Fish Species Affected by Passage Barriers in California


Anadromous Species


California streams and rivers with access to the ocean were historically home to several native anadromous fish species. These include Chinook salmon, coho salmon, steelhead/rainbow trout, coastal cutthroat trout, green and white sturgeon,pacific lamprey, river lamprey, eulachon, and threespine stickleback. American shad and striped bass are also prevalent non-native anadromous species in many systems.


Green sturgeon life cycleHistorically, anadromous fish passage efforts in California have focused on Chinook salmon, coho salmon, and steelhead. Pink salmon have only occurred rarely in California since the latter half of the 20th century. Chum salmon are slightly more common that pink salmon, but are still highly limited in California. Coastal cutthroat trout are a State of California Species of Special Concern, but have no federal status and have generally not been the focus of fish passage efforts. Passage impacts on green and white sturgeon are almost exclusively limited to large dams and therefore, passage improvement projects for sturgeon are complex, expensive, and not common. Currently, there are efforts across the Pacific Northwest to analyze and mediate the impact of barriers on lampreys. These efforts are often linked to passage projects associated with salmon and steelhead and once refined, will likely consist mainly of additions or alterations to traditional salmonid passage designs. Passage does not likely have a major impact on eulachon as they are found in the lower reaches of coastal rivers and streams and spend very little time in freshwater. Finally, threespine sticklebacks are highly adaptable and show a wide variety of life history strategies that likely greatly reduce the impact of barriers.


Other Species


Beyond anadromous fish species, California has a fairly limited number of species that are federally listed or included in the State Wildlife Action Plan (SWAP) that occur in anadromous waters. Delta smelt are listed as threatened under the federal and California Endangered Species Acts (ESAs). Longfin smelt are listed as threatened under the California ESA but are not listed federally. Both delta and longfin smelt have been subjected to massive changes in their native habitat and environment but passage is not considered an important factor in these species declines.


Shortnose suckers are listed as endangered under the federal and California ESAs. Klamath largescale suckers are included in the SWAP but are not listed under the federal or California ESA. Both of these sucker species are uncommon in the anadromous reach of the Klamath River.


The Forum will continue to focus on fish passage assessment, prioritization, and implementation for salmonids and lamprey. Also, the Forum will consider actions to address other anadromous and resident species in anadromous watersheds as the need arises and cost-effective passage methods are developed.