Size and priority at settlement determine growth and competitive success of newly settled Atlantic cod

Abstract

Research on the declin~ng stocks of North Atlantlc cod Gadus rnorhua has focused on the survival of planktonic larvae as a predictor of recruitment to the fishery Very little is known of the ecology of benthic young-of-year cod, although it has been suggested that abundance of demersal O+ fish may be a better indicator of year-class strength than larval abundance We studied settlement and growth of lndividual age 0+ Atlant~c cod i n situ using visual census and visual length estlmatlon hcivly settled cod were slteattached and defended terntones around a shelter site Terntory slze increased exponentlally with fish length Growth and terntory size were also determ~ned by size at settlement and by prionty, fish that settled largest/earliest grew more quickly and held larger terntones than smaller/later settlers Population dynamics of Atlantic cod may therefoie be regulated In the eally juvenile stage by post-settlement competit ~o n S ~z e at settlement, in addition to the tlming of settlement may determine the competitive success of an lndividual KEY WORDS. Atlantic cod .