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  Evaluation of the 2003 and 2004 Chinook Mark-Selective Fisheries, Marine Areas 5 and 6 PDF Format - [203KB]
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Evaluation
of the 2003 and 2004 Chinook Executive Summary
During the summers of 2003 and 2004, a mark-selective
Chinook salmon Oncorhynchus tshawytscha ("Chinook") recreational
fishery was implemented in waters of the Strait of Juan de Fuca with the
objectives of: 1) increasing meaningful recreational opportunity while
meeting conservation goals for Puget Sound Chinook salmon defined by the
Puget Sound Chinook Harvest Management Plan; and 2) collecting information
necessary to enable evaluation and planning of future potential Chinook
mark-selective fisheries. The 2003 Chinook Mark-Selective Fishery started
on July 5, 2003 and ran continuously through August 3, 2003 in Marine
Area 5 and the western portion of Marine Area 6. The 2004 Chinook Mark-Selective
Fishery started on July 1, 2004 and ran continuously through August 8,
2004 in the same areas. Marine Areas 5 and 6 (hereafter: Areas 5 and 6)
are located in Washington waters of the Strait of Juan de Fuca, running
from the Sekiu River easterly to Low Point, and from Low Point to approximately
Whidbey Island, respectively.
Anglers were allowed to retain two marked (adipose fin
clipped) Chinook > 22" (56 cm) as part of their daily limit, and
were required to immediately release, unharmed, any unmarked Chinook caught.
During the Chinook Mark-Selective Fishery anglers were also allowed to
retain pink O. gorbuscha, sockeye O. nerka, and marked hatchery
coho O. kisutch salmon.
This report focuses on evaluating the two years of the
pilot Chinook Mark-Selective Fishery. Some general comparisons to the
2001 and 2002 non-selective Chinook fisheries in Area 5 are presented
for the purpose of evaluating success of the Mark-Selective Fishery with
respect to the general objective of increasing recreational opportunity
compared to non-selective alternatives. We also compared alternative methods
for determining mark rates and encounters with sublegal-size fish. Expected
impacts of the mark-selective fishery from the Fishery Regulation Assessment
Model (FRAM) pre-season planning tool are compared with the measured outcomes.
Finally, recommendations for applications to future mark-selective fisheries
are also presented.
Angler opportunity increased three ways due to this selective
fishery. First, recreational Chinook fishing opportunity was expanded
from 10-day and 5-day seasons in 2001 and 2002, respectively, to 30-day
and 39-day seasons in 2003 and 2004, respectively. Second, anglers harvested
nearly twice as many Chinook in 2003 and 2004 than they did in 2001 and
2002. Third, a portion of Area 6 was open for Chinook retention during
the summer compared to all of Area 6 being closed for Chinook retention
during the summer in 2001 and 2002. Increases in effort were modest compared
to 2001 but approximately double the effort levels observed in 2002. Other
than simply having more days of fishing open for anglers, the increased
opportunity is attributable to a relatively high mark rate of approximately
45% for legal-size Chinook and reasonably good catch rates (approximately
one retained Chinook for every 7-8 anglers).
Success of the Pilot Project is also indicated by the
results of WDFW public education and Enforcement activities. Information
collected by the Enforcement program and from creel surveys over these
two seasons indicated consistently high compliance with not retaining
wild (unmarked) Chinook during the fishery.
Since the impacts on Chinook stocks are based on assumptions
about the overall level of angler encounters with unmarked Chinook, we
estimated the number of unmarked Chinook encounters and compared those
estimates with the pre-season FRAM expectations. Except for the unmarked
sublegal-size fish in 2003, the estimates of encounters of unmarked legal-size
Chinook and unmarked sublegal-size Chinook were below predicted levels.
We tested the assumption that test boat catches were representative
of angler catches and found that for marked legal-size Chinook they were
similar, suggesting they were probably similar for unmarked fish and sublegal-size
fish as well. In strata with sufficient sample sizes for comparison, estimates
of mark rates and ratios of legal/sublegal-size derived from test boat
data and Voluntary Trip Report (VTR) information were very similar. We
recommend a more rigorously structured VTR program that includes training
and certification by WDFW staff. Based on our findings, we recommend that
test fishing or VTR data, or a combination of both, be used to provide
information on both mark rates and legal/sublegal-size categories in future
Chinook Mark-Selective Fisheries.
In conclusion, this mark-selective Chinook fishery was
successful at many levels. First, we met our two primary objectives of
increasing opportunity and collecting the information necessary to evaluate
pertinent biological impacts, including impacts to coded wire tagged Chinook.
Second, we have likely captured the magnitude of this mark-selective fishery
in terms of effort and harvest, and that magnitude was similar to pre-season
expectations. Third, a level of enforcement was achieved to ensure that
angler compliance with fishing regulations was high. Fourth, we were able
to evaluate two different methods of obtaining mark rates and legal to
sublegal ratios, and they were very similar when sample sizes were sufficient.
And finally, although dependent upon factors unique to the proposed area,
season, stock composition, and management logistics, our findings have
provided a solid foundation for building successful mark-selective Chinook
fisheries in the future.
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