Scottish MPA Project Data confidence assessment SMALL ISLES POSSIBLE NATURE CONSERVATION MPA

Transcription

1 Scottish MPA Project Data confidence assessment SMALL ISLES POSSIBLE NATURE CONSERVATION MPA

2 Document version control Version Date Author Reason / Comments Version 1 07/09/2012 Ben James, Laura Clark and Andy Douse Revised protected features / MPA proposal format, updating search location version (ver. 12). Version 2 11/09/2012 Ben James Formatting revisions to take account of initial comments. Version 3 24/09/2012 Ben James Addition of representative features. Version 4 02/10/2012 Ben James Inserted updated figures (revised map projection information; consistent colouring on northern feather star aggregations, refinement of representative feature class name). Version 5 15/10/2012 Ben James and Laura Clark Version 6 15/10/2012 John Baxter QA review. Version 7 19/10/2012 Laura Clark and Lisa Kamphausen Initial review. Production and insertion of revised mapping. Refinements in response to QA review comments. Version 8 09/11/2012 Ben James Review. Version 9 29/11/2012 Ian Bainbridge QA review and sign-off. Version 10 31/07/2013 Laura Clark Updated into possible MPA format. Version 11 16/08/2013 Ben James Review. Version 12 22/08/2013 John Baxter QA review and sign-off. Distribution list Format Version Issue date Issued to Electronic 9 14/12/2012 SNH web publication. Electronic 12 22/08/2013 SNH web publication [A / 6(#6)].

3 Figure 1 The Small Isles possible MPA 1

4 Name of possible MPA Small Isles Assessor(s) BJ; LC; SM; AD The Small Isles possible MPA (Figure 1) incorporates the sea area used for foraging by breeding black guillemots (~95% of foraging activity occurs within 2 km of the coastline where they nest), and encompasses most of the marine extensions of the existing Rum, and Canna and Sanday Special Protection Areas (SPAs). These are designated in part for their breeding seabird assemblages. Beyond this, the possible MPA is shaped around a complex geological backdrop, including bedrock highs to the west of Canna and an excellent example of a shelf deep (glaciated channel/trough) that extends from the Sound of Canna north towards Skye. In turn, this shelf deep encompasses a range of seabed habitats and species. This includes extensive areas of open coast burrowed mud with tall seapens surrounding the largest known fan mussel aggregation in UK waters (the only known example in Scotland s seas), a horse mussel bed (the deepest known example in Scotland), northern sea fan and sponge communities and dense fields of northern feather stars on muddy substrates. These seabed habitat features are intermixed with or overlie a range of deep muddy sand communities representative of Scotland s seas more generally. The landward boundary of the possible MPA incorporates the coastal nesting areas used by an estimated 850 breeding black guillemots (ca. 2.2% of the GB population - Mitchell et al., 2004). Proposed protected features Biodiversity Black guillemot (BG) Burrowed mud (BM) Circalittoral sand and mud communities 1 (CSM) Fan mussel aggregations (FM) Horse mussel beds (HM) Northern feather star aggregations on mixed substrata (NF) Northern sea fan and sponge communities (NS) Shelf deeps (SD) White cluster anemones (WCA) [aggregations or associated with NS] Geodiversity Quaternary of Scotland - glaciated channels/troughs, glacial lineations, meltwater channels, moraines, rock basins, streamlined bedforms (GEO) Data used in assessment Version of GeMS database Ver.2 (i10) Other datasets used in feature map (specify) - Marine Scotland Science Nephrops underwater TV survey database. Civil Hydrography Programme (CHP) and Marine Scotland multibeam dataset (2010/ 11) with BGS / SNH interpretation. Marine Recorder habitats dataset (for CSM records). Summary of data confidence assessment (see detailed assessment on following pages) Confident in underpinning data Yes Partial No Confident in presence of identified features? Summary All Data suitable to define extent of individual proposed protected features Partial BG;BM;FM;NS; SD;WCA;GEO CSM;HM;NF We have high confidence in the data underpinning this possible MPA and in the presence of all proposed protected features (for known distribution see Figures 2i & ii). The majority of biodiversity feature data have been collected since 2009 using a range of sampling methods, underpinned by full coverage high resolution multibeam bathymetry. Collectively these data are suitable for defining the broad extent of these features across the possible MPA. Future sampling should be targeted to establish the southern limit of the horse mussel bed within the Sound of Canna and to define the distribution of northern feather star aggregations, which are scattered throughout the site and vary in size. 1 Comprising Amphiura filiformis, Mysella bidentata and Abra nitida in circalittoral sandy mud (SS.SMu.CSaMu.AfilMysAnit - A5.351) and Deep circalittoral sand (SS.SSa.OSa - A5.27) 2

