End of year report

Tamar, Camel, Fowey and Slapton Ley Catchments May 2004 - May 2005

Dr Polly Bown Mr Toby Russell

September 2005 Summary The Westcountry Rivers Trust is the UK partner of the Indicang Project through which four river catchments are being investigated: the Tamar, Camel, Fowey and Slapton Ley. These river catchments are all located in the South-West of the UK.

Physical Characteristics of the Catchments The Tamar catchment is the largest of the four with an area of 927.75 km2, followed by the Camel catchment at 413.0 km2, the Fowey catchment 177.5 km2 and the catchment of Slapton Ley 47.4 km2. These catchments all have a strong rural and farming influence and experience climatic conditions typical of Atlantic Britain with mild wet winters and cool, moist summers.

Data regarding river flow is available for all the catchments from large datasets held by the UK Environment Agency. These datasets can be obtained and used in the project if found to be relevant. Water Quality data for the Tamar and Camel have been located for 2002-2004 covering a wide range of parameters. More data of this type is available from the Environment Agency but the most relevant data to the project needs to be identified before collection of further information.

The locations of dams, weirs and waterfalls have been mapped for all catchments. One dam and a series of weirs in the Tamar catchment, one dam in the Camel catchment and two dams in the Fowey catchment were found to be impassable to fish. Fish would have free circulation throughout the Slapton Ley catchment.

Eel Exploitation Initial investigation into eel fishing within the four catchments has produced information from the Environment Agency regarding eel licences and catch returns for 2003 in Devon and Cornwall. Methods identified for capturing elvers and eels are Fyke nets, Dip nets and traps. Future work will involve expanding upon this data.

Eel Resource Data concerning the presence and absence of eels in the Tamar catchment has been located for 1987-2004 and length data for the eels for 2002-2004 show an increase in average length with increasing site distance from the tidal limit. Only three specific densities estimates have been found for eels in the Tamar catchment. Further work will involve locating more length and density data for eels within the Tamar catchment.

Data concerning the presence and absence of eels within the Fowey catchment have also been located for 1977-2004 spanning the impoundment of Colliford Reservoir and the creation of the impassable fish barrier. Length and density data have also been gathered for 1977-1987 and show increasing average length and decreasing density with increasing site distance from the tidal limit.

An elver trap has been established at the entrance to the Slapton Ley catchment through collaboration with the Slapton Ley National Nature Reserve.

Project Promotion and Contacts A number of contacts have been established through the Indicang Project such as agencies, research groups, the National Nature Reserve at Slapton Ley, local fishing groups and larger groups such as the Association of Rivers Trusts.

Project promotion has included newsletter articles, a press release, a presentation, a BBC radio interview and website promotion.

All maps have been reproduced by permission of Ordnance Survey on behalf of HMSO. © Crown Copyright and database right 2005. All rights reserved, Environment Agency. Ordnance Survey Licence Number 100026380.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 1 1. INTRODUCTION...... 3 2. THE CHARACTERISTICS OF THE FOUR UK CATCHMENTS STUDIED FOR THE INDICANG PROJECT...... 4

2.1. THE TAMAR CATCHMENT ...... 4 2.1.1. The Physical Environment...... 4 2.1.2. Rate of River Flow ...... 5 2.1.3. Water and Sediment Quality...... 6 2.1.4. Location of Dams, Weirs and Waterfalls...... 7 2.2. THE CAMEL CATCHMENT ...... 8 2.2.1. The Physical Environment...... 8 2.2.2. Rate of River Flow ...... 9 2.2.3. Water and Sediment Quality...... 9 2.2.4. Location of Dams, Weirs and Waterfalls...... 9 2.3. THE FOWEY CATCHMENT...... 10 2.3.1. The Physical Environment...... 10 2.3.2. Rate of River Flow ...... 11 2.3.3. Water and Sediment Quality...... 11 2.3.4. Location of Dams, Weirs and Waterfalls...... 11 2.4. THE SLAPTON LEY CATCHMENT ...... 12 2.4.1. The Physical Environment...... 12 2.4.2. Rate of River Flow ...... 13 2.4.3. Water and Sediment Quality...... 13 2.4.4. Location of Dams, Weirs and Waterfalls...... 13 3. EEL FISHING WITHIN THE FOUR UK CATCHMENTS ...... 14 4. THE EEL RESOURCE WITHIN THE FOUR UK CATCHMENTS...... 14

