COPEPOD AND BARNACLE NAUPLIUS DISTRIBUTIONS IN THE IRISH SEA - RELATION TO SPRINGTIME HYDROGRAPHIC VARIABILITY

The distributions and abundances of copepod and barnacle nauplii are described along a five-station transect in the Irish Sea from Liverpool Bay, England, to Dundalk Bay, Ireland, in May 1989. Correspondence analysis revealed that various hydrographic regions in the Irish Sea are characterized by distinct nauplius assemblages. Acartia, Centropages and Temora nauplii were associated with the Welsh coastal water east of the Liverpool Bay front. The western stratified water to the west of the seasonal, western Irish Sea front was distinguished from the mixed water to the east by abundances of Calanus, Pseudocalanus, Oithona Microcalanus and harpacticoid nauplii. The Liverpool Bay and western Irish Sea fronts are, apparently, boundaries between coastal and offshore assemblages of crustacean nauplii.