Recruitment in a temperate demersal fish: Does larval supply matter?

Abstract

The importance of larval supply to spatial patterns of larval settlement and recruitment was determined for a common Gulf of Maine fish (the cunner Tautogolabrus adspersus). The number of presettlement pelagic fish differed among the four sites sampled. Inshore sites had significantly greater densities than offshore sites, and this difference was consistent over time. The average size of presettlement fish also differed; fish at inshore sites averaged ∼2 mm less in standard length than those at offshore sites. Settlement was quantified by using artificial substrata suspended above the benthos, and a nonsignificant trend for greater settlement at offshore vs. inshore sites was revealed. Recruitment surveys after the settlement season showed that densities of recruits were significantly greater offshore than inshore. Correlation analyses showed either significant inverse or nonsignificant relationships between densities of presettlement fish and settlement depending on the size of presettlement fish. The relationship between recruitment and densities of presettlement fish was not significant with each of the size classes of presettlement fish analyzed, but there was a strong positive relationship between settlement and recruitment.