Last updated on 17 July 2008
Virtually 100% of the landed catch in the troll fishery is reported with a fish ticket reporting system and compliance is complete and monitored. However an estimated 14% of reported catch in the Southeast Alaska troll fishery (which accounts for 40% of Alaskan Chinook salmon harvest) is lost to incidental mortality, including sublegal fish (shakers) killed in the regular retention fishery and both legal and sublegal fish killed in the non-retention (coho) fishery. Programs to monitor incidental mortality rates are inconsistent.
Hatchery stocks and many wild stocks coastwide are coded-wire tagged. Many of these programs have been on-going since the mid-1970’s and provide a wealth of information on distribution of various stocks in coastwide fisheries. The CTC currently measures the exploitation rate on 48 tagged stocks and abundance of 31 indicator stocks in the Chinook Model. Genetic studies have also been conducted to confirm the stock composition of Alaska troll catches.
A variety of methods are used to count escapements for the over 70 Alaskan Chinook salmon stocks managed to achieve escapement goals. There are continuing efforts to improve on escapement monitoring methods. The escapements of all major Chinook salmon stocks in the Southeast Alaska troll fishery are measured and documented in annual reports of the Chinook Technical Committee (CTC) of the Pacific Salmon Commission. This fishery is managed under the auspices of the Pacific Salmon Treaty. The CTC documents the escapements of 50 stocks outside of Alaska and 11 Transboundary and Southeast Alaska Stocks.
Last updated on 9 March 2016
Harvest is actively and accurately monitored through the fish ticket system. The reporting of subsistence harvests is likely less accurate than for other components of the fishery (SCS 2007). Estimated numbers of AYK area Chinook salmon taken in the pollock fishery are available, although there is limited stock specific data (SCS 2007).
Escapements for most Arctic-Yukon-Kuskokwim stocks are measured through the use of aerial surveys, while a relatively small number are fully enumerated through the use or weirs, counting towers and sonar detection (Munro and Volk 2012). A large proportion of stocks have some sort of escapement monitoring, though measurements are not carried out in every year for every system, particularly those relying on aerial surveys.Quality of aerial surveys can also vary considerably depending on environmental conditions. In their 2007 assessment of the Alaska salmon fishery, the Marine Stewardship Council noted that escapement monitoring and methods to estimate escapement were improving in the Kuskokwim and Norton Sound Management Areas (SCS 2007).
Last updated on 17 July 2008
Alaska Department of Fish & Game (ADF&G) managers may set two types of target reference points: Biological Escapement Goals and Sustainable Escapement Goals. Biological Escapement Goals are generally based on a more extensive and complex analysis of stock performance in light of escapement observations and are considered to represent the escapement with the greatest potential for maximum sustainable yield. In contrast, Sustainable Escapement Goals represent an escapement level that is known to provide for sustained yield over a 5- to 10-year period.
Regional escapement goal review occurs once every three years and ADF&G recommendations for stock-specific goals of either type go before the Board of Fisheries afterward for consideration and approval. The Board of Fisheries may substitute its own Optimum Escapement Goal for either a Sustainable Escapement Goal or a Biological Escapement Goal if the Board finds a need to do so to meet competing objectives.
The Chinook Technical Committee (CTC) also reviews and formally accepts escapement goals for those stocks harvested in the Southeast troll fishery. There is bilateral (US and Canadian) participation in CTC escapement goal approval proceedings.
Chinook and sockeye stocks account for over 50% of the 300 escapement goals currently in use in Alaska. All Southeast Alaska Chinook escapement goals are BEGs, having undergone extensive monitoring and analysis, including through the CTC approval process (all Southeast Alaska goals have been reviewed by the CTC). In contrast, in the Arctic-Yukon-Kuskokwim (AYK) fishery, only three of 26 stocks have BEGs, and the rest of the stocks are managed to achieve SEGs. Reductions to 13 out of 25 existing Yukon River and Kuskokwim Management Area escapement goals have occurred at least once, and several additional Kuskokwim River goals are likely to be lowered during the next review. In one case, goals were lowered twice (Middle Fork Goodnews River). Escapement goal reductions were associated with missed management objectives for the East Fork Andreafsky River stock (Yukon Management Area) and the Middle Fork Goodnews River stock (Kuskokwim Management Area).
There are instances where well-intentioned managers have set escapement goals too high, and after careful analysis conclude that by lowering the goals there will be a better balance between future needs (conservation) and the immediate benefits to the fishery participants (yield)—which is the balance managers are attempting in a sustained fishery. However, there can also be instances when escapement goals are lowered without a careful consideration of these tradeoffs.
Last updated on 17 Jul 2008
The greatest cause for concern with respect to performance against reference points lies with the Arctic-Yukon-Kuskokwim (AYK) region, where depressed stock status has been noted for the last decade. Economic ramifications of associated fishery closures were severe to the extent that both areas were among three Alaska salmon fisheries granted federal disaster status by the United States Department of Commerce in 2012.
