TidewaterGoby 512

The Tidewater goby, shown above, is one of the few endangered species found at Humboldt Bay NWR.


Humboldt Bay provides habitat for approximately 95 species of fish, 41 of which contribute to sport or commercial fisheries.  Salmon Creek provides a passage corridor and habitat for various life stages of steelhead, Coho salmon, and Chinook salmon which are all federally listed species, as well as coastal cutthroat trout which are state listed.  These species begin their lives in streams and, after passing through larval stages, move out to the marine environment to mature. Finally they return to freshwater streams to deposit and fertilize eggs, and begin the cycle again.  Chinook salmon utilize the main channels of larger rivers and some use of smaller tributaries. They are typically present in low-gradient area streams (1–2 percent grade) from October to January.  Steelhead, an anadromous form of rainbow trout, utilize tributary channels with less than 8 percent grade, and may use stable side channels as well. Steelhead are typically present in area streams from winter through spring. Coho salmon utilize accessible reaches of streams, especially side channels with small gradients for breeding. Coho are typically present in area streams from November to February and are proving to have several different “patterns” of outmigration.  Since 2002, CDFG has been assessing salmonid populations at multiple locations in tributaries around the bay, including Salmon Creek.  Monitoring has indicated that recent restoration activities have significantly increased the numbers of anadromous fish found on the Refuge.


Tidewater goby are small fish (~2”), that are found in coastal lagoons and brackish edges of estuaries in northwestern CA.  They are a federally listed endangered species, and have been found in numerous locations on the Refuge, particularly brackish water with little current.  Tidewater goby proposed critical habitat includes most of the Humboldt Bay NWR units in South Bay. The entire life history of the goby can be completed in Refuge habitats.  Tidewater goby can “migrate” upstream in tributaries up to 0.6 mile from estuaries. Sub-adult and adult goby migrate upstream in tributaries in summer and fall for reproduction. Nesting burrows are dug in coarse, sandy substrate. They primarily feed on small benthic crustaceans and aquatic insects. Individuals typically live for 1 year.