.99 3.04 6.58 0.42 3.46 2.02 3.12 40.81 11.21 2010/11 15 0.00 0.00 0.31 23.54 1.64 0.23 12.39 0.70 0.70 8.18 4.68 7.79 1.17 9.04 23.07 6.55 2011/12 16 0.00 5.24 2.66 41.06 2.14 0.74 1.55 2.36 0.74 1.48 0.22 0.52 0.15 5.76 29.17 6.20 2012/13 17 0.00 0.00 0.96 54.95 5.11 3.51 3.83 4.79 0.00 1.60 6.39 4.79 0.00 1.28 8.31 4.47 2013/14 18 0.00 0.36 3.36 60.64 10.29 3.93 4.07 1.71 0.07 0.14 1.00 1.43 0.07 2.93 9.43 0.57 2014/15 19 0.00 0.00 2.41 72.35 0.65 6.82 0.18 0.00 0.00 0.24 0.59 0.47 0.00 0.59 14.88 0.82
47 Curlew: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 14.50 36.00 19.00 16.50 8.50 76.50 21.50 42.00 7.00 21.00 0.00 35.50 10.50 16.00 81.50 63.00 8.00 30.00 19.50 8.00 79.00 613.50 1999/00 2 7.33 38.33 69.00 40.67 24.00 89.67 92.33 171.00 3.33 10.00 0.00 17.33 11.33 23.33 58.67 55.33 38.33 52.33 20.33 21.67 39.00 883.33 2000/01 3 6.00 38.33 126.33 43.67 16.33 89.67 60.00 80.00 0.33 2.33 0.00 31.33 12.33 33.33 91.67 51.00 35.33 40.33 24.00 51.00 29.33 862.67 2001/02 4 12.75 43.75 77.00 37.75 10.00 92.50 73.00 123.00 1.75 8.50 0.00 44.50 19.00 37.75 111.00 73.00 55.25 39.25 27.75 59.25 62.00 1008.75 2002/03 5 12.50 42.75 69.75 29.00 11.25 72.75 39.50 130.00 2.00 2.50 0.00 32.25 19.00 45.25 87.75 45.00 31.25 41.50 26.00 20.00 35.00 795.00 2003/04 6 13.00 55.00 55.25 16.00 15.00 90.50 72.25 155.75 3.25 6.25 0.25 42.75 31.00 58.00 80.75 69.50 37.50 39.25 18.75 15.75 24.25 900.00 2004/05 7 14.75 40.50 45.25 25.50 27.75 59.25 76.50 157.25 1.25 3.00 0.50 89.25 32.50 36.75 28.75 49.50 27.00 32.75 23.00 20.00 28.00 819.00 2005/06 8 10.75 47.25 66.50 20.50 32.75 56.75 51.00 137.50 3.75 6.25 0.00 7.25 13.75 32.25 64.00 31.00 39.00 53.00 21.75 20.25 44.00 759.25 2006/07 9 16.75 31.25 72.75 41.00 10.00 62.25 44.25 137.75 3.25 11.75 0.00 61.50 23.50 64.50 50.25 45.25 52.50 24.50 41.75 21.00 32.00 847.75 2007/08 10 15.00 28.00 75.00 26.00 13.50 93.50 45.00 139.50 2.50 13.50 0.00 10.00 16.00 32.50 63.50 60.00 37.00 35.00 15.50 15.00 26.50 762.50 2008/09 11 21.33 46.33 78.00 31.00 28.67 117.67 74.33 115.00 1.33 26.33 0.00 33.33 32.00 28.00 38.00 96.33 27.33 42.00 24.67 10.33 23.00 895.00 2009/10 12 12.50 51.50 70.25 39.00 27.00 88.25 53.25 190.50 1.75 9.00 0.00 81.50 16.75 23.25 78.75 122.25 47.50 54.25 21.75 28.50 24.75 1042.25 2010/11 13 17.25 52.75 79.25 44.00 14.50 32.50 46.75 150.50 3.25 9.25 0.00 43.75 14.50 27.25 79.50 101.75 48.25 45.75 22.75 23.50 25.25 882.25 2011/12 14 20.50 56.50 97.25 40.50 17.50 43.50 29.75 94.50 1.75 13.00 0.00 90.75 19.50 53.00 120.00 76.50 25.25 41.25 22.50 58.50 29.25 951.25 2012/13 15 18.00 55.50 103.00 41.50 49.00 44.00 27.00 72.50 4.00 11.50 0.00 37.00 12.50 28.50 121.50 75.50 32.00 47.00 31.50 38.00 40.00 889.50 2013/14 16 46.33 43.67 91.00 31.00 23.00 54.00 51.67 90.67 2.33 14.67 0.00 58.00 14.67 23.67 133.00 66.00 16.67 54.33 29.00 10.33 49.00 903.00 2014/15 17 29.67 35.33 69.00 53.00 16.33 22.33 24.00 41.67 2.33 11.00 0.33 26.33 16.00 113.33 76.33 50.00 48.67 54.33 26.00 12.67 30.00 758.67
