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Coastal
Dungeness Crab Summer Fishery Management Plan
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Westport
Crab Fleet |
Purpose
The purpose
of the Coastal Dungeness Crab Summer Fishery Management Plan is
to guide Washington Department of Fish and Wildlife (WDFW) staff,
and provide predictability to the coastal crab industry, on the
implementation of specific management measures to protect soft-shelled
crab.
Background
The Washington
coastal Dungeness crab season is open from December 1 through
September 15 of the following year. The fishery is closed provide
protection for soft-shelled crab during the peak male recruitment
molt period when they are more susceptible to handling mortality
(see Appendix A). However, historical shell condition data shows
that peak molt timing varies annually, particularly in Northern
Oregon and Washington, and the primary recruitment molt often
occurs prior to the season closure. In some cases, the molt may
occur in late fall causing a delay in the opening of the following
season.
A test fishery
is conducted in the fall to assess the shell condition of male
crabs. In order for the commercial crab season to open on December
1, less than 50% of the crabs sampled must be in shell grades
II and III. If more than 50% of the crabs sampled are in shell
grade II and III, then additional testing is required. Following
additional tests, the decision of whether to open the season on
December 1 is made by mutual agreement between WDFW and the Oregon
Department of Fish and Wildlife (ODFW). The crab season in Washington
and Oregon will open on December 1 if it can be determined with
reasonable certainty that meat recovery testing in all areas will
be 23% by December 1. If the meat recovery does not meet the criteria,
then further testing is conducted. If the season opening is delayed
as a result, then WDFW and ODFW will take consistent regulatory
action.
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Commercial
Crab Fishing
off the coast of Washington State. |
Recent Management
While test
fishing to determine shell condition does occur in the summer,
it is rare that the fishery closes prior to September 15. In the
last ten years, this has occurred once in 1998 when the fishery
closed on September 3 after it was discovered that large quantities
of soft-shelled crab were being sold in Westport. Also in 1998,
WDFW promulgated a permanent regulation to close the crab fishing
area outside four miles, effective July 1, because shell condition
data indicate that soft-shelled crabs are typically found further
offshore than hard-shelled crab. WDFW believes that by closing
the area outside four miles, the majority of the soft-shelled
crab will be protected during the peak of the molt cycle.
In June 2001,
WDFW was notified that large quantities of soft-shelled crab were
being caught in the commercial fishery. In response, we closed
the area outside four miles two weeks early (June 18) and imposed
a 4,000-pound per week landing limit on August 12. WDFW staff
continued to collect shell condition data and monitored the fishery
to evaluate the effectiveness of these regulations. We then began
working with coastal crab industry members to prepare a management
plan to address management issues associated with the summer crab
fishery to be implemented in June 2002.
Development
of Management Options
In September
2001, the Director of WDFW requested that staff and industry work
together to prepare a plan that would address summer fishery issues
to be implemented in 2002. In response, WDFW staff have held a
series a meetings with the Coastal Dungeness Crab Advisory Group
and members of the industry to develop options for the management
of the summer crab fishery. These meetings are summarized below.
March 5,
2002:
Seventeen crab
fishermen and industry members attended this initial meeting to
begin developing alternatives for summer crab fishery management
measures. Two options were discussed—one option similar
to the current Oregon regulations which would place a weekly landing
limit on all fishers beginning in June and cap the summer harvest
level at 7% of the previous winter’s catch. This would essentially
be a passive management approach that would not require in-season
sampling and monitoring.
The second
option would require weekly sampling to collect shell condition
data to indicate the need for additional restrictions on the fishery,
such as trip limits, smaller pot limits and closures. This option
would also allow the restrictions to be removed if shell condition
improved prior to the season closure.
April 1,
2002:
Thirty crab
fishermen and industry members attended this meeting to continue
discussing options for the summer fishery. Some fishers indicated
that they favored an active management option that would implement
restrictions when crab condition demonstrated a need. WDFW staff
proposed a plan that would use shell condition data from shipboard
trips to guide management restrictions.
It was also
decided that the summer management period would be defined as
July 1 through September 15.
April 19,
2002:
Twenty-five
fishermen and others attended this meeting. Staff presented a
flexible option that includes landing limits if crab shell condition
does not meet minimum criteria. These measures are contingent
upon bi-weekly shell condition testing, which was acceptable to
the majority of the fishers present.
It was decided
that this was the appropriate course of action to manage the coastal
Dungeness crab fishery and that WDFW staff would be recommending
these measures to the Director.
Summer Crab
Fishery Management Measures
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Management
period is July 1 – September 15 |
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The
area west of four miles will be closed each year from July
1 - September 15. The four-mile line is defined in WAC 220-52-046.
