© 2004 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
Small-scale distribution of juvenile gadoids in shallow inshore waters; what role does maerl play?
University Marine Biological Station Millport, Marine Parade Isle of Cumbrae KA28 0EG, Scotland, UK
*Correspondence to N. A. Kamenos: tel: +44 1475 530581; fax: +44 1475 530601. e-mail: nick.kamenos{at}millport.gla.ac.uk.
The indirect effects of demersal fisheries, such as habitat degradation, are currently thought to be impacting gadoid stocks. Maerl fulfils nursery area prerequisites for several invertebrate species, so its role in similar ecosystem service provision for gadoids has been addressed. Juvenile cod (Gadus morhua), saithe (Pollachius virens), and pollack (Pollachius pollachius) in shallow (<7 m) inshore waters were surveyed with fykenets and scuba off western Scotland over a period of 12 months. Juvenile densities were highest from September to November, and at that time, significantly more were present during the day and associated with maerl (that lacked macroalgal cover) than with heavily vegetated rocky and gravel substrata. Juvenile cod were present throughout the year, whereas saithe appeared in July, and pollack from September to January. With its abundance of food, maerl probably has a high holding capacity for juvenile gadoids, and thus is an important part of the inshore nursery system.
Keywords: gadoid, holding capacity, inshore waters, juvenile, nursery area, Scotland
Received 14 November 2003; accepted 28 February 2004.
1 Present address for J. M. Hall-Spencer: Marine Biology and Ecology Research Group, Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, England, UK.