The migration of coastal cod (Gadus morhua L.) tagged in a fjord of western Norway
Original version
This report is not to be cited without prior reference to the authorsAbstract
This study is part of a research program investigating the possibility of enhancing
the production of coastal cod via a large scale release of pond produced fish in
Masfjorden, a fjord of western Norway. An analysis of parts of the ecosystem are
being carried out prior to the large scale experiment with a special focus on the cod
population of the fjord. The paper deals with the migration pattern of wild cod which
were caught, tagged and recaptured and also, pond produced cod released in small scale
tag-release-recapture experiments. We applied Spearman's rank correlation test and
Kolmogrov-Smirnov two-sample test to assess whether larger individuals migrate longer
distances than smaller cod. The major proportion of the immature wild and pond produced cod were nearly stationary
and only 15.0 and 7.0 percent, respectively were recaptured more than five kilometers
from the release site. However, a larger proportion, 54 percent, of mature cod were
recaptured outside the release site, of which the !argest individuals were found to
migrate the longest distances, with some of the latter intermingling with cod from
contiguous fjords.