Nature Notes

LARRY PENNY

A major cold snap is in store. Up until now, it's been rather balmy. Unlike the oaks, many of the Norway maples still have leaves that are more green than yellow. Dolphins are still playing in our bays; warm-water fish species linger in the seas.

Though Halloween came by, the frost has yet to touch the pumpkin.

The dolphins will swim away, the warm-water fish will beat a slow retreat, the sea turtles an even slower one; they don't swim very fast. Studies have shown that if they don't get south of Montauk Point by the end of November, they will likely spend their winter in the North - and that spells doom!

A Busy Year

Sea turtles like their water on the tepid side. Once it falls below 50 degrees, it can be fatal.

Robert DiGiovanni of the Riverhead Foundation for Marine Research is stranding supervisor of the state Marine Mammal and Sea Turtle Stranding Program. It's been a busy year.

In the spring, it was a never-ending stream of sick seals. In late summer, it's been eclectic dolphins. And now Bob is gearing up for cold-stunned sea turtles. They'll be showing up at his doorstep any day now.

Thus far, 1998's population of marine turtles in local waters is approaching normality. About 30 turtles have been reported, the most unusual of which was the big green female that came ashore to fashion a nest on an Amagansett ocean beach in midsummer.

Loggerheads, Ridleys

In 1997, not counting hypothermic turtles and cold-killed turtles, the Riverhead Foundation recovered about the same number.

Loggerheads and Ridleys have headed this season's list of stranded and captured turtles. Green turtles are the next most common; then come the largest, the leatherbacks. (Two years ago, the foundation recovered a dead leatherback that tipped the scales at just over 1,000 pounds.)

The fifth Atlantic species of sea turtle, the hawksbill, very rarely makes it as far north as Long Island. One was found here after the hurricane in 1938.

Gigantothermy

When the cold hits, the numbers shoot up. Last year, 14 cold-stunned or cold-killed turtles were collected from Long Island waters and beaches - how many will it be this year?

The smaller the turtle, the more susceptible it is to falling temperatures. That is why the diminutive Ridleys make up the large majority of the turtles stranded in November and December.

In fact, one turtle, the leatherback, is able to maintain its body temperature above ambient levels, the way tunas can, and, perhaps, dinosaurs could. Bob DiGiovanni refers to this ability of some mammoth cold-blooded animals to keep warm when it is cold as "gigantothermy."

Quick Freezes

The little Ridley does not practice gigantothermy, and it is a sitting duck for quick freezes.

The Ridley does have an advantage over the others with respect to boat collisions, however. First, at just 12 to 20 inches long, it is the smallest target of the five Atlantic species.

Second, it can stay down for 300 minutes, so it is not as likely to be found at the surface as often as the others. The leatherback can dive the deepest, to 1,000 meters, but its dives are short, 10 times shorter than the Ridley's.

Moreover, the Ridley doesn't eat jellyfish, salps, or other gelatinous blobs like the leatherback. It feeds on bottom shellfish and other benthic organisms. It is therefore not likely to swallow a wafting balloon thinking it is prey.

On average, local waters reach the danger threshold on the 20th of November and stay that way until the end of April. Since 1980, the Riverhead Foundation (nee Okeanos) has logged 290 cold-related sea turtle recoveries in Long Island waters, of which 95 have come in alive. Of those 95, 57 survived and were released.

The most active period of recovery is between December 1 and Dec. 20, during which 80 percent of the cold-stranded turtles are found.

Rudderless

Long Island Sound beaches account for 70 percent of the cold-stunned turtles. Interestingly, most of these are found on the eastern half of Long Island, from Riverhead to Orient Point.

There is the suggestion that, once hypothermic, the turtles drift with the winds, which tend to be northwesterly in November and December; the turtles move south and east.

It is also hypothesized that some of these Long Island Sound strandings are turtles that summered in New England waters; while trying to get back south, they become rudderless because of the cold and were swept into the Sound by tides and currents.

Of the 290 turtles, 66 percent were Ridleys, 29 percent loggerheads, and 5 percent greens. Because their size makes them so vulnerable to even short periods of exposure, only 14 percent of the cold-stunned Ridleys survive.

Eyes And Ears

If it weren't for the foundation and its cadre of volunteers and cooperators and, in general, the eyes and the ears of the public who walk the beaches, there would be no survivors.

Out of water, exposed to the rigors of December wind chills, the turtles die in a matter of a few hours.

It sounds like a lot of trouble, doesn't it. But when you realize that the number of Atlantic Ridley females that actually breed is only 1,400 or so, and can be as few as 400 in any given year, the 18 Ridleys that the foundation has saved and rehabilitated, most of which are females, still adds up to a lot!

Immediately

The trick in rescuing these rare beauties is finding them and immediately reporting them to the foundation via their hotline, 369-9829. A cell phone helps.

As they say in the public television and public radio business, "Bob and his helpers are standing by to receive your calls."

To all of you beachwalkers and beachdrivers, to all of you fishermen and fisherwomen: May you be diligent, watchful, and circumspect, and may you find that cold-stunned turtle on the beach before nature claims it first.