| Pacific Lamprey (Lampetra tridentate) FSC |
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Large (to 2 feet long) parasitic lamprey that migrates to the ocean to
mature. The blind larvae rear in bottom mud for 2-4 years before transforming
to adult body form (developing eyes and parasitic sucking disk) and migrating
to the ocean. They return in winter to their natal stream after 2 years
in the ocean. They are restricted to larger streams of the region (Pescadero,
Soquel, Llagas, Uvas and Coyote creeks, San Lorenzo and Guadalupe rivers),
and are relatively uncommon except in the San Lorenzo River. Lampreys have
declined for some of the same reasons that steelhead and salmon have (water
diversions, channelization and dams that affect migration and rearing conditions).
Lampreys are able to surmount some barriers that block steelhead (such
as the spillway of Uvas Reservoir) and are sometimes able to complete their
life cycle in freshwater if landlocked by dam construction. |
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| Coho Salmon (Oncorhynchus kisutch) SE, FT |
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Coho are found in cool coastal streams with flat reaches containing good
woody pools (Pescadero, Gazos, Waddell, Scott and San Vicente creeks).
They were formerly more widespread, but still rare compared to steelhead,
which use a much wider variety of habitats. Coho are sensitive to nest
destruction by winter storms because of early spawning (January and February)
and to access problems due to early winter drought. Wild females almost
always spawn and die as 3-year olds, so year classes are distinct and subject
to loss from storms or drought. Even in streams where they are present,
one or more year classes may have been lost (i.e. the 1994/1997/2000 year
class was gone from all but Scott Creek, where it was scarce in 2000).
Accelerated growth in hatcheries (such as the Big Creek hatchery in the
Scott Creek watershed) can produce 2-year old spawning females to potentially
fill in lost year classes. In addition, in years of extremely high coho
abundance (Scott Creek in 2002) many coho grow slowly and some may spend
two years in freshwater;this may result in 4-year old fish to fill in weak
or missing year classes. |
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| Chinook Salmon (Oncorhynchus tshawytscha) FE, SE |
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Chinook are large salmon of larger north coast and Central Valley streams,
with separate fall, late-fall, winter and spring spawning runs. Spring
and winter runs are federally listed. Anecdotal records indicate that chinook
were originally present in some south Bay streams, at least
occasionally (such as during wet periods). The marginal original stocks
were probably eliminated by diversions, dam building and severe pollution
in south San Francisco Bay. However, runs of several hundred fall-run fish
now annually enter Coyote Creek and the Guadalupe River in Santa Clara
County. The recent runs apparently originated as strays from Central Valley
streams and hatcheries, and much of each run is probably still strays.
However, some successful spawning and smolt production has occurred in
both streams. |
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| Steelhead (Oncorhynchus mykiss) FT |
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Steelhead are still present in most coastal and some San Francisco Bay
streams (San Francisquito, Stevens and Penitencia creeks and the tributaries
of the Guadalupe River), although numbers have been substantially reduced
by sedimentation, water diversion and dam construction. They are able to
use steeper, faster habitats than coho, and can also use warmer stream
habitats if fast-water riffles are present as feeding areas. Summer lagoons
and some seasonal on-channel ponds can often provide important rearing
habitat if water temperatures are not too warm and food is abundant. Poor
access and reduced stream flows temporarily reduce abundance during droughts,
but populations generally rebound quickly because of flexible freshwater
and ocean life history. They commonly occur as resident (non-migratory)
rainbow trout above natural and man-made barriers. Resident fish above
complete natural barriers and most large reservoirs (except Uvas Reservoir)
are not included in the federal listing. |
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| Speckled Dace (Rhinichthyes osculus) |
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Speckled dace are widespread as several probable subspecies in California,
but have been lost from most San Francisco Bay area sites (Alameda, Coyote
and Llagas creeks and the Pajaro River). Dace are present only in the San
Lorenzo River watershed, where they are reasonably common in riffles of
the river and low gradient tributaries. Dace are small (to 4 inches) benthic-feeding
insectivores found in warm (San Benito River) or cool (San Lorenzo River)
streams. They are usually rare or absent where sculpins, another benthic
insectivore, are common. |
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| Sacramento Perch (Archoplites interruptus) FSC, CSC, possibly extirpated |
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Originally present in the Pajaro River, Coyote Creek and other lowland streams
connected to the Central Valley, this species has been extirpated from almost
all of its native range due to the introduction of more competitive sunfishes
from the eastern U.S. Sacramento perch have been introduced outside their
native range in California (including Crowley Lake east of the Sierra and
Clear Lake in Modoc County) and into other western and mid-western states
(including Pyramid Lake in Nevada) because they often do relatively well in
alkaline habitats stressful to other species. If reproducing populations of
Sacramento perch are present in the bioregion, they are probably in farm ponds. |
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| Tule Perch (Hysterocarpus traski) |
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This freshwater member of the surf perch family was extirpated from Coyote
Creek and the Pajaro River, but is still common in the Sacramento River
delta and portions of the central valley (including San Luis Reservoir).
Recently tule perch have been captured in Coyote Creek and in the Guadalupe
River system, apparently entering the streams from the San Felipe Pipeline
(from San Luis Reservoir) and other water distribution pipelines. Their
reappearance restores a species mostly lost from the bioregion (they persisted
in Lake Merced near San Francisco), but also indicates that other fish
and invertebrates, including exotic invaders, can enter Santa Clara Valley
streams from the Central Valley. |
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| Tidewater Goby (Eucyclogobius newberryi) FE |
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This very small (<2 inch) fish is restricted to coastal lagoons, and
apparently capable of only limited short-distance movements along the coast. Gobies
avoid strong stream flow and tidal action, and heavily depend upon summer
sandbar formation to produce calm water conditions for summer breeding
(ecologically, it is a lagoon goby rather than a "tidewater" goby). When
sandbars fail to form, the summer population explosions of this "annual" fish
usually do not occur. Gobies are tolerant of a wide range of salinities
(fresh to hypersaline), temperatures and dissolved oxygen conditions, but
have been lost from lagoons without backwater habitats to serve as winter
high flow refuges (including Waddell Creek). Some populations (Moran Lagoon
and Soquel and Aptos creeks) may be lost in flood years and be reestablished
from closely adjacent more secure populations (Corcoran Lagoon). Six populations
easily came through recent flood and drought years, and are probably relatively
secure (San Gregorio, Pescadero, Arroyo de los Frijoles, Baldwin, Wilder,
Corcoran). They are apparently present at 8+ other "at risk" sites that
are subject to severe flood or drought impacts (Scott, Laguna, Lombardi,
Younger, Moores, Moran, Soquel, Aptos, Pajaro). |
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