Progress on Fish Passage at Beaver Lake Spillway

Check out any river on Long Island and chances are you will find a series of dams running its length. Thus virtually every river on Long Island has compromised to completely blocked fish passage resulting in the virtual elimination of anadromous fish from our waters. The Shu Swamp/Beaver Lake watershed  is impacted by four dams. About the only LI stream I can think of that doesn’t have at least one dam is Alewife Creek in Southamptom, famous for its huge alewife run in March and April, and considered an “ecosystem rarity” by New York Department of Environmental Conservation.

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Nature Conservancy and its partners meeting with engineers for Fuss and O’Neill at the Beaver Lake Spillway May 19.

This past fall the Nature Conservancy was awarded Long Island Sound Future Fund money towards fish passage plan development and implementation for three sites in Connecticut and New York. The site in New York is the spillway on Beaver Lake that impedes passage to and from the brackish Mill Creek. The grant provides money to develop plans for a fish ladder and apply for the necessary construction permits. I am a matching partner on the grant, providing data on water levels below the spillway as well as observations on river herring approaching the spillway. This Monday we had a “project kickoff” meeting at the spillway in which the various partners and supporters of the project met with Josh Wilson the engineer from Fuss and O’Neill, the environmental engineering firm contracted by Nature Conservancy. As you can see, there was a pretty good crowd in attendance including Sally Harold of the Nature Conservancy, director of the project,  other members of the Nature Conservancy, and representatives from the Town of Mill Neck, New York DEC, North Shore Wildlife Sanctuary, North Shore Land Alliance, USGS, Trout Unlimited, and Friends of the Bay.

It seems like the engineer is leaning towards installing a steeppass ladder, which I think is  similar to this one:

Alaska steeppass ladder

The engineer hopes to have a completed “permit-ready” design by August. And assuming funds can be found and the permits are approved in a timely manner, installation may occur as early as next Spring!

So that will solve one big problem for anadromous river herring and brook trout by allowing easier passage through the Oyster Bay estuary up into Shu Swamp. I hope to document an improvement in passage through PIT-tagging studies. But we have one other really big problem. Namely, if you don’t have fish it doesn’t matter how easy it is to pass! For the past three years I have been monitoring the herring spawning runs at the spillway. The previous two years I witnessed at best a handful of alewives attempting to enter the lake (see my post from last May). This year I have yet to see a single alewife. Lifelong residents of the area report seeing hundreds perhaps thousands of alewives  entering the lake, and as one person told me “backing up” in Beaver Lake like it was a traffic jam. This occurred in spite of a dam with minimal passage! What happened and how are we going to bring them back? One thought we tossed around was bringing in some spawning alewives from one of the successful runs elsewhere on Long Island. These would be used to “seed” the swamp and lake with babies imprinted to the watershed and likely to return as spawning adults in three years. This strategy may have shown some success when applied at other places such as the Bronx River.

According to Lehman College Professor Joseph Rachelin featured in the video, adult progeny of the spawning alewives released into the Bronx River in 2006 returned in 2009 indicating success. However, Queens College Professor John Waldman, reports in his excellent book, Running Silver, that the returning alewives were too old to have been progeny of the 2006 spawning alewives and were more likely native alewives, which is quite a suprise since everyone thought they had been eradicated long ago.

I think a big step forward was taken this week at Beaver Lake. Improving fish passage has been kicked around for a long time but finally people are acting. Given the amount of collaborative interest I am optimistic.

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