Bluemull and Colgrave Sounds Proposed Special Protection Area (pSPA) NO. UK9020312

SPA Site Selection Document: Summary of the scientific case for site selection

Document version control

Version and Amendments made and author Issued to date and date Version 1 Formal advice submitted to Marine Scotland on Marine draft SPA. Scotland Nigel Buxton & Greg Mudge. 10/07/14

Version 2 Updated to reflect change in site status from draft Marine to proposed and addition of SPA reference Scotland number in preparation for possible formal 30/06/15 consultation. Shona Glen, Tim Walsh & Emma Philip Version 3 Creation of new site selection document. Emma Susie Whiting Philip 17/05/16 Version 4 Document updated to address requirements of Greg revised format agreed by Marine Scotland. Mudge Glen Tyler & Emma Philip 16/06/16 Version 5 Quality assured Emma Greg Mudge Philip 17/6/16 Version 6 Final draft for approval. Andrew Emma Philip Bachell 22/06/16 Version 7 Final version for submission to Marine Scotland. Marine Emma Philip Scotland 24/06/16

Contents

1. Introduction ...... 1 2. Site Summary ...... 2 3. Bird survey information ...... 4 4. Assessment against the UK SPA Selection Guidelines ...... 4 5. Site status and boundary ...... 6 6. Information on qualifying species ...... 7 7. References ...... 9 Annex 1. Site map ...... 11 Annex 2. Citation ...... 12

1. Introduction

This document provides Scottish Natural Heritage’s (SNH) advice on the proposed classification of a Special Protection Area (SPA) in the marine waters of Bluemull and Colgrave Sounds for foraging areas for breeding red-throated diver. The document summarises the evaluation for the species of interest according to the SPA site selection guidelines (JNCC, 1999) and provides an overview of how the site boundary was developed.

Bluemull and Colgrave Sounds pSPA has been selected as an important foraging area for breeding red-throated diver, falling within the foraging area of a high concentration of nesting birds in Yell and South . The protection of these inshore waters will make a key contribution to the maintenance of this species in its natural range in UK marine waters and form part of a coherent network of sites at a European level.

The importance of the marine environment for birds which spend all or part of their lives around our coasts is well recognised, particularly in Scotland. A total of 106 species of bird are thought to use UK marine waters of which 45 occur in numbers greater than fifty each year and are dependent on the marine environment for a large part of their lifecycle. All of these 45 species except one (black guillemot1) are considered rare or vulnerable bird species (Annex 1), or regularly occurring migratory species by the Birds Directive (EC Directive on the conservation of wild birds (amended) - 2009/147/EC). This means that all Member States are obliged to take account of the requirements of Article 4.1 of the Birds Directive for each of these 44 species.

Article 4.1 states that “Member States shall classify in particular the most suitable territories in number and size as special protection areas for the conservation of these species, taking into account their protection requirements in the geographical sea and land area where this Directive applies”. EU guidance on the establishment of SPAs in the marine environment (2007) sets out the groups of marine birds for which SPAs should be considered in the marine environment. This includes sites for feeding areas for breeding divers, including those used by birds from existing terrestrial SPAs to ensure they have continued access to key food sources.

In the UK, whilst some coastal SPAs include marine waters below the Mean High Water Springs (MHWS) there are only four entirely marine SPAs classified; Outer Thames Estuary SPA (England), Liverpool Bay/Bae Lerpwl SPA (England/Wales) and Bae Caerfyrddin/Carmarthen Bay SPA (Wales) and Belfast Lough - Open Water SPA (Northern Ireland). In Scotland, 31 marine extensions to seabird colony SPAs have also been classified. The existing suite of sites is not considered sufficient to meet the requirements of Article 4.1 because it currently does not include suitable territories at sea for all of the species that the UK has a responsibility for.

1 Nature Conservation Marine Protected Areas were designated in August 2014 for black guillemot.

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This site is being proposed as part of a suite of marine sites that aim to fulfil the requirements for SPAs in the marine environment for rare or vulnerable birds and regularly occurring migratory birds in the UK. As required by Article 4 of the Directive, the classification of this site will enable the application of special conservation measures concerning the habitat of Annex 1 and regularly occurring migratory birds in order to ensure their survival and reproduction in their area of distribution.

Full details of the site survey methodologies, data and analysis used to inform the proposed selection of this site for breeding red-throated diver are provided in Black et al (2014). All scientific work received full external independent peer review at key stages.