4.1. THE TAMAR CATCHMENT ...... 14 4.1.1. Presence and absence of eels ...... 14 4.1.2. Length data ...... 14 4.1.3. Density data ...... 15 4.2. THE FOWEY CATCHMENT...... 15 4.2.1. Presence and absence of eels ...... 15 4.2.2. Length data ...... 17 4.2.3. Density data ...... 18 4.3. THE SLAPTON LEY CATCHMENT ...... 19 4.3.1. Eel Migration...... 19 5. PROJECT PROMOTION AND CONTACTS ...... 19 6. REFERENCES AND SOURCES OF INFORMATION ...... 20

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 2 1. Introduction The International Council for the Exploration of the Seas (ICES) has concluded that the North Atlantic eel stock is now below safe biological limits. The reasons for the decline are unclear although several factors such as changes in the marine environment are generally agreed to be significant (Environment Agency, 2005). Due to the nature of their life cycle, the decline in the stock of eels has occurred across Europe thus it is imperative that all eel fisheries and their habitats are managed to common objectives. The Indicang Project promotes this cooperation and the Westcountry Rivers Trust as the UK partner is to provide data concerning the eel resource, their environment and their exploitation for four river catchments in the UK.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 3 2. The characteristics of the four UK catchments studied for the Indicang Project The following section contains information regarding the physical environment of the four UK catchments that are being investigated through the Indicang Project. The position of the four catchments, the Tamar, Camel, Fowey and Slapton Ley are displayed as Figure 1.

DEVON

Tamar Catchment Camel Catchment

Slapton Ley Catchment CORNWALL Fowey Catchment

Figure 1 - Position of the four river catchments in the South West of the UK

2.1. The Tamar Catchment

2.1.1. The Physical Environment The Tamar catchment is the largest of the four UK catchments that are under investigation through the Indicang Project. It is often separated and discussed in terms of the freshwater Tamar and tributaries, and the Tamar estuary and tributaries. For the purpose of this study the former is under investigation regarding eel colonisation and habitat.

The catchment of the freshwater Tamar and tributaries is 927.75 km2 (Figure 2). The main river channel of 167 km forms the county boundary between Devon and Cornwall for much of its length with 447.9 km of controlled water draining into it. Tributaries of the Tamar include the rivers Carey, Thrushel, Lyd, Ottery, Kensey, Inny, Deer and Claw.

The headwaters of the Tamar lie within 10km of the Atlantic coast with the resultant streams forming narrow, deep channels with no floodplain development. Higher order streams are incised in valleys with moderately sloping sides with narrow floodplains. Lower down the catchment the floodplains widen to between 300-500m until it reaches the tidal limit at Gunnislake Weir. Climatic conditions over the Tamar Catchment are typical of Atlantic Britain with mild wet winters and cool, moist summers with the long term average annual whole rainfall over the catchment being 1190mm.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 4 Tamar Catchment Drainage Network

River Deer

River Claw River Carey

River Ottery River Thrushel

River Kensey River Lyd

River Inny River Tamar

Catchment Boundary N Open Water Stream Order 1 Stream Order 2 W E Stream Order 3 Stream Order 4 Stream Order 5 4 0 4 Kilometers Stream Order 6 S Stream Order 7

