Last updated on 30 October 2018
Recommendations to Retailers & Supply Chain
- Monitor the performance of the fishery and its management to ensure the fishery continues to be eligible for condition-free MSC re-certification.
The age-structured assessment model for Gulf of Alaska pollock is regularly reviewed by experts. Results and methods are publicly available. Regular surveys and extensive research increase the robustness of assessments. Data inputs include fishery catch at age and total catch, several federal surveys and a separate survey run by the Alaska Department of Fish and Game (ADF&G), and acoustic surveys. Only minor changes in the input data and assessment methodology in the most recent stock assessment (Dorn et al. 2015).
Research priorities to improve the quality of the stock assessment include (Dorn et al. 2015): (1) reduce datasets by removing older and less reliable data in the time series; (2) improve the relative weightings given to different data sets; (3) consider alternative modeling platforms; (4) analyze different approaches to model fishery and survey selectivity; (5) explore the implications of non-constant natural mortality on pollock assessment/management.
Scientists’ advised fishing mortality level for 2016 (FABC=0.23) remains below the level authorized by the harvest strategy (max FABC=0.25) at the current biomass level, an indication of precaution. The recommended FABC represents an Allowable Biological Catch (ABC) of 254,310 tonnes in 2016 (Dorn et al. 2015).
The harvest policy includes multiple measures to reduce potential for overfishing. A buffer between OFL and ABC is applied to take into account uncertainties in stock assessment (NPFMC 2015): the maximum permissible FABC harvest rate is 85.0% of the OFL harvest rate. The harvest strategy also requires a decrease in F when biomass declines below (B40%), and a complete ban to directed fishing if biomass is projected to fall below B20% in the coming year (Dorn et al. 2015; NPFMC 2015).
Reference points from latest assessment (SAFE) report are as follows:
2015 SAFE (Dorn et al. 2015)
|B100%||750,000 t |
|B35%||262,000 t |
|B40%||300,000 t |
|max FABC||0.25 |
Biomass target reference point (Btrp) = B40%, which was estimated at 300,000 t in 2015.
Proxy for Blim = B20%. According to the current harvest control rule, if biomass drops below this level, the harvest policy bans directed fishing (F=0) on Pollock (Dorn et al. 2015; NPFMC 2015).
Ftrp = max FABC: For the Gulf of Alaska pollock stocks, the max FABC corresponds to 85% of FOFL (Dorn et al. 2015).
Recommended FABC in 2015: 0.20. This reflects the assessment authors’ further adjustment to FOFL.
The stock remains below target levels, but is not overfished and overfishing is not occurring. Spawning biomass has been dropping since a peak in 2013, and was estimated at 251,000 t in 2015, i.e., 16% below the target reference point (B40%). Fishing mortality has been increasing since 2009, and is at a historical high, but remains below the fishing mortality reference points - (FOFL) and the maximum permissible FABC (Dorn et al. 2015).
Following a historical peak in 1984, spawning stock biomass (SSB) remained at relatively high levels till 1994 (the second highest value of the time series). In the following decade, the stock biomass showed a decreasing trend, dropping to below (B40%) in 1998 and reaching a minimum in 2003, at 21% of unfished stock size and just above the limit reference point (Blim). From 2003 to 2013, the stock started rebuilding and SSB was estimated at above B40% in 2012 and 2013 (the highest value since the mid-90s). The latest model estimates indicate SSB has been dropping since and is now below the target reference point (B40%); the stock size is projected to start increasing again in the upcoming years as the strong 2012 year-class starts maturing (Dorn et al. 2015).
Fishing mortality has been increasing since 2009 but remains below the fishing mortality reference points - (FOFL) and the maximum permissible FABC (Dorn et al., 2014). In terms of catch, the fishery started as a foreign fishery in the early 1970s, and developed rapidly in the late 70s and early 80s, with a peak in catches in 1984. After 1985, catches dropped considerably and have been fluctuating between 50 and 140 thousand tonnes since 1986 (Dorn et al. 2015).
The Council consistently sets catch limits within the bounds advised by scientists. For 2015, the North Pacific Fishery management Council set a TAC for Gulf of Alaska pollock at 191,309 t, which includes the pollock Guideline Harvest Level (GHL) for Prince William Sound (Dorn et al. 2015).
The current harvest strategy includes multiple precautionary measures, including a linear reduction of fishing mortality rate is reduced when biomass drops below B40% and a ban to directed fishing (F=0) on Pollock, if biomass drops below B20%. Spatial and temporal TAC apportionments are also in place to reduce potential impacts on Stellar sea lions and other important pollock predators (Dorn et al. 2015; NPFMC 2015).
Not applicable. The biomass is well above critical levels and the current TAC is estimated to yield a “negligible” chance of pushing stock below the lower limit of B20% in the next years (Dorn et al. 2015).
Pollock catches in the Gulf of Alaska in general have been well controlled. In the last decade (with the exception of 2003 and 2009), catches were always below the set TAC (Dorn et al. 2015).