2. Site Summary

The Bluemull and Colgrave Sounds proposed Special Protection Area (pSPA) (Figure 1) stretches from the north coast of Yell through Bluemull Sound down through Colgrave Sound as far south as the White Hill of Vatsetter (approximately 3km south of ).

The site supports a population of European importance of the following Annex 1 species:

Red-throated diver (Gavia stellata)

The site comprises in total and area of 46.65 km2.

The coastline of the pSPA is mostly cliff albeit well interspersed with sandy beaches and bays. Inshore through much of the site depths are generally less than 40m but offshore, especially to the south of , water depth rapidly increases (Barne et al 1997). Sediments are largely gravel and sand and support a diversity of fish, polychaete worms, gastropod and bivalve molluscs. The inshore waters are also provide nursery areas for a number of species including sandeels. Both pelagic and demersal fish shoal and spawn in the seas surrounding .

Shetland is a stronghold for breeding red-throated divers with one third of the UK’s breeding population occurring in Shetland (Dillon et al 2009). During the summer months, these waters are an important foraging area for a high concentration of red- throated diver nesting territories on adjacent islands. Red-throated divers breed on freshwater lochs on blanket bog and moorland. Although red-throated divers nest inland in Shetland, they fly to forage in nearby inshore waters. Foraging dives are usually less than 10m deep, mostly in shallow coastal waters within 9km of the nest location while breeding.

Their main prey items are a range of fish species including cod (Gadus morhua), herring (Clupea harengus) and a number of small species such as gobies (Gobidae). In some areas (including Shetland) sandeels (Hyperlopus lanceolatus and Ammodytes sp) form an important part of the diet.

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Figure 1. Location of Bluemull and Colgrave Sounds pSPA

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3. Bird survey information Feeding areas of breeding red-throated divers2

The breeding distribution of red-throated divers in the UK is limited to Scotland and is largely restricted to the north and west of the country, with major strongholds in Shetland, Orkney, and the Outer Hebrides (Gibbons et al 1993, Dillon et al 2009).

Four main survey areas were chosen at which to undertake detailed data collection. These were selected to focus on the most important breeding areas, representing the geographical spread of breeding areas, and be practical in terms of field work logistics. The selected study areas were Unst, Yell and Fetlar (northern Shetland); Shetland Mainland; Isle of Hoy (Orkney); and North Uist (Outer Hebrides).

A full national survey of red-throated diver was undertaken in 2006 (Dillon et al 2009) which provides data on breeding populations. Local surveys prior to the inshore work were also undertaken in Shetland based on recent knowledge of diver breeding sites. Models were then developed to map predicted foraging distributions within maximum foraging flight range of breeding sites (Black et al, 2015). These models used observed correlations between environmental variables and diver distribution, as recorded in boat-based transect surveys and by visual or radio tracking of individual birds in four areas between 2003 and 2007, to predict areas that divers are likely to use in un-surveyed areas of sea. The data underpinning the models included locations in Shetland including the where boat survey and visual tracking data were collected in summer 2005.

To provide population estimates for red-throated divers within identified important areas, the number of breeding sites within foraging range was used as an estimate of number of pairs potentially using the area.

4. Assessment against the UK SPA Selection Guidelines

The UK SPA Selection Guidelines establish a two stage process for SPA identification (JNCC, 1999).

Stage 1

To qualify under Stage 1 the area needs to meet one or more of the following four guidelines:

1.1. The area is used regularly by 1% or more of the Great Britain population of a species listed in Annex I to the Birds Directive in any season. 1.2. The area is used regularly by 1% or more of the biogeographical population of a regularly occurring migratory species (other than those listed in Annex I) in any season.

2 Full details of the methodologies, data and analysis used are provided in the Joint Nature Conservation Committee (JNCC) Report 541: Black et al 2014 and the JNCC generic document ‘Red- throated diver marine SPA identification: Data collection and analysis’. JNCC Report received full external independent peer review. 4

1.3. The area is used regularly by over 20,000 waterbirds (waterbirds as defined by the Ramsar Convention) or 20,000 seabirds in any season. 1.4. The area meets the requirements of one or more of the Stage 2 guidelines in any season, where the application of Stage 1 guidelines 1.1-1.3 for a species does not identify an adequate suite of most suitable areas for the conservation of that species.

