2005 Strategic Environmental Assessment SEA6 Technical Report - Benthos. Synthesis of information on the benthos of area SEA6 (Irish Sea)

This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report provides a synthesis of current knowledge of the benthic communities and seabed habitats in the SEA6 area. The area is a predominantly shallow, well flushed, fully saline, partially enclosed, temperate sea. The seabed is predominantly sedimentary, ranging between mud and cobbles but consisting mainly of sand. The coastal fringe hosts excellent examples of a broad range of habitat types including exposed rocky shores, sheltered rias, highly productive sand flats, estuaries and areas exposed to rapid tidal currents. This diverse range of habitats supports a broad range of animals and plants with numerous species. The focus of the report is on dominant species and broad descriptions of community types (biotopes). The benthos associated with the littoral (intertidal) and sublittoral zones from the Mull of Kintyre and the Northern Irish coast in the north to Milford Haven, Pembrokeshire in the south are discussed. This area includes the important industrial estuaries of Morecambe, Liverpool and the Mersey, together with a number of minor estuaries, and the major islands of Anglesey and the Isle of Man. The deep water (depth greater than 50 m) and offshore areas are also discussed. Where appropriate, details of rare or unusual species are included, together with the threat offered by oil and gas related activities. Other major human activities in the SEA6 area that are currently affecting the benthos are also discussed.本报告为贸易和工业部（现更名为能源与气候变化部）开展的战略环境评估（Strategic Environmental Assessment, SEA6）相关研究成果。本报告系统梳理了SEA6海域内底栖生物群落（benthic communities）与海底生境（seabed habitats）的现有研究认知。该海域为浅海环境，具备水交换充分、盐度稳定、半封闭的温带海域特征；海底以沉积型底质为主，底质类型涵盖泥质与砾石，主体为沙质底质。沿岸带分布有多样的典型生境，包括裸露岩岸、受庇护的溺谷湾、高生产力潮间沙滩、河口湾以及受强潮流作用的区域。这类多样的生境支撑了种类繁多的动植物类群。 本报告聚焦于优势物种与群落类型（biotopes）的宏观描述。本次报告的讨论范围北起金蒂尔岬（Mull of Kintyre）与北爱尔兰海岸，南至彭布罗克郡米尔福德港（Milford Haven, Pembrokeshire），覆盖潮间带（littoral zone）与潮下带（sublittoral zone）的相关生境。该区域包含莫克姆湾、利物浦湾与默西河河口等重要工业河口，以及若干小型河口，同时涵盖安格尔西岛（Anglesey）与马恩岛（Isle of Man）两大主要岛屿。报告同时对水深大于50米的深水区域与远海海域进行了探讨。 在适宜的章节中，本报告纳入了稀有或特殊物种的相关细节，并阐述了油气相关活动对其造成的生存威胁。此外，报告还讨论了当前对该SEA6海域底栖生物造成影响的其他主要人类活动。