Bycatch of juvenile fish in the shrimp fishery - management based on bioeconomic criteria
Original version
This report is not to be cited without prior reference to the authorsAbstract
The bycatch of juvenile fish can be a major problem in fisheries with small meshed trawls,
such as fisheries for shrimp, (Pandalus borealis). A sorting grid that effectively removes
most of the undersized fish has been developed for shrimp trawls and it is not legal to fish
for shrimp in the Barents Sea without the use of this sorting grid. Apart from this, the
existing catch-regulation of shrimp fishery in the Barents Sea is closing of shrimp fisheries
on fishing-grounds, where the bycatch of juvenile fish exceeds the criteria for allowable
bycatch in numbers per ton of shrimp set by The Notwegian- Russian Fishery
Commission.
In this paper a new method for calculation of a criteria for closing shrimp fisheries based
on both biological and economic considerations is established. This bio-economic approach
is an alternative to the existing biological approach. The main concept in the bio-economic
approach is that if the expected future value of the bycatch exceeds the value of the shrimp
catches, the shrimp fishery should be closed. In this paper a joint criteria for allowable
bycatch is developed and calculated, including all the commercially interesting species,
(cod; Gadus morhua, haddock; Melanogrammus aeglefinus, redfish; Sebastes mentella and
Greenland halibut; Reinhardtius hippoglossoides) whose juveniles are caught as bycatch in
the shrimp fisheries in the Barents Sea.