(CN) — A petition seeking to extend federal wildlife protections to spring-run Chinook salmon found along Oregon’s coast has merit and could warrant listing the fish under the Endangered Species Act, the Trump administration said Friday.
The spring-run salmon are the main food source for the Southern Resident killer whales, an endangered population of orca living in the Pacific Northwest.
Chinook salmon populations are also found in Washington state, Idaho and California.
The National Marine Fisheries Service (NMFS) decision came after a 90-day review process and means the Chinook salmon could be listed as threatened or endangered pending an additional one-year in-depth analysis.
After the year-long study, the agency could determine that the salmon — scientific name Oncorhynchus tshawytscha — could be listed as a threatened or endangered Evolutionarily Significant Unit, or ESU, under federal law.
The process will allow scientists, commercial fishing representatives, wildlife advocates and others to submit additional information on impacts stemming from protecting the salmon population and its habitat under the Endangered Species Act.
The salmon could be listed as endangered if it faces the threat of extinction throughout its range or “threatened” if it’s likely to become endangered in the foreseeable future.
Destruction of fish species’ habitats, the presence of commercial fishery operations, disease and predation, and the lack of regulatory protections all factor in federal agencies’ decision-making.
The federal agency determined in 1999 that four segments of spring-run and fall-run Chinook salmon on the Oregon coast should not be listed under the act.
Those segments lived in river basins stretching from the Elk River in Oregon north to the mouth of the Columbia River.
The review did find, however, that spring-run and fall-run Chinook salmon in the Snake River, Columbia River and Sacramento River drainages were separate ESUs.
Conservation groups Native Fish Society, the Center for Biological Diversity, and Umpqua Watersheds submitted a new petition in September 2019 specifically for spring-run salmon.
“The petitioners assert that new research into the genomic basis for premature migration in salmonids demonstrates that significant genetic differences underlie the spring- and fall-run life history types, and that the unique evolutionary lineage of spring-run Chinook salmon warrants their listing as a separate ESU,” the fisheries service wrote in a 24-page memo issued Friday.
The petition cites, as evidence for its argument, recent scientific surveys of genetic variation between mature and premature-migrating populations of steelhead and Chinook salmon from California, Oregon, and Washington state.
“The petitioners suggest that the results of these studies indicate that premature migration (e.g. spring-run Chinook salmon) arose from a single evolutionary event within the species and, if lost, is not likely to re-evolve in time frames relevant to conservation planning,” the memo said.
The Oregon Department of Fish and Wildlife’s Coastal Multi-Species Conservation and Management Plan found that independent spring-run Chinook salmon populations are only found in the North and South Umpqua Rivers, the petition said.
Conservation groups also point to historical and ongoing logging operations and dam construction in Oregon as a major factor in destruction of salmon habitat.
“The petitioners also assert that timber harvest and road construction harm [Oregon Coast] spring-run Chinook salmon by altering stream flow, increasing sediment loading, contaminant concentrations, and temperatures, and decreasing dissolved oxygen,” the memo said. “The petitioners further assert that dams, water diversions, and other barriers impact OC spring-run Chinook salmon by blocking suitable riverine habitat, impeding migration, and reducing water quality and quantity.”
The groups request that any listing under the act include a designation of critical habitat for the salmon population.
The federal agency determined in 1991 that while Pacific salmon are a distinct population under the act, further review could warrant listing segments as ESUs if they reproduce in separate areas and represent a key component in the “evolutionary legacy of the species,” the memo said.
Spokespersons for the conversation group petitioners did not immediately respond to a request for comment.
The fisheries service is a division of the National Oceanic and Atmospheric Administration under the U.S. Department of Commerce.