Figure 2 - The Freshwater Tamar Catchment and Tributaries

2.1.2. Rate of River Flow Rate of river flow in m s-1 has been measured by the Environment Agency for a number of years throughout the Tamar catchment. There are 12 river gauging stations across the catchment that have taken river level /flow measurements every 15 minutes. These stations along with catchment areas and lengths of records are shown in Table 1. In addition to these station data exist from spot measurements throughout the catchment. The future work on this project will involve determining what aspect of this information is useful to the Indicang Project and then collating the appropriate data.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 5 Table 1 - Hydrometric gauging stations in the Tamar Catchment Catchment Station River NGR Start Date Area (km2) Beals Mill Inny SX 3589 7706 11.10.1988 105.0 Crowford Bridge Tamar SX 2905 9910 21.06.1972 76.7 Germansweek Wolf SX 4458 9422 27.08.1991 11.0 Gunnislake Tamar SX 4263 7252 26.06.1956 916.9 Hayne Bridge Thrushel SX 4160 8670 01.08.1988 58.4 Lifton Park Lyd SX 3888 8424 19.02.1988 218.1 Moors Mill Hennard Stream SX 4245 9385 07.04.1991 7.2 Polson Bridge Tamar SX 3530 8490 22.12.1987 470.3 Roadford Wolf SX 4190 8980 31.03.1988 31.1 Compensation Roadford LB Tributary to Wolf SX 4190 8975 03.06.1986 0.3 Tributary Tinhay Thrushel SX 3976 8549 01.10.1969 112.7 Werrington Park Ottery SX 3374 8658 25.06.1985 120.7

2.1.3. Water and Sediment Quality Water Quality is also measured within the Tamar catchment by the Environment Agency. These data sets are also long term and the measurements taken are for a wide range of chemical, physical and biological parameters. Currently we have received data for the Tamar taken from 2000-2004 (Table 2), but as is the case with the rate of river flow, the future work will involve determining what aspect of this information is useful to the Indicang Project.

Table 2 - Water Quality Data for the Tamar Catchment for 2000-2004 Year 2000 2001 2002 2003 2004 Parameter Units Min Max Min Max Min Max Min Max Min Max Aldrin g/l <0.001 <0.0012 <0.001 <0.0011 <0.001 <0.001 ND ND ND ND Atrazine g/l <0.03 <0.0343 <0.003 <0.03 <0.003 <0.0345 <0.003 0.011 <0.003 0.024 Benzo-[A]- g/l ND ND ND ND ND ND <0.01 <0.01 <0.01 <0.01 pyrene Benzo-[B]- g/l ND ND ND ND ND ND <0.01 <0.01 <0.01 <0.01 fluroanthene Benzo-[K]- g/l ND ND ND ND ND ND <0.01 <0.01 <0.01 <0.01 fluroanthene BOD 5 day ATU mg/l <1.0 12.5 <1.0 73.7 <1.0 >8.7 <1.0 318.0 <1.0 3.8 filtrate - as O BOD ATU as O2 mg/l <1.0 13.8 <1.0 96.5 <1.0 82.5 <1.0 370.0 <1.0 11.8 Organic Carbon mg/l 0.94 9.15 0.84 6.98 0.82 8.38 0.92 8.47 0.93 19.0 Total - as C COD as O2 mg/l <12.0 51.0 <12.0 54.0 <12.0 100.0 <12.0 59.0 <12.0 73.0 Conductivity @ S/cm <10.0 255.0 85.0 320.0 67.0 288.0 65.0 454.0 92.0 234.0 20˚C DDE (OP) g/l <0.001 0.002 <0.001 <0.0011 <0.001 <0.001 ND ND ND ND DDE (PP) g/l <0.001 0.0021 <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Dieldrin g/l <0.001 <0.0012 <0.001 <0.0011 <0.001 <0.001 <0.001 0.002 <0.001 <0.001 Endosulphan g/l <0.001 <0.001 <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Alpha Endosulphan g/l <0.002 <0.0043 <0.002 <0.002 <0.002 <0.0022 <0.002 <0.002 <0.002 <0.002 Beta Endrin g/l <0.001 <0.0012 <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 HCH Gamma g/l 0.0007 <0.011 <0.0022 0.0252 <0.0022 0.0385 <0.002 0.005 <0.002 <0.003 Indeno - [1,2,3 - g/l ND ND ND ND ND ND <0.02 <0.02 <0.02 <0.02 CD] - pyrene Nitrate as N mg/l 0.186 9.22 0.173 7.77 0.192 21.0 0.178 24.2 <0.192 19.9 Nitrite as N mg/l <0.004 0.143 <0.004 0.245 <0.004 0.676 <0.004 0.339 <0.004 0.195

