Tomales Bay invaded by self-cloning sea anemones from Southern Hemisphere

1000’s of small, self-cloning sea anemones native to the Southern Hemisphere are quickly spreading in Tomales Bay, an occasion researchers say may very well be the primary recorded sighting of the species above the equator.

After the anemone was reported final 12 months via a citizen science app, iNature, researchers on the College of California at Davis’ Bodega Marine Laboratory confirmed the species to be Anthopleura hermaphroditica, often known as the small brown sea anemone. The striped anemone, which is lower than an inch, is native to New Zealand, Australia and Chile.

UC Davis researchers, led by doctoral pupil Keira Monuki, are considering how the species may have an effect on the bay’s ecosystems.

One of many causes the anemones have unfold so efficiently in Tomales Bay is that they will reproduce asexually, mentioned Eric Sanford, a UC Davis biology professor. A single sea anemone may make 1000’s of clones of itself.

“They will proliferate quickly as a result of they don’t want one other particular person to breed. They will simply spit out these genetically similar clones of themselves,” Sanford mentioned. “So in a variety of methods, it’s one thing out of a science fiction film when you’re pondering of what could be the right invader from outer house.”

Sanford mentioned genome sequencing will permit researchers to estimate what number of anemones first colonized Tomales Bay. It’s attainable, he mentioned, that the 1000’s of anemones matting the intertidal areas in japanese Tomales Bay got here from only one or two people.

The anemones additionally host a symbiotic algae that shall be researched to find out if it influenced the species’ profitable proliferation in Tomales Bay.

One other query researchers want to reply is whether or not the anemone will compete with native species within the bay, together with one often known as the aggregating sea anemone. Utilizing a club-shaped organ hidden beneath their tentacles that incorporates stinging cells, the anemones battle one another for territory.

“Anemones could have these aggressive interactions and one will quit and shut up or drift away,” Sanford mentioned. “What we need to know is that if this launched anemone from far off is it out-competing the native anemone.”

There’s additionally the query of how the anemones may impression Tomales Bay’s famend oyster farms. Sanford mentioned he doesn’t consider the anemones shall be a risk. Whereas oysters filter algae within the water for his or her meals, anemones use their tentacles to seize small marine critters or zooplankton.

“There shouldn’t be direct competitors for meals or something like that,” Sanford mentioned.

Hog Island Oyster Co. co-owner Terry Sawyer mentioned he has not seen any impacts on oysters to this point.

“That’s the excellent news,” Sawyer mentioned. “The dangerous information is that we nonetheless are involved as a result of it’s an ecosystem out of stability and all of us have to be taking note of that, what area of interest they’re occupying and displacing. Now that they’re right here, we’ve to look at what’s happening.”

Tomales Bay and the California coast are not any strangers to non-native or invasive species. Species have lengthy hitched rides on the bottoms of ships or in ballast water, ultimately detaching or being dumped into new territories during which they flourish. They may also be launched via aquaculture or individuals dumping their aquarium pets right into a physique of water.