Anadromous Fishes of California's Central Coast Region

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An environmental summary created by the ENVS 560/L Watershed Systems class at CSUMB.

This page lists all of the anadromous fish found within the California Central Coast Region, and includes a small description about each species. Specific information about salmonids in the region can be found in the Salmonids in California's Central Coast Region: Salmon, Trout, and Steelhead page and general information regarding anadromous fishes in the Pacific Northwest can be found on the Anadromous Species of Washington, Oregon, and California page.


Anadromous fish are born in freshwater, and generally stay in freshwater through their juvenile stage. As they mature anadromous fish migrate into brackish estuaries and the ocean. Anadromous fish spend the majority of their lives in the ocean to feed and gain mass and only return to freshwater to spawn. This is the opposite of catadromous fish, who are born in a marine environment but spend the majority of their life in a freshwater environment [1].

There are many species of anadromous fish in the California Central Coast Region. Some types of anadromous fish like salmonids return to the same tributary they were born in to spawn. It is postulated that they have the ability to use a combination of the earth's magnetic fields and their sense of smell to navigate back to the same tributaries they were born in [2]. The spawning migration can often be grueling on anadromous fish. Pacific Salmon stop eating and use their remaining fat stores to fuel them during the spawning migration causing them to perish after spawning [3]. Pacific Lamprey and Armored Threespined Stickleback also perish after they spawn. Steelhead and Striped Bass can survive the spawning migration and may have multiple spawning migrations throughout their lives.


There are three species of salmonids found in the California Central Coast (CCC) Region: Rainbow trout, Coho Salmon, and Chinook Salmon. Declines in their populations from human development, fishing pressure, and climate change has necessitated state and federal recovery plans to ensure their conservation.[4] Chinook salmon are encountered by commercial and recreational ocean fisherpeople during periods of a given year, however, there are no known naturally reproducing populations of Chinook salmon in CCC region watersheds.[5].

Coho Salmon

Coho salmon (Oncorhynchus kisutch), commonly referred to as Silver salmon, are among the most resilient of the Pacific salmon species and are observed to spawn (reproduce) in streams as far south as Aptos Creek in Santa Cruz County. In the Central Coast Region there are seven populations of Coho salmon, all of which are found in the northern section of the region and are part of the Central California Coast Coho Salmon (COCCC) DPS.[6]. More information about the struggles Coho Salmon have faced in California can be found on the Coho Salmon Crisis page.

Rainbow trout

Rainbow trout (Oncorhynchus mykiss) have the greatest migratory diversity of any salmonid.[7] Many populations in the CCC Region are composed of both anadromous and non-anadromous individuals, making management and conservation in the region challenging. When rainbow trout do not migrate to the ocean as juveniles and remain in freshwater they are described as resident rainbow trout. Rainbow trout that migrate to the ocean as juveniles and return to freshwater as adults to spawn are described as Steelhead or Steelhead trout. Though juvenile fish from multiple populations may enter the ocean from the region's numerous coastal streams, adaptations enable many of these steelhead to return and spawn in the same stream where they were born. Over many generations, this has resulted in subtle differences between populations from different sections of the California coast.

The CCC Region is a section of California's coast where multiple of these distinct population groups overlap. These groups are collectively called Distinct Population Segments (DPS), and there are only DPS designations for steelhead trout and not resident rainbow trout in California. The three Steelhead DPS in the CCC Region are...

  • Central California Coast Steelhead (STCCC) DPS
  • South-Central California Coast Steelhead (STSCC) DPS
  • Southern California Steelhead (STSCA) DPS

Chinook Salmon

Chinook salmon (Onchorhynchus tshawyatscha) are commonly called king salmon, and support substantial commercial and recreational (sport) fishing industries on the California coast. Anthropogenic factors have lead to a decrease in their abundance and diversity throughout California, with most individuals in remaining populations being of hatchery origin.

While there are no spawning populations of Chinook salmon in the CCC region, the Monterey Bay Salmon and Trout Project (MBSTP) participates in an annual stocking program with the California Department of Fish and Wildlife (CDFW) to support local fishing industries. Juvenile salmon are transported (trucked) from the Central Valley (Sacramento River Watershed) fish hatcheries to the Monterey Bay and released as part of a state-wide hatchery supplementation strategy to abate fishing pressures on threatened and endangered stocks, and promote economic stability in local coastal communities.