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 6 Year 2000 2001 2002 2003 2004 Parameter Units Min Max Min Max Min Max Min Max Min Max Orthophosphate mg/l <0.01 2.79 <0.01 1.91 <0.01 6.73 <0.02 5.32 <0.02 2.96 as P pH pH 5.5 9.9 5.98 10.47 5.15 9.85 4.31 9.84 5.68 9.84 units pH in situ pH 6.41 7.59 6.96 7.35 ND ND ND ND ND ND measurements units Phosphate mg/l 0.03 1.17 0.036 0.235 0.027 0.229 0.025 0.175 0.03 0.273 Phosphorous mg/l <0.02 0.612 0.02 2.08 <0.02 0.7 <0.02 3.78 <0.02 0.369 total - as P Potassium as K mg/l 0.99 7.69 0.45 7.78 0.38 17.3 0.4 85.9 0.34 12.7 Potassium mg/l 2.9 7.27 1.0 4.11 ND ND ND ND ND ND dissolved as K Temperature CEL 0.1 19.0 3.9 22.2 2.0 22.01 2.1 23.3 2.34 21.9 water ND - No data available

We have currently not found data describing the sediment quality of the Tamar.

2.1.4. Location of Dams, Weirs and Waterfalls There are a number of dams, weirs and waterfalls within the Tamar catchment, most of which are described as passable to fish. In only two instances are structures described as impassable. The first is a series of weirs at the top of the catchment just below Tamar Lakes; the second is the dam at Roadford Reservoir. The location of dams, weirs and waterfalls within the Tamar catchment are displayed on Figure 3.

Weirs passable to fish Weirs Impassable to fish Dams Impassable to fish Waterfalls

Figure 3 - Dams, Weirs and Waterfalls in the Tamar Catchment

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 7 2.2. The Camel Catchment

2.2.1. The Physical Environment Rising at 280m on Hendraburnick Down, the river Camel drains a 413km2 area between Bodmin Moor and St Breock (Figure 4). With an average gradient of 7m km-1, it flows for approximately 40km before joining the sea near Padstow. The river Allen is a major tributary of the Camel and enters the Camel estuary just upstream of Wadebridge.

The catchment is mainly made up from sandstones, slates and shales, with granite being found closer to Bodmin Moor. Historically, mining and quarrying was once an important industry with slate quarrying still occurring at Delabole, towards the top of the river Allen. Redundant coastal lead mines now form an important habitat for bats. The upper and middle reaches of the Camel are essentially moorland, passing into woodland. Most of the land is undulating farmland, principally livestock farming, with mixed farming/rough grazing on the poorer land. Indeed, agricultural land covers approximately 93% of the catchment.

The Camel Valley is currently designated as a Special Site of Scientific Interest (SSSI) and has also been attributed candidate Special Area of Conservation (cSAC) status under the EU Habitats Directive, due to the presence of otters and bullheads. Further designations include Area of Outstanding Natural Beauty (AONB) status for the Camel estuary and Area of Great Landscape Value (AGLV) status for the Camel and Allen valleys. Many species, including some rare ones, can be found in the Camel and Allen catchment including bullheads, lamprey, cockles and many other red data book species. The Camel and Allen rivers have been recorded as being amongst the most productive rivers for salmon and sea trout in the South West, due to their high water quality, suitable flow regimes and appropriate habitats.

Crowdy Reservoir

River Allen De Lank River

River Camel

Stream Order 1 River Ruthern Stream Order 2 Stream Order 3 Stream Order 4 Stream Order 5 Stream Order 6 Stream Order 7

Figure 4 - The Camel Catchment

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 8 2.2.2. Rate of River Flow The rate of river flow has been measured by the Environment Agency within the Camel catchment with data stretching over a number of years. The future work on this project will involve determining what data is available and what is useful to the Indicang Project.

2.2.3. Water and Sediment Quality Water Quality is measured within the Camel catchment by the Environment Agency. As with the Tamar Catchment, these data sets are also long term and the measurements taken are for a wide range of chemical, physical and biological parameters. Currently we have received data for the Camel taken from 2000-2004 (Table 3), but as is the case with the rate of river flow, the future work will involve determining what aspect of this information is useful to the Indicang Project.

