Papers from the Echinoderm Conference. 9. A biometrical study of populations of the European sea-urchin Echinus esculentus (Echinodermata: Echinoidea) from four areas of the British Isles
Results submitted by mainly amateur diving groups during Underwater Conservation Year 1977 in the United Kingdom show that there are regional differences in the relationship between both size and shape of specimens of the European sea-urchin Echinus esculentus Linnaeus and the depth at which they occur. Populations from South-West England are significantly bigger at all depths than those from the other areas surveyed, those from Western Scotland increase in size more rapidly with increasing depth of water, and those from the North Sea decrease in size with increasing depth. Two sites surveyed in South-West Ireland show that exposure may affect the size of urchins inhabiting shallow waters. The results are compared with those of a similar survey by Larsson (1968) on the same species in Swedish waters.