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.00 1.67 4.33 59.67 8.00 32.00 20.33 17.00 0.67 12.33 4.33 21.33 142.00 179.33 40.33 1.33 544.67 1997/98 2 1.00 3.60 1.80 43.20 7.20 10.40 30.60 15.40 4.80 8.80 1.40 54.40 135.40 292.60 44.20 6.00 660.80 1998/99 3 0.00 3.67 3.00 67.33 8.67 11.00 96.00 27.00 7.33 10.67 0.67 58.33 76.33 200.00 25.67 7.33 603.00 1999/00 4 0.00 7.50 1.75 37.25 6.75 4.00 33.75 87.25 7.75 8.25 2.50 106.50 86.00 247.25 70.75 5.50 712.75 2000/01 5 0.00 3.25 2.75 51.00 5.25 3.75 26.00 92.50 3.50 6.25 6.75 81.75 137.00 162.00 50.50 3.25 635.50 2001/02 6 0.00 1.75 2.00 127.50 7.75 3.75 13.25 84.50 1.25 9.50 23.75 81.75 203.25 191.50 36.25 4.25 792.00 2002/03 7 0.00 2.50 2.25 51.25 7.00 6.25 14.75 91.50 1.50 8.50 7.75 89.75 131.50 206.25 51.50 6.50 678.75 2003/04 8 0.00 4.75 3.50 57.00 11.00 3.50 21.75 62.00 1.75 8.25 8.75 58.25 109.00 231.50 70.00 6.75 657.75 2004/05 9 0.00 2.50 2.50 35.00 8.50 5.00 70.00 86.00 2.00 9.50 18.50 72.50 105.50 303.50 47.50 13.00 781.50 2005/06 10 0.00 0.67 2.67 11.00 13.00 2.00 15.33 53.67 0.67 7.67 4.00 110.33 204.00 241.00 22.00 6.67 694.67 2006/07 11 0.00 1.25 4.50 9.50 16.75 4.50 47.75 61.50 2.00 8.25 6.00 59.00 173.75 298.25 39.25 6.50 738.75 2007/08 12 0.00 0.67 3.67 11.33 24.00 4.67 35.33 56.67 3.00 10.67 4.33 47.33 143.67 271.33 26.67 14.33 657.67 2008/09 13 0.00 1.00 3.50 11.50 10.00 5.00 16.75 59.75 2.25 10.75 4.25 45.75 79.50 165.50 28.50 13.00 457.00 2009/10 14 0.00 1.00 2.00 13.33 14.67 2.67 24.67 68.33 0.00 9.00 6.33 33.00 102.67 182.67 49.33 29.67 539.33 2010/11 15 1.00 1.00 2.67 10.67 14.00 2.00 22.67 53.00 2.33 7.00 8.33 41.67 95.00 228.33 41.00 16.67 547.33 2011/12 16 0.33 2.67 2.00 6.33 14.33 4.00 25.00 25.67 6.00 8.33 10.33 39.00 109.00 186.00 35.33 11.33 485.67 2012/13 17 0.33 3.33 1.33 13.00 13.00 8.33 18.33 41.33 1.00 6.00 6.67 28.00 106.33 158.00 44.00 12.33 461.33 2013/14 18 0.25 0.75 1.00 12.00 13.50 6.25 14.50 55.75 3.50 5.75 16.50 32.25 134.25 190.25 35.75 7.75 530.00 2014/15 19 0.00 0.67 3.33 16.00 12.33 6.33 12.33 37.00 2.67 9.67 23.67 16.67 101.00 188.00 70.33 9.00 509.00
48 Curlew: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 2.36 5.87 3.10 2.69 1.39 12.47 3.50 6.85 1.14 3.42 0.00 5.79 1.71 2.61 13.28 10.27 1.30 4.89 3.18 1.30 12.88 1999/00 2 0.83 4.34 7.81 4.60 2.72 10.15 10.45 19.36 0.38 1.13 0.00 1.96 1.28 2.64 6.64 6.26 4.34 5.92 2.30 2.45 4.42 2000/01 3 0.70 4.44 14.64 5.06 1.89 10.39 6.96 9.27 0.04 0.27 0.00 3.63 1.43 3.86 10.63 5.91 4.10 4.68 2.78 5.91 3.40 2001/02 4 1.26 4.34 7.63 3.74 0.99 9.17 7.24 12.19 0.17 0.84 0.00 4.41 1.88 3.74 11.00 7.24 5.48 3.89 2.75 5.87 6.15 2002/03 5 1.57 5.38 8.77 3.65 1.42 9.15 4.97 16.35 0.25 0.31 0.00 4.06 2.39 5.69 11.04 5.66 3.93 5.22 3.27 2.52 4.40 2003/04 6 1.44 6.11 6.14 1.78 1.67 10.06 8.03 17.31 0.36 0.69 0.03 4.75 3.44 6.44 8.97 7.72 4.17 4.36 2.08 1.75 2.69 2004/05 7 1.80 4.95 5.53 3.11 3.39 7.23 9.34 19.20 0.15 0.37 0.06 10.90 3.97 4.49 3.51 6.04 3.30 4.00 2.81 2.44 3.42 2005/06 8 1.42 6.22 8.76 2.70 4.31 7.47 6.72 18.11 0.49 0.82 0.00 0.95 1.81 4.25 8.43 4.08 5.14 6.98 2.86 2.67 5.80 2006/07 9 1.98 3.69 8.58 4.84 1.18 7.34 5.22 16.25 0.38 1.39 0.00 7.25 2.77 7.61 5.93 5.34 6.19 2.89 4.92 2.48 3.77 2007/08 10 1.97 3.67 9.84 3.41 1.77 12.26 5.90 18.30 0.33 1.77 0.00 1.31 2.10 4.26 8.33 7.87 4.85 4.59 2.03 1.97 3.48 2008/09 11 2.38 5.18 8.72 3.46 3.20 13.15 8.31 12.85 0.15 2.94 0.00 3.72 3.58 3.13 4.25 10.76 3.05 4.69 2.76 1.15 2.57 2009/10 12 1.20 4.94 6.74 3.74 2.59 8.47 5.11 18.28 0.17 0.86 0.00 7.82 1.61 2.23 7.56 11.73 4.56 