It is spawning season for alewives, the once-plentiful river herrings native to Long Island, and the environmental group that helped Babylon Village build its fish ladder last year is looking for volunteer fish counters.
The Islandwide survey will cover Babylon's Carlls River and other tributaries where the alewives are believed to still run. The survey calls for volunteers to look for the foot-long, green-gray fish over 15-minute sessions that can be repeated throughout the day.
"This is one of the first species that starts to move" in the spring, said Enrico Nardone, executive director of the Islip-based Seatuck Environmental Association, one of the survey's organizers. "At this time of spring, if you see fish swimming in a circle, engaging in spawning behavior, there's a good chance it's alewives."
The alewife may not have the culinary or sporting cachet of its larger brethren, Nardone said, but it plays an important role in the coastal ecosystem. "Each female lays a quarter million eggs and all these little fry hatch. Out on the [continental] shelf, tuna, whales and dolphins feed on them. In the estuary it's eels, striped bass, bluefish; in rivers it's osprey, river otters. . . . These are fish you should care about."
Alewives spend most of their lives schooling over the Atlantic Ocean's continental shelf and swim miles upstream into the relative security of freshwater ponds to spawn. But almost all of Long Island's approximately 100 tributaries have been blocked by dams or other structures, Nardone said, reducing the number of fish who make that odyssey from millions to hundreds of thousands.
Organizers hope the count also will give a better indication of which tributaries the alewives use, Nardone said.
The Carlls River count is particularly significant because it could help biologists determine the effectiveness of the fish ladder built last year by Skip Gardner and members of the village Highway Department with a $31,500 grant from the National Association of Counties and the National Oceanic and Atmospheric Administration.
That ladder -- actually a 72-foot-long aluminum tunnel -- permitted alewives to travel upstream from Carlls River to Argyle Lake for the first time in the 120 years since the dam was built, Nardone said.
It was installed too late for much of last year's spawning season, he said. But volunteer spotters and a video system that uses software to detect objects in motion -- human review is still needed because it sometimes records eels, bass and sticks -- suggest that alewives are present at least by the dozens.
"We're excited," Nardone said. "We'd like to see them restored to the whole river."
Anyone interested in counting should contact Nardone at firstname.lastname@example.org or 631-581-6908.