Email one from Leon Shaul

I did e-mail several of the DFO guys last July 9 predicting a Babine coho escapement of 15,000 or more. It seemed pretty brash at the time given that it would be the 3rd largest escapement in 52 years (surpassed only by 1962 and 1965) and that the total Babine run dropped by half between 1978 and 1981 (coincident with the peak in sockeye enhancement) to a lower though stable trend for the past 20 years (5,619 was the largest escapement estimate since 1978). Of course no fishery in B.C. helped, which I factored in by adding 66% to account for a roughly 40% average Canadian harvest rate. The fence was pulled on Nov. 23 due to ice buildup at a cumulative count of 14,907 coho with about 50-100 still passing daily.

We have three inseason indicators in Alaska that track pretty well with north B.C. coast coho in general and specifically with upper Skeena stocks. I've sent all the data sets to the Rupert staff and Blair Holtby and can forward them if you are interested in the nuts and bolts. Northern B.C. mainland coast coho are relatively distinct from Alaskan stocks early in the season (up to mid-August) in fisheries in Dixon Entrance. Local Alaskan stocks in that area are highly migratory and don't arrive in large numbers until late August and September. The best general abundance indicator for Canadian coho in that area is early CPUE (mid-June to mid-July) in the Tree Point gillnet fishery. Catch rates for coho are very low at that time (average 2 to 3 per boat-day) but effort has been historically so stable (80-100 boats fishing about 3.5 days per week) that it serves as an excellent test fishery on the pool of primarily Canadian coho that mill in Dixon Entrance in June and July. Hopefully, whatever means are used to maintain compliance with the treaty for Nass sockeye don't compromise Tree Point's value as a test fishery for Canadian coho abundance. The other fishery that samples the early pool of coho in Dixon Entrance is the troll fishery near the boundary from Duke Island to Cape Muzon. Catch rates in that fishery are the current triggers for Alaskan management action for Canadian coho under the treaty. However, troll effort in that area has dwindled and is typically low while statistics are gathered through dockside sampling rather than a 100% sample of effort from fish tickets like at Tree Point.

The third method we use that is much more stock-specific and fishery-general is rapid processing of inseason coded-wire tag data. Because our troll fishery operates at a relatively stable exploitation rate early in the season, cumulation of tags from specific stocks (including upper Skeena tags from Toboggan and Babine) in the region-wide troll catch can be used to project total marine survival for specific stocks. For Alaskan coho stocks, marine survival has accounted for about 60% of the variation in adult abundance while smolt production (escapement and freshwater factors) has accounted for about 40%. So you can see that having a good estimate of marine survival is valuable. It is even more valuable for cases like Toboggan Creek where a real-time estimate of wild smolt production the previous spring is also available. In 1999, all of these indicators pointed to exceptional production from Skeena coho stocks from the very beginning. The fact that the general fishery indicators work so well for upper Skeena coho suggests that there is a high degree of synchrony between upper Skeena stocks and the more abundant mainland coastal stocks in northern B.C. Despite the fact that upper Skeena coho inhabitat an interior environment (and that concerns have been expressed about spawning levels), they still seem to be responding largely to the same influences as coho on the northern mainland coast in general (parent escapements at Babine and Toboggan that produced the large 1999 run were well below the recent average).

A couple of additional elements are needed to develop a first-class management program for northern B.C. coho stocks, the most important of which is establishment of biological escapement goals. Appropriate procedures and realistic goals is an area where we currently appear to differ substantially with DFO stock assessment staff. Observed results through 2004 from the extreme 1997 (low) and 1999 (high) escapements should help substantially in narrowing an appropriate escapement range. The recent DFO policy paper is encouraging in that it proposes a relatistic approach to defining stocks and escapement targets, although nothing specific is included for north coast coho. Second, development of similar inseason measures in Canadian fisheries would strengthen inseason assessments. Historically, relatively little weight has been put on performance of the north coast troll fishery for inseason coho management because of valid concerns that effort and species targeting were highly variable, while freezer trollers were not sampled for tags. However, despite all of that, the total season Canadian north coast troll catch tracked amazingly closely with our reconstructions of upper Skeena coho abundance. Closer monitoring and sampling of the troll fleet which is projected to be more stable in the future (combined with inseason monitoring of sport fishery performance where possible) could be very useful. With biological goals and accurate inseason stock assessment, we should at a very minimum be able to determine when broad, early fishery restrictions are needed that extend into Alaska as well as to identify situations like 1999 when there is a large surplus available for terminal harvest (above ocean fleet capacity) that might be taken from directed estuarine fisheries upriver to sport and subsistence fisheries in locations like Toboggan Creek (where the 1999 escapement of 9,400 coho was several times either average or optimum for MSY). This inseason management approach has worked well for our coho stocks and fisheries in Southeast Alaska.