Habitat point records from 1983 Rostron Isles of Scilly sublittoral sediment survey

The survey was carried out in July 1983 to obtain information on the communities present in the extensive shallow sublittoral sediments of the Isles of Scilly in relation to the proposals to establish a marine nature reserve there. Sites were chosen to be representative of different depths and exposures and also fairly evenly spaced throughout the survey area. A total of 9 sites were sampled. Sampling was achieved by means of a diver-operated suction sampler. Two 0.1 m/2 samples were obtained from each site for biological analysis and also one core sample for sediment analysis. All animals present in the samples were identified and the individuals of each taxon counted although no quantitative analyses of the data were attempted. Numbers of taxa obtained in each 0.2 m/2 area of sea bed ranged from 31 in homogeneous sand sediment to 104 from mixed gravel. Sediments around the Isles of Scilly were found to support a diverse fauna, especially at the deeper sites. The large variation in habitat conditions resulted in a mosaic of community types, some of which resembled communities previously described from other areas. Sediment particle size analyses were carried out for 6 of the 9 sites. Sediments were predominantly coarse gravel with small quantities of fine sand associated organic material. Many of the species present in the Isles of Scilly were characteristic of coarse sediments although areas of fine sand sediment were also present. The extensive beds of Zostera marina were of interest as they provided a particular habitat for a variety of species. The present survey was sufficient to describe only a limited number of sites. However, the results confirm the high diversity of communities present in the Isles of Scilly and demonstrate the very wide variety of rich and unusual shallow sedimentary habitats present within a small area.

本次调查于1983年7月进行，旨在获取关于塞文岛群广泛浅层海底沉积物中存在的社区信息，并与在该地设立海洋自然保护区的提案相关联。选取的地点旨在代表不同深度和暴露度，并在整个调查区域内分布较为均匀。总计采集了9个地点的样本。采样通过潜水员操作的水下吸泥器完成。每个地点获取了两个0.1米/2的样本用于生物分析，以及一个柱状样用于沉积物分析。所有样本中的动物均被鉴定，并统计了每个分类单元的个体数量，尽管并未尝试进行数据的定量分析。每个0.2米/2海底区域的物种数量从均质沙质沉积物中的31个到混合砾石中的104个不等。塞文岛群周围的沉积物被发现支持着多样的生物群落，特别是在较深的地点。栖息地条件的巨大变化导致了社区类型的拼贴图案，其中一些与来自其他地区的先前描述的社区相似。对9个地点中的6个地点进行了沉积物颗粒大小分析。沉积物以粗砾石为主，伴有一定量的细沙和有机物质。许多在塞文岛群中出现的物种是粗粒沉积物的特征，尽管也存在细沙沉积物的区域。宽阔的海洋草床（Zostera marina）引起了人们的关注，因为它们为多种物种提供了特定的栖息地。本次调查仅足以描述有限的几个地点。然而，结果证实了塞文岛群中社区的高多样性，并展示了在狭小区域内存在的丰富和独特的浅层沉积物栖息地的广泛多样性。