5 Figures 2i and ii The known distribution of proposed protected features within the Small Isles possible MPA 3

6 Data confidence assessment Our assessment of data confidence is based on consideration of the age and source of the data, sampling methods used and overall coverage across the possible MPA (see also Maps A - D). Existing protected areas are shown on Map E. Age of proposed protected feature data (Map A) Number of records collected within last 6 years Comments Many All features Number of records collected 6-12 years ago 4 None Number of records >12 years old Many BG The vast majority of the seabed habitat records within the possible MPA have been collected over the last four years following the discovery of the fan mussel aggregation in the Sound of Canna in A number of older volunteer Seasearch diver records of northern sea fan and sponge communities in the sound were resurveyed in The records of burrowed mud primarily originate from a subset of the Marine Scotland Science (MSS) Nephrops TV survey database covering the three year period and from nature conservation-orientated surveys undertaken since There is a scattering of additional burrowed mud records to the east of the area derived from a Fisheries Research Services (predecessor to MSS) survey undertaken in The black guillemot data collected as part of the Britain and Ireland Seabird 2000 census (counted in 2000) and are now >12 years old. Provisional results from a count undertaken in 2013 are available but are not mapped here. Source of proposed protected feature data (Map B) Targeted data collection for nature conservation purposes Data collection associated with development proposals (EIA etc.) Comments Statutory monitoring (marine licensing etc.) Recreational / volunteer data collection Other (specify) - Fisheries survey work Most of the records of seabed proposed protected features within the Small Isles possible MPA were collected in 2010 and 2011 through SNH and Marine Scotland-commissioned nature conservation-orientated surveys respectively. The surveys undertaken for nature conservation purposes were centred primarily on the Sound of Canna and the shelf deeps to the north, with sampling scattered across all seabed habitat types (using a range of methods) to derive a broad understanding of the features present. There are dispersed records across the area from the Marine Scotland Science Nephrops underwater TV database (fisheries stock assessment survey work). The MSS video sampling is targeted at areas of suitable seabed sediment substrates and utilises a towed camera system. The dataset also includes a number of volunteer diver survey records from Seasearch (shown on Map B), primarily of northern sea fan communities on the steeply sloping and vertical underwater cliffs. The 2013 black guillemot survey work and the nationwide Seabird 2000 census (Mitchell et al., 2004) were undertaken for nature conservation purposes and conducted by professional and volunteer ornithologists (following standard approved survey protocols). Sampling methods / resolution Feature Modelled Acoustic / remote sensing Remote video / camera Infaunal - grab / core Sediment Diving Visual census BG BM CSM FM HM

7 Sampling methods / resolution Feature Modelled Acoustic / remote sensing Remote video / camera Infaunal - grab / core Sediment Diving Visual census NF NS SD WCA Comments A number of sampling methods have been used to collect information on the proposed protected features. Remote sampling techniques such as drop-down or towed video cameras and infaunal grabs have been essential because of the depth of water in parts of the possible MPA. Diver sampling, whilst limited to ca. 35 m, has provided detailed information on the northern sea fan and sponge communities and white cluster anemone features of interest from otherwise inaccessible vertical cliff areas (e.g. within the Sound of Canna). Burrowed mud habitats have been surveyed by divers in shallower areas. The multibeam bathymetry dataset (Map C) provides full coverage of the sea bed within the possible MPA and has played a key role in delineating the shelf deeps, sublittoral sediment plains and areas of circalittoral bedrock. When sampled, the latter invariably supported northern sea fan and sponge communities. Black guillemot records were obtained using visual census methods in 2013 and as part of Seabird 2000 (Mitchell et al., 2004). In almost all cases, records are based on a single count. Counts are conducted within 2 hours of first light in the pre-breeding period when birds can be counted on the sea just offshore from their breeding areas. Proposed protected feature data coverage (Maps A - D) Across the possible MPA Large numbers of proposed protected feature records distributed across the possible MPA For individual features Multiple records of individual proposed protected features providing an indication of extent and distribution throughout the possible MPA Numerous proposed protected feature records scattered across the possible MPA with some clumping Few or scattered records of specific proposed protected features making extent and broad distribution assessment difficult Are acoustic remote sensing data available to facilitate the development of a full coverage predictive seabed habitat map? Numerous proposed protected feature records possibly with some clumping. Boundary not defined solely by recorded feature distribution Few or isolated proposed protected feature records - possibly clumped Few or isolated records of specific proposed protected features Yes - full coverage multibeam dataset acquired through Pan-Government agreement and processed in conjunction with British Geological Survey (BGS) and the National Oceanography Centre (NOC) (Map C). 5