The primary protected species of concern in the Gulf of Alaska (GOA) pollock fishery is Alaska’s western population of Steller sea lion (SSL), which is listed as Endangered. Between 2002 and 2006 lethal takes of SSL averaged 4/year (Rice et al. 2010). There has been increased research on the potential role of the pollock fishery on the dynamics of western stock of SSL. In light of no scientific evidence of negative effects of the pollock fishery on the dynamics of SSL, it has been concluded in the latest MSC assessment report that the fishery is “unlikely to create unacceptable impacts” on this species (Rice et al. 2012).
To protect prey supplies for the endangered western stock of Steller sea lions, the harvest policy bans directed pollock fishing if biomass drops below 20% of its estimated unfished level. Since 1992, spatial and temporal TAC apportionments are also in place to reduce potential impacts on Steller sea lions and other important predators of Alaska pollock (Dorn et al. 2015; NPFMC 2015). A number of other management actions such as no-entry zones and closed trawling areas around rookeries, and spatial and temporal allocation of GOA pollock, are also used to minimize impacts on protected species (Dorn et al. 2015; NMFS 2015).
In terms of other groups such as seabirds, the trawl fisheries for pollock (and other species) account only for a small fraction of the total seabird bycatch in the Alaska region. The most affected seabirds by the pelagic trawl fisheries are Northern fulmars Fulmarus glacialis (IUCN red list: "Least Concern"; BirdLife International 2015), but bycatch rates are considered very low; around 120 seabirds, all Northern fulmars, were estimated (based on observer reports) to be captured as bycatch on the pelagic and demersal groundfish trawls in the GOA during 2010 – an estimated 0.3% mortality due to this fishery component (AFSC 2011; Bowen et al. 2016).
Bycatch in the Gulf of Alaska (GOA) directed pollock fishery is considered to be low. According to the latest stock assessment, “on average about 95% of the catch by weight of FMP species consisted of Pollock” (Dorn et al. 2015). Retained bycatch is relatively similar to the observed in previous years, with main retained bycatch species being: arrowtooth flounder, Pacific cod, Pacific ocean perch, flathead sole, shallow-water flatfish, and squid. The most common non-target species are still Eulachon, other osmerids, miscellaneous fish, and jellyfish (Dorn et al. 2015).
Among the prohibited species, Chinook salmon is the most incidentally caught in the GOA pollock fishery. An increase in Chinook salmon bycatch in 2010 led managers to adopt several measures to reduce salmon bycatch, including a bycatch limit of 25,000 salmon in the directed pollock fishery (NOAA 2012b; Dorn et al. 2015). Concerns over the impact of the pollock fishery on the Chinook salmon stocks have also led to the creation of three conditions during the previous first MSC re-assessment (Rice et al. 2010). These conditions were then closed, as enough information was considered to exist to evaluate that both direct and indirect impacts of the fishery and impacts were considered to be within acceptable limits (Rice et al. 2013). Chinook salmon bycatch has since been well below the peak observed in 2010, at about less than half the observed that year (Dorn et al. 2015). The fishery was just re-certified (second MSC re-assessment) and the MSC Public Certification Report noted that Chinook salmon bycatch estimates have been well below the management cap of 25,000 fish, and that "there is also no evidence to indicate that the groundfish fisheries’ take of Chinook salmon is causing escapement failures in Alaska rivers" (Bowen et al. 2016).
Halibut bycatch has been also of concern for other groundfish fisheries, but in the specific pollock directed fishery the halibut bycatch levels are relatively small compared to other groundfish fisheries. Besides the specific bycatch limits, a number of additional measure such as closed areas and seasons and specific incentives are in place to minimize bycatch of prohibited species in the GOA groundfish fisheries (NPFMC 2012, 2015; NPFMC undated).
Bottom trawling is known to cause severe disturbance to substrate and associated biota (e.g. corals, sea sponges and other epibenthic organisms). However, most of the fishery is conducted by midwater trawls, which contribute to about 90% of total pollock catch in the Gulf of Alaska (Dorn et al. 2015). There are also a number of Habitat Areas of Particular Concern (HAPC), which are closed to bottom trawling year-round and designated specifically to protect vulnerable benthic habitats (NPFMC 2015; Zador 2015). Impacts on the seabed are thus considered to be mitigated (Rice et al. 2010; Bowen et al. 2016). Research to identify and designate additional HAPCs in the Gulf of Alaska (GOA) region is an ongoing management objective (NPFMC 2015).
Bottom trawling is prohibited year-round in large areas of the Gulf of Alaska and Southeast Alaska. Fishing effort may be restricted, both spatially and temporarily, around areas important to marine mammals, and other protected and prohibited species. Additional closures restrict scallop dredging and other fishing gears in parts of this region. A number of coral Habitat Areas of Particular Concern (HAPC) has been established, and the designation of other habitats of special importance, such as known areas of skate-egg concentrations, is under consideration (NPFMC/NMFS 2012; NPFMC 2015). A map of current marine protected areas in the US North Pacific by species may be found online here.