Four Chinook salmon stocks in the AYK region failed to achieve escapement goals in eight or more of the recent 15 years, or at least five of the past seven years. Among these are the Kwiniuk River and Shaktoolik River stocks in the Norton Sound Management Area, which failed both the 15-year and 7-year benchmarks on the basis of 1997-2011 data. The Shaktoolik River goal has been recommended for elimination in 2013. While the Shaktoolik River Chinook salmon stock is a stock of yield concern, the Kwiniuk River Chinook salmon stock has not been recommended as a stock of concern. In addition, roughly 25% stocks region-wide are noted as lacking escapement goals.
The other district fishery where federal disaster status was granted in 2012 is that of Upper Cook Inlet. Six stocks in that district are currently exhibiting chronic inability to meet escapement and/or yield targets.
As for Alaska-origin stocks harvested in the Southeast Alaska troll fishery, of the 11 Southeast Alaska escapement systems, 10 had decreasing trends in escapement from 1999-2011, two of which (Stikine River and Situk River) exhibited annual decreases over 5%. The Situk is the most northern Chinook salmon stock in Southeast Alaska and very few Situk fish are caught in the troll fishery. The Stikine River is managed under provisions of the Pacific Salmon Treaty Transboundary Agreement and few Chinook salmon from this system are caught in the troll fishery (an average of 4% of the total run). Although most river systems in Southeast Alaska are currently exhibiting decreasing escapements, only 9% of the time do escapements fall below escapement goal ranges.
Last updated on 9 March 2016
Chinook salmon are currently managed to achieve 26 escapement goals throughout the AYK Region (Munro and Volk 2012).Three are classified as “Biological Escapement Goals” while the rest are “Sustainable Escapement Goals” as defined by the Alaska Department of Fish and Game.All are expressed as ranges. Fourteen of these goals are for stocks located in the Kuskokwim Management Area, five are for Norton Sound Management Area stocks, six are for Alaskan stocks in the Yukon Management Area and one allocates for agreed upon passage of Canadian bound Yukon River stocks. The latter is directed by the U.S. – Canada Yukon River salmon treaty (Estensen et al. 2010). Total abundance of Chinook salmon in each of the region’s areas is difficult to quantify due to the vastness and remoteness of spawning area and the mixed stock nature of the fisheries (Brazil et al. 2010; Estensen et al. 2010; Menard et al. 2010).Most of the region’s escapement goals reflect measures of relative rather than total spawning abundance.Among the AYK stocks that are enumerated for total escapement, the Kogrukluk and Kwethluk River stocks of the Kuskowkim River drainage have the largest escapement goals with ranges of 5,300 – 14,000 and 6,000 – 11,000 fish respectively. There are larger and more numerous stocks present in both the Yukon and Kuskokwim Management Areas than the Norton Sound Management Area, with estimates of total returns for the Kuskokwim River exceeding those for the Yukon River in most years during the last decade (ADF&G 2012f; Bue et al. 2012).
Multiple stocks in the AYK region have had lowered escapement goals in association with missed management objectives in the previous 10 years, and in one case goals were lowered twice (Middle Fork Goodnews River).Escapement goal reductions in association with failure to achieve escapement goals and lack of escapement goals for a number of stocks contributed to an overall score of 6.5 for the Arctic-Yukon-Kuskokwm Chinook salmon fishery (Table 2).
Last updated on 09 Mar 2016
A score of “6” on Sub-Criterion 4.1 (Escapement) was largely due to missed escapement goals for four stocks occurring in excess of seven out of 15 years and/or five out of ten consecutive years for several stocks. Additionally, eight stocks that lack both escapement goals and have missing or poor data to estimate escapement trends were awarded a score of ‘6’. The overall sub-criterion score represents the 25th percentile per- stock performances against the scoring definitions for escapement levels (Table 3). As the lower score of the two nested sub-criteria, this score is also retained as the overall stock status criterion score.
Four stocks in the Arctic-Yukon-Kuskokwim fishery received scores of “6” due to eight or more failures in the last 15 years and/or five failures in the last seven years to achieve escapement goal lower bounds. The Kwiniuk River failed both benchmarks and the East Fork Andreafsky was below the lower bound nine times between 1997 and 2011 (Figures 1 and 2).
Figure 1: East Fork Andreafsky River (Yukon Management Area) Chinook salmon escapement estimates and escapement goal lower bounds: 1992-2012 (ADF&G 2004; Volk et al 2009; ADF&G 2011c; ADF&G 2012f; Estensen et al. 2012; Munro and Volk 2012). The two escapement series presented are comprised of weir counts, aimed at complete enumeration of total annual spawning abundance, and standardized peak aerial survey counts that capture indices of annual abundance. The 2012 weir escapement estimate is preliminary, and aerial index estimates are only available through 2010. The sustainable escapement goal (SEG) range established in 2005 reduced the lower benchmark established in 1992 (ADF&G 2004) and the 2005 SEG was altered in 2010 from an aerial index escapement goal to a weir based goal (Volk et al. 2009). Weir based escapement estimates are a more reliable and complete estimate of abundance; however, because the escapement units of measure changed with the 2010 SEG, it is not clear whether the new SEG is indicative of a lower, higher or status quo benchmark relative to the previous goal. While escapement estimates were below the Andreafsky River goal a total on nine times over a 15 year period (1997-2009), and aerial escapement estimates cleared the lower bound of the 2005 SEG only once between 2006 and 2009, the weir-based SEG was achieved in both 2010 and 2011, and was likely met in 2012. It should be noted that aerial surveys in years 1992, 1994, 2003, 2006, 2008 and 2009 were documented as being poor quality and escapements were likely underestimated in those years. Variable quality and consistency of aerial surveys are not atypical in many areas of Alaska due to frequent poor weather and unfavorable counting conditions.
