Maine's sea stars ‘undergoing steep population declines'

Maine’s two common sea star species, the Forbes sea star (Asterias forbesi) and the northern sea star (Asterias rubens) have both been listed as “Species of Greatest Conservation Need” by the state. The 2016 listing claims sea stars are “undergoing steep population declines,” which, if unchecked, likely will lead to “local extinction and/or range contraction.”

“Since sea stars aren’t a commercial species, DMR (Maine’s Department of Marine Resources) devotes its limited resources to monitoring work versus population mitigation,” wrote Jeff Nichols, a senior DMR staffer, in an email.

Yet Maine’s sea stars are considered keystone species, meaning “they have a disproportionately large effect on their community,” said Giakoumis. “It’s important to protect them because they help keep other species in check, which increases stability and resilience in the entire ecosystem.”

The sea stars may already be helping themselves survive SSWD.

Giakoumis has documented that the hybridization of Maine’s two major sea star species is occurring from the southern Canadian Maritimes to New England.

“This adaptation perhaps provides genetic variation the species need to survive,” said Giakoumis.

McCracken also wants to know if and how the sea stars might adapt and survive. Last spring, he was awarded a three-year National Science Foundation Graduate Research Fellowship to study how thermal extremes impact physiological changes in echinoderms, work that has specific relevance for the Gulf of Maine.

“By the time it takes to unravel the possible multiple causes of SSWD, it may be too late,” said McCracken. “Working to protect the surviving populations is something I’m excited about. Are there actual traits that make them immune? Do they have the genetic capacity to adapt? These are the questions I hope to help answer.”

Getting the answers will take help from the community.

That’s why Giakoumis is working on an app that will allow citizen scientists and trained scientists to plug in data on when and where they see sea stars, and if they observe evidence of SSWD.

“Sea stars tend to be more visible in the summer when they come into shallower waters,” said Giakoumis. “In winter months they tend to stay in deeper water.”

The work by Giakoumis and McCracken will help us better understand SSWD and hopefully help scientists lessen future population declines. But we can help sea stars and all marine life now by “protecting what we can control,” said McCracken.

“By not overfishing and not raking the sea floor, we will protect marine habitat and give sea stars and other marine life the best chance of survival.”