The Port Gamble S’Klallam Tribe is finding more juvenile salmon in small bays than in other nearshore environments, even those adjacent to large estuaries in Hood Canal and Admiralty Inlet.
“We’re not seeing fish near the mouths of big river systems like we expected, such as the Duckabush or Dosewallips rivers,” said Hans Daubenberger, the tribe’s habitat biologist. “Fish appear to be quickly leaving the marine waters around our large river estuaries in search of smaller and calmer areas with shallow water to find food.”
Since 2011, the tribe has been using beach seines, surface trawls and a hydroacoustic “torpedo” to determine where and how juvenile fish are using nearshore environments. The beach seining and surface trawls show what types of fish are in the nearshore; and the hydroacoustic equipment show the abundance of fish.
The largest densities of fish were found in Port Gamble Bay, Pleasant Harbor, Jackson Cove, Hood Head, Port Ludlow, Kilisut Harbor, and Quilcene and Dabob bays and surprisingly not in waters adjacent the Duckabush and Dosewallips river systems.
“While we know juvenile salmon typically use estuaries for refuge and feeding, the data we’ve collected indicate that the small embayments we survey are consistently more productive in terms of nutrients in the water column.” Daubenberger said.
Forage fish, such as surf smelt and herring, spawn in embayments and their larvae are a high energy food source for salmon, so it’s important to recognize the forage fish populations too, he said.
The tribe conducted further hydroacoustic surveys and beach seining in 2013 to expand on the data collected. EPA’s National Estuary Program supported the project.