SMALL SEAL ISLANDS SNH, and office Site of Special Scientific Interest Western Isles Area Stilligarry SITE MANAGEMENT STATEMENT South Uist HS8 5RS Site code: 1446 Tel: 01870 620238 e: [email protected]

Purpose This is a public statement prepared by SNH for owners and occupiers of the SSSI. It outlines the reasons it is designated as an SSSI and provides guidance on how its special natural feature should be conserved or enhanced. This Statement does not affect or form part of the statutory notification and does not remove the need to apply for consent for operations requiring consent. We welcome your views on this statement. This statement is available in Gaelic on request.

Natural feature of Condition of feature Other relevant Small Seal Islands SSSI (date monitored) designations

Grey seal Favourable maintained, (October 2002)

Description of the site The site consists of six small, relatively isolated and exposed islands which are scattered off the western coastlines of Harris and , and south of Barra. Together they are a SSSI for their breeding grey seal populations.

Pup production is assessed annually by the Sea Mammal Research Unit (SMRU). Recent numbers appear to be relatively stable varying between a maximum of 2247 in 2000 and a minimum of 1823 in 2002. However, the apparent trends on the islands are different. Since the first surveys in the 1960s Gasker has always had the highest pup production (and accounts for about 50% of production within the SSSI). In contrast, the trend over the last 20 years is of decline in numbers of pups produced on all the other islands. Furthermore, pup production on Causamul has been consistently lower than on the other islands and recent counts have been the lowest recorded, although the assessment of production on Causamul is complicated by moulted pups moving to the colony from other islands. The SSSI was last formally reported on in 2002 when the seal colony was assessed as in a favourable condition. The numbers of pups on the islands varied between: 1179-1388 on Gasker; 105-224 on Coppay; 446-519 on ; 55-80 on ; and 13-48 on Causamul. Pup mortality has not been specifically studied though Gasker and Shillay are both muddy colonies and this is thought to lead to increased pup mortality there. In the 1969 edition of “Natural History in the Highlands & Islands”, Fraser Darling & Boyd note that grey seals pup on Flodday, south of Barra, but this seems to be erroneous.

There are very few activities which affect the breeding seal colonies at present. The seals congregate on the islands to give birth, breed and rear their young from Mid-September to early December. Females come ashore to moult during January and February, whereas males moult between February and April. During these times the seals are vulnerable to disturbance from visitors and boats/helicopters. Seals moving rapidly away from a perceived threat can squash pups and cause fights as adults stray into other territories. However, the weather and the position of the islands on the exposed west coast tends to minimise visitor numbers.

Although the SSSI contains no other protected natural features, the islands support other coastal habitats, with healthy coastal heath on Gasker and Shillay. The latter also contains a breeding storm petrel population, and is used as a roost site for wintering barnacle geese.

Past and present management Gasker and Coppay are known to have been grazed in the past but Shillay is the only island still used for stock - winter grazing for young male sheep (wedders). It is also a Scottish Wildlife Trust nature reserve. Causamul is part of the RSPB’s Balranald nature reserve. There are no visitor facilities or formal arrangements for visitors to any of the islands.

Haskeir and Gasker have Northern Board (NLB) lights which require occasional repair and maintenance.

Objectives for Management (and key factors influencing the condition of natural feature) We aim to work with the owners and tenants to protect the site and to maintain, and where necessary, enhance its feature of special interest. SNH, with SMRU, aims to carry out survey, monitoring and research as appropriate to increase our knowledge and understanding of the site and its natural feature and monitor the effectiveness of the management arrangements.

1. To maintain the population of grey seals and avoid significant disturbance Ensure activities do not adversely affect the areas used by pupping or moulting seals. Ensure activities do not cause significant disturbance when seals ashore to pup (September to December), and moult (January to April).

Other factors affecting the natural features of the site Oil pollution The position of the islands on the west coast, close to the west coast passage, makes them vulnerable to oil pollution from shipping accidents. Large scale oil pollution could affect large numbers of adults who return to the sea to feed and sometimes to breed. The pups may eventually starve if their mothers perished, or could be directly affected by oil laden spray. Oil pollution at other times of the year could affect fish stocks which in turn could reduce the breeding success of the seals.

Climate change: Global climate change is predicted to lead to increased storminess and sea-level rise which could have an impact on areas used for pupping or moulting.

Date Last Reviewed: 11 November 2009