414 



Abstract-A total of 7244 Greenland 

 halibut (Reinhardtius hippoglossoides, 

 Walbaum) were tagged in Greenland 

 waters between 1986 and 1998 to in- 

 crease information on stock delinea- 

 tions, to clarify migration routes, and to 

 describe the seasonal movements of fjord 

 populations. At present 517 recaptured 

 Greenland halibut have been recorded. 

 For Greenland halibut released in Davis 

 Strait, Baffin Bay, and the fjords of south- 

 western and eastern Greenland, a sub- 

 stantial portion of recovered fish dem- 

 onstrated migratory behavior, up to 

 2500 km, primarily to Denmark Strait 

 between Greenland and Iceland. The 

 recaptured fish provided evidence of 

 intermingling between the population in 

 Denmark Strait and the populations in 

 Davis Strait and the southwest Green- 

 land fjords. These observations support 

 those of other studies that indicate 

 that Greenland halibut inhabiting Davis 

 Strait and the fjords of southwestern 

 and eastern Greenland originate in the 

 spawning grounds west of Iceland. The 

 high mobility of offshore Greenland hal- 

 ibut within Baffin Bay and Davis Strait 

 suggests that Greenland halibut migrate 

 extensively between feeding and spawn- 

 ing areas. Greenland halibut in the Qords 

 of northwestern Greenland appear to be 

 resident in behavior and do not inter- 

 mingle with offshore or more southerly 

 inshore populations. A seasonal pattern 

 in the recovery of these fish indicates 

 that Greenland halibut aggregate in the 

 inner part of ^ords during the second 

 half of the year (when inshore waters 

 are not covered with ice). 



Intermingling and seasonal migrations of 

 Greenland halibut {Reinhardtius liippogiossoides) 

 populations determined from tagging studies 



Jesper Boje 



Department of Marine Fishenes 



Danish Institute for Fisheries Research 



Charlottenlund Slot DK-2920 



Charlottenlund, Denmark 



Present address Greenland Institute of Natural Resources 



PO Box 570 



3900 Nuuk, Greenland 

 E mail address |esper(atnaturgl 



Manuscript accepted 3 October 2001. 

 Fish. Bull. 100:414-^22 (2002). 



Greenland halibut, Reinhardtius hip- 

 poglossoides (Walbaum), are widely dis- 

 tributed in the Northwest Atlantic. 

 Their range covers a geographical area 

 from Smith Sound, between Greenland 

 and Canada, southward throughout 

 Baffin Bay and Davis Strait to the 

 northeastern coast of the United States 

 and eastward along eastern Greenland 

 to Iceland (Smidt, 1969; Bowering and 

 Brodie, 1995). The spawning grounds 

 of Greenland halibut are believed to be 

 located southwest of Iceland (Sigurds- 

 son') and cover an extended area from 

 Davis Strait, south of 67°N (Jensen, 

 1935: Smidt, 1969) to south of Flemish 

 Pass off Newfoundland (Junquera and 

 Zamarro, 1994) between 800 and 2000 

 m depths. The Greenland halibut popu- 

 lations off the eastern coast of Canada, 

 in Davis Strait, in the fjords of western 

 Greenland, in the Denmark Strait, and 

 in Icelandic waters are believed to be re- 

 cruited from these spawning grounds 

 (Templeman. 1973;Sigurdsson' ). Anum- 

 ber of scientists have examined interac- 

 tions among different local populations 

 of Greenland halibut in the Northwest 

 Atlantic. They have considered and, in 

 some cases, attempted to quantify mer- 

 istic characteristics (Templeman, 1970; 

 Misra and Bowering, 1984; Riget et al., 

 1992; Rasmussen et al., 1999), genetic 

 variability (Fairbairn, 1981; Riget et al., 

 1992; Vis et al., 1997), the occurrence of 

 parasites as natural tags (Khan et al., 

 1982; Boje et al. , 1997 ), and tagging data 

 (Smidt, 1969; Bowering, 1984; Riget and 

 Boje, 1989; Boje-). The results of these 

 investigations suggest that the entire 

 Greenland halibut population between 



Greenland and Canada must be consid- 

 ered a single stock unit. There is some 

 evidence that the populations between 

 Greenland and Iceland originate from a 

 spawning stock situated along the conti- 

 nental slopes west of Iceland. A number 

 of Greenland halibut populations seem 

 to maintain a degree of isolation with- 

 out any prespawning migration to their 

 original spawning areas; this is charac- 

 teristic of the Greenland halibut popu- 

 lation in the Gulf of St. Lawrence ( Khan 

 et al., 1982) as well as for populations 

 in the Qords of northwestern Greenland 

 (Riget and Boje, 1989). Spawning has 

 been observed in the Gulf of St. Law- 

 rence (Bowering, 1980), but only a few 

 ripe females have been sighted in the 

 Qords of western Greenland (Riget and 

 Boje, 1989). 



Previous tagging experiments in the 

 fjords of western Greenland (Smidt, 

 1969; Riget and Boje, 1989; Boje^) 

 suggest that Greenland halibut stocks 

 in the southernmost fjords may be 

 recruited from Icelandic spawning 

 grounds. The Irminger Current and the 

 East Greenland Polar Current carry 

 eggs and larvae from these spawning 



' Sigurdsson,A. 1979. The Greenland hal- 

 ibut [Reinhardtius hippoglossoides (Wal- 

 baum)) at Iceland. Hafrannsbknir. 16, Ma- 

 rine Research Institute. Reykjavik, Iceland. 



- Boje, J. 1993. Migrations of Greenland 

 halibut in the Northwest Atlantic from tag- 

 ging experiments in West Greenland 1986- 

 89. ICES (International Council for the 

 Exploration of the Sea) C. M. Doc. 1993/ 

 G:65, 14 p. ICES, Pategade 2-4, DK-1261 

 Copenhagen K, Denmark. 



