Outer Thames Estuary Potential Special Protection Area
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Departmental brief: Outer Thames Estuary potential Special Protection Area Natural England and JNCC November 2015 Outer Thames Estuary SPA Departmental Brief Final version for Formal Consultation Page 1 of 72 December 2015 Contents Summary 3 1. Assessment against SPA selection guidelines ....................................................... 4 1.1. Stage 1 .................................................................................................................. 4 1.2. Stage 2 .................................................................................................................. 4 2. Rationale and data underpinning site classification ................................................ 5 2.1. Data collection – defining the suite of breeding features and numbers supported by the Outer Thames Estuary pSPA ........................................................................................... 7 2.2. Defining the boundary of Outer Thames Estuary pSPA .......................................... 7 3. Site Status and Boundary ....................................................................................... 7 3.1. Existing Boundary .................................................................................................. 7 3.2. Outer Thames Estuary pSPA boundary ................................................................. 9 3.3. Seaward boundary of the pSPA ........................................................................... 11 3.4. Landward boundary of the pSPA .......................................................................... 11 3.4.1. Identification of important marine areas for little terns ............................................................ 11 3.4.2. Identification of important marine areas for larger terns ......................................................... 14 3.4.3. Composite boundary of Outer Thames Estuary pSPA ........................................................... 21 4. Location and habitats ........................................................................................... 21 5. Assessment of ornithological interest ................................................................... 22 5.1. Survey Information and summary ......................................................................... 22 5.2. Annex I species .................................................................................................... 23 5.2.1. Breeding season ................................................................................................................... 23 5.2.2. Comparison of counts for breeding sites ............................................................................... 25 5.2.3. Non-breeding season ............................................................................................................ 25 5.2.4. Species not currently meeting SPA selection guidelines ........................................................ 25 6. Comparison with other sites in the UK .................................................................. 26 7. Conclusion ....................................................................................................................... 27 7. References ........................................................................................................... 27 Annex 1 Site maps .............................................................................................................. 30 Annex 2 Site Citation ........................................................................................................... 34 Annex 3 Sources of bird data ............................................................................................. 36 Annex 4 Defining little tern foraging areas and seaward boundary ..................................... 37 1. Background and overview .................................................................................... 37 1. Data collection...................................................................................................... 37 1.1. Seaward extent of little tern distribution (boat-based survey) ................................ 37 1.2. Alongshore extent of little tern distribution (shore-based surveys) ........................ 38 2. Data analysis ....................................................................................................... 38 3.1 Site-specific options ................................................................................................... 38 3.2 Generic options .......................................................................................................... 39 4 Boundary delineation............................................................................................ 43 Annex 5 Defining larger tern foraging areas and seaward boundary .................................. 47 1. Data collection...................................................................................................... 47 2. Data preparation and analysis .............................................................................. 48 3. Boundary Delineation ........................................................................................... 55 Annex 6 Implementation of Natural England Evidence Standards ..................................... 61 8. Annex 7 Common terns breeding at Foulness SPA ............................................. 71 Outer Thames Estuary SPA Departmental Brief Final version for Formal Consultation Page 2 of 72 December 2015 Summary Outer Thames Estuary potential Special Protection Area (pSPA) detailed in this Departmental Brief is proposed to protect important areas of coast and sea used for a variety of purposes by the qualifying features. The new pSPA enlarges the existing Outer Thames Estuary SPA (classified solely for non- breeding red-throated divers Gavia stellata) to include three new areas identified for foraging terns breeding at other (already classified) SPAs on shore; these are parts of the Rivers Yare and Bure, a small riverine section at Minsmere, and both estuarine and marine areas around Foulness. The pSPA therefore comprises areas for foraging breeding seabirds and non-breeding waterbirds. The feature of the existing SPA is retained, and new qualifying features are added based on a review of up-to-date bird abundance information. The total area of the Outer Thames Estuary pSPA is approx. 391,910 ha (3919 km2). The two species of tern relevant to the pSPA are common tern Sterna hirundo and little tern Sternula albifrons. From north to south, the adjacent SPAs with these tern species as qualifying features (all little tern unless stated) are: Great Yarmouth North Denes SPA; Breydon Water SPA (common tern only); Benacre to Easton Bavents SPA; Minsmere – Walberswick SPA; Alde-Ore Estuary SPA; Foulness SPA (common tern and little tern); and Thanet Coast & Sandwich Bay SPA. In addition to these, common and little terns breeding at Scroby Sands, a sand bank completely contained within the pSPA, and other coastal nesting locations functionally linked to terrestrial SPAs, are included in determining the abundance of terns at the site. However, Sandwich terns at the Alde-Ore Estuary and Foulness SPAs are not included in determining the details of the pSPA because the feature has been absent at these SPAs for too long to merit influencing the size and shape of the site (Wilson et al. 2014). Marine extensions to Hamford Water SPA are the subject of a separate Departmental Brief and do not influence the Outer Thames Estuary pSPA, whilst small numbers of little terns at Colne Estuary, Blackwater Estuary and Medway Estuary and Marshes SPAs are not expected to forage within the marine pSPA based on generic foraging models (Parsons et al. 2015). This Departmental Brief makes use of the most recent available estimates of the population sizes of these species at these sites to derive the populations of birds supported by the pSPA. However, in respect of the existing classified (terrestrial) SPAs, this Departmental Brief does not make any proposal to add or remove qualifying features, amend baseline population figures, or alter site boundaries. This Departmental Brief sets out the scientific case for the classification of the Outer Thames Estuary pSPA. This site qualifies under Article 4 of the Birds Directive (2009/147/EC) for the following reasons (summarised in Table 1): The site regularly supports more than 1% of the Great Britain breeding populations of three species listed in Annex I of the Birds Directive. Therefore, the site qualifies for SPA classification in accordance with the UK SPA selection guidelines (stage 1.1). Table 1 Summary of qualifying ornithological interest in Outer Thames Estuary pSPA Species Count (period) % of subspecies or Interest Selection Status of population type criteria feature Little tern 746 individuals 19.64% of GB Annex 1 Stage 1.1 New Sternula albifrons (2011 – 2015) population (in breeding season) Common tern 532 individuals 2.66% of GB Annex 1 Stage 1.1 new Sterna hirundo (in (2011 – 2015) population breeding season) Red-throated diver 6,466 individuals 38.0% of GB Annex 1 Stage 1.1 From Gavia stellata (in (1989 – 2006/07)1 population existing non- breeding SPA season) 1 Citation value from original Outer Thames Estuary SPA classification, 2010 Outer Thames Estuary SPA Departmental Brief Final version for Formal Consultation Page 3 of 72 December 2015 1. Assessment against SPA selection guidelines The UK SPA selection guidelines require that SPA