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Invasive Species Haven’t Made The Bering Sea Their Home…Yet

Feb 7, 2018

 

Reaserchers ranked the European green crab as one of the biggest invasive species threats for the Bering Sea.
Credit Courtesy of Washington Sea Grant

Native species are well adapted to living in the challenging environment of the Bering Sea, but increased shipping means there are more opportunities for invasive species to hitch a ride in. And as the waters warm, the ecosystem will become more hospitable making it easier for them to settle.

Zoologist Jesika Reimer is part of a team studying the threat.

“What we really wanted to do was look at what invasive species have the potential to arrive,” Reimer said. “We wanted to know where should we be looking for them — so, what ports are getting a lot of traffic? And we wanted to know if a species arrives, can it survive?”

 

The reason to focus on the Bering Sea was twofold — first, there aren’t really invasive species there yet and second, it’s one of the largest commercial fisheries in the world and serves as a link to the Arctic.

For the past three years, the team at the Alaska Center for Conservation Science has been compiling data to identify the largest threats. At the top of the list researcher Amanda Droghini says are species that are geographically nearby, reproduce quickly, change their environment or are in direct competition with existing species.

One of the biggest threats is the European green crab.

“The European green crab tends to be a very voracious hungry predator with a high reproductive rate,” Droghini said.

While the green crab can survive in the Bering Sea right now, Reimer says it can’t reproduce.

“It’s not warm enough for them to have offspring and for those offspring to survive, grow, become adults and go on to reproduce themselves, Reimer said. “But when we do look at the climate models and we look in the future we see that as things are warming up we jump over this threshold where European green crab weren’t able to reproduce, where now it opens up so they can.”

Removing invasives once they have taken root is challenging on land, but it is especially difficult in marine environments. So the researchers believe taking a proactive approach will help keep non-native species at bay.

Ideally all of Alaska’s coastline would be monitored — scientists would keep tabs of what organisms exist in a given area and look for changes. And Droghini says there is some monitoring right now being done in Dutch Harbor, Nome, and the Pribilof Islands, but the efforts are patchy and dependent on funding.

“Without a consistent monitoring program how will we ever be able to detect the species when they arrive?”Droghini said. ” We know that the earlier we detect them the greater chance we have of eradicating them”

The next step for the science is fine tuning the modeling to imagine if invasives arrive how they might spread through the Bering Sea and might interact with the existing ecosystem.

Without strict international regulations, ships may continue to — knowingly or unknowingly — transport non-native species wherever they travel.

The Bering Sea has kept invasives at bay for now, but warming waters look to make it a more welcoming environment in the future.