Salmon Bycatch
"Bycatch” is the term used to describe fish that are caught
incidentally while fishing for other species.
Although fishermen try to catch only fish that can be sold, fishing
gear is not 100% selective, and some undesirable fish and other
organisms are caught incidentally in the course of fishing operations. These non-target organisms are considered bycatch. Many people
are concerned about environmental and allocative effects of catching
fish that are not targeted and may be discarded. Fish are discarded
for two reasons: either they are required to be thrown back due to
regulations (prohibited species), or they are unwanted because they
are not economically profitable to be retained (not a preferred
species or size for the markets).
Limits on the bycatch of prohibited species (crab, herring, halibut,
and GOA and BSAI salmon) have been established to reduce the impacts on these
species traditionally harvested by other gear types. When bycatch
limits are reached, fisheries responsible for the bycatch are closed
for the rest of the season or are prohibited from fishing in areas with
historically high bycatch rates. Bycatch limits for 2002 Bering Sea and
Aleutian Island groundfish trawl fisheries included 3,675 mt of halibut
mortality, 1,526 mt of herring, 97,000 red king crabs, 3,950,000 C.
bairdi crab, 4,350,000 C. opilio crab, 33,000 chinook salmon, and
42,000 other salmon. These bycatch limits equate to less than about
1% of the halibut, crab, herring, and chum salmon populations.
Bycatch of chinook salmon is slightly larger, in the order of 2% to 3%, and the Council and industry are pursuing several initiatives to further reduce this level. In addition to bycatch limits, gear restrictions and other regulations have been implemented to reduce bycatch. Biodegradable panels are required for pot gear to minimize bycatch associated with so-called ghost fishing of lost gear. Tunnel openings for pot gear are limited in size to reduce incidental catch of halibut and crabs. Gillnets for groundfish have been prohibited to prevent ghost fishing and bycatch of non-target species. With the implementation of an individual fishing quota system for halibut and sablefish longline fisheries, bycatch and waste were reduced because the race for fish was eliminated, allowing for more selective fishing practices and significant reductions in actual gear deployment/loss. In 1999, the use of bottom trawl gear was prohibited for vessels targeting pollock in the Bering Sea, to reduce crab and halibut bycatch.