5.21 2.09 2.73 2.37 2010/11 13 1.96 5.98 8.98 4.99 1.64 3.68 5.30 17.06 0.37 1.05 0.00 4.96 1.64 3.09 9.01 11.53 5.47 5.19 2.58 2.66 2.86 2011/12 14 2.16 5.94 10.22 4.26 1.84 4.57 3.13 9.93 0.18 1.37 0.00 9.54 2.05 5.57 12.61 8.04 2.65 4.34 2.37 6.15 3.07 2012/13 15 2.02 6.24 11.58 4.67 5.51 4.95 3.04 8.15 0.45 1.29 0.00 4.16 1.41 3.20 13.66 8.49 3.60 5.28 3.54 4.27 4.50 2013/14 16 5.13 4.84 10.08 3.43 2.55 5.98 5.72 10.04 0.26 1.62 0.00 6.42 1.62 2.62 14.73 7.31 1.85 6.02 3.21 1.14 5.43 2014/15 17 3.91 4.66 9.09 6.99 2.15 2.94 3.16 5.49 0.31 1.45 0.04 3.47 2.11 14.94 10.06 6.59 6.41 7.16 3.43 1.67 3.95
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.00 0.31 0.80 10.95 1.47 5.88 3.73 3.12 0.12 2.26 0.80 3.92 26.07 32.93 7.41 0.24 1997/98 2 0.15 0.54 0.27 6.54 1.09 1.57 4.63 2.33 0.73 1.33 0.21 8.23 20.49 44.28 6.69 0.91 1998/99 3 0.00 0.61 0.50 11.17 1.44 1.82 15.92 4.48 1.22 1.77 0.11 9.67 12.66 33.17 4.26 1.22 1999/00 4 0.00 1.05 0.25 5.23 0.95 0.56 4.74 12.24 1.09 1.16 0.35 14.94 12.07 34.69 9.93 0.77 2000/01 5 0.00 0.51 0.43 8.03 0.83 0.59 4.09 14.56 0.55 0.98 1.06 12.86 21.56 25.49 7.95 0.51 2001/02 6 0.00 0.22 0.25 16.10 0.98 0.47 1.67 10.67 0.16 1.20 3.00 10.32 25.66 24.18 4.58 0.54 2002/03 7 0.00 0.37 0.33 7.55 1.03 0.92 2.17 13.48 0.22 1.25 1.14 13.22 19.37 30.39 7.59 0.96 2003/04 8 0.00 0.72 0.53 8.67 1.67 0.53 3.31 9.43 0.27 1.25 1.33 8.86 16.57 35.20 10.64 1.03 2004/05 9 0.00 0.32 0.32 4.48 1.09 0.64 8.96 11.00 0.26 1.22 2.37 9.28 13.50 38.84 6.08 1.66 2005/06 10 0.00 0.10 0.38 1.58 1.87 0.29 2.21 7.73 0.10 1.10 0.58 15.88 29.37 34.69 3.17 0.96 2006/07 11 0.00 0.17 0.61 1.29 2.27 0.61 6.46 8.32 0.27 1.12 0.81 7.99 23.52 40.37 5.31 0.88 2007/08 12 0.00 0.10 0.56 1.72 3.65 0.71 5.37 8.62 0.46 1.62 0.66 7.20 21.84 41.26 4.05 2.18 2008/09 13 0.00 0.22 0.77 2.52 2.19 1.09 3.67 13.07 0.49 2.35 0.93 10.01 17.40 36.21 6.24 2.84 2009/10 14 0.00 0.19 0.37 2.47 2.72 0.49 4.57 12.67 0.00 1.67 1.17 6.12 19.04 33.87 9.15 5.50 2010/11 15 0.18 0.18 0.49 1.95 2.56 0.37 4.14 9.68 0.43 1.28 1.52 7.61 17.36 41.72 7.49 3.05 2011/12 16 0.07 0.55 0.41 1.30 2.95 0.82 5.15 5.28 1.24 1.72 2.13 8.03 22.44 38.30 7.28 2.33 2012/13 17 0.07 0.72 0.29 2.82 2.82 1.81 3.97 8.96 0.22 1.30 1.45 6.07 23.05 34.25 9.54 2.67 2013/14 18 0.05 0.14 0.19 2.26 2.55 1.18 2.74 10.52 0.66 1.08 3.11 6.08 25.33 35.90 6.75 1.46 2014/15 19 0.00 0.13 0.65 3.14 2.42 1.24 2.42 7.27 0.52 1.90 4.65 3.27 19.84 36.94 13.82 1.77
49 Redshank: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 62.00 100.50 137.00 41.50 17.50 153.50 42.50 144.00 91.50 507.50 10.00 242.00 32.00 58.50 194.50 131.50 112.00 66.00 25.00 16.00 63.50 2248.50 1999/00 2 65.33 105.67 182.33 73.00 23.33 35.67 115.00 333.33 185.33 139.67 4.33 108.33 32.67 17.33 88.67 62.67 144.67 76.00 34.00 60.33 80.33 1968.00 2000/01 3 106.67 107.33 122.00 82.33 67.00 36.67 60.67 111.33 87.00 77.00 3.00 116.00 40.33 43.00 240.67 57.00 100.33 64.67 20.67 49.00 89.33 1682.00 2001/02 4 93.50 133.25 117.50 70.75 38.75 72.50 65.25 138.00 118.00 143.75 11.25 83.00 43.75 63.25 163.75 263.00 53.25 67.50 36.50 78.25 73.75 1928.50 2002/03 5 91.00 111.75 109.50 74.50 43.50 131.50 52.25 157.50 64.00 85.00 6.25 80.50 42.00 54.00 76.75 117.00 62.00 59.75 33.75 21.50 42.00 1516.00 2003/04 6 86.00 