ABSTRACT
CThe overall
goal of this project was to initiate the establishment
of production standards and a health baseline for intensive
clam production on the west coast of the United States.
The baseline data on manila clam health can be used to
assist state and tribal shellfish biologists in assessments
of public and tribal clam resources. The following tasks
were proposed in order to implement these objectives and
were fulfilled, with small modifications necessitated
by results obtained during the study and additional input
from shellfish producers during the study:
Task 1.
Cooperative industry clam survival and performance study.
Sites of intensive clam production were monitored
over a one-year period using defined plots in which clam
growth, survival, condition, and health was measured in
conjunction with monitoring for a variety of environmental
parameters. Clam growers participated directly in the
study.
Task 2.
Survey of clam health and disease in Washington, Oregon,
and California. Adult and seed clams were examined
histologically for the presence of infectious diseases
to initiate a health baseline for clam production areas.
As a result, a baseline of clam health for the west coast
was established.
Task 3.
Evaluation of short-term freezing and freshwater exposure
effects on clams. Experimental studies were conducted
at a clam production facility to define, in detail, tolerance
of various clam populations to low-salinity exposures,
followed by recovery periods. Additionally, clams were
analyzed by detailed necropsy and histology methods in
order to define the pathological criteria for the diagnosis
of low-salinity and freezing condition exposures.
Task 4.
Clam mortality response team. The project staff, along
with associated scientists from the University of Washington,
responded to several clam mortality events during the
study.
