The Bottom Fauna Communities and Their Sediment Relationships off the Coast of Northumberland

Abstract

A quantitative survey has" been carried out over an area of about 750 mi2 of the North Sea adjacent to the southern half of the Northumberland coast. Bottom samples were obtained with a 0.1 m2 Van Veen type grab and supplemented by trawls and dredges. Particle size analysis of sediment samples was carried out for every station. The distribution of the benthic communities and of the bottom sediments is given. Three communities are recognized and their constitution is quantitatively described together with their variations. These are 1) the Amphiura filiformis-A chiajei community which in this area can be split into two subcommunities, one characterized by A. filiformis, which has four recognizable variations, and the other by A. chiajei, 2) the Haploops tubicola community, and 3) the Venus striatula community. The communities are shown to be poorly correlated with the texture of the bottom sediments. When the sediments of the various associations are compared it is found that there is a very broad overlapping of conditions which is not associated with a similar mixing of the fauna. Also similar sediments are shown to contain very different faunas.