Article: Marine benthos, substrate and palaeoecology

The distribution of marine benthos in the Irish Sea is influenced by the nature of the substrate. The majority of epifaunal species are suspension feeders or carnivores and are associated with rocks or coarse-grained sediments. The majority of infaunal species are deposit feeders and are associated with fine-grained sediments. The relationships of the organic content of the sediment and the physical nature of the substrate to the benthos are discussed. It is argued that epifauna, and benthos living in well-sorted sands, are more likely to be transported after death than most infauna. Fossil epifauna are most likely to be found in situ at unconformities, disconformities, and bioherms. Over half of the species of epifauna but only one-third of the species of infauna have hard parts and are preservable as fossils.