106.00 136.00 53.25 55.00 65.75 65.25 141.25 113.25 132.25 12.75 106.75 80.75 43.25 114.50 121.25 70.50 79.75 39.00 20.25 54.75 1697.50 2004/05 7 94.50 157.50 90.50 34.25 83.25 69.75 58.50 94.75 188.00 226.50 21.75 55.50 78.50 44.25 58.50 107.25 74.50 55.75 47.50 29.25 68.50 1738.75 2005/06 8 98.75 110.25 143.50 46.75 163.50 62.75 54.25 109.50 154.50 97.50 15.50 74.00 45.50 39.25 102.25 166.25 55.25 81.50 49.25 39.75 74.00 1783.75 2006/07 9 86.00 102.25 87.25 62.75 42.75 31.50 39.50 88.00 184.25 120.50 5.25 37.25 15.00 20.50 63.00 52.25 66.75 39.75 27.25 9.25 65.00 1246.00 2007/08 10 65.00 121.50 180.00 61.50 67.00 91.00 52.00 34.50 159.00 85.50 17.00 26.50 10.50 13.50 228.50 104.50 56.50 114.50 36.00 28.50 66.00 1619.00 2008/09 11 85.67 117.00 87.00 58.00 113.00 72.67 28.33 97.67 172.33 37.00 16.33 57.00 33.00 19.67 171.00 155.33 42.00 37.00 31.67 23.67 74.67 1530.00 2009/10 12 82.75 94.75 85.75 78.25 93.50 42.75 24.25 110.00 128.25 28.25 15.00 122.50 39.25 14.50 128.75 112.00 78.00 49.25 43.00 21.25 52.50 1444.50 2010/11 13 109.00 86.75 105.25 105.50 58.50 39.00 47.75 101.00 157.25 48.25 10.50 86.75 20.25 21.25 104.50 78.25 65.75 52.25 58.50 15.75 57.75 1429.75 2011/12 14 73.00 61.75 103.25 52.00 31.25 43.00 22.00 51.50 172.50 28.00 11.75 29.50 37.25 19.75 86.50 123.00 62.25 47.50 15.75 28.00 61.50 1161.00 2012/13 15 69.50 81.50 102.50 38.50 25.50 49.00 36.00 40.50 54.00 54.00 5.50 22.50 44.00 9.50 66.50 166.50 38.50 44.50 9.50 19.00 47.50 1024.50 2013/14 16 62.67 87.00 110.00 31.67 54.67 32.33 41.00 20.00 123.00 39.33 2.67 84.00 35.33 7.67 82.67 86.33 35.00 52.00 28.67 27.67 48.00 1091.67 2014/15 17 163.00 41.00 45.33 54.00 32.33 36.67 24.33 15.00 100.67 75.33 3.00 106.67 32.67 17.33 57.33 58.00 73.00 25.67 22.00 25.67 25.00 1034.00
ORWELL Section
Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total29B 1996/97 1 4.67 167.67 30.33 387.33 123.33 36.00 56.67 33.00 5.33 100.67 0.33 61.00 119.00 313.67 379.00 157.00 1975.00 1997/98 2 3.60 71.80 12.60 369.80 176.00 85.00 48.40 33.40 6.40 103.00 0.00 76.20 143.40 327.40 301.00 129.80 1887.80 1998/99 3 3.33 75.33 19.67 262.33 182.33 58.33 53.00 33.00 8.33 73.67 0.00 82.33 120.67 180.67 181.33 199.33 1533.67 1999/00 4 3.50 15.75 11.00 263.75 217.50 26.00 57.00 108.25 12.00 115.00 0.75 125.50 73.50 327.75 140.00 120.50 1617.75 2000/01 5 2.00 28.25 18.50 254.50 66.00 15.25 43.75 73.25 15.00 78.25 3.25 113.00 110.50 359.25 183.50 122.00 1486.25 2001/02 6 0.75 22.50 19.25 326.75 124.00 15.25 38.50 106.50 12.50 89.25 31.50 117.25 211.75 354.50 179.25 161.25 1810.75 2002/03 7 0.75 37.00 20.25 330.25 68.75 25.00 33.25 94.75 18.25 98.25 43.50 119.00 236.00 223.75 171.50 156.00 1676.25 2003/04 8 1.50 37.50 37.00 330.75 74.50 19.00 35.75 81.50 4.00 86.75 59.50 96.50 185.25 323.00 159.00 160.00 1691.50 2004/05 9 2.50 43.00 47.00 162.00 125.00 12.00 55.00 73.00 3.50 70.50 64.50 62.00 271.50 226.50 159.00 126.00 1503.00 2005/06 10 2.67 68.67 15.67 264.00 159.67 11.33 36.00 64.33 6.33 40.33 63.67 100.00 166.67 315.33 123.33 132.00 1570.00 2006/07 11 0.25 17.75 7.75 569.25 159.75 19.00 35.25 80.25 6.50 45.00 20.00 64.00 108.50 220.25 145.75 148.25 1647.50 2007/08 12 18.67 61.67 8.67 118.33 128.00 67.67 76.00 68.33 7.67 80.00 47.33 85.00 109.00 199.33 113.67 67.67 