On North American shores, student and faculty researchers at Monmouth University have recorded the first confirmation of the anemone species Actinia equina, also known as the beadlet anemone.
A common inhabitant of the rocky coastlines of the British Isles and Northern Europe, the anemone has found a new home which bears some similarities – the jetties that protrude into the waters of the New Jersey Shore. The team located the anemones on a half-dozen beaches from Long Branch to Manasquan in Monmouth County.
“We don’t really have the kind of rocky ecosystems where they thrive here in the Mid-Atlantic, but they have invaded the human-made groins that were constructed decades ago for sand retention,” said Diederik Boonman, a senior marine and environmental biology and policy student at Monmouth. “The boulders provide the shelter, structure and food that make for a hospitable habitat in an otherwise sandy environment where they wouldn’t survive.”
Boonman first encountered the anemones while cataloging marine life in the intertidal zone at a beach near campus as part of a homework assignment. Neither he nor Endowed Professor of Marine Science Jason Adolf recognized what they were seeing, and a review of existing literature and databases didn’t turn up any likely matches known to live in the region. Around that time, a few other local beachgoers had posted pictures of similar specimens on a crowdsourcing website where nature enthusiasts and scientists can share information about wildlife and plants they’ve encountered. None were sure what they had found.
But Adolf and Boonman continued the search and consulted with anemone experts from around the globe, including James Carlton of Williams College and Craig Wilding of Liverpool John Moores University (U.K.). The group zeroed in on the likelihood that it was Actinia equina but needed verification. A comparison of DNA samples from one of the New Jersey anemones and a native specimen provided by Wilding in England turned up a match.
“It is a privilege to work with motivated and enthusiastic students like Diederik to document important changes to the marine fauna of our region like this,” Adolf said. “The next step is to expand what we know about this anemone’s distribution and how it fits in with the local ecosystem.”
Although the species can be a variety of colors, the ones located in New Jersey have a blue ring at their bottom, pale green bodies, and matching green tentacles with blue tips. They are known as aggressive predators which use their tentacles to capture small fish, crabs and mollusks, then retract them and close up during low tide to conserve moisture.
While their tentacles do produce a toxin to stun prey, they don’t pose a serious threat to humans and can’t penetrate the skin, Boonman said. They also tend to live in the crevices between the rocks, where bathers are unlikely to come in contact with them.
The researchers believe the anemones most likely arrived as hitchhikers aboard an international ship traveling to the Port of New York/New Jersey. They release clones into the water that can float and survive extreme conditions until they find a surface to cling to, Boonman said. These juvenile organisms may have been discharged in a ship’s ballast water or from an anemone living on a hull, then carried by the currents from the New York Harbor area to Northern Monmouth County.
Boonman and Adolf are working on a GIS map showing the locations of sightings in the area in an effort to track their spread. Anyone who sees one is asked to email jadolf@monmouth.edu with the date and location of the observation.
A study by the group, “First record of the sea anemone Actinia equina (Cnidaria: Anthozoa) on the Mid-Atlantic coast of the United States,” was published this month in the Journal of the Marine Biological Association of the United Kingdom.
