Nature Notes: Will Terrapins Endure?

The eastern diamondback terrapin is semi-marine and an inhabitant of our local waters
Jean Held spotted this eastern diamondback terrapin hatchling at Havens Beach in Sag Harbor last week and helped it to safety at Little Northwest Creek. Jean Held

It is the time of the year when migration at sea is almost over for the bluefish, striped bass, and marine turtles. The marine turtles — green, leatherback, loggerheads, and Kemp’s ridleys — are sluggardly in their movement south and don’t swim faster than most people walk. The endangered ridley, the smallest of them all, is the slowest and very often gets cold-stunned and washes up on our shores before it gets to warm water. If you find one dead or alive, please call the Riverhead Foundation for Marine Research and Preservation.

There is a fifth local turtle — the eastern diamondback terrapin — that is semi-marine and an inhabitant of our local waters, especially those subject to dilution with freshwater. It’s been here as long as the first European settlers. It frequents lagoons and tidal creeks. If you wait long enough at, say, Accabonac Harbor, Hog Creek, Northwest Creek, or Georgica Pond, you are liable to see one come up for air.

Across the bay in Mattituck, where I grew up, the diamondback was still called a torrup, a local Native American word of Algonkian origin. It is a smallish turtle, rarely a foot long, and is flatter than the familiar box turtle, which is almost strictly terrestrial. Come winter it behaves like the box and our freshwater turtles, finding a quiet spot in the mud and staying there until spring. You begin to see its head bobbing up here and there by the end of March.

Come May and June if you walk on Sammy’s Beach at the mouth of Three Mile Harbor you may find a female making its way inland, up and down over the low dunes, looking for a spot to lay her eggs. The eggs are half the size of a chicken egg and have a leathery coating rather than a hard shell. If you don’t find a turtle in the flesh, you may find a set of turtle tracks leading from the water into the sand or parts of turtle eggs from a nest that has been savaged by a raccoon.

They have a reproductive cycle comparable to that of the box turtle and snapping turtle. Females excavate a shallow nest in a sunny place and deposit their eggs, covering them with some sand to protect them from would-be marauders. The eggs are laid in May and June and hatch out the end of August or in September. 

As with other aquatic turtles that hatch in land nests, then seek waters to grow up in — as the snapping, painted, spotted, mud, and musk turtles — the hatchlings are about the size of a silver dollar and somehow know how to make their way to the nearest creek, bay, or lagoon, where they take up their aquatic lifestyles.

On land they can be preyed upon by foxes and raccoons. They can’t defend themselves like snapping turtles, and they can’t pull all their limbs, tail, and head into the shell and seal the edges of it as the box turtle can.

Some of these hatchlings find themselves stranded and succumb or are predated. Jean Held was at Havens Beach in Sag Harbor last Thursday and found one that seemed to be lost. The area was loaded with gulls, which would find such an object fit for eating. So, after photographing it, she let it go in Little Northwest Creek in a safe spot where it runs under the road on the way to the Sag Harbor Golf Course. 

Every once in a while there is a massive diamondback terrapin die-off similar to a fish kill when the water becomes too befouled and the dissolved oxygen level reaches dangerous lows. Such a die-off happened in Flanders Bay in the Peconic Estuary three years ago during a harmful algae tide in May and massing of menhaden in shallow coastal waters. 

Diamondbacks are also caught in crab and conch traps, and hit by the props of motorboat engines. 

Once a common ingredient in soup, diamondbacks were formerly fished for money, but their populations dropped to the point where the various Atlantic states put them under protection. In Rhode Island they are considered endangered, in Massachusetts threatened, and in most of the other coastal states from Florida into Canada they are a species of “special concern.”

New York State has lagged behind the others, but as of May 1 of this year, diamondback terrapins can no longer be harvested commercially.


Larry Penny can be reached via email at Larrypenny9@gmail.com.