1257.00 2008/09 13 2.50 46.75 19.25 294.50 104.25 14.00 49.00 69.50 7.25 99.25 46.50 73.75 116.50 175.75 109.50 84.50 1312.75 2009/10 14 0.00 46.67 3.67 435.67 112.33 24.00 29.00 67.00 14.00 92.33 104.33 77.67 110.33 258.00 145.67 127.00 1647.67 2010/11 15 0.33 25.00 33.00 371.00 128.33 4.00 25.67 48.33 15.67 26.67 47.67 37.33 118.00 177.67 146.33 168.00 1373.00 2011/12 16 1.33 65.00 31.67 267.67 38.00 5.33 21.00 39.67 30.67 31.00 59.00 76.67 95.33 111.33 128.67 106.67 1109.00 2012/13 17 19.00 38.33 17.67 347.00 79.33 39.67 23.00 76.33 11.33 43.67 58.33 86.33 72.33 88.67 58.33 95.00 1154.33 2013/14 18 0.00 65.50 7.75 307.75 100.25 48.75 9.00 92.50 4.25 21.00 4.50 67.75 34.75 111.50 100.50 66.25 1042.00 2014/15 19 0.67 37.00 7.67 228.67 40.00 46.00 16.00 56.67 17.00 37.33 72.67 47.00 78.67 148.00 180.00 151.33 1164.67
50 Redshank: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 2.76 4.47 6.09 1.85 0.78 6.83 1.89 6.40 4.07 22.57 0.44 10.76 1.42 2.60 8.65 5.85 4.98 2.94 1.11 0.71 2.82 1999/00 2 3.32 5.37 9.26 3.71 1.19 1.81 5.84 16.94 9.42 7.10 0.22 5.50 1.66 0.88 4.51 3.18 7.35 3.86 1.73 3.07 4.08 2000/01 3 6.34 6.38 7.25 4.89 3.98 2.18 3.61 6.62 5.17 4.58 0.18 6.90 2.40 2.56 14.31 3.39 5.97 3.84 1.23 2.91 5.31 2001/02 4 4.85 6.91 6.09 3.67 2.01 3.76 3.38 7.16 6.12 7.45 0.58 4.30 2.27 3.28 8.49 13.64 2.76 3.50 1.89 4.06 3.82 2002/03 5 6.00 7.37 7.22 4.91 2.87 8.67 3.45 10.39 4.22 5.61 0.41 5.31 2.77 3.56 5.06 7.72 4.09 3.94 2.23 1.42 2.77 2003/04 6 5.07 6.24 8.01 3.14 3.24 3.87 3.84 8.32 6.67 7.79 0.75 6.29 4.76 2.55 6.75 7.14 4.15 4.70 2.30 1.19 3.23 2004/05 7 5.43 9.06 5.20 1.97 4.79 4.01 3.36 5.45 10.81 13.03 1.25 3.19 4.51 2.54 3.36 6.17 4.28 3.21 2.73 1.68 3.94 2005/06 8 5.54 6.18 8.04 2.62 9.17 3.52 3.04 6.14 8.66 5.47 0.87 4.15 2.55 2.20 5.73 9.32 3.10 4.57 2.76 2.23 4.15 2006/07 9 6.90 8.21 7.00 5.04 3.43 2.53 3.17 7.06 14.79 9.67 0.42 2.99 1.20 1.65 5.06 4.19 5.36 3.19 2.19 0.74 5.22 2007/08 10 4.01 7.50 11.12 3.80 4.14 5.62 3.21 2.13 9.82 5.28 1.05 1.64 0.65 0.83 14.11 6.45 3.49 7.07 2.22 1.76 4.08 2008/09 11 5.60 7.65 5.69 3.79 7.39 4.75 1.85 6.38 11.26 2.42 1.07 3.73 2.16 1.29 11.18 10.15 2.75 2.42 2.07 1.55 4.88 2009/10 12 5.73 6.56 5.94 5.42 6.47 2.96 1.68 7.62 8.88 1.96 1.04 8.48 2.72 1.00 8.91 7.75 5.40 3.41 2.98 1.47 3.63 2010/11 13 7.62 6.07 7.36 7.38 4.09 2.73 3.34 7.06 11.00 3.37 0.73 6.07 1.42 1.49 7.31 5.47 4.60 3.65 4.09 1.10 4.04 2011/12 14 6.29 5.32 8.89 4.48 2.69 3.70 1.89 4.44 14.86 2.41 1.01 2.54 3.21 1.70 7.45 10.59 5.36 4.09 1.36 2.41 5.30 2012/13 15 6.78 7.96 10.00 3.76 2.49 4.78 3.51 3.95 5.27 5.27 0.54 2.20 4.29 0.93 6.49 16.25 3.76 4.34 0.93 1.85 4.64 2013/14 16 5.74 7.97 10.08 2.90 5.01 2.96 3.76 1.83 11.27 3.60 0.24 7.69 3.24 0.70 7.57 7.91 3.21 4.76 2.63 2.53 4.40 2014/15 17 15.76 3.97 4.38 5.22 3.13 3.55 2.35 1.45 9.74 7.29 0.29 10.32 3.16 1.68 5.54 5.61 7.06 2.48 2.13 2.48 2.42
