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.
The leafcutter bee (Megachile wheeleri) is one of the of specialized, solitary, ground-nesting bees that are crucial to the survival of our native dune mat community. The leafcutter bee, shown here pollinating dune goldenrod, cuts semi-circular pieces from goldenrod leaves and uses them to construct its nest cell. Native bees are gaining increased attention as pollinators due to the decline of the imported honey bee (Apis mellifera) through colony collapse disorder. Photo courtesy of Andrea Pickart.