GUALALA RIVER ESTUARY STUDY
BEGINS
The State Coastal Conservancy has provided $150,000 in funding to
the Sotoyome RCD and the Gualala River Watershed Council for the
preparation of a Lower Gualala River and Estuary Assessment and
Enhancement Plan.
The Gualala River Estuary is located near the town of Gualala in
southern Mendocino County. The Gualala River supports populations
of steelhead trout and coho salmon. Due to dramatic declines of
wild populations over most of their range in California, both coho
salmon and steelhead are federally listed as “threatened” under
the Endangered Species Act. In order to preserve and restore these
valuable fishery resources, we need knowledge of Gualala River coho
and steelhead life history characteristics. It is also important
to identify critical salmonid habitats and determine factors that
limit their growth and survival. A particular area of the Gualala
River watershed that is lacking in terms of habitat information
is the estuary/lagoon.
The Gualala River estuary/lagoon likely plays an important role
as habitat for steelhead and coho salmon. It is the nexus between
freshwater and marine environments that Gualala River salmonids
pass through as juveniles during seaward migrations, and as adults
to gain access to spawning grounds. In addition to being a migratory
gateway, estuaries are recognized as important fish nursery areas
because they provide abundant food supplies, offer protection from
predation, and are diverse habitat areas. Studies have shown that
juvenile salmonids that remain in estuaries for an extended period
of time before ocean entry have had better survival rates to adulthood
as compared to their non-estuarine reared siblings. Their higher
survival rate is due in part to their larger size that may reduce
their susceptibility to predation and an increase in the amount
of prey items that can be used for food.
The Department of Fish & Game recommends that, “baseline data that
describes how the biological, physical and chemical components of
the estuarine ecosystem interact to form habitat for salmonids and
other valuable fishery resources”.
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The goal of the estuary study being undertaken by the Sotoyome
RCD and the Gualala River Watershed Council is to collect reliable
baseline data that assesses current habitat conditions, identifies
factors which may limit salmonid production and provides an overview
of how the estuarine ecosystems functions as habitat for salmonids
and other fisheries. Data will be used in the development of an
Estuary Enhancement Plan that will provide guidelines/recommendations
for any restoration of the estuary.
In May the Gualala River Watershed Council selected two consultants
to assist with the assessment of the estuary. They are Kamman Hydrology
and Engineering will perform the hydrologic & geomorphic studies
and ECORP Consulting, Inc. will perform aquatic biology, terrestrial
and marsh ecology studies and water quality assessments. Both consultants
will be integral to the development of the Estuary Enhancement Plan.
Sotoyome RCD and ECORP staff, led by Tom Keegan, began fish sampling
(catch & release) on June 19th at various locations in the estuary.
Fish were weighed, measured and freeze banded, then thrown back
into the water. Tri-weekly monitoring will continue through October
of this year and be repeated next season. Specific water quality
measurements will include temperature, conductivity, salinity, total
dissolved solids, dissolved oxygen and water depth.
If you would like additional information about the study contact
Rick Kaye, Sotoyome RCD at (707) 569-1448 or via email at rickk@sonic.net.
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