Figure 2: Kwiniuk River (Norton Sound Management Area) Chinook salmon escapement estimates vs. the escapement goal lower bound, 1992-2012 (ADF&G 2004; Volk et al 2009; Menard et al 2012; Munro and Volk 2012; ADF&G 2012a). Since the Kwiniuk River Chinook salmon escapement goal was established in 2009, this stock has achieved the lower bound of the goal only four times and escapements have been below the lower bound in six out of the past seven years. The Kwiniuk River stock is not among the Norton Sound stocks that have been designated stocks of concern by the Alaska Department of Fish and Game (ADF&G 2012d); there has been no directed commercial harvest of Chinook salmon in Norton Sound since 2004.
Last updated on 17 July 2008
Stock status is assessed based on multi-year escapement trends and performance against escapement goals (see synopsis under reference point section and more detailed information under district profiles). There are a number of stocks of regulatory concern in the AYK, Cook Inlet, and Kodiak districts. See "Recovery Plan" section for more detail.
Last updated on 17 Jul 2008
Chinook harvests by the commercial fishery in Alaska have not varied much over the past 90 years, with the last ten decadal averages ranging from about 600,000 to 800,000 Chinook salmon. On the other hand, significant use of Chinook salmon in Alaska occurs in sport and subsistence fisheries and those harvests have increased substantially. In several areas of Alaska, Chinook harvests in the commercial fishery are restricted to provide for other users. Harvest declines in the last few years related to fishery curtailment in response to depressed stock status are visible in Figure 2.
The FishSource method examines 15-year trends in wild stock harvest at the district fishery scale. Meaningful (≥5%) annual declines in wild harvest are visible in the Arctic Yukon Kuskokwim fishery and in the Copper River fishery.
Last updated on 9 March 2016
Stock status is assessed based on multi-year escapement trends and performance against escapement goals (see synopsis under reference point section). Alaska's Policy for the Managment of Sustainable Salmon Fisheries guides designation of concern status for poorly performing fish stocks. In the AYK, Yukon River and Norton Sound (districts 4 & 5) Chinook salmon stocks are formally designated stocks of yield concern, the lowest of three posible levels of concern (ADF&G 2012d). See "Recovery Plan" section for more detail.
Last updated on 09 Mar 2016
A score of “8” was awarded on Sub-Criterion 4.2 due an overall decreasing wild yield trend for Arctic-Yukon-Kuskokwim salmon over the past 15 years (1997-2011). Using the method of Geiger and Zhang (2002), wild harvest in the Arctic-Yukon Kuskokwim Chinook salmon fishery decreased at an average annual rate of 6%. Declining catch trends for Alaska Chinook salmon are not unique to the Arctic-Yukon-Kuskokwim Region; rates are roughly the same as for Copper River Chinook salmon in Central Alaska, and just 2% more than for Yakutat Chinook salmon near Southeast Alaska (Figure 5). The rate is about 5% different than for Cook Inlet in Central Alaska, where Chinook salmon stocks showed a slight average increase in harvest. Over the past decade, Arctic-Yukon-Kuskokwim area Chinook salmon stocks have been the subject of moderate to severe commercial fishery restrictions to allow for escapement and subsistence priorities.
Figure 3: Comparison of wild Chinook salmon harvest trends between the Arctic-Yukon-Kuskokwim Region and the Copper River, Yakutat and Cook Inlet Management Areas using the method of Geiger and Zhang (2002). Years in sequence: 1997-2011. Arctic-Yukon-Kuskokwim Region data is taken from ADF&G 2011 season summaries, Brazil et al 2011 (p. 67), Estensen et al 2012 (p. 150) and Menard et al 2012 (p. 106). Copper River harvest data is taken from Botz et al. (2012, Appendix A4) and the ADF&G Prince William Sound post season summary (ADF&G 2012j). Yakutat harvest data is taken from the annual Yakutat set net management report series (ADF&G Various Authors, 2007-2012, Table E3). Cook Inlet wild harvest data is derived from the Alaska Enhancement Annual Report Series for 1997-2011 (1998-2012, Table 5).
The overall score for the Stock Status Criterion 4 is “6” reflecting the lower of the two sub-criterion scores which was awarded to sub-criterion 4.1.