Publication Abstract

Regional variability in the dynamicsof reproduction and growth of
Irish Sea plaice, Pleuronectes platessa L

Nash, RDM; Witthames, PR; Pawson, M; Alesworth, E

The differences in size-specific fecundity in relation to size/age at maturity, and inreproductive and somatic investment were analysed for female plaice caught in four regionsof the Irish Sea (Cumbrian coast, Liverpool Bay, Cardigan Bay and western Irish Sea), eachof which contains a spawning focus. Both the reproductive investment (gonad weight as afunction of body size) and fecundity-size relationship of plaice in the western Irish Seawere significantly different from those in the other regions. Rates of annual somaticgrowth appeared to fall into three distinct groups (Cumbrian coast; Liverpool Bay andCardigan Bay; western Irish Sea) and, in all cases, the rate of somatic growth fellrapidly after maturity. The data suggest that the highest surplus production (as spawnedeggs) occurs in the sub-populations of plaice on the Cumbrian coast and in Liverpool Bay,and is linked to reduced intra-specific competition for food.

Reference:

Nash, RDM; Witthames, PR; Pawson, M; Alesworth, E, 2000. Regional variability in thedynamics of reproduction and growth of Irish Sea plaice, Pleuronectes platessa L.. Journalof Sea Research, 44(1-2): 55-64