Tulalip
Crab Condition Sampling Project
Unresolved
Hunting and Fishing Fund
Final
Report
Dungeness
crab, Cancer magister, are of commercial, recreational,
and subsistence importance. Crab grow by going through
a molting process in which the hard shell is discarded.
During a four to six week period, crab are in a soft
stage while calcium is absorbed and deposited in the
new shell. Harvest of during periods of soft-shell conditions
can increase the mortality of soft crab, thereby decreasing
future abundance.
The
State of Washington has traditionally used June 1 through
July 15 as a time period to close its fishery to protect
soft-crab. The original data was collected from northern
Puget Sound, where the majority of the crabs are harvested.
It was recognized that the molting period is not consistent
throughout the Puget Sound area and additional information
needs to be collected. This project was designed to
collect additional baseline data to determine the molting
period of crab for the inside waters of Whidbey Island,
assist with the compilation and distribution of data,
and determine the best management strategy using the
data collected.
Project
Accomplishment
The
following are the accomplishments of the project.
Crab
Hardness Testing
In
the 1998-99 agreement between the State and Tribes states
that for the Port Susan and Possession Sound area (Zone
3) samples will be collected between November 1 and
June 29 to better determine the peak molt period. The
crab hardness test fisheries were conducted at the predetermined
reference stations (Station 231 and 232). In addition
to the set stations, an additional sampling location
was added to collect additional information. The zones
and reference stations areas are shown in Attachment
A. The methodology to determine shell hardness was agreed
to by all parties of the overall management agreement.
During the time the tribes agreed to monitor, the fishery
can be opened or closed using agreed to sampling criteria.
The
1998 Region 2 crab hardness testing was initiated in
September at the three locations within Zone 3. Additional
tests were conducted intermittently through the end
of June 1999. A summary of the hardness testing results
was compiled. The tests were done with the cooperation
of the commercial crab fishermen and State employees.
As a result of the testing, a minor molt was identified
in the September test and the fishery was closed during
the first three weeks of October. There was no test
in November. During the December test, another molt
was identified, and the fishery was closed December
31. Subsequent tests indicated that the hardness criteria
were met in March 1999. However, there was no agreement
between the State and tribes on a spring fishery and
the fishery did not reopen until May 1999.
Data
from this project, in conjunction with historical data
collected by Tulalip, indicate that crab experience
a major molt beginning in December and ending sometime
in the beginning of March. There are "minor"
molts which are indicated by a slight drop in the percentage
of hard crab at various times throughout the year (see
Chart).
Crab
Hardness Testing Database
The
Tulalip Tribes worked along with the Point No Point
Treaty Council to create a database for the test results.
This database was developed so that information could
be shared and used by all parties. The reports generated
through this program would be produced in a consistent
manner. The data collected from this study was entered
into the database and the summary reports printed. There
were, however, several glitches in the reports which
still need to be modified.
Distribution
of Information
The
information collected during this study was summarized
and reported to the other tribes in the region and with
the State. Combining this data with the State and other
tribes may help determine the molt period of the Dungeness
crab in the area and determine the best management strategy.
Data from the State test was also incorporated into
the working database. Summary information of all tests
was also compiled and distributed.
