By-catch management

The fishing of Walleye Pollock in the Far East seas is conducted only with mid-water trawl. Pelagic or mid-water trawl is considered as one of the most environmental friendly fishing gear. It targets solid slow-moving aggregations of Pollock in the pelagic layer of water with 100 mm mesh nets what makes “specialized” pollock fishery highly selective one.
 
Besides, natural factors influencing low by-catch there is a set of measures that constitutes a strategy of effective by-catch management and supports mitigation of by-catch. These include:

• All by-catch species must be recorded, and reported; 
• When by-catch species exceeds 2% for TAC species and 49% for PC (possible catch) species there is a “move-on” rule of at least five miles from areas of high by-catch; 
• If by-catch exceeds 2% or 49% depending on by-catch specie in a trawl, the excess catch must be returned to the sea, and reported;
• Vessels can have quotas for multiple species which eliminates the need to apply mitigation as long as the allocation to the vessel for the by-catch species is not exceeded;
• If by-catch is in excess of the TAC or PC, the management authority can enforce time-area closures to mitigate further excess by-catches; 
• Bottom trawling is prohibited; 
• Full or partial ban in some fishing zones. Trawling is not permitted less than 30 miles off-shore and 5-12 miles from islands; 
• Vessel captains must keep records of by-catch and submit daily vessel report (DVR) to the Fisheries Monitoring System electronic database; 
• Vessels, trawling operations, and catches are observed by scientific observers from fishery research institutes, Coast Guard inspectors, and FFA inspectors. The cross referencing system between data systems and inspections suggests that there is little scope for misreporting of retained catches or discarding.

Multi-year surveys of the bycatch on the Sea of Okhotsk mid-water trawl Pollock fisheries show that Walleye Pollock share in the catch is in average 98-99%. Due to very low volume of the bycatch species, mid-water Pollock trawl fisheries have no threat to the biological limits of many of the species what is proven during annual rigorous stock assessment for all commercial bycatch species.