Other Anadromous Species

Pacific Lamprey

Lamprey are in a primitive group of fishes called Agnathans that are identified as being jawless. Lamprey have an eel-like appearance, no paired fins, and usually a dorsal and caudal fin. Pacific lamprey (Entosphenus tridentatus) spawn similarly to salmon, migrating up rivers to lay eggs in gravel and die. Unlike most or all other anadromous fishes, their life-cycle involves a larval form called an ammocoete. Ammocoetes filter feed fine sediments for the first few years of life before metamorphosing into juveniles and migrating to the ocean. As juveniles and adults, these lamprey parasitically attach themselves to host fish to feed on blood and tissue. After a couple of years in the ocean, Pcific lamprey return to freshwater streams to spawn and continue the cycle.[8] They are not listed as a species of special status on the California Endnagered Species Act, but they are listed as a species of concern under the Federal ESA.[9][10]

Armored Threespine Stickleback

Sticklebacks are a scaleless fish that are characterized by having strong, clearly isolated spines in their dorsal fin. Threespine sticklebacks (Gasterosteus aculeatus) are native to California and similar to rainbow trout, their life history is highly variable. Not only can a single population have anadromous and resident individuals, but they can spawn in freshwater or saltwater. Threespine sticklebacks do not have scales but have the potential for developing a natural armor plating if their is a high abundance of predators in their habitat. Though the degree of armor plating can vary within a population, there are two subspecies that exist in California: armored and unarmored.[11] The unarmored variation is listed as endangered under both the CESA and ESA while armored threespine sticklebacks are quite widespread and do not hold any special listing status in California.[9][10]

Striped Bass

Striped Bass (Morone saxatilis) were first introduced to the Sacramento Delta in 1879. Striped Bass naturalized and migrated quickly along the California Central Coast , because of their prolific nature. Striped Bass spawn from April to Mid-June in open swift waters and prefer water temperatures between 61-69 degrees Fahrenheit. A five pound Striped Bass has the ability to spawn 180,000 eggs in one season [12]. . After their spawn many Striped Bass migrate into brackish and saltwater to feed. Striped Bass feed on small fish, and shrimp. They are considered an Invasive Species of California's Central Coast Region, because they consume juvenile steelhead and compete for the same food sources with adult steelhead. The Carmel River Steelhead Association is advocating for the removal of Striped Bass from the Carmel River Lagoon, in order to protect native steelhead populations [13].



  1. Bloom D, Lovejoy N. 2014. The evolutionary origins of diadromy inferred from a time-calibrated phylogeny for Clupeiformes (herring and allies). Proceedings of the Royal Society B: Biological Sciences. 281(1778):2013-2081
  2. Zielinski S. February 7, 2013. Animal Magnetism: How Salmon Find Their Way Back Home. National Public Radio [Date accessed 2020 April 8]
  3. United States Geological Survey. (date unknown). Why do salmon change color and die after they spawn?.[Date accessed 2020 April 8]
  4. California Department of Fish and Wildlife. Salmon and Steelhead. Ocean Protection Council. [accessed 2020 Apr 8. ]
  5. MBSTP chinook salmon release program. Monterey Bay Salmon and Trout Project. [accessed 2020 Apr 8.]
  6. Coho Salmon ESU. 2003. Central California Coast-NOAA [ds804.]
  7. Barnhart R. 1986. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Pacific southwest) -- steelhead. United States Fish and Wildlife Service, Biological Report 82(11.60). United States Army Corps of Engineers, TR EL-82-4. 21 pp.
  8. Pacific Lamprey - Fact Sheet. 2007. United States Fish and Wildlife Service.
  9. 9.0 9.1 Listing of Endangered Species, California Endangered Species Act. 1970. California Department of Fish and Wildlife (CDFW).
  10. 10.0 10.1 Federal Endangered Species Act. 1973. United States Environmental Protection Agency.
  11. Fuller, P., K. Dettloff, and R. Sturtevant, 2020, Gasterosteus aculeatus Linnaeus, 1758: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL,, Revision Date: 9/12/2019, Peer Review Date: 2/6/2015, Access Date: 4/13/2020
  12. California Department of Fish & Wildlife. (Date Unknown). Fishing for Striped Bass Biology & History[date accessed 2020 April 8]
  13. Schmalz D. September 21, 2017. Just as the Carmel River is bouncing back, its most iconic species—steelhead trout—are under attack. Monterey County Weekly


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