The Port Gamble S’Klallam Tribe is finding more juvenile salmon in small bays than other nearshore environments, including 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; the hydroacoustic “torpedo” shows 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. Surprisingly, they were not in waters adjacent to the Duckabush and Dosewallips river systems.
“While we know juvenile salmon typically use estuaries for refuge and feeding, the data we’ve collected indicates 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 the larvae is a high energy food source for salmon, so it’s important to recognize the forage fish populations too, he said.
The tribe has conducted further hydroacoustic surveys and beach seining in 2013 to expand on the data collected.