ICHTHYOPLANKTON DISTRIBUTION AND ABUNDANCE IN THE CELTIC SEA

The larval stages of 70 fish species and the eggs of two of these species were identified from plankton samples taken in the Celtic Sea during April, May, and June 1980 and 1983. Seven of these species formed 92% of all the recorded fish larvae, and mackerel (Scomber scombrus) larvae accounted for 72% of the total. The distribution and abundance of these major species are illustrated and discussed. Numerical classification of the fish data indicated three major faunal zones, neritic, transition, and oceanic, the mackerel being the most dominant fish species in all zones. Indices for species diversity, species richness, and species evenness all differed between the faunal zones. The Celtic Sea ichthyoplankton community appears to be quite diverse, but discriminant analyses indicated that ichthyoplankton assemblages were associated with particular suites of environmental factors. Possible predator-prey interactions are discussed.