It’s a brief but spectacular sight for a few lucky boaters on Long Island Sound particularly near the mouth of the Connecticut River — a plus-sized fish leaping out of the water and returning with a prodigious splash. The fish in this case is the Atlantic sturgeon, a behemoth that can grow to more than 14 feet long and 800 pounds. Leaping, called breaching, may be a form of communication and is a signature behavior.
The Atlantic sturgeon is anadromous, meaning it spends adulthood at sea, swimming to reproduce below the fall line of rivers from Quebec to Georgia. Although imperiled due to dams, pollution, and overfishing — its eggs are caviar — Atlantic sturgeon still show up in the Sound, especially in spring and fall, and may even be resuming their spring spawning runs up the Connecticut River after a generations-long absence.
An abundance of small fish and invertebrates make the Sound an attractive feeding ground for sturgeon, which vacuum the bottom with their toothless mouths, said Jacque Benway, who inherited an ongoing research program at the state’s Department of Energy and Environmental Protection from the agency’s sturgeon guru Tom Savoy, recently retired.
Benway told CT Examiner she was excited about the possible resumption of Atlantic sturgeon spawning in the Connecticut River and encouraged citizen scientists to take part in a DEEP Sturgeon Sighting Survey.
Using the website, you can report encountering the Atlantic sturgeon or its smaller, look-alike Connecticut River cousin, the shortnose sturgeon, which can grow to 40 inches long. Sighting reports help fill in the blanks about sturgeon in area waters, even of dead specimens, like the seven-foot Atlantic sturgeon that washed up on a riverbank in Lyme in 2014 and the five footer found on White Sands Beach in Old Lyme two years ago.
Commercial fishermen on the Sound also occasionally net Atlantic sturgeon as a bycatch. Word around the shoreline this past season was that a dragger from Clinton caught and released a nine-footer. Benway said she wished commercial fishermen would report sightings but said he understands why they may be “uncomfortable about it.”
Many fishermen chafe under the increasing regulation of the industry and prefer to keep government agencies at arm’s length. Benway offered assurances that they need not worry and could be an important source of information.
There are more than two dozen species of sturgeon, a fish changed in form, if not genetically, since it shared the waters with plesiosaurs and ichthyosaurs more than 150 million years ago. Sturgeon retain primitive traits. Instead of a backbone, they have a flexible, cartilaginous notochord running dorsally. Modified scales called scutes armor sturgeons against many predators but not against human activities that threaten their survival.
Atlantic sturgeon ceased spawning in the Connecticut River generations ago but the discovery of 64 tiny young in the river hint that hiatus may over. Surveys by biologists of the Connecticut Department of Energy and Environmental Protection, published in 2017, revealed that the small sturgeon, an inch or two long, were collected from Deep River and south. Fish that small could not have migrated from the sea, said Benway, so they must have resulted from spawning in the river. “We were floored,” she said of the discovery.
There is good news about the shortnose sturgeon as well. It is believed shortnose sturgeon spawn below the dam at Turners Falls, Mass. A fish lift that carries them up and over the Holyoke dam to the south provides upstream access. Turners Falls was assumed to be the upstream limit for the species but in 2017 an angler caught one north of Turners Falls, below the dam in Vernon, Vermont. Fisheries biologists were amazed. Then, in 2022 and 2023, two different people captured footage of sturgeon upstream, one taken just below the dam at Bellows Falls, Vt.
Dr. Kate Buckman, aquatic ecologist with the Connecticut River Conservancy, a conservation organization based in Greenfield, Mass., began sampling waters above Turners Falls for shortnose sturgeon DNA last June and July and found with traces that proved the fish were indeed there. How the sturgeon got there, says Buckman, is a mystery but, “It’s very cool.” The fish could have not traveled over fish ladders at Turners Falls dam because this mode of transport does not work for sturgeon. “It may be a population that has been there for hundreds of years. We just don’t know,” Buckman told CT Examiner.
Typically, Atlantic sturgeon showing up in the Sound come from a variety of breeding stocks along the Atlantic coast. All are officially endangered or threatened. Sizeable numbers still spawn in, at most, 20 rivers, including the Hudson and St. John River in New Brunswick, Canada. Benway said the juveniles found recently in the Connecticut River possessed genetic traits of those from south stock.
Benway and her colleagues have been tracking sturgeon with acoustic telemetry technology, a prime tool for scientists studying marine animals, including sharks. Hydrophones pick up ultrasound signals from transmitters attached to sturgeon released back into the water. Each transmitter has a unique identification code allowing individuals to be tracked.