Forage Fish, Eelgrass & Kelp Surveys

NEARSHORE HABITAT STUDIES

Forage-fish spawning beaches, eelgrass, kelp, and other nearshore habitats can influence the location, footprint, timing, and mitigation for Puget Sound docks, piers, floats, bulkheads, dredging, and beach projects.

Forage fish and spawning beaches

Surf smelt, Pacific sand lance, and Pacific herring support the marine food web. Spawning information can be important because eggs may occur on beaches or aquatic vegetation in areas affected by armoring, excavation, access, nourishment, demolition, or overwater construction. Maps are useful screening tools, but a qualified professional may need to evaluate site conditions or conduct sampling under an accepted protocol.

What a forage-fish review may consider

• Mapped documented or potential spawning habitat.
• Beach elevation, slope, shade, sediment size, and sediment movement.
• Seasonal spawning periods and survey timing.
• Existing armoring, vegetation, driftwood, and shoreline processes.
• Proposed excavation, nourishment, access, fill, or waterward encroachment.
• Construction timing, methods, restoration, and mitigation.

Eelgrass surveys

Eelgrass provides important nearshore habitat and can be sensitive to direct disturbance and reduced light. A survey may map presence, absence, density, and the edge of a bed within a defined area around the project. Survey season, tidal elevation, visibility, method, positioning accuracy, and repeat observations can affect the results.

Kelp and other aquatic vegetation

Floating and submerged kelp, macroalgae, and freshwater aquatic vegetation may also need review. The relevant species and survey approach depend on the waterbody and project. Anchors, piles, dredging, propeller wash, shading, and construction access can each affect vegetation differently.

How survey results can change a project

• Shift the pier, float, lift, pile, anchor, dredge area, or access route.
• Reduce overwater coverage or the number of piles.
• Use grating, narrower components, increased height, or a favorable orientation to improve light.
• Change the construction season or sequence.
• Remove obsolete structures or restore beach and vegetation as mitigation.
• Establish monitoring, no-work buffers, or field verification requirements.

Schedule surveys before final design

Some surveys are seasonal, tidal, weather-dependent, or require agency-approved methods. If the team waits until the permit package is nearly complete, the study can cause redesign or delay the entire submittal. Early screening allows the concept to avoid sensitive areas before engineering and fabrication advance.

Questions for the biologist and design team

• Which agency protocol and survey area apply?
• When can the survey produce reliable results?
• Are mapped records current, and is field verification necessary?
• How will the survey coordinates connect to the engineering survey?
• What project alternatives should be shown if habitat is present?
• Will mitigation or post-construction monitoring be required?
• How will habitat boundaries be marked for the contractor?

Related WCI guides

• Salmon and in-water work windows
• Soft shoreline construction
• Washington HPA requirements
• Washington waterfront permit checklist

This educational guide does not replace site-specific biological work or current agency requirements. Engage qualified professionals and confirm the applicable methods before relying on survey results.