A Nature Wade At Napeague Harbor

I recently joined two colleagues from the Group for the East End, Steve Biasetti and Anita Wright, for a “nature wade” on the east side of Napeague Harbor close to the entrance to the Walking Dunes nature trail.Armed with hand nets and a two-person seine, we waded out to thigh-deep water in search of small clumps of eelgrass (which has notably decreased in the area over the past several decades) and rockweed, cover and habitat for many types of marine creatures. Steve briefed participants on handling potential catches, pointing out that some species, for example the Atlantic silversides, is very fragile and should be released from the net as soon as possible.

In a short time, we had assembled quite an interesting array of marine specimens. An empty knobbed whelk shell was converted into a flat for a large flat-clawed hermit crab, whose flat-mates included several flat slipper snails.

Related to the more commonly encountered common slipper shell (Crepidula fornicata), whose empty shells are sometimes found entirely covering the lower section of bay beaches here, the flat slipper shell (Crepidula plana) is pure white in color and found tightly secured to the insides of large whelk and moon snail shells, and on horseshoe crabs. It is sometimes so flat that it is hard to believe there’s room between it and the surface of its host for its foot and other soft organs. This species rarely creates stacks on one another as is commonly found among its C. fornicata relatives.

Gently sliding the hand net through a small eelgrass bed, we scooped up several northern pipefish and a long, slender, 2.5-inch-long fish that at first resembled the pipefish, but upon closer inspection proved to be a two-year-old American eel, at this point called an elver.

This prompted a discussion among Anita, Steve and me about the mysterious life history of the American eel, and exactly how old this elver was. After spawning in the Sargasso Sea in January, the eggs hatch and the larva, called leptocephalus larvae, drift with the currents. At this stage, they are unpigmented, clear and ribbon-like in shape. They swim and drift northward with the Gulf Stream, metamorphosing a year after they hatch into long cylindrical, eel-shaped but clear glass eels or glass elvers.

By spring, they are gathering at the mouths of tidal rivers and creeks, and estuaries and bays, where they develop pigmentation. The 2.5-inch-long elver we caught was one-and-a-half years old. If a male, it might reside in the bottom sediments of Napeague Harbor for another five years before making the thousand-mile journey back to the Sargasso Sea to spawn and die; if a female, it may make its way up Beeman’s Creek at the south end of the harbor, pass under Napeague Meadow Road and follow the maze of mosquito ditches into a suitable freshwater marsh in Napeague State Park where it will reside for 20 years, slowly growing to a length of 3 feet before heading back to sea to spawn ... amazing!

We next made our way over to a small fringe of salt marsh grasses, and in the shallows there Steve flushed a 1.5-foot-long American eel. Although considered largely nocturnal, there are so many sightings and accounts of eels taking fishermen’s bait during the day that one of my references states with regard to their nocturnal habits, “this cannot be the general rule.”

Consider joining Steve and Anita on one of their “Nature Wades” scheduled this month. On Thursday, August 8, from 10 to 11:30 a.m. they will be at the north end of Three Mile Harbor (opposite Sammy’s Beach). For reservations, directions, or more information, please contact Anita Wright at acwright@eastendenvironment.org. On Saturday, August 24, from 10 a.m. to noon they will be at Shinnecock Bay in Hampton Bays searching for tropical fish. For reservations or more information, please contact Steve Biasetti at 631-765-6450 ext. 205, or sbiasetti@eastendenvironment.org.

For other fun and informative programs with Group for the East End, visit groupfortheeastend.org/nature-outings.