Migration patterns, ambient temperature, and growth of Icelandic cod (Gadus morhua): evidence from storage tag data
Pálsson, Ó.K.; Thorsteinsson, V. (2003). Migration patterns, ambient temperature, and growth of Icelandic cod (Gadus morhua): evidence from storage tag data. Can. J. Fish. Aquat. Sci. 60(11): 1409-1423. dx.doi.org/10.1139/f03-117
In: Canadian Journal of Fisheries and Aquatic Sciences = Journal canadien des sciences halieutiques et aquatiques. National Research Council Canada: Ottawa. ISSN 0706-652X; e-ISSN 1205-7533, more
|  |
| Keywords |
Aquatic organisms > Marine organisms > Fish > Marine fish
Behaviour > Migrations
Population functions > Growth
Properties > Physical properties > Thermodynamic properties > Temperature
Spawning grounds
Gadus morhua Linnaeus, 1758 [WoRMS]
Marine/Coastal |
| Authors | | Top |
- Pálsson, Ó.K.
- Thorsteinsson, V.
|
|
|
| Abstract |
Sixty data storage tags were analysed with respect to depth and ambient temperature and for relationships between depth, ambient temperature, and growth. The fish were tagged and released in April 1996-1999 on the spawning grounds at the southwest coast of Iceland. Profiles of depth and ambient temperature suggest that cod (Gadus morhua L.) that spawn in the study area select between two alternatives in foraging strategies, i.e., deep- or shallow-water migrations. The shallow-water fish appear to follow the seasonal trend in temperature characteristic for the shelf waters. The deep-water fish, however, migrate to deeper and cooler waters outside the spawning season and increase their vertical movement. A significant positive relationship between depth and ambient temperature was observed for the shallow-water fish, and a significant negative relationship was observed for the deep-water fish. Daily variation in depth and ambient temperature showed increasing trends with increase in depth, in particular for deep-water fish. Growth was negatively related to depth and positively related to ambient temperature. This indicates higher growth rate of cod that forage in shallow waters versus deeper waters. Supply of food, for which depth may be a reasonable proxy, offers a more likely explanation for this growth pattern than environmental temperature. |
|
