Fraser River Sockeye Fisheries and Fisheries Management - Cohen ...

Table 28 Average age composition of sockeye stocks in Bristol Bay, Alaska from1991-2010. Values represent the average percent of individuals that belongto each freshwater age (FA) and ocean age (OA) combination.FA.OA Alagnak Egegik Igushik Kvichak Naknek Nushagak Togiak Ugashik Wood Average1.3 47% 18% 71% 16% 53% 63% 66% 30% 43% 33%2.2 9% 41% 3% 50% 11% 1% 5% 25% 3% 27%1.2 38% 9% 21% 25% 16% 12% 19% 27% 50% 23%2.3 5% 30% 4% 9% 18% 2% 8% 17% 2% 15%0.3 0% 0% 0% 0% 0% 14% 1% 0% 0% 1%1.4 1% 0% 0% 0% 1% 6% 1% 0% 0% 1%2.1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%3.2 0% 1% 0% 0% 0% 0% 0% 0% 0% 0%0.4 0% 0% 0% 0% 0% 2% 0% 0% 0% 0%0.2 0% 0% 0% 0% 0% 1% 0% 0% 0% 0%Inside test fishingADF&G operates gillnet test fishing from skiffs above commercial fishing boundariesbut below escapement enumeration projects on the Ugashik, Egegik, Kvichak, andIgushik rivers (Igushik has not operated since the early 2000s). These projects weredeveloped because there is a two-day lag or better from the district fishing boundary tothe enumeration projects (Minard and Meacham 1987). Somewhat more quantitativethan district test fishing, inside test fishing provide managers with tide-by-tide indicationof fish moving above the fishing district. The estimation method involves finding thetravel time (measured discretely in days) by which to lag the daily test fish index tomaximize the correlation with daily counts at the upstream enumeration project (countingtower). Once this is done, one can determine the fish per index (FPI) that each test fishindex point represents and use this as a multiplier for the most recent days’ test fishresults to estimate the current “in-river fish” that are between the fishing district andescapement enumeration projects.Aerial surveysAt key times during the season when uncertainty about the run strength is at its greatest,AMBs will fly aerial surveys of the rivers between their fishing districts and the towersites to augment or verify the estimates obtained from inside test fishing. Surveyingdifferent stages of fishery openings can also provide the AMB with an indication of how157