Sampling Plan | Beach Sampling | Nearshore| Offshore | Schedule

Our premise is that a basic understanding of HAB dynamics is necessary to design effective monitoring strategies. Local sampling efforts must be grounded on the broader base of a credible scientific framework.

The Sampling Plan

Because the coastal currents are variable, samples must be obtained at no less than weekly intervals during the summer-fall HAB season. Detailed measurements include weekly measurements of the following in March through November: nutrient concentrations (nitrate, ammonium, phosphate, silicate, and nitrite), phytoplankton species enumeration, Pseudo-nitzschia abundance with positive species determinations by SEM and molecular probes, domoic acid concentrations in seawater, chlorophyll concentrations, temperature, salinity. Twice monthly measurements of these same parameters are made in December, January, and February. Razor clams (up to 12 per beach site) will be collected twice per month at low tides in August, September, and October and once per month during all other months. Both clam meat (a composite of 6 clams analyzed by WDOH) and clam viscera (individual clams analyzed by NWFSC) are analyzed for DA content.

Beach Sampling

Our study focuses on 7 locations on the Washington coast that are the sites of major razor clam beds and where a substantial amount of historical data are already available. Sampling is done by the Makah and Quinault Tribes, WDFW, and WDOE.

1, 2: Makah and Neah Bays: These are Makah tribal beaches where subsistence harvest of several shellfish species is common. Commercial mussel operations have been proposed in these bays.

3. Kalaloch Beach. This is a location of the NWFSC and Quileute tribe pilot study and of a 4-year monitoring project by the (UW). The highest levels of domoic acid in razor clams have been consistently measured here.

4: Copalis Beach. This is an area representative of a Quinault Tribe and WDFW CO-management that has been sampled by UW on a twice-monthly basis since 1996 for phytoplankton identification, nutrients, and environmental data. This area represents one of the largest recreational clam digging interests along the Washington coast. This is possibly a transition zone separating southern (Columbia River influence) and northern (upwelling enhanced) physical oceanographic components of the Washington coast.

5: Twin Harbors. This is another important razor clam harvest beach managed by WDFW that has been monitored by the UW twice monthly since 1996. It is the beach site closest to a deployed UW offshore mooring that measures PAR, fluorescence and currents.

6. Willapa Bay: One of the largest commercial oyster industries, in the U.S., valued annually at $40 million is located here. The WDOE has a long-term state monitoring study including moorings with PAR, fluorescence and autosamplers in this bay.

7.: Long Beach. This beach is managed by WDFW and represents an area of tremendous economic interest to the state. It is the largest single beach supporting razor clam populations in Washington. This site is likely the region of strongest Columbia River influence and any nutrient changes that might be due to freshwater input.

Razor clam domoic acid levels have been analyzed at portions of sites 3-7 on a seasonal basis by the WDOH since the early 1990s.

Nearshore Components

Nearshore sampling components, consisting of 9-12 stations from 5-20 nautical miles off the coast at La Push and moorings off of Grays Harbor are used to define the specific locations where moorings are placed. A nearshore sampling effort occurs off La Push on a weekly basis during bloom season (August - October). Sampling occurs at 15 stations and at up to three depths (0, 5, 15 m) using the OCNMS zodiac. Samples are collected for the following analyses: toxin in seawater, phytoplankton composition, Pseudo-nitzschia abundance, turbidity (Secchi depth), nutrients, chlorophyll, temperature and salinity (using CTD). Additional environmental data are obtained from the buoy at Destruction Island.

Offshore Components

Cruises of opportunity off the Washington coast within the OCNMS are conducted in the summer of each year. Whenever possible, sampling with CTD occurs in 5 nautical mile increments. Scheduled transects take place (south to north) at Columbia River, Willapa Bay, Grays Harbor and La Push, and possibly Cape Alava and Cape Flattery. Samples are collected during all cruises for the following analyses at each station (3 depths): phytoplankton species composition, Pseudo-nitzschia abundance, toxic species determination, nutrients, chlorophyll, toxin in seawater, CTD (temperature and salinity at all depths).

Sampling Schedule

Sampling Plan | Beach Sampling | Nearshore| Offshore | Schedule

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