Total stock size and cannibalism regulate recruitment in cod (Gadus morhua) on the Faroe Plateau

• Published in: ICES Journal of Marine Science
• Main Authors: Steingrund, Petur, Mouritsen, Rógvi, Reinert, Jákup, Gaard, Eilif, Hátún, Hjálmar
• Format: Text
• Language: English
• Published: Oxford University Press 2009
• Subjects: Article; Gadus morhua
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/fsp240v1; https://doi.org/10.1093/icesjms/fsp240

<qd> Steingrund, P., Mouritsen, R., Reinert, J., Gaard, E., and Hátún, H. 2010. Total stock size and cannibalism regulate recruitment in cod ( Gadus morhua ) on the Faroe Plateau. – ICES Journal of Marine Science, 67: 000–000. </qd>Year-class strength of fish is often considered to be determined at the pelagic larval stage, but we show that year-class strength of cod on the Faroe Plateau seems to be determined later, at the 1- or 2-group stage. Adult cod ( C ), measured in terms of the catch per unit effort (cpue) of small longliners, move into nearshore nursery areas of juvenile cod when in poor condition and probably displace 1-year-old cod to deeper water, where they are cannibalized. In addition, the recruitment of 2-year-old cod, at least up to a certain level, is positively related to the total biomass ( B ) of older cod on the Faroe Plateau, which are present at about the same time as the recruitment event. This feature, which seems to be a new observation in terms of the recruitment dynamics of cod, is possibly related to enhanced foraging or a reduced predation risk. The recruitment of 2-year-old cod during the years 1984–2006 is described by aB / C + d ( r 2 = 0.87), where a and d are fitted constants. The implications for stock assessment and management are discussed.