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.24 8.49 1.54 19.61 6.24 1.82 2.87 1.67 0.27 5.10 0.02 3.09 6.03 15.88 19.19 7.95 1997/98 2 0.19 3.80 0.67 19.59 9.32 4.50 2.56 1.77 0.34 5.46 0.00 4.04 7.60 17.34 15.94 6.88 1998/99 3 0.22 4.91 1.28 17.10 11.89 3.80 3.46 2.15 0.54 4.80 0.00 5.37 7.87 11.78 11.82 13.00 1999/00 4 0.22 0.97 0.68 16.30 13.44 1.61 3.52 6.69 0.74 7.11 0.05 7.76 4.54 20.26 8.65 7.45 2000/01 5 0.13 1.90 1.24 17.12 4.44 1.03 2.94 4.93 1.01 5.26 0.22 7.60 7.43 24.17 12.35 8.21 2001/02 6 0.04 1.24 1.06 18.05 6.85 0.84 2.13 5.88 0.69 4.93 1.74 6.48 11.69 19.58 9.90 8.91 2002/03 7 0.04 2.21 1.21 19.70 4.10 1.49 1.98 5.65 1.09 5.86 2.60 7.10 14.08 13.35 10.23 9.31 2003/04 8 0.09 2.22 2.19 19.55 4.40 1.12 2.11 4.82 0.24 5.13 3.52 5.70 10.95 19.10 9.40 9.46 2004/05 9 0.17 2.86 3.13 10.78 8.32 0.80 3.66 4.86 0.23 4.69 4.29 4.13 18.06 15.07 10.58 8.38 2005/06 10 0.17 4.37 1.00 16.82 10.17 0.72 2.29 4.10 0.40 2.57 4.06 6.37 10.62 20.08 7.86 8.41 2006/07 11 0.02 1.08 0.47 34.55 9.70 1.15 2.14 4.87 0.39 2.73 1.21 3.88 6.59 13.37 8.85 9.00 2007/08 12 1.49 4.91 0.69 9.41 10.18 5.38 6.05 5.44 0.61 6.36 3.77 6.76 8.67 15.86 9.04 5.38 2008/09 13 0.19 3.56 1.47 22.43 7.94 1.07 3.73 5.29 0.55 7.56 3.54 5.62 8.87 13.39 8.34 6.44 2009/10 14 0.00 2.83 0.22 26.44 6.82 1.46 1.76 4.07 0.85 5.60 6.33 4.71 6.70 15.66 8.84 7.71 2010/11 15 0.02 1.82 2.40 27.02 9.35 0.29 1.87 3.52 1.14 1.94 3.47 2.72 8.59 12.94 10.66 12.24 2011/12 16 0.12 5.86 2.86 24.14 3.43 0.48 1.89 3.58 2.77 2.80 5.32 6.91 8.60 10.04 11.60 9.62 2012/13 17 1.65 3.32 1.53 30.06 6.87 3.44 1.99 6.61 0.98 3.78 5.05 7.48 6.27 7.68 5.05 8.23 2013/14 18 0.00 6.29 0.74 29.53 9.62 4.68 0.86 8.88 0.41 2.02 0.43 6.50 3.33 10.70 9.64 6.36 2014/15 19 0.06 3.18 0.66 19.63 3.43 3.95 1.37 4.87 1.46 3.21 6.24 4.04 6.75 12.71 15.46 12.99
51 Turnstone: mean numbers
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 Total 1996/97 1 5.00 10.50 30.50 4.00 0.00 3.00 0.00 4.50 0.00 0.00 0.00 0.50 4.50 0.00 1.50 40.50 4.00 62.50 11.00 9.00 33.50 224.50 1999/00 2 4.33 8.33 29.33 27.00 15.00 1.67 0.33 4.33 0.33 0.00 0.00 0.67 1.33 1.00 1.67 6.67 22.00 69.67 13.33 11.00 47.67 265.67 2000/01 3 1.67 5.67 23.00 21.00 18.33 1.00 1.00 1.33 0.00 0.00 0.00 1.67 2.67 0.00 0.00 3.33 23.33 85.33 41.33 13.33 75.33 319.33 2001/02 4 2.75 6.25 15.25 10.75 9.25 1.00 0.50 4.25 0.00 0.00 0.00 0.00 2.25 0.75 0.00 6.75 36.00 82.25 22.75 22.50 109.25 332.50 2002/03 5 10.75 10.25 18.75 21.50 16.25 2.50 2.75 7.00 1.50 0.50 0.00 0.50 1.75 0.25 0.00 4.50 36.50 63.25 29.75 18.50 78.00 324.75 2003/04 6 8.00 4.75 27.75 21.00 26.00 0.50 1.00 3.75 0.00 1.00 0.00 0.00 2.00 1.50 0.00 3.75 55.25 65.25 35.25 6.00 53.00 315.75 2004/05 7 11.00 6.25 11.25 12.25 76.75 7.25 0.50 10.25 0.00 4.00 0.00 1.75 0.50 2.25 0.00 30.50 37.00 100.00 36.50 32.75 109.75 490.50 2005/06 8 9.75 9.00 20.75 16.25 50.00 0.25 0.25 11.75 2.00 3.25 0.00 0.50 1.00 0.00 14.75 15.75 21.00 88.25 42.00 21.00 112.50 440.00 2006/07 9 17.00 1.75 13.00 20.25 16.50 3.75 1.75 3.25 1.00 0.25 0.00 3.50 1.00 0.00 1.00 14.25 29.50 73.75 35.50 24.50 111.25 372.75 2007/08 10 8.50 13.00 34.50 14.50 14.00 9.00 0.50 1.00 0.00 0.00 0.00 0.00 0.00 0.00 2.50 22.00 47.00 94.50 37.50 6.00 72.00 376.50 2008/09 11 13.67 12.00 27.33 33.67 46.33 2.33 0.00 10.33 0.67 0.00 0.00 1.67 1.67 1.33 10.33 43.67 32.00 76.33 17.67 15.33 138.33 484.67 2009/10 12 6.50 4.00 35.25 25.75 37.25 2.75 0.50 0.75 0.00 0.00 0.00 2.25 0.75 0.50 0.00 32.00 13.25 80.00 37.00 5.50 89.00 373.00 2010/11 13 4.75 15.25 46.25 35.25 32.25 2.25 1.00 6.25 0.50 0.25 0.00 1.75 2.00 0.00 7.25 73.50 19.25 85.75 25.75 11.25 85.25 455.75 2011/12 14 5.25 8.75 9.75 24.50 