[acn-l] 1999 NSA-PCS Meeting Green Crab Abstracts

Jay DeLong (thirdwind at att.net)
Tue, 02 Nov 1999 18:19:36 -0800

Forwarded from the Pacific NW Aquatic Nusiance Species list.

Jay DeLong
Olympia, WA

--------------------------------

On September 29 - October 1, 1999, the National Shellfisheries Association,
Pacific Coast Section (NSA-PCS) and the Pacific Coast Shellfish Growers
Assocaition (PCSGA) held a joint annual meeting at the Heathman Lodge in
Vancouver, WA. There were several papers presented on green crab. Just in
case you were not able to make it to the meeting, I have attached a copy of
the abstracts for the green crab papers.

In addition, this is just a reminder that the call for papers is out for
the NSA national meeting that will be held in Seattle from March 19-23,
2000. There will be a session on invasive exotic species. I have attached
a reminder at the end of this message.

Please let me know if you have any questions or comments.

Derrick Toba
Tulalip Shellfish Program
7615 Totem Beach Road
Marysville, WA 98271
360-651-4479; 350-651-4480
FAX: 360-651-4490
E-mail: dtoba at tulalip.nsn.us

1999 NSA-PCS Meeting Green Crab Abstracts

PROGRESS IMPLEMENTING A PLAN TO MONITOR AND CONTROL POPULATIONS OF THE
EUROPEAN GREEN CRAB (CARCINUS MAENAS) IN WASHINGTON COASTAL ESTUARIES.
Elizabeth M. Carr*, Brett Dumbauld, Washington State Department of Fish and
Wildlife, P.O. Box 190, Ocean Park, WA 98640
The European green crab (Carcinus maenas) was first noted in Washington
State waters during the summer of 1998, having steadily progressed northward
from California where its presence in San Francisco Bay was first recorded
in 1989. The two distinct year classes present appear to have resulted from
strong larval recruitment events and not from new introductions.
The response to this bio-invasion was rapid and resulted in a plan to
monitor and control green crab populations in Willapa Bay and Grays Harbor,
Washington which was approved and implemented in 1999. Monitoring results
suggest the same two year classes are still present. Although mating
couples and females with viable eggs have been found, no new recruitment has
been noted to date. Catch per unit effort has declined as the population
has apparently spread out in both estuaries making control efforts
potentially more difficult. Trapping methods continue to be refined as the
primary control technique.

PROGRESS IMPLEMENTING A PLAN TO MONITOR FOR PRESENCE OF THE EUROPEAN GREEN
CRAB (CARCINUS MAENAS) IN PUGET SOUND, WASHINGTON
Anita E. Cook*, Sandra Hanson, Washington Department of Fish and Wildlife
(WDFW), Point Whitney Shellfish Lab, Brinnon, WA 98320
A significant population of the European green crab, whose first persistent
presence on the U.S. west coast was recorded in 1989 in San Francisco, was
first noted in Washington State in 1998 in coastal Willapa Bay and Grays
Harbor. The green crab likely arrived in Washington via larval drift on
ocean currents. To date no European green crab have been confirmed in Puget
Sound.
A large-scale Puget Sound green crab monitoring program was established in
1999, with WDFW as the coordinating agency. The primary aim of this initial
phase was thorough geographical sampling coverage of Puget Sound (including
the Strait of Juan de Fuca and the San Juan Islands) to maximize the
potential of detecting green crab that might have spread to Puget Sound by
larval transport or other means. This was accomplished by enlisting and
training various volunteers to set crayfish traps at monitoring sites spread
throughout the Puget Sound. Over 15 groups sampled more than 50 monitoring
stations in 1999. Participants included non-profit volunteer organizations,
shellfish growers, tribes, marine science centers, government agencies,
schools, and the general public. In addition to providing information about
the potential presence of green crab in Puget Sound, the trapping supplied
some general baseline data about populations of small native crab in the
sampling areas. In the year 2000 WDFW will focus on increasing the number
of sample sites (for higher potential of discovering green crab presence),
identifying sites with the highest likelihood for introductions, and
examining other green crab detection techniques.

