September 23, 2023

Hundreds of small, self-cloning sea anemones native to the Southern Hemisphere are quickly spreading in Tomales Bay, an occasion researchers say could possibly be the primary recorded sighting of the species above the equator.

After the anemone was reported final 12 months by means of 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 scholar 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, stated 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 stated. “So in a number of methods, it’s one thing out of a science fiction film when you’re considering of what can be the right invader from outer house.”

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

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

One other query researchers wish 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 below their tentacles that comprises stinging cells, the anemones battle one another for territory.

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

There may be additionally the query of how the anemones may influence Tomales Bay’s famend oyster farms. Sanford stated he doesn’t imagine the anemones will probably 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 stated.

Hog Island Oyster Co. co-owner Terry Sawyer stated he has not seen any impacts on oysters thus far.

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

Tomales Bay and the California coast aren’t any strangers to non-native or invasive species. Species have lengthy hitched rides on the bottoms of ships or in ballast water, finally detaching or being dumped into new territories by which they flourish. They can be launched by means of aquaculture or individuals dumping their aquarium pets right into a physique of water.