Global warming may be sending Hopkins rose nudibranch sea slugs much farther north than their typical habitat — although the exact reason why is leaving scientists scratching their heads.
Warmer ocean temperatures have caused the populations of the nudibranch to suddenly explode in Central and Northern California tidal pools, far north of their typical spots in Southern California, according to a Santa Cruz Sentinel report.
The sea slug, which is a brilliant pink color, is very rare north of San Francisco, but scientists have been finding them all over tide pools in the area.
Scientists believe that rare wind patterns have been heating waters along the West Coast, which has been allowing the nudibranch to survive. And there have been other species showing up as well, including a sea turtle typically found off the coast of Mexico and the Galapagos Islands, as well as humpback whales and dolphins in the Monterey Bay.
Researchers believe that a phenomenon known as upwelling is resulting in ocean temperatures that are 5 degrees higher than normal for much of 2014, resulting in water tempratures that are about 58 degrees in the Monterey Bay. Upwelling is when Northwesterly winds blow away water on the surface and bring up colder water from deeper down to replace it. However, scientists haven’t noticed these winds, said Logan Johnson, a National Weather Service forecaster who was quoted in the report.
The sea moss they feed on lives along the Pacific Coast up to British Columbia. Now that northward currents are carrying the slug’s larvae to tide pools, the upwelling isn’t washing them away, allowing them to stick around in northern areas.
Scientists believe that global warming may be to blame for this phenomenon, although they don’t yet know this for sure.