Habitat point records from 1984 Smith Loch Sween mollusc and polychaete littoral survey

Loch Sween is one of 7 sites currently proposed by the Nature Conservancy Council as Marine Nature Reserves. It has been selected on the basis of its high scientific interest and conservation value. The present study forms part of a series of studies by or for NCC to provide more detail on the scientific interest and to provide information essential for designation and subsequent management. In addition to this study, a number of other studies were carried out in 1984, including work on the littoral habitats, communities and species described in Rostron & Hiscock (1985). Loch Sween is a sea loch some 20 km in length on the east side of the Sound of Jura. Although facing south-westwards its mouth is partly sheltered by a number of islands. The main body of the loch is linear and relatively uniform but there are several main off-shoots or 'arms' to the loch which add considerably to the habitat diversity. The objectives of this survey included surveying a number of sites not previously visited, to describe their mollusc and polychaete communities in particular as well as revisiting old sites to look at annual variation in community structure. Seasonal and longer term variations were investigated using the mollusc samples obtained from the washing of Fucus serratus. Considerable changes in community composition between years were found, often contradictory in trend. The implications of major meteorological variations between years is disclosed although no firm conclusions can be drawn. Although not mentioned in this report, the effects of FW ponding, which occurs extensively during periods of prolonged and heavy rainfall, may also contribute to the annual variation. In addition to these variations, major changes were noted between years for local community dominants such as Ascidiella aspersa and Ophiocomina nigra. A moderate range of communities was recorded, the habitat diversity being less than that found at sites outwith sea lochs investigated elsewhere on the west coast of Scotland. This would be expected and results from the reduced habitat diversity and water exchange and the increase in variability in water 'quality' found in sea lochs. Areas of increased habitat, community and species diversity were associated with shores at the entrance to several of the arms of Loch Sween where water movement was locally enhanced. Records currently considered sensitive have been removed from this dataset.

洛赫斯温是自然保护理事会目前提议的7个海洋自然保护区之一。其选择基于其极高的科学价值和保护意义。本研究构成了自然保护理事会或为其进行的一系列研究的一部分，旨在提供更多关于科学价值的详细信息，并为指定及后续管理提供必要信息。除本研究外，1984年还进行了一系列其他研究，包括对罗斯特恩与希科克（1985年）所描述的沿岸生境、群落和物种的研究。洛赫斯温是一个长达约20公里的海角，位于朱拉海峡的东侧。尽管其面向西南，但其入口部分受到多个岛屿的部分庇护。湖泊主体呈线性且相对均匀，但有几条主要支流或“臂”延伸至湖泊，大大增加了生境的多样性。本次调查的目标包括对一些未曾访问过的地点进行考察，特别是描述其软体动物和环节动物群落，同时回访旧地点以观察群落结构的年度变化。通过从锯齿状马尾藻的冲洗中获得的软体动物样本，研究了季节性和长期变化。在年度间群落组成中发现了相当大的变化，趋势往往相互矛盾。尽管无法得出明确结论，但年度间主要气象变化的含义已揭露。尽管在本报告中未提及，但广泛发生的FW积水效应，即在长时间强降雨期间发生，也可能对年度变化产生影响。除了这些变化外，本地群落优势物种如阿西迪埃拉·阿斯珀拉和奥菲科米娜·尼格拉在年度间也出现了重大变化。记录的群落多样性适中，生境多样性低于苏格兰西海岸其他海角调查地点的生境多样性。这符合预期，并由此产生的生境多样性减少、水体交换增加以及海角中水体‘质量’变异性增加所致。生境、群落和物种多样性增加的区域与洛赫斯温多个臂入口处的海岸相关，这些区域的水流运动在当地得到增强。目前被认为敏感的记录已被从本数据集中移除。