Catches of Greenland halibut (Reinhardtius hippoglossoides) in ghost fishing gillnets on the Norwegian continental slope
Working paper
Permanent lenke
http://hdl.handle.net/11250/106085Utgivelsesdato
2000Metadata
Vis full innførselSamlinger
Originalversjon
This report is not to be cited without prior reference to the authorsSammendrag
Catches in deliberately “lost” gillnets were studied during a ten-day cruise conducted at
Storegga 70 nm off the coast of mid-Norway in July 2000. Gillnet fleets were deployed at
depths of between 537 and 677 m, and soak time varied from one to seven days. Four fleets
set 45 days earlier were also retrieved during the cruise. Most of the catch (94 %) consisted of
the target species Greenland halibut (Reinhardtius hippoglossoides). All individuals were
categorized according to seven condition stages ranging from “alive with no injuries” to
“only bones remaining”. Results revealed that fish could be fully decomposed/consumed
within a 24-hour period, probably due to amphipod and isopod scavenger activity. A decline
in total catches was first observed after five days whereas catch composition remained stable
during the first seven days. After 45 days a relatively high total catch was obtained but only
25 % were still at stages 1-4 (consumable). The cumulative catch after 45 days was estimated
at 2.7 and 3.0 tons on the basis of two different methods. Gillnets retrieved after 45 days were
evaluated as being highly effective, with gear saturation being the only factor leading to
decreased efficiency.