Juvenile Salmon Update
The nearshore marine environment is a unique zone, with consistently higher species diversity, density, and production, than deeper water marine habitats.
Current Issues (as of July 2006)
The Clallam Country MRC is invovled in a number of issues surrounding protection of Clallam County's marine resources. Following are highlights of recent and ongoing work.
Preferential use of Nearshore Kelp Habitats by Juvenile Salmon and Forage Fish
The nearshore marine environment is a unique zone, with consistently higher species diversity, density, and production, than deeper water marine habitats.
Forage Fish Work
Anne Shaffer, WDFW Region 6 habitat staff, supervised two Peninsula college interns that sampled central and western Strait beaches from August 1. A total of 61 miles of beach were sampled and spawn was documented on eleven sites (combined to eight beaches). Six of these eight beaches are newly recognized spawning sites, although two beaches yielded only a single egg. Repeated sampling of these beaches indicates that seasonal variation in beach habitat plays a significant role in surf smelt spawning. Percent of eggs within each development stage changed with month. Mortality was not significantly different with month. Average monthly egg mortality was 32%.
Sand lance spawn habitat mapping. Prior to this study, only a small portion of the shoreline within the Strait has been determined to serve as spawning habitat for Pacific sand lance. Anne Shaffer, WDFW Region 6 habitat staff, supervised two Peninsula college interns that sampled central and western Strait beaches for sand lance spawn continuously from November to February. Fourteen beaches, totaling 8.25 miles, were sampled. Spawn was detected at one site, Pillar Point. This is the first Strait sand lance spawning site documented west of Port Angeles Harbor, and the first documented Strait spawning site that is not within a large embayment. Comparing this site to the total linear distances of spawning beaches previously documented (Penttila 1999) this site represents approximately 2% of documented Strait sand lance spawning ground.
Although adult herring are known to congregate and spawn at various sites within Puget Sound, sampling to determine spawning sites within the Strait of Juan de Fuca has been limited. The primary objective of this project was to sample potential herring spawning substrate (marine vegetation) in locally reported or suspected herring spawning sites, within the central and western Strait of Juan de Fuca, that had not been previously surveyed by the WDFW. Seven embayments were sampled once per month for herring spawn during February and March . Spawn was found at one site, Dungeness Bay, which has been previously documented as spawning habitat and is sampled annually by the WDFW. Stock biomass was calculated for Dungeness Bay for the dates collected using WDFW protocol.
This study was conducted to quantify, for the first time, some basic parameters of juvenile salmon and forage fish use of kelp bed habitats. Five nearshore areas adjacent to central creek mouths were sampled monthly from May thru August. Sampling included beach seines and snorkeling surveys.
Findings include:
1) Juvenile salmon and surf smelt appear to preferentially use kelp bed habitats over unvegetated habitats.
2) Juvenile salmon appear to prefer the middle of the kelp surface canopy while surf smelt show no habitat use partitioning within the kelp bed.
3) While prevalent in the nearshore, juvenile sand lance show no preference for kelp over unvegetated habitats.
4) Juvenile salmon prefer shallow waters, but distance from shore and creek mouth do not appear to be factors for selecting habitats.
5) Water depth, distance from shore, and distance from creek mouth are not selecting factors for juvenile surf smelt.
6) Sand lance appear to select for deeper water.
Together, these results indicate that juvenile salmon, surf smelt, and sand lance exhibit complex habitat partitioning within the nearshore. Further defining and understanding these habitat preferences is critical for future wise management of these species and the nearshore habitats that support them.
Data Gaps
- Need to compile and synthesize existing nearshore data for baseline, including local knowledge.
- Model nearshore areas of the Strait for circulation and water quality.
- Dungeness Bay
o Identify fecal coliform sources:
o Study septic fields of homes along the shoreline and their contribution to water quality declines (both fecal coliform and nutrients).
o Define trace and heavy metal and organic (PAH, PCB’s, DDT, etc.) concentrations.
o Define levels and sources of nutrients in the nearshore and relationship to ulvoid blooms.- Sequim Bay
o Define circulation.
o Define relationship between the bay and groundwater.- Updated survey on red and green sea urchins.
- Need to define water quality thresholds for embayments of the Strait and priorities for management (e.g. nutrients, temperature, sedimentation, toxic chemicals, etc.).
- Need to define linkages between riverine systems and the nearshore.
o Priority on sediment, nutrients, fecal coliform.
o Physical processes.- Need to define and analyze applicability of different types of Marine Protected Areas (for example, depth contour no take areas vs. boundary area MPA).
- Need to define nearshore habitat use by juvenile salmonids and rockfish.
- Need to define kelp bed function within the Strait.
o Long-term site specific monitoring for baseline data, particularly for MPA/kelp bed restoration.
- An inventory of forage fish (Pacific herring, surf smelt, Pacific sand lance) spawning grounds to discover current and new sites.
- Research on “food chain” lower than baitfish (i.e. krill, plankton, shrimp).
- Monitor and measure the amount of fecal coliform in Dungeness Bay; where it originates.
2001 Annual Report
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