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Fishery Bulletin 100(3) 



Ammassalik was recaptured north of the Faroe Islands 

 four years after release, which indicates a link between 

 the Greenland halibut populations in the Northwest At- 

 lantic and those in the Northeast Atlantic and suggests 

 some intermingling of halibut populations in the Atlantic 

 Ocean. Studies on genetic differentiation have shown that 

 Greenland halibut in the North Atlantic are genetically 

 homogenous, indicating that populations do intermingle 

 (Riget et al., 1992; Vis et al., 1997). Tagging experiments 

 in Icelandic waters (Sigurdsson, 1981) included recoveries 

 at long distances east of the release sites (Norway), even 

 to the Barents Sea, also suggesting that there are interac- 

 tions between the Northwest Atlantic and the Northeast 

 Atlantic populations of Greenland halibut. 



The 17 Greenland halibut recovered in Denmark Strait 

 from tagging sites in West Greenland indicated a mix be- 

 tween West and East Greenland stocks, confirming previ- 

 ous work, especially tagging studies by Smidt (1969) and 

 Boje^ who documented recaptured Greenland halibut off 

 western Iceland from releases in the Godthaab and Lic- 

 thenau fjords of southern Greenland. Genetic studies and 

 studies using parasites as natural tags (Riget et al., 1992; 

 Boje et al., 1997) have shown that Greenland halibut in 

 the Qords of southwestern Greenland differ considerably 

 from offshore fish in Davis Strait. Riget and Boje (1988) 

 h}rpothesized that young Greenland halibut in the south- 

 ernmost coastal areas of western Greenland originate from 

 different spawning grounds than those in the northern 

 part of western Greenland. Larval distribution studies 

 provide additional information on a link between the 

 populations of southwestern Greenland and those of Den- 

 mark Strait. Magnusson's^ data and more recently data 



on Icelandic 0-group Greenland halibut, 1970-97 (Hjorlei- 

 fsson') have provided evidence of larvae in a continuous 

 belt from the Icelandic spawning grounds westward along 

 the continental slope of eastern Greenland and southward 

 to Cape Farewell. From pelagic Greenland halibut eggs and 

 larvae in the western and southeastern Greenland areas, 

 Smidt (1969) distinguished two groups of larvae with 

 different growth patterns and hypothesized the intermin- 

 gling of larvae from two different spawning areas, namely 

 the spawning complex in Davis Strait and the stock west 

 of Iceland (Denmark Strait). These authors have suggested 

 that Greenland halibut eggs and larvae are transported by 

 the East Greenland Current from Denmark Strait to the 

 southernmost areas of western Greenland, a route shown 

 earlier for cod (Taning, 1937; Buch et al., 1994). 



The behavior of Greenland halibut tagged in the ^ords 

 of northwestern Greenland is quite remarkable. The ma- 

 jority have remained within 50 km of release sites, even up 

 to eight years after release and very few fish have under- 

 gone large-scale migrations of 100 to 500 km. Greenland 

 halibut released from the fjords of northwestern Green- 

 land have never been reported outside the fjord areas, but 

 apparent residency may also be the result of almost no 

 fishing activity in Baffin Bay (area adjacent to Uumman- 

 naq and Upernavik fjord). However, an assumed spawn- 

 ing migration to Davis Strait, is not plausible because a 

 considerable fishery has developed in this area since the 

 late 1980s (Anonymous, 1998). My data are consistent 

 with the general assumption that Greenland halibut in 

 the Qords of northwestern Greenland are recruited from 

 the Davis Strait spawning stock (Smidt, 1969, 1998; Riget 

 et al., 19891 and that adults thereafter remain resident in 

 the fjords, i.e. do not undertake any significant spawning 



^ Magnusson, J. 1977. Notes on eggs and larvae of Greenland 

 halibut at Iceland. ICES (International Council for the Explo- 

 ration of the Sea) CM. 1977/F:47, 6 p. ICES, Palaegade 2-4, 

 DK-1261 Copenhagen K, Denmark. 



' Hjorleifsson, E. 1999. Personal commun. Marine Research 

 Institute, P.O. Box 1390, Skiilagata 4, 18-121 Reykjavik, Iceland. 