Stage 2

Those areas that meet one or more of the Stage 1 guidelines undergo further consideration using one or more of the ecological judgements set out in Stage 2. There are seven Stage 2 judgements. These judgments are used to facilitate the selection of the most suitable areas from the areas identified at Stage 1 to produce a network of marine SPAs in Scotland. The Stage 2 judgements are:

2.1 Population size and density 2.2 Species range 2.3 Breeding success 2.4 History of occupancy 2.5 Multi-species area 2.6 Naturalness 2.7 Severe weather refuges

Assessment against Stage 1 of the UK SPA Selection Guidelines

Red-throated diver is an Annex 1 species and was present in numbers at or above 1% of the GB population. This species met Stage 1.1 of the SPA guidelines (Table 1).

Table 1. Assessment against Stage 1 of the UK SPA Selection Guidelines

Species and Annex 1 Population % of GB Stage 1 season or size in site population guideline migratory (pairs) Red-throated diver Annex 1 194 15.4 1.1 (breeding)

Assessment against Stage 2 of the UK SPA Selection Guidelines

One or more of the Stage 2 guidelines are used to identify the most suitable areas for classifying as SPA from those areas that meet the Stage 1 guidelines. The focus for considering which areas were most suitable concentrated on three of the seven judgements; population size and density, species range and multi-species areas.

Bluemull and Colgrave Sounds has been selected because the marine waters support the second largest concentration of foraging red-throated diver during the breeding season in the UK. The site is the most northerly site in the UK and is an important component of the species northern breeding range.

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The area was initially considered because it overlapped with a foraging area identified for foraging Arctic tern during the breeding season. Arctic tern was not progressed as a qualifying feature due to low numbers at the respective breeding colonies (SNH, 2016). However, because breeding red-throated are restricted in range to north Highlands and islands and the area supports the second largest concentration in the UK the site merits inclusion as a single species site.

With regard to the other Stage 2 judgements, all sites where considered largely ‘natural’ and no information is available to provide further consideration to ‘breeding success’ and ‘severe weather refuge’.

Further details on the selection process and the final suite of sites being proposed is provided in the SNH supplementary document ‘Site selection of the marine SPA suite’ (SNH, 2016).

Table 2: Summary of assessment against Stage 2 of the UK SPA Selection Guidelines.

Stage 2 Red-throated diver (b) judgement Population size 2nd largest population in Scotland and UK. Species range Northern most representation of their range in UK. Multi-species Single species interest. area History of Further detail provided in section 6. occupancy

5. Site status and boundary

The proposed name for this site is the “Bluemull and Colgrave Sounds SPA”.

Marine sites present no visual surface features by which a seaward boundary can be identified. A site boundary was developed by reviewing the modelled predicted usage of foraging red-throated divers and selecting those areas which contained the highest densities.

The final boundary was created selecting all cells that exceed the density threshold (maximum curvature) and drawing the boundary as tight as possible to the highest density areas ensuring all cells exceeding density thresholds where included within the boundary. To avoid creating an over-complex boundary however some rationalisation of the final boundary was required, resulting in small areas with cells not exceeding the density threshold also being included in the final boundary. Whilst these areas did not exceed the density threshold, they are still likely to support lower densities of red-throated diver.

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The proposed site extends to 38.23 km2. Boundary co-ordinates for the pSPA are given on the site map in Annex 1.

6. Information on qualifying species

Red-throated diver The breeding range of red-throated divers in Great Britain is restricted to Scotland, with the coastal waters adjacent to many nesting localities being of particular importance for feeding. In the most recent national survey of red-throated divers in 2006 (Dillon et al 2009), the birds on Shetland formed the largest concentration in Scotland (more than 400 pairs). The birds able to forage in the Bluemull and Colgrave Sounds pSPA (194 pairs in 2006: 15.4% of the GB population) nest on the surrounding islands of Fetlar, the east of Yell and the south of Unst (Figure 2).

Nesting territories tend to be traditional and are occupied repeatedly with birds habitually using the marine areas within 10km of the nest site for foraging. Nesting territories are reported present on surrounding islands every year (Shetland Bird Club annual Reports). Hence, feeding within the pSPA can be assumed and there is high confidence in regularity of use of the site for foraging by breeding red-throated divers.

Population size and density The Shetland population of breeding red-throated divers is far greater than those in the other parts of the breeding range, inclusive of the other island groups and the mainland Highlands. The archipelago supports over 32% of the total breeding population in Great Britain with Fetlar, Yell and Unst supporting the majority of these. Within Shetland the breeding abundance of red-throated divers on the islands of Fetlar, Yell and Unst is particularly high, such that the site, potentially supporting the food supplies of up to 194 pairs of birds, is particularly important. The area supports the second largest feeding population of all localities examined.

Distribution within the site The species is distributed throughout the pSPA when foraging, as this is a single species SPA the boundary is based on this species’ distribution alone (Figure 2).

