Identification of UK BAP Priority River Reaches in Bedfordshire and Luton
Total Page：16
File Type：pdf, Size：1020Kb
Identification of UK BAP Priority River Reaches in Bedfordshire and Luton March 2012 Acknowledgements This study was based on work conducted by the Bedfordshire Rural Communities Charity. Data were provided by the Bedfordshire and Luton Biodiversity Recording and Monitoring Centre (BRMC), Bedfordshire Bat Group, Environment Agency, Bedfordshire Rural Communities Charity and BirdTrack. Special thanks to Rachel Broomfield of the BRMC for her ever-patient MapInfo tuition. Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 2 March 2012 Preliminary analysis The current list of UK Biodiversity Action Plan (BAP) species and habitats was released in 2007. At that time the new priority habitat ‘Rivers’ was not fully defined. Since then the Rivers BAP Working Group has been refining the definition. In July 2010 qualifying criteria were set for identifying BAP priority stretches of river. These criteria are: 1. Riverine water bodies of high hydromorphological/ecological status 2. Headwaters 3. Occurrence of the EC Habitat Directive Annex I Habitat (H3260 Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation) 4. Chalk rivers as given in the existing BAP definition 5. Active shingle rivers 6. A/SSSI (Areas or Sites of Special Scientific Interest) designated for river species, riverine features or fluvial geomorphology 7. Species, including i. Annex II Habitats Directive species ii. BAP Priority Species iii. Invertebrate species which are strongly indicative of river shingle (BRIG 2010). This study relates to criterion 7 regarding species presence and richness. The Joint Nature Conservation Committee (JNCC) developed a list of priority river indicator species. The Rivers BAP Working Group had determined that river stretches home to six or more indicator species would qualify as priority BAP habitat. In 2011 the Bedfordshire Rural Communities Charity (BRCC) plotted records of these species, creating a map of their distribution and highlighting ‘hotspots’ which could indicate priority river reaches (Figure 1). A tetrad resolution was used for this exercise. The BRCC study revealed that the most likely priority river areas were located at: • The River Ivel through Biggleswade • The River Ivel near and at the confluence with the River Great Ouse • The River Great Ouse east of Priory Park, Bedford. Other important but not necessarily priority areas were likely to be found at: • The River Great Ouse at Priory Park, Bedford • The River Great Ouse loops through Milton Ernest, Sharnbrook and Felmersham. Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 3 March 2012 Figure 1 Tetrad-based preliminary identification of UK BAP priority river reaches in Bedfordshire and Luton Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 4 March 2012 Refined analysis The indicator species list and methodology for identifying priority river reaches were subsequently refined. Indicator species have been assigned to one of three criterion levels (A, B or C). To qualify, an ECS or WFD water body needs to have either: • Records of any one species from criterion levels A (BAP priority species strongly dependent on river habitat quality) or C (non-BAP priority species, indicative of shingle rivers), or • From criterion level B (widespread BAP species which are less dependent on river habitat quality alone), records of 6 or more species. This threshold has been selected by looking at available records for all criteria and identifying a level which returns a manageable proportion of the river network. (BRIG 2010). Thirteen of the indicator species selected by the Rivers BAP Working Group have been recorded in Bedfordshire (Table 1). These were used to determine which stretches of the county’s rivers qualify as priority BAP habitat. Table 1 Priority river habitat indicator species recorded in Bedfordshire Criterion Scientific name Common name Classification level A Cobitis taenia Spined loach Bony fish A Emberiza schoeniclus Reed bunting Bird A Pisidium tenuilineatum Fine-lined peamussel Mollusc B Anguilla anguilla European eel Bony fish B Cottus gobio Bullhead Bony fish B Arvicola amphibius European water vole Mammal B Lutra lutra European otter Mammal B Pipistrellus pygmaeus * Soprano pipistrelle * Mammal B Pseudanodonta complanata Depressed river mussel Mollusc B Oenanthe fistulosa * Tubular water-dropwort * Vascular