Habitat point records from 1973-75 University of Bristol Severn estuary littoral sediment survey

Variations in invertebrate densities within the Severn Estuary have been examined on four shores over a period of two years. Variability due to seasonal changes was combined with a patchy distribution of some species, while others showed consistent densities at the same tidal level and at different sampling times. Some species showed more consistent densities in winter than in summer. Biological interactions, varying periods of spawning and recruitment and beach instability are thought to be three of the major factors influencing distribution. No marked community changes such as seen in some sublittoral areas have been found.

在为期两年的研究期间，对塞文河口四个岸段的节肢动物密度变化进行了考察。季节性变化引起的变异性与某些物种的零星分布相结合，而其他物种在相同潮位和不同采样时间显示出一致的密度。一些物种在冬季比夏季表现出更一致的密度。生物相互作用、繁殖和补充期的变化以及海滩不稳定被认为是影响分布的三大主要因素。尚未发现如某些海底区域所见到的显著群落变化。