Table 3 - Water Quality Data for the Camel Catchment for 2000-2004 Year 2000 2001 2002 2003 2004 Parameter Units Min Max Min Max Min Max Min Max Min Max Aldrin g/l <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Atrazine g/l <0.03 <0.034 <0.003 <0.03 0.00356 0.00572 0.003 0.055 <0.003 0.007 BOD ATU as O2 mg/l <1.0 11.7 <1.0 6.8 <1.0 47.2 <1.0 5.1 <1.0 7.3 Organic Carbon mg/l 1.41 4.38 1.19 3.77 1.27 3.78 0.98 3.19 1.2 4.15 Total - as C COD as O2 mg/l <12.0 30.0 <12.0 30.0 <12.0 19.0 <12.0 14.0 <12.0 26.0 Conductivity @ S/cm 136 182 134 216 136 163 148 200 126 164 20˚C DDE (OP) g/l <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 ND ND ND ND DDE (PP) g/l <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Dieldrin g/l <0.001 0.003 <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Endosulphan g/l <0.001 <0.001 <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Alpha Endosulphan g/l <0.002 <0.0043 <0.002 <0.0021 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 Beta Endrin g/l <0.001 <0.0011 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 HCH Gamma g/l <0.0005 <0.011 <0.0022 <0.011 <0.0022 <0.0022 <0.002 <0.003 <0.002 <0.002 Nitrate as N mg/l 0.182 8.08 0.192 6.84 0.188 7.67 0.192 10.80 0.252 7.95 Nitrite as N mg/l <0.004 0.124 <0.004 0.139 <0.004 0.357 <0.004 0.0625 <0.004 0.349 Orthophosphate mg/l <0.01 0.407 <0.01 0.645 <0.01 1.01 <0.02 0.557 <0.02 1.13 as P pH pH 6.15 8.05 6.1 8.15 5.79 8.26 6.1 8.01 6.13 8.18 units Phosphate mg/l ND ND ND ND ND ND <0.02 0.054 ND ND Phosphorous mg/l 0.045 0.197 0.061 0.212 0.03 0.118 0.034 0.23 0.067 0.282 total - as P Potassium as K mg/l ND ND 0.81 5.91 0.49 5.23 0.51 5.51 0.57 4.75 Temperature CEL 1.0 17.7 4.3 18.1 3.7 20.74 2.9 20.65 1.91 22.0 water

2.2.4. Location of Dams, Weirs and Waterfalls There is one major dam at Crowdy Reservoir within the Camel catchment and many weirs. It appears that all the weirs are passable to fish and the dam impassable, but further investigation of the presence and absence of eels would be needed to confirm this. The location of the dam and weirs within the Camel catchment are displayed on Figure 5.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 9 Weirs Dams

Figure 5 - Dams and Weirs in the Camel Catchment

2.3. The Fowey Catchment

2.3.1. The Physical Environment

The river Fowey is one of the largest river catchments in south Cornwall, draining an area of approximately 177.5km2 from central and southern Bodmin Moor (Figure 6) and includes two strategic reservoirs - Colliford and Siblyback - which supply water to a large part of the county's population. The river rises on Bodmin Moor at a height of 290m, flowing in a southerly direction for approximately 35km before reaching the tidal limit at Lostwithiel. The estuary continues for a further 9km before reaching the coast at Fowey town. There are several tributaries that enter the Fowey estuary, the largest of which is the river Lerryn. The landscape of the catchment is characterised by heathland, moorland and rough pasture in the upper reaches and broadleaf, coniferous and mixed plantation woodland in the middle and lower sections. The majority of the catchment is rural, the only notable urban areas being Lostwithiel and Fowey town. There are 4 Sites of Special Scientific Interest (SSSIs) within the catchment, in addition to the majority of the upper catchment being designated as an Area of Great Scientific Value (AGSV) and also an Area of Great Historical Value (AGHV).

