© 2003 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
Cod in fjords and coastal waters of North Norway: distribution and variation in length and maturity at age
Institute of Marine Research N-9291 Tromsø, Norway
*Correspondence to E. Berg; tel: +47 55 238500; fax: +47 55 238531. e-mail: erik.berg{at}imr.no; ole.thomas.albert{at}imr.no.
The distribution of cod along the Norwegian coast and in fjords from 62°N north to the Russian border was examined using data from annual trawl surveys carried out between 1995 and 2001. Based on differences in growth zones of the otoliths, cod are traditionally classified into two types: Northeast Arctic cod and coastal cod. Both types were found throughout the area investigated. The catch rate of both increased northwards and from offshore to inshore. In a statistical model of length at age, abiotic factors such as area and year of capture explained more of the variance than biotic factors such as sex, stage of maturity, and type of cod. Length at age increased in a southward direction and was higher for cod captured offshore than for those captured inshore. In a statistical model of the proportion mature at age, area, type, and year of capture explained more of the variance than sex and depth of capture. On average, coastal cod attained 50% maturity (M50) more than a year younger than a year younger than Northeast Arctic cod attained maturity. Although there were relatively large differences in age at maturity between neighbouring areas, age at maturity was lowest in the south and inshore, and in general, lower inshore than offshore. As genetic analysis clearly indicates that cod in the study area consist of at least two genetically separated stocks, it is likely that the differences found here in age at M50 might have a genetic component.
Keywords: coastal cod, distribution, growth, maturity, northeast Arctic cod, North Norway
Received 3 December 2002; accepted 14 February 2003.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  F. F.L. Almeida, G. L. Taranger, B. Norberg, O. Karlsen, J. Bogerd, and R. W. Schulz Photoperiod-Modulated Testis Maturation in Atlantic Cod (Gadus morhua, L.) Biol Reprod, April 1, 2009; 80(4): 631 - 640. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Williams, K. Helle, and M. Aschan The distribution of chondrichthyans along the northern coast of Norway ICES J. Mar. Sci., October 1, 2008; 65(7): 1161 - 1174. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Lunde, O. R. Godo, and R. Rosland Reliability of trawl surveys on cod in Norwegian fjords ICES J. Mar. Sci., September 1, 2008; 65(6): 937 - 945. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Michalsen, E. Johannesen, and B. Bogstad Feeding of mature cod (Gadus morhua) on the spawning grounds in Lofoten ICES J. Mar. Sci., May 1, 2008; 65(4): 571 - 580. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Karlsen, B. Norberg, O.S. Kjesbu, and G.L. Taranger Effects of photoperiod and exercise on growth, liver size, and age at puberty in farmed Atlantic cod (Gadus morhua L.) ICES J. Mar. Sci., January 1, 2006; 63(2): 355 - 364. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.L. Taranger, L. Aardal, T. Hansen, and O.S. Kjesbu Continuous light delays sexual maturation and increases growth of Atlantic cod (Gadus morhua L.) in sea cages ICES J. Mar. Sci., January 1, 2006; 63(2): 365 - 375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Silva, M.B. Santos, B. Caneco, G. Pestana, C. Porteiro, P. Carrera, and Y. Stratoudakis Temporal and geographic variability of sardine maturity at length in the northeastern Atlantic and the western Mediterranean ICES J. Mar. Sci., January 1, 2006; 63(4): 663 - 676. [Abstract] [Full Text] [PDF]
|
|