100+ fish species could disappear in California due to climate change
Scientists believe that California may lose certain salmon species and other native freshwater fish species within the next century due to climate change if current trends continue. These species would then be ceding their habitats to non-native fish which are more resilient in warmer waters.
The study by scientists from the Centre for Watershed Sciences at the University of California, Davis (UCSD), published online in May in the journal PLOS ONE, assessed how vulnerable each of freshwater species in California is to climate change and gauged the probability that those species would go extinct in 100 years.
Of 121 native fish species, 82 per cent are likely to be driven to extinction or very low numbers as climate change decimates already low populations. In contrast, only 19 per cent of the 50 non-native fish species in the state face a similar risk of extinction, according to the study.
The species to disappear include coho salmon, most runs of steelhead trout and chinook salmon, Sacramento perch and obscure species of minnows, suckers and pupfishes, he stated.
“If present trends continue, much of the unique California fish fauna will disappear and be replaced by alien fishes, such as carp, largemouth bass, fathead minnows and green sunfish,” said Peter Moyle, a professor of fish biology at UC Davis who has been documenting the biology and status of California fish species for the past four decades.
Fish requiring cold water, such as salmon and trout, are particularly likely to die out, the study said, while non-native fish species are anticipated to thrive, although due to the stronger heat, some will lose their aquatic habitats during severe droughts and dry summers.
The top 20 native California fish most likely to become extinct in California within 100 years as the result of climate change include Klamath Mountains Province summer steelhead, McCloud River redband trout, unarmored threespine stickleback, Shay Creek stickleback, Delta smelt, Long Valley speckled dace, Central Valley late fall chinook salmon, Kern River rainbow trout, Shoshone pupfish, razorback sucker, Upper Klamath-Trinity spring chinook salmon, southern steelhead, Clear Lake hitch, Owens speckled dace, Northern California coast summer steelhead, Amargosa Canyon speckled dace, Central coast coho salmon, Southern Oregon Northern California coast coho salmon, Modoc sucker and pink salmon. Some of these are already listed as threatened or endangered.
Moyle believes some native species could avoid extinction if more cold water is stored behind existing dams and released during periods important to each species. Also helpful may be restoring access above large dams for some species, such as salmon, but it remains unknown if these efforts will help enough fish to protect entire populations, The Sacramento Bee reports.
Moyle expects the method presented in the study to be useful for conservation planning.