The geology of the Fowey catchment varies from igneous granite on Bodmin moor, through to Devonian slates in the middle reaches and Straddon grits and Meadford beds in the lower part of the catchment. Copper and china clay mining have been major activities within the catchment, leading to contamination from metalliferous compounds and sediment. Although contamination levels are no longer considered to cause major water quality problems, disused china clay mines continue to act as a source of suspended solids.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 10 River Fowey

Colliford Reservoir Siblyback Reservoir

River Lerryn

Stream Order 1 Stream Order 2 Stream Order 3 Stream Order 4 Stream Order 5

Figure 6 - The Fowey Catchment

2.3.2. Rate of River Flow The rate of river flow has been measured by the Environment Agency within the Fowey catchment with data stretching over a number of years. The future work on this project will involve determining what data is available and what is useful to the Indicang Project.

2.3.3. Water and Sediment Quality Water Quality measurements are also taken by the Environment Agency within the Fowey catchment. The future work on this project will involve determining what data is available and what is useful to the Indicang Project.

2.3.4. Location of Dams, Weirs and Waterfalls There are two major dams within the Fowey catchment, at Colliford Reservoir and Siblyback Reservoir. Both of these dams are impassable to fish. The remaining weirs and the one large waterfall (Golitha Falls) are both passable. The location of the dams, weirs and waterfalls within the Fowey catchment are displayed on Figure 7.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 11 Weirs passable to fish Dams Impassable to fish Waterfalls

Figure 7 - Dams, Weirs and Waterfalls in the Fowey Catchment

2.4. The Slapton Ley Catchment The Slapton Ley Catchment

2.4.1. The Physical Environment The Slapton Ley Catchment is the smallest of the four UK catchments that are under investigation through the Indicang Project (Figure 8). Slapton Ley is the largest freshwater lake in south-west England and a National Nature Reserve. The main river, the River Gara is approximately 10.5 km long and drains directly into the Higher Ley (an area of rich fen), which is separated from the main, Lower Ley by a causeway and road-bridge. The other main watercourse is the Start Stream which drains into the Lower Ley. The Lower Ley is 73ha and drains a catchment area of approximately 47.4 km2 which consists mainly of mixed undulating farmland with arable on the steep surrounding slopes. The outflow from the Lower Ley to the sea is through a single artificial weir at its Southern end where the water leaves the Ley and flows across the shingle beach. Seepage also occurs from both Leys through the shingle bar.

The climate is mild, wet and windy with an annual average rainfall of 1051mm and a high relative humidity.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 12 River Gara

Start Stream

Stream Order 1 Stream Order 2 Slapton Ley Stream Order 3 Stream Order 4 Weir

Figure 8 - The Slapton Ley Catchment

2.4.2. Rate of River Flow The rate of river flow has been measured by the Environment Agency and Slapton Ley Reserve within the catchment with data stretching over a number of years. The future work on this project will involve determining what data is available and what is useful to the Indicang Project.

2.4.3. Water and Sediment Quality Water Quality measurements are also taken by the Environment Agency and the Slapton Ley Reserve within the catchment. The future work on this project will involve determining what data is available and what is useful to the Indicang Project.

2.4.4. Location of Dams, Weirs and Waterfalls There is only a single weir in the Slapton Catchment which is the weir located at the outflow from the Lower Ley to the sea at its Southern end where the water leaves the Ley and flows across the shingle beach. This weir is not a significant migration barrier to eels. There are no dams or waterfalls within the catchment.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 13 3. Eel fishing within the four UK catchments Little data has been gathered concerning eel fishing and numbers of fishermen on the four UK catchments, however, past data has been recorded by the Environment Agency and the future work of the project will include locating and presenting this data. The type of data that is available is highlighted by data received for 2003. In this year 2753 licences were sold in England and Wales of which 49 were for fishermen based in Devon and Cornwall. Of those sold the following data (Table 4) describes licences sold for different methods of fishing and the size of catches. No data has yet been found that highlights catches of sport fishermen.

Table 4 - Eel Licences and catch returns for Devon and Cornwall in 2003 Catches (kg) Type of gear Number of licences sold Elver Eel Fyke Nets 6 - 59.21 Dip Nets 25 94.70 - Traps 2 - 3.50 Double Fyke Nets 16 - 39.50 Total 49 94.70 102.21

4. The eel resource within the four UK catchments Past and current data concerning the presence/absence and density of eels within the catchments has been gathered for two of the four UK catchments, the Tamar and the Fowey. Coupled with this, data on eel length is also available for these two catchments. Further work in this area is to extend the data gathering process to include the Camel and Slapton Ley catchments. A search will also be made of the availability of data concerning the age of the eel population, health observations and information about eel migration. The data displayed below was captured by the Environment Agency and collated by Knights et al. (2001) and through the work of the Indicang Project.