CURRENT STATUS OF THE EUROPEAN GREEN CRAB, CARCINUS MAENAS, AND NATIVE CRAB
SPECIES IN YAQUINA AND COOS BAYS.
Laura L. Hauck*, Student, Department of Biology, Oregon State University,
Corvalis, OR 97331
Sylvia Behrens Yamada, Department of Zoology, Oregon State University,
Corvalis, OR 97331
Four different sampling methods were employed at four sites in Yaquina Bay
and five sites in Coos Bay to monitor the progress of the invasive Carcinus
maenas (CM) population. We also recorded the status of native crab species:
Cancer magister, Cancer productus, Hemigrapsus oregonensis, Hemigrapsus
nudus and Pachygrapsus crassipes; in the intertidal zone at the current
invasion level.
The first method used at each site was a tethered snail predation line. The
method gives the best natural estimation of predation rate at a given
location, and allows us to compare predation rates from site to site. Crab
species hitting the line are identified by their shell cracking technique
when the lines are checked. Trapping followed the first method to verify
the identity and presence of crab species. Rock turning was the third
method used which yielded information on shore crab species. The last
method used was to search for molts of a new year class at the high tide
water line.
No recruitment evidence of a CM new year class has yet been found in either
bay by any sampling method. Data recorded in 1997 for all crab species was
compared to data collected this year.

THE DISTRIBUTION OF THE EUROPEAN GREEN CRAB, CARCINUS MAENAS, IN YAQUINA
BAY, OREGON.
Chris Hunt*, Environmental Science Department, Oregon State University,
Corvalis, OR 97331-2914
Carcinus maenas, first discovered in Coos Bay, Oregon in 1997, was found in
at least eight Oregon estuaries in 1998. With the absence of a successful
1999 year class to date, their present population exists of what is believed
to be two and three year old crabs. These older, and much larger, crabs are
present lower in the estuary than last year, creating the potential for more
interaction with the larger native Cancrids. As intensive trapping effort
during the summer of 1999 documented the distribution of this older year
class of C. maenas and other crab species in Yaquina Bay. It appears that
C. maenas coexists in areas with the native Dungeness crab, Cancer magister,
but appears to be absent, or limited, in areas suitable for another native
crab, the Red Rock crab, Cancer productus. Although C. maenas appears to be
abundant in areas with fewer of these larger crabs, it appears dense
populations of adult C. productus may be the primary limiting factor in the
lower estuary for this new invasive species.

GROWTH OF 1997/1998 YEAR CLASS OF THE GREEN SHORE CRAB, CARCINUS MAENAS, IN
OREGON
Alex Kalin*, Sylvia Behrens Yamada, Department of Zoology, Oregon State
University, Corvalis, Oregon 97331.
During the spring of 1997, a strong new year class of Carcinus maenas
appeared in seven Oregon estuaries. The carapace width of these crab
averaged 14 mm June, 27 mm in July and 45 mm in September 1998. By the
summer of 1999, the crabs had reached between 44 and 80 mm in carapace
width. The growth of tagged crabs and a molt increment study of captive
crabs support these rapid size increases.
Carapace width data collected from Oregon bays suggest that C. maenas is
growing faster in Oregon than in the North Sea or Maine. Our data supports
the theory that C. maenas reaches sexual maturity within one year in Oregon,
while in the North Sea and Maine sexual maturation may take two or three
years. Molt increment data, however, suggests that growth per molt is
constant in C. maenas populations regardless of geographic location.
Regression equations of molt increment data of Oregon specimens showed no
statistically significant difference for similar regression equations
describing the North Sea and Maine populations. The molt increment
statistical analyses lead to the inference that C. maenas molts more
frequently in Oregon than in the North Sea or Maine.

-------------------------------------------------------
NATIONAL SHELLFISHERIES ASSOCIATION - SEATTLE 2000

CALL FOR PAPERS AND MEETING ANNOUNCEMENT
Annual meeting, Seattle, March 19 - 23, 2000

The NSA annual meeting will include presentations on the biotechnology,
genetics, physiology, biochemistry, ecology, aquaculture and management of
shellfish together with presentations on the effects of pollution, harmful
algae, diseases and invasive exotic species. Deadline for papers is
December 3rd 1999. For more details of the meeting or on how to contribute
a paper, contact Chris Langdon (Program Chair) at 541-867-0231 or
chris.langdon at hmsc.orst.edu.

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