Unprecedented Number of Warm-Water Species Moved Northward During Marine Heatwave
Tropical Species Near San Francisco? New Range Limit Records Indicate Future Face of California Coast
By Kat Kerlin on March 12, 2019
During the marine heatwave of 2014-16, scientists from the University of California, Davis, noticed creatures typically seen only in places like Baja California, Mexico, showing up outside the UC Davis Bodega Marine Laboratory. These included warm-water species of jellyfish, crabs, nudibranchs, fish and even dolphins and sea turtles.
Their study, published today in the journal
Scientific Reports, documents an unprecedented number of southern marine species moving northward into California and as far north as Oregon. Of 67 rare, warm-water species sightings observed by the authors and citizen scientists, 37 had never been documented so far north before.
Among the 37 with new northern range limits are tropical creatures like the striated sea butterfly, which had not been found north of Baja. This is the first record of them in the state of California. Another unexpected visitor was the pelagic red crab, normally restricted to the waters off central and southern Baja. But during 2014-16, when water temperatures were 3.5 to 7 degrees Fahrenheit warmer than usual, the crabs were seen as far north as Newport, Oregon. And the molt of a spiny lobster an important fishery species in Baja turned up in Bodega Bay.
Species rarely or never seen in Northern California until the 2014-2016 marine heatwave. Top row from left: Hiltons nudibranch, blue buoy barnacle, short-beaked common dolphin, Olives nudibranch. Middle row: Spanish shawl nudibranch, violet sea snail, pelagic red crab, Hopkins rose nudibranch. Bottom row: brown booby, striated sea butterfly, glass-spined brittle star, scarlet sea cucumber
(Brown booby photo by Roger Harshaw; scarlet sea cucumber and striated sea butterfly by Eric Sanford; all others by Jacqueline Sones.)
Against the backdrop of climate change, we hope southern species will track northward because thats necessary for their persistence and survival, said lead author Eric Sanford, a UC Davis professor of ecology and evolution. Its perhaps a glimpse of what Northern Californias coast might look like in the future as ocean temperatures continue to warm.