4.1. The Tamar Catchment

4.1.1. Presence and absence of eels Data concerning presence and absence of eels in the Tamar catchment has been obtained from 1987 to 2004. This data has been inputted into the GIS as a layer over the Tamar catchment along with the locations of the weirs, dams and waterfalls. Future work involves creating a map of the stream orders so that all the data can be displayed together in a number of maps thus allowing ease of reference for the presence/absence of eels within the Tamar catchment.

Presence/absence comparisons can be made for the data which has already been gathered. For example, in 1993 eels were found in 91 of 139 sites (65.5%), in 1995 they were only found in 24 out of 58 sites (41.4%) whereas in 2004 they were found in 40 out of 58 sites (47.1%). However, in each of these years different sites were surveyed with only 14 sites surveyed during each year. Of the 14 sites eels were present at nine in 1993 (64.3%), seven in 1995 (50.0%) and three in 2004 (21.4%).

4.1.2. Length data Data has been obtained concerning the length of eels captured in the Tamar catchment for 2002-2004 (Figure 9). The minimum average eel length for a site was 8.2 cm at a site that was approximately 29.9 km from the tidal limit while the maximum average length was recorded as 52.0 cm at a site approximately 42.1 km from the tidal limit. The minimum approximate site distance from the tidal limit was 13.6 km while the maximum was 55.8 km.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 14 The data indicates increasing average eel length with increasing site distance from the tidal limit as expected (ref), but statistics have not yet been applied to this data to confirm this.

60 50 40 Length cm 30 20 10 0 0 10 20 30 40 50 60

Approximate distance km

Figure 9 - Tamar Catchment - Mean length (cm) per site (2002-2004) v. approximate distance from tidal limit (km)

4.1.3. Density data Currently only three specific densities estimates have been located for the Tamar catchment with each of these recorded in 1978. Eel density was recorded as 10.12, 22.32 and 27.84 eels 100m-2 at sites less than 25km from the tidal limit. Further work will involve locating more eel density data for the Tamar catchment.

4.2. The Fowey Catchment

4.2.1. Presence and absence of eels Data concerning presence and absence of eels in the Fowey catchment has been obtained from 1977 to 2004. This data is presented below (Figures 10-14) along with the locations of the weirs, dams and waterfalls.

Presence/absence comparisons can be made for the data as was the case for the data collected for the Tamar catchment. For example, in 1994 eels were found in 47 of 49 sites (95.9%), in 1997 they were found in 41 out of 48 sites (85.4%), in 2000 they were found in 38 of 41 sites (92.7%) whereas in 2004 they were found in 21 out of 25 sites (84.0%). In each of these years different sites were surveyed with 23 sites surveyed during each year. Of the 23 sites eels were present at 23 in 1994 (100.0%), 21 in 1997 (91.3%), 22 in 2000 (95.7%) and 19 in 2004 (82.6%).

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 15 Figure 10 shows eels recorded at 29 sites Colliford Dam between 1977 and 1986. This map shows clearly that the weirs and the waterfall within the Fowey catchment are passable to eels. It also suggests that Colliford Dam is also passable; however some of the eel surveys were conducted before the creation of the dam in March 1981 and its subsequent impoundment in July 1982. Figures 11-14 that show data after 1986 clearly show the absence of eels above this dam.

Stream Order 1 Weirs passable to fish Stream Order 2 Dams Impassable to fish Stream Order 3 Waterfalls Stream Order 4 Presence of eels Stream Order 5

Figure 10 - Presence of eels at sites within the Fowey catchment 1977-1986.

Forty nine sites were surveyed for eels during 1987-1996. Eels were present at 47 sites and were absent at two.

