Tisbury shellfish constable Danielle Ewart began getting calls a few days ago from her commissioners about the dead scup on the Lagoon Pond beaches. And Times contributor Jonathan Burke wrote to tell us of scup littering the beach at Tashmoo.
“It seems to happen every year,” Ms. Ewart said, recalling an article by Matt Pelikan that documented a kill last January (“Wild Side: Fish bodies on the Lagoon, as far as the eye could see”). “People have been telling me they’ve seen them over at Medeiros Cove from the Hudson Avenue extension.”
According to Ms. Ewart, the fish were likely “cold stunned.” She attributed the event to a combination of a cold snap and an extreme low tide this past week. Ms. Ewart uses the tide chart at USHarbors as a reference, which shows the afternoon low tides as 0.4 feet below mean sea level (the low for the month) for three days, Dec. 13 to 15, near the full moon.
As Mr. Pelikan documented in his article last January, scup kills due to cold snaps are common. “In New England,” reads the Division of Marine Fisheries webpage for the species, “water temperatures in early fall occasionally plunge below the scup’s tolerance level, killing large numbers of fish.” Scup (also known as “poagies” or “porgies”) do not like it when the water temperature falls below 45°, according to the DMF. Their range extends from Cape Hatteras to Cape Cod, so the Vineyard is near the northern edge of its range. They generally migrate offshore and southward after October, in order to avoid colder temperatures.
“They decided to stay here a little longer than they should have,” said Dave Grunden, the shellfish constable for Oak Bluffs. When asked if scup had an effect on the shellfish larval population, Mr. Grunden said he believed they generally fed on smaller fishes, and did not have an impact on shellfish.
A check on the beach near Lagoon Heights on Monday afternoon revealed no dead fish remaining there.