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View a chronology of the annual Puget Sound chum salmon management activities conducted by state and tribal managers |
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In Puget Sound, chum salmon
are cooperatively managed by WDFW and the Puget Sound Treaty Indian Tribes.
The guiding principles for salmon management are contained in the Puget
Sound Salmon Management Plan, adopted by the co-managers in 1985.
Several additional processes influence chum salmon management, most notably
the North of Falcon planning sessions, and the U. S./Canada Treaty. The
following is a thumbnail sketch of some of the elements that make up an
extremely complicated management process.
Fishing seasons for chum salmon
are designed to harvest fish that are over and above the numbers needed
for spawning. Those fish that successfully survive all sources of mortality
(e.g., fisheries and predation) and arrive on the spawning grounds represent
the escapement number for each stock. For each stock or run, an escapement
objective (goal) has been established to guide fishery managers in annually
planning and conducting fisheries to harvest any fish surplus to escapement
needs.
In the late 1970s, Puget Sound
chum salmon escapement estimation methodologies were upgraded using the
data from several major tagging studies and counts from more intensive
spawning ground surveys. Chum salmon escapement numbers were recalculated
for the period 1968 through 1977, and new escapement goals were developed
for Puget Sound streams.
At the time, it was recognized
that chum salmon run-sizes and escapements were different on even- and
odd-numbered years (see figure in the Introduction
to Puget Sound Chum Salmon). The odd-numbered years had significantly
lower run-sizes and escapements than the even-years, apparently because
of negative competitive interactions with odd-year pink salmon runs. Separate
chum salmon escapement goals were developed for even- and odd-year runs
(see Table below), based on past escapement levels that had successfully
produced large returns.
These escapement goals have
generally been used for chum salmon management since 1979, however, some
individual stock goals have been refined as new data have become available.
The substantial increases in Puget Sound chum salmon production over the
last two decades indicates that the established escapement goals have
been effective for successfully managing chum salmon.
| Region |
Run
Timing |
| Summer |
Fall |
Winter |
| Even
Yrs |
Odd
Yrs |
Even
Yrs |
Odd
Yrs |
Even
Yrs |
Odd
Yrs |
| North
Puget Sound |
none |
none |
198,900 |
84,100 |
none |
none |
| South
Puget Sound |
32,000 |
9,300 |
80,200 |
64,350 |
30,000 |
20,100 |
| Hood
Canal |
See note 1 |
See note 1 |
54,250 |
39,900 |
none |
none |
| Strait
of Juan de Fuca |
See note 1 |
See note 1 |
3,600 |
3,600 |
none |
none |
| 1 Hood Canal and Strait of Juan de Fuca summer chum are managed
for recovery, with the objective of escaping 90% or more of
returning fish to spawning streams. |
Pre-season chum salmon forecasts
are designed to predict the numbers of adult chum salmon returning to
Puget Sound each year. There are three distinctly timed runs of chum salmon
in Washington (summer, fall and winter), and separate forecasts are made
for each. These fish are bound for various streams throughout the Puget
Sound region. Washington's Puget Sound chum salmon stocks are grouped
into major management areas for pre-season forecasting: Strait of Juan
de Fuca summer and fall run; North Puget Sound fall run; upper South Puget
Sound summer, fall and winter run; and the Hood Canal summer and fall
run.
The pre-season forecasts attempt
to predict the numbers of fish that will return to the region. The purpose
of making a runsize forecast is to provide guidelines for fisheries management
that will help to ensure an adequate escapement of adult spawners to the
region. Pre-season forecasts are one of several tools used for planning
the management of upcoming fisheries, and to determine allowable fishing
rates during the early weeks of the chum return period. As the run progresses,
the pre-season forecasts are replaced by in-season forecasts which are
based on actual catch rate information.
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Forecasts predict the numbers
of 3-, 4-, and 5-year old adult returning chum salmon. The forecast is
a combination of a recruit per spawner (R/S) prediction and a sibling
prediction. The recruit per spawner forecast is based on the average number
of fish of the three age classes that have returned from their parent
spawners. The age compositions used in the forecast are calculated by
averaging past years' age data derived from scale samples collected from
chum caught in various fisheries. The R/S method has historically overestimated
adult returns (by as much as 35%). The sibling approach uses the number
of adults that have returned in the two most recent years from the same
brood (parentage) as the fish being forecasted to return. For example,
a return of age-3 chum can be used to predict the return of age-4 fish
from the same parent spawning, using average age composition information.
The sibling method tends to be a bit more accurate than the R/S model.
Because each approach uses different information about future run size,
an average of the two methods is used to make the final runsize prediction
for Puget Sound chum.
The 2000 Puget Sound chum salmon
forecast for fall timed chum is for a return of 1.2 million fish, and
the winter timed chum salmon forecast will be available in the near future.
Sport, tribal and commercial fisheries for 2000 will be designed to harvest
any fall and winter chum salmon in excess of escapement needs based on
the pre-season and in-season forecasts.
The recreational and commercial
salmon fishing seasons for chum are set in the same manner as other salmon
fisheries. The basic method is to review
the pre-season forecast of abundance and then design fisheries that open
in areas and during times when healthy stock predominate and weak stocks
are relatively unaffected. Hood Canal Summer Chum are of special concern
because of their threatened status under the Endangered Species Act. Consequently,
fishing for chum salmon is prohibited in Hood Canal (Catch Record Card
Area 12) and Admiralty Inlet (Catch Record Card Area 9) through the summer
and early fall.
The fall and winter chum runs
in Puget Sound are very healthy. The run size of fall chum is monitored
in-season by test fisheries in Area 20 south of Vancouver Island as the
fish pass through the Strait of Juan de Fuca and during October in Puget
Sound in the vicinity of Apple Cove Point. If these test fisheries indicate
the run is either much larger or much smaller than predicted in the pre-season
forecast then commercial seasons are adjusted accordingly. Because the
recreational harvest of chum is still relatively small, in-season adjustments
to recreational fishing seasons focused on chum are rare.
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