Lakeside Living

Better docks for salmon

Have your dock and salmon, too

Why are docks bad for salmon?

Each winter thousands of young chinook emerge from our creeks and streams to begin their journey out to sea. Most are gobbled up by predators before they ever make it to salt water. Lakeshore property owners play a vital role in salmon survival. You can improve the salmon's childhood home as you protect and care for your own.

Photos: Shapiro & Associates (left), D. Natelson (right)
Neighborhood bully: bass Chinook smolts

Young salmon are instinctively ingrained to avoid docks. By doing so, they venture out into deeper water and often end up in the bellies of cutthroat trout and other denizens of the deep. Along Lake Washington alone, there are about 3,000 residential piers and marinas so you can imagine what a challenge they pose to young salmon trying to make their way out to sea. Circumnavigating all these docks not only puts salmon in harm's way, but it adds a considerable distance to their outbound journey.

Fish-friendly dock alternative

Something good comes out of something bad

The listing of chinook as threatened under the Endangered Species Act has resulted in much scientific research about the specific habitat needs of salmon, and has brought about improvements to the lakeshore. Among these positive changes, the shoreline design and construction industry has responded with many creative solutions. There are now design alternatives that enable the presence of fish-friendly docks.

Elements of fish-friendly docks

Let the sun shine in

Light permeable docks have narrower ramps, surface grating for decking, or in some conditions, glass light tubes to let more light down under the dock. These features all result in a dappled light pattern similar to being under shoreline vegetation. Deck grating is made either from wood such as teak or ironwood (which does not need chemical treatment) or from recycled plastic lumber that comes in a variety of colors to match the rest of the dock. The surface is non-skid – and splinter-free. Homeowners like its low maintenance and durability. Remember, when it's time for periodic maintenance, existing docks can be made more salmon-friendly by replacing some of the decking with surface grating.

Span the nearshore lightly

Dock built as a bridge The most critical area for juvenile salmon is the first 30 feet from the edge of the shoreline. In order to minimize the impacts of docks in this nearshore region, it is important to reduce conditions favored by predators, including pilings, dark shadows, and the sense of a dock that would force chinook out into deeper water. Docks along the nearshore can be built more like a "bridge" to span this area with few or no pilings. Salmon-friendly dock designs can be architecturally graceful. The use of glue-laminated beams and steel pilings enables a span of 20 feet between pilings. Or for a continuous 30 foot span without any pilings, a prefabricated aluminum bridge can be employed.