35.25 6.50 3.00 1.50 0.00 0.50 0.00 5.25 1.50 0.25 4.75 35.75 26.75 89.75 14.50 10.50 62.25 346.25 2012/13 15 3.00 1.50 17.50 6.50 27.50 9.00 4.50 8.50 0.00 3.00 0.00 0.00 0.00 0.00 3.00 47.00 14.50 108.50 11.50 3.00 20.00 288.50 2013/14 16 8.33 3.33 33.33 14.67 40.33 12.00 2.33 3.00 0.67 0.00 0.00 0.33 5.33 2.33 10.00 39.00 7.33 83.67 21.00 4.33 87.33 378.67 2014/15 17 11.00 2.33 38.00 6.33 17.00 3.00 0.00 1.33 0.33 0.67 0.00 0.00 0.33 0.00 6.67 38.33 23.67 55.67 23.33 12.00 67.67 307.67
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 Total 1996/97 1 0.33 2.33 0.00 4.00 3.00 1.67 5.33 4.67 0.00 2.00 1.33 3.00 2.00 4.00 13.00 1.33 48.00 1997/98 2 0.00 4.00 0.20 4.40 3.00 1.80 0.00 3.60 2.60 8.60 0.00 0.80 12.00 7.00 19.60 1.00 68.60 1998/99 3 0.33 5.00 1.00 4.33 3.00 2.00 2.67 1.33 1.00 10.67 0.00 4.00 9.00 15.33 29.33 1.33 90.33 1999/00 4 0.25 9.25 2.50 11.50 0.75 0.00 3.00 11.50 4.75 20.25 0.00 4.25 10.25 5.25 56.00 7.75 147.25 2000/01 5 0.00 7.00 2.75 12.00 1.00 3.25 5.75 6.00 4.25 9.50 0.00 9.50 10.00 9.50 45.50 20.50 146.50 2001/02 6 0.25 6.25 0.50 12.25 1.00 0.25 2.50 10.25 1.00 13.50 0.00 3.00 8.75 4.00 55.50 4.25 123.25 2002/03 7 0.25 4.50 3.75 26.00 0.50 2.25 6.25 24.00 4.50 11.25 2.00 6.25 13.25 8.00 50.25 9.25 172.25 2003/04 8 0.75 3.00 0.00 23.50 0.00 1.50 7.50 19.75 1.00 21.25 1.50 5.75 21.25 12.25 28.25 11.75 159.00 2004/05 9 1.50 23.50 3.50 23.50 0.00 0.00 0.00 18.00 7.00 11.00 2.00 5.00 65.50 16.50 44.50 11.50 233.00 2005/06 10 0.67 0.67 2.00 27.67 3.00 0.00 3.00 20.33 7.33 19.67 4.67 4.00 26.33 44.33 18.33 1.33 183.33 2006/07 11 0.25 7.00 2.50 13.75 2.50 10.00 0.75 12.00 1.25 6.50 0.00 2.75 29.50 94.00 6.50 0.00 189.25 2007/08 12 3.33 10.67 0.00 7.00 0.00 0.67 2.00 10.00 2.00 4.00 1.67 26.00 18.00 27.67 3.00 0.00 116.00 2008/09 13 0.50 8.25 1.50 9.00 0.25 0.00 3.25 15.50 3.25 1.25 0.25 16.25 21.25 24.75 5.25 2.50 113.00 2009/10 14 0.00 9.00 0.00 3.00 0.33 0.00 0.00 6.67 1.00 2.33 0.00 2.00 25.00 29.33 3.00 0.33 82.00 2010/11 15 0.00 0.33 1.00 16.00 0.00 0.00 0.00 7.67 2.00 1.67 0.00 0.67 0.67 56.00 6.67 2.33 95.00 2011/12 16 0.33 4.00 0.00 7.00 3.33 0.00 0.67 9.33 3.00 2.33 0.33 0.00 9.67 58.00 3.33 1.67 103.00 2012/13 17 0.00 2.33 0.00 0.00 0.00 0.00 1.33 20.33 8.00 0.33 1.00 4.00 1.67 76.00 3.67 2.67 121.33 2013/14 18 0.00 0.00 0.00 0.75 2.00 0.75 1.25 5.25 0.50 0.00 0.00 3.50 3.25 47.75 3.25 2.00 70.25 2014/15 19 0.00 0.33 0.00 1.67 3.67 0.00 0.00 7.00 0.67 1.00 0.00 2.33 9.67 80.67 0.00 0.00 107.00
52 Turnstone: mean proportions of winter estuary population
STOUR Section Winter No. 1 2-5 6-9 10-12 13-14 15-16 17 18-20 21-22 23 24 25 26 27 28-30 31-32 33 34-35 36-37 38 39-40 1996/97 1 2.23 4.68 13.59 1.78 0.00 1.34 0.00 2.00 0.00 0.00 0.00 0.22 2.00 0.00 0.67 18.04 1.78 27.84 4.90 4.01 14.92 1999/00 2 1.63 3.14 11.04 10.16 5.65 0.63 0.13 1.63 0.13 0.00 0.00 0.25 0.50 0.38 0.63 2.51 8.28 26.22 5.02 4.14 17.94 2000/01 3 0.52 1.77 7.20 6.58 5.74 0.31 0.31 0.42 0.00 0.00 0.00 0.52 0.84 0.00 0.00 1.04 7.31 26.72 12.94 4.18 23.59 2001/02 4 0.83 1.88 4.59 3.23 2.78 0.30 0.15 1.28 0.00 0.00 0.00 0.00 0.68 0.23 0.00 2.03 10.83 24.74 6.84 6.77 32.86 2002/03 5 3.31 3.16 5.77 6.62 5.00 0.77 0.85 2.16 0.46 0.15 0.00 0.15 0.54 0.08 0.00 1.39 11.24 19.48 9.16 5.70 24.02 2003/04 6 2.53 