Absence of eels Presence of eels

Figure 11 - Absence of eels at sites within the Figure 12 - Presence of eels at sites within the Fowey catchment 1987-1996 Fowey catchment 1987-1996

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 16 Forty nine sites were surveyed for eels during 1997-2004. Eels were present at 44 sites and were absent at 20.

Absence of eels Presence of eels

Figure 13 - Absence of eels at sites within the Figure 14 - Presence of eels at sites within the Fowey catchment 1997-2004 Fowey catchment 1997-2004

4.2.2. Length data Data has been obtained concerning the length of eels captured in the Fowey catchment for 1977-1987 (Figure 15). The minimum average eel length for a site was 17.0 cm at a site that was 4.8 km from the tidal limit while the maximum average length was recorded as 47.9 cm at a site 30.3 km from the tidal limit. The minimum site distance from the tidal limit was 4.8 km while the maximum was 36.8 km.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 17 60

50

40 Length cm 30

20

10

0 0 5 10 15 20 25 30 35 40

Distance from tidal limit km

Figure 15 - Fowey Catchment - Mean length (cm) per site (1977-1987) v. distance from tidal limit (km)

4.2.3. Density data Despite the fact that a multi-species survey method was used to provide the density data for eels between 1977-1987, mean densities per site were relatively high downstream (15-20 eels 100 m-2) with decreasing density with distance upstream to approximately +25 km. -2 Densities then decreased markedly above +25 km to less than 1 eel 100m . Past density data often displays marked seasonal differences in catches at the same site which may account for some of the outliers.

60

50

-2 Density N 100m 40

30

20

10

0 0 5 10 15 20 25 30 35 40

Distance from tidal limit km

Figure 16 - Fowey Catchment - Mean density (N 100m-2) per site (1977-1987) v. distance from tidal limit (km)

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 18 4.3. The Slapton Ley Catchment

4.3.1. Eel Migration Through collaboration with the Slapton Ley National Nature Reserve, an elver trap has been established at the entrance to the Slapton Ley catchment (Figure 17). Results for the trap should be available for the following report.

Figure 17 - The Elver Trap at the entrance to Slapton Ley

5. Project Promotion and Contacts

Through the Indicang project a number of contacts have been established. Current contacts include:  Agencies such as the Environment Agency (EA) and the Centre for Environment, Fisheries and Aquaculture Science (CEFAS)  Research groups such as those based at Kings College, London and Westminster University  The Slapton Ley National Nature Reserve  Local fishing groups  Larger groups such as the Association of Rivers Trust who is made up of members comprising riparian owners, fishermen and other river managers.

Project promotion has involved two articles in the Westcountry Rivers Trust newsletters (http://www.wrt.org.uk/newsletter.htm. Issues - Summer 2004 and Summer 2005), an article in the Slapton Ley National Nature Reserve newsletter (Figure 18), a press release in the national press, a presentation given at the Field Studies Council Research Seminar in 2004, a BBC radio interview and articles on the Westcountry Rivers Trust http://www.wrt.org.uk/projects/indicang.htm and BBC websites http://www.bbc.co.uk/devon/content/articles/2005/07/26/eels_slapton_feature.shtml.

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 19 Figure 18 - Excerpts from the Westcountry Rivers Trust and the Slapton Ley National Nature Reserve Newsletters

6. References and Sources of Information BBC. (2005). Slapton key to eels' future [online]. Available from: [Accessed October 2005]

Environment Agency. (2005). Our Nations’ Fisheries [online]. Available from: [Accessed October 2005]

Knights, B., Bark, A., Ball, M., Williams, F., Winter, E., Dunn, S. (2001). Eel and Elver Stocks in England and Wales - Status and Management Options. Environment Agency. Pp. 293.

Slapton Ley National Nature Reserve. (2005). Eels’ future rests in Slapton. Summer Newsletter. Pp. 4.

Westcountry Rivers Trust. (2004). Indicang Report. Confluence. Pp. 12.

Westcountry Rivers Trust. (2005). Indicang Project Update. Confluence. Pp. 16.

Westcountry Rivers Trust (2005). The Indicang Project. [online]. Available from: [Accessed October 2005]

INDICANG. End of year report. Tamar, Camel, Fowey and Slapton Ley Catchments. 20