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Beginning
the third week of June, WDFW will begin bi-weekly crab condition
testing using ride-along trips with consenting commercial
fishers. The condition sampling will be done consistent with
the summer crab condition sampling protocols listed in Appendix
B. |
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If
any single shell condition test indicates that less than 50%
of the male crab sampled are grades 1A and/or 1B, WDFW will
impose a 2,500 pound weekly landing limit. |
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Following
the implementation of the 2,500-pound landing limit, WDFW
will continue to test the shell condition of crab. |
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If
any single shell condition test indicates that 60% - 79% of
the male crab are grades 1A and/or 1B, the weekly landing
limit will be increased to 4,000 pounds. |
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If
any single shell condition test indicates more than 80% of
the male crab are grades 1A and/or 1B, the weekly landing
limit will be removed for the balance of the season (September
15). |
Term
The term
of this Coastal Dungeness Crab Summer Fishery Management Plan
is from July 1, 2002, through September 15, 2006. WDFW staff will
evaluate the effectiveness of the plan at the end of each summer
period, and will modify as needed.
Appendix
A.
Dungeness
Crab Handling Mortality Studies
Washington
Coast 1949:
Tag return data from this study indicated that survival of “new
soft shell” and “new slightly soft” crab was
reduced by 68.5% and 8.1% respectively, compared to “new
hard shell” crab (Cleaver, 1949).
Washington
Coast 1970:
To test whether mortality was a function of time, additional handling
or both, triplicate lots of 25 soft-shelled crab were held for
2 days, 4 days or 6 days in tanks kept in 3-7 fathoms of water
in the same location they were caught (Tegelberg, 1970).
- Crabs that
were held for 2-days were handled once, crabs held for 4 days
were handled twice and crabs that were held for 6 days were
handled three times.
- In all
cases, for comparable holding periods, additional handling caused
higher mortality.
- Mortality
of untagged crabs ranged from 15% for crabs that were held for
2 days/handled once to 33% for crabs held 6 days/handled three
times.
- Mortality
of tagged crabs ranged from, 23% for crabs held 2 days/handled
once to 41% for crabs held 6 days/handled three times.
Washington
Coast 1972:
Testing to estimate mortality from specific injuries and treatments.
(Tegelberg, 1972)
- Mixtures
of hard and soft crabs (stage 3) were placed in posts to test
cannibalism effects. Mortality was 6.8% for soft crab and 0.0%
for hard crab.
- Soft crabs
were thrown into a 30-gallon box of water to simulate being
thrown from the boat during normal fishing operations. Mortality
of these crabs was 8.9%.
- To simulate
being pinched by another crab the carapace was crushed with
needle nose pliers, mortality was 6.7%.
- One claw
or one of the first walking legs was broken to simulate typical
injuries caused when crab are removed from traps, mortality
was 42.2%.
- Tegelberg
notes that stage 3 crab were difficult to obtain so some of
the “stage 3” crab were actually stage 2.
Oregon
Coast 1958:
Tag return data from a study conducted in Oregon coastal waters
showed that 19.8% fewer tags were recovered from crab tagged at
stage 2 compared to crab tagged at stage 1 crab (Waldron, 1958).
Appendix
B.
Summer
Shell Condition Sampling Protocols
I. Shell
condition data will be collected during at least one ride-along
trip during each of the sampling periods described below:
- Third
week in June
- First
week in July
- Third
week in July
- First
week in August
- Third
week in August
- First
week in September
II. Shell
condition from all male crab sampled will be collected. Definitions
of shell condition grades are described below.
III. A separate
data sheet will be used to record shell condition data from
different depths.
IV. A pot
will be included in the sampled only if all crabs in the pot
can be sampled.
V. Other
information collected will be: date, location (Latitude/ Longitude)
and soak time.
VI. If needed,
shell condition data may also be collected by fishing WDFW gear,
working with WDFW enforcement officers while they do routine
checks of commercial gear for compliance with existing regulations,
or by chartering commercial vessels and their gear.
Shell
Condition Grades
Crab shell
condition grading is based on shell flexibility when moderate
pressure is applied with the fingers to the underside of the carapace.
Shell condition grades are defined as:
- Grade
1A Hard-shell - Inflexible carapace and leg segments
- Grade
1B - Slightly flexible carapace or moderately flexible leg
segments, lateral shell of merus on first pair of walking legs
breaks if bent
- Grade
II Intermediate
- Moderately flexible carapace and leg segment, on the first
pair of walking legs bends without breaking
- Grade
III Soft-shell -
Very flexible carapace and leg segments
Grade 1A Dungeness
crab are noted as “old shell” when the exoskeleton
is dark yellow and fouled with barnacles, some crabs soften as
the development of the underlying, new exoskeleton assimilates
calcium from the old exoskeleton.
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