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Figure 2. The predicted usage of feeding red-throated divers in Bluemull and Colgrave Sounds pSPA.

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Species range Shetland lies at the extreme north of the breeding range of red-throated divers in Great Britain; a range which is restricted to Shetland, Orkney, the Hebrides and north and west mainland Scotland. The bulk of the population (40.2%) lies in the Northern Isles, with over 32% in Shetland. The birds in this area are the northern– most representatives in the core of the British range of this species.

History of occupancy This area has long been associated with breeding red-throated divers. The species has been mentioned in the literature for at least 100 years (Buckley & Evans 1899, Venables & Venables 1955) and was recorded as a widely distributed breeding species throughout the islands in the two earlier breeding atlas periods (Sharrock 1976, Gibbons et al 1993).

7. References

Barne, J. H., Robson, C. F., Kaznowska, S. S., Doody, J. P. & Davidson, N. C. eds 1997. Coasts and seas of the United Kingdom. Region 1: Shetland. Peterborough, Joint Nature Conservation Committee. (Coastal Directories Series.)

Black, J., Dean B.J., Webb A., Lewis, M., Okill D. & Reid J.B. 2014. Identification of important marine areas in the UK for red-throated divers (Gavia stellata) during the breeding season. JNCC Report No 541. JNCC, Peterborough.

Buckley, T. E. & Evans, A.H. 1899. A Vertebrate Fauna of the Shetland Isles. Edinburgh, David Douglas.

Dillon, I. A., Smith, T. D., Williams, S. J., Haysom, S. & Avery, M. A. 2009. Status of Red-throated divers Gavia stellata in Britain in 2006. Bird Study 56 (2). 147-157.

European Commission (2007) Guidelines for the establishment of the Natura 2000 network in the marine environment. Application of the Habitats and Birds Directives. http://ec.europa.eu/environment/nature/natura2000/marine/docs/marine_guidelines.p df

Gibbons, D. W., Reid, J. B. & Chapman, R. A. 1993. The New Atlas of Breeding Birds in Britain and Ireland: 1988-1991. T. & A. D. Poyser, London

JNCC. 1999. The Birds Directive. Selection Guidelines for Special Protection Areas. Peterborough, JNCC.

JNCC generic documents: Red-throated diver marine SPA identification: Data collection and analysis

Musgrove, A., Aebischer,, N Eaton, M., Hearn, R., Newton, S Noble S., Parsons, M., Risely, K. & Stroud, D. 2013. Population estimates of birds in Great Britain and the United Kingdom. British Birds 106; 64-100.

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Sharrock, J. T. R. 1976. The Atlas of Breeding Birds in Britain and Ireland. T. & A. D. Poyser.

Shetland Bird Club – Shetland Bird Reports, published annually (most recent 2013).

SNH 2016. ‘Site selection of the marine SPA suite’. Supplementary document.

Venables, L. S. V. & Venables, U. M. 1955. Birds and Mammals of Shetland. Edinburgh and London, Oliver and Boyd.

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Annex 1. Site map

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Annex 2. Citation

Directive 2009/147/EC of the European Parliament and of the Council on the conservation of wild birds (this is the codified version of Directive 79/409/EEC as amended)

CITATION FOR PROPOSED MARINE SPECIAL PROTECTION AREA (SPA)

BLUEMULL AND COLGRAVE SOUNDS (UK9020312)

Site Description: The Bluemull and Colgrave Sounds proposed Special Protection Area (SPA) stretches from the north coast of Yell through Bluemull Sound down through Colgrave Sound to the south of Hascosay. Inshore through much of the site depths are generally less than 40metres (m) but offshore, especially to the south of Fetlar, water depth rapidly increases. The east coast of Shetland is relatively sheltered compared to the west and much of the coastline is cliff albeit well interspersed with sandy beaches and bays such that the sediments are largely gravel and sand, supporting a diversity of fish, polychaete worms, gastropod and bivalve molluscs forming potential prey for waterbirds frequenting the area.

Qualifying Interest: The Bluemull and Colgrave Sounds proposed Special Protection Area (SPA) qualifies under Article 4.1 by regularly supporting a population of European importance of the following Annex 1 species during the breeding season: red- throated diver Gavia stellata (up to 194 pairs in 2006, up to 15.4% of the GB population).

Area: 38.23 km2 (3823.27 ha). Location: 60o 63.225’ N 01o 00.729’ W. OS Sheet 1:50,000 – 1

16/6/16 Scottish Natural Heritage

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