1.50 8.79 6.65 8.23 0.16 0.32 1.19 0.00 0.32 0.00 0.00 0.63 0.48 0.00 1.19 17.50 20.67 11.16 1.90 16.79 2004/05 7 2.24 1.27 2.29 2.50 15.65 1.48 0.10 2.09 0.00 0.82 0.00 0.36 0.10 0.46 0.00 6.22 7.54 20.39 7.44 6.68 22.38 2005/06 8 2.22 2.05 4.72 3.69 11.36 0.06 0.06 2.67 0.45 0.74 0.00 0.11 0.23 0.00 3.35 3.58 4.77 20.06 9.55 4.77 25.57 2006/07 9 4.56 0.47 3.49 5.43 4.43 1.01 0.47 0.87 0.27 0.07 0.00 0.94 0.27 0.00 0.27 3.82 7.91 19.79 9.52 6.57 29.85 2007/08 10 2.26 3.45 9.16 3.85 3.72 2.39 0.13 0.27 0.00 0.00 0.00 0.00 0.00 0.00 0.66 5.84 12.48 25.10 9.96 1.59 19.12 2008/09 11 2.82 2.48 5.64 6.95 9.56 0.48 0.00 2.13 0.14 0.00 0.00 0.34 0.34 0.28 2.13 9.01 6.60 15.75 3.65 3.16 28.54 2009/10 12 1.74 1.07 9.45 6.90 9.99 0.74 0.13 0.20 0.00 0.00 0.00 0.60 0.20 0.13 0.00 8.58 3.55 21.45 9.92 1.47 23.86 2010/11 13 1.04 3.35 10.15 7.73 7.08 0.49 0.22 1.37 0.11 0.05 0.00 0.38 0.44 0.00 1.59 16.13 4.22 18.82 5.65 2.47 18.71 2011/12 14 1.52 2.53 2.82 7.08 10.18 1.88 0.87 0.43 0.00 0.14 0.00 1.52 0.43 0.07 1.37 10.32 7.73 25.92 4.19 3.03 17.98 2012/13 15 1.04 0.52 6.07 2.25 9.53 3.12 1.56 2.95 0.00 1.04 0.00 0.00 0.00 0.00 1.04 16.29 5.03 37.61 3.99 1.04 6.93 2013/14 16 2.20 0.88 8.80 3.87 10.65 3.17 0.62 0.79 0.18 0.00 0.00 0.09 1.41 0.62 2.64 10.30 1.94 22.10 5.55 1.14 23.06 2014/15 17 3.58 0.76 12.35 2.06 5.53 0.98 0.00 0.43 0.11 0.22 0.00 0.00 0.11 0.00 2.17 12.46 7.69 18.09 7.58 3.90 21.99
ORWELL Section Winter No. A2 A3 B1 B2 B3 C1 C2 C3 D1 D2&3 D4 E1 E2 F1 F2 F3 1996/97 1 0.69 4.86 0.00 8.33 6.25 3.47 11.11 9.72 0.00 4.17 2.78 6.25 4.17 8.33 27.08 2.78 1997/98 2 0.00 5.83 0.29 6.41 4.37 2.62 0.00 5.25 3.79 12.54 0.00 1.17 17.49 10.20 28.57 1.46 1998/99 3 0.37 5.54 1.11 4.80 3.32 2.21 2.95 1.48 1.11 11.81 0.00 4.43 9.96 16.97 32.47 1.48 1999/00 4 0.17 6.28 1.70 7.81 0.51 0.00 2.04 7.81 3.23 13.75 0.00 2.89 6.96 3.57 38.03 5.26 2000/01 5 0.00 4.78 1.88 8.19 0.68 2.22 3.92 4.10 2.90 6.48 0.00 6.48 6.83 6.48 31.06 13.99 2001/02 6 0.20 5.07 0.41 9.94 0.81 0.20 2.03 8.32 0.81 10.95 0.00 2.43 7.10 3.25 45.03 3.45 2002/03 7 0.15 2.61 2.18 15.09 0.29 1.31 3.63 13.93 2.61 6.53 1.16 3.63 7.69 4.64 29.17 5.37 2003/04 8 0.47 1.89 0.00 14.78 0.00 0.94 4.72 12.42 0.63 13.36 0.94 3.62 13.36 7.70 17.77 7.39 2004/05 9 0.64 10.09 1.50 10.09 0.00 0.00 0.00 7.73 3.00 4.72 0.86 2.15 28.11 7.08 19.10 4.94 2005/06 10 0.36 0.36 1.09 15.09 1.64 0.00 1.64 11.09 4.00 10.73 2.55 2.18 14.36 24.18 10.00 0.73 2006/07 11 0.13 3.70 1.32 7.27 1.32 5.28 0.40 6.34 0.66 3.43 0.00 1.45 15.59 49.67 3.43 0.00 2007/08 12 2.87 9.20 0.00 6.03 0.00 0.57 1.72 8.62 1.72 3.45 1.44 22.41 15.52 23.85 2.59 0.00 2008/09 13 0.44 7.30 1.33 7.96 0.22 0.00 2.88 13.72 2.88 1.11 0.22 14.38 18.81 21.90 4.65 2.21 2009/10 14 0.00 10.98 0.00 3.66 0.41 0.00 0.00 8.13 1.22 2.85 0.00 2.44 30.49 35.77 3.66 0.41 2010/11 15 0.00 0.35 1.05 16.84 0.00 0.00 0.00 8.07 2.11 1.75 0.00 0.70 0.70 58.95 7.02 2.46 2011/12 16 0.32 3.88 0.00 6.80 3.24 0.00 0.65 9.06 2.91 2.27 0.32 0.00 9.39 56.31 3.24 1.62 2012/13 17 0.00 1.92 0.00 0.00 0.00 0.00 1.10 16.76 6.59 0.27 0.82 3.30 1.37 62.64 3.02 2.20 2013/14 18 0.00 0.00 0.00 1.07 2.85 1.07 1.78 7.47 0.71 0.00 0.00 4.98 4.63 67.97 4.63 2.85 2014/15 19 0.00 0.31 0.00 1.56 3.43 0.00 0.00 6.54 0.62 0.93 0.00 2.18 9.03 75.39 0.00 0.00
53