plant B Salmo trutta Brown/sea trout Bony fish B Sium latifolium * Greater water-parsnip * Vascular plant B Stellaria palustris ** Marsh stitchwort ** Vascular plant only records of breeding near rivers * river records only ** river-bank records only A 1km grid square resolution was chosen for the exercise; this scale was felt to be coarse enough to be feasible while being scientifically robust. Where a square included one or more A species or six B species, any river located within that square would therefore be designated as priority habitat. Only records dated 2000 onwards were used. This eliminated several species not recorded in the county since that time: Pisidium tenuilineatum , Sium latifolium and Stellaria palustris . Also eliminated was Oenanthe fistulosa , which was more recently recorded but not strictly along rivers as required by the methodology. Data sources included: • Bedfordshire and Luton Biodiversity Recording and Monitoring Centre • National Biodiversity Network Gateway • Bedfordshire Bat Group • Bedfordshire Bird Atlas data 2007-2011 • BirdTrack Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 5 March 2012 • Ecological reports included in planning applications • Environment Agency survey data Grid squares containing records of each species were plotted in MapInfo. Results Fourteen 1km grid squares were identified as having priority river habitat (Table 2, Figure 2). Table 2 1km grid squares in Bedfordshire with priority river habitat under the UK Biodiversity Action Plan Grid ref Location TL0155 River Great Ouse at Milton Ernest TL0247 River Great Ouse – lower Kempston loop TL0747 Elstow Brook at Shortstown TL0748 River Great Ouse at Priory Country Park TL0849 River Great Ouse at Priory Country Park TL0749 River Great Ouse New Cut at Priory Country Park TL0805 River Great Ouse at Goldington Road, Bedford TL1455 South Brook west of Chawston TL1552 River Ivel at Cannocks Castle, Blunham TL1550 River Ivel at South Mills, Chalton TL1846 River Ivel at Lower Caldecote TL1837 River Hiz at Arlesey Rail Station SP9223 River Ouzel at Leighton Lock, Leighton Buzzard TL1217 River Lea at East Hyde Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 6 March 2012 Figure 2 Identification of UK BAP priority river reaches in Bedfordshire and Luton, at 1km 2 resolution Contains Ordnance Survey data © Crown Copyright and database right (2011) Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 7 March 2012 Discussion Results of the two mapping exercises were broadly similar, highlighting important river habitat along the Bedford section of the River Great Ouse and its confluence with the River Ivel. Identification of the additional priority areas on the second map was a result of using extra data sources like ecological reports and BirdTrack. There are likely other river reaches in Bedfordshire which, if data were available, would qualify as priority habitat. This illustrates the need for precise, accurate records and the surveying and monitoring which generate them. For example, reed bunting – a criterion level A species – is known to breed in large areas of north eastern and south western Bedfordshire (Bedfordshire Bird Club 2012). Reed bunting breeding near a river qualifies that river as priority habitat under the JNCC methodology. The Bedfordshire Bird Atlas – like other bird atlases – record the breeding status of the county’s avian fauna. The atlas data however are collected by tetrad, which is not sufficiently precise to be able to determine whether the confirmed breeding occurs ‘near’ the river. More precise records are available from the local record centre, however these rarely include breeding status. Some 1km 2- based data with breeding status were available from BirdTrack, a project of the British Trust for Ornithology. These records most certainly underrepresent the true distribution of reed bunting breeding along Bedfordshire’s rivers. Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 8 March 2012 References Bedfordshire Bird Club. 2012. Bedfordshire Bird Atlas, New Breeding Atlas (2007-2011): Reed Bunting [ONLINE]. Available at http://atlas.bedsbirdclub.org.uk/2007/RB.shtml . Accessed 16 March 2012. [BRIG] Biodiversity Reporting and Information Group. 2010. UK Biodiversity Action Plan Priority Habitat Descriptions: Rivers. Peterborough: Joint Nature Conservation Committee, 10 p. Identification of UK BAP Priority River Reaches in Bedfordshire and Luton 9 March 2012 .