8 Proposed protected feature data coverage (Maps A - D) Comments Records of the proposed protected features are clumped around the Sound of Canna where recent survey efforts have focused on defining the extent of the fan mussel aggregations present. Fewer, more widely dispersed seabed habitat records exist in the northern and western parts of the possible MPA with many non-biodiversity proposed protected feature records associated with a rocky shoal to the west of Canna (see Map A). This part of the possible MPA is primarily of interest from a geodiversity perspective. There are no seabed habitat records to the south of Rum within the possible MPA boundary. The coarse nature of the shelf deeps dataset within GeMS (blue and pink polygons in Map A) is apparent when compared to the high resolution multibeam mapping shown in Map C. The black guillemot data displayed on Figure 2 are presented at a finer resolution (Seabird 2000 census counts by relevant section of the coastline) on Map D that also shows the extent of the SPA extension and the 2 km zone used to define the foraging area for this species. The sampling undertaken in 2000 estimated approximately 850 individuals that equates to ca. 2.2% of the GB population (Mitchell et al., 2004). The provisional results of survey work undertaken in 2013 suggest that numbers have remained fairly stable on Canna where 214 birds were counted, whilst on Rum there was an increase from 642 in 2000 to 1,013 in 2013 (a total of 1,227 breeding black guillemots within the possible MPA). However, no firm conclusions can be drawn because the rise in number is within normal count variability. Map D also illustrates the relationship with the Sound of Canna third-party proposal, submitted by the Small Isles Community Council, upon which the wider Small Isles possible MPA has been developed. Map E shows existing protected areas and the overlapping Skye to Mull MPA search location. Data sources and bibliography Year Title Survey (Map B) Features covered 2013 Brooks, A.J., Kenyon, N.H., Leslie, A., Long, D. and Gordon, J.E. (2013). Characterising Scotland's marine environment to define search locations for new Marine Protected Areas. Part 2: The identification of key geodiversity areas in Scottish waters (final report). Scottish Natural Heritage Commissioned Report No GEO 2012 Howe, J.A., Dove, D., Gafeira, J., Bradwell, T., McIntyre, K.L., Cooper, R. and Smart, N. (2012). Submarine geomorphology and glacial history of the Sea of the Hebrides, UK. Marine Geology, , 15 June 2012, pages Available from < Axelsson, M., Allen, C. and Dewey, S. (2012). Infaunal analysis of grab samples collected from Canna, Small Isles, in June Report by Seastar Survey Ltd. Scottish Natural Heritage. Commissioned Report No Available from < Moore, C.G. (2012). An assessment of the conservation importance of benthic epifaunal species and habitats identified during a series of research cruises around NW Scotland and Shetland in Scottish Natural Heritage Commissioned Report No Available from < MS Canna PMF survey 2011 MS Canna PMF survey GEO BM; CSM; FM; HM; NF; SD BM; FM; NF; NS; SD 6

9 Data sources and bibliography Year Title Survey (Map B) Features covered 2012 Howson, C.M., Clark, L., Mercer, T.S. and James, B. (2012). Marine biological survey to establish the distribution and status of fan mussels Atrina fragilis and other Marine Protected Area (MPA) search features within the Sound of Canna, Inner Hebrides. Scottish Natural Heritage Commissioned Report No Available from < SNH (2012). Marine Protected Areas and black guillemot (Cepphus grylle). Position paper for 4 th MPA Workshop, Heriot-Watt University, March Available from < Moore, C.G. and Roberts, J.M. (2011). An assessment of the conservation importance of species and habitats identified during a series of recent research cruises around Scotland. Scottish Natural Heritage Commissioned Report No Available from < Seasearch. (2004) Rum Survey June 2004 Summary report. Available from < Mitchell, P.I., Newton, S.F., Ratcliffe, N. and Dunn, T.E. (eds.) (2004). Seabird Populations of Britain and Ireland: results of the Seabird 2000 census ( ). T and A.D. Poyser, London, pp 511. ISBN Available from < SNH fan mussel survey BM; CSM; FM; NF; NS; SD BG 2010 MSS camera survey CSM; FM; HM 2004 MCS Seasearch survey - Rum Seabird 2000 Census ( ) 1989 Mackinnon, M.C. (1989). Seasearch Canna Expedition. NCC CSD Report No Canna sublittoral survey NS BG BM; CSM 7

10 THE EVIDENCE-BASE A B 8

11 C D 9

12 E 10