Beneficial Impacts Of Sandy

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Among the 16 natural history presentations at Friday’s Long Island Natural History Conference, three were directly related to the impacts of Hurricane Sandy on our beaches and shorelines, and our flora and fauna. One of those three presentations was by Charlie Flagg of Stony Brook University, who discussed his work monitoring the new inlet that Sandy punched through the eastern end of Fire Island National Seashore. On Saturday, Mike Bilecki, resources management chief for the Fire Island National Seashore, led a field trip to see the inlet and other changes in the barrier island landscape brought about by Sandy.Our attitudes regarding inlets that link small bays and harbors with larger bodies of water are somewhat schizophrenic. Most everyone agrees that they provide an important ecological function by improving the water quality of the smaller bays, and many serve as important access routes between fishing grounds and safe harbors for boaters.

Although most inner bay marine life prefers low salinity levels—for example, commercially valuable shellfish and the egg and juvenile stages of many finfish—increased salinity levels are often cited as a positive impact of inlets. And then there’s the role of inlets as “flushers,” improving water quality by diluting polluted inner bay water with cleaner water from the larger bay, sound or ocean. This is the old management strategy of “the solution to pollution is dilution,” in contrast to the strategy of identifying the source of pollution and reducing or eliminating it.

As with all physical features on a sandy coast, inlets are subject to tides, tidal currents, wind, storms, waves and littoral currents. They are dynamic. They move, widen and narrow, deepen and shoal, open and close.

The maintenance of existing inlets by dredging and armoring, and the creation of new inlets, such as the one at Gerard Drive between Accabonac Harbor and Gardiners Bay, is seen as so important that there is a backlog of requests for dredging work. Yet when a storm creates an inlet naturally, at no cost to the taxpayer, there is usually a clamor of protest and a call to fill in the breach.

Okay, perhaps “schizophrenic” is too strong a word here. In most cases, the new inlet might have formed in a very inconvenient location. But one of the several new inlets created by Sandy was far from any houses or roads in the designated wilderness area of Fire Island National Seashore. One would be hard-pressed to find a more convenient location for a new inlet on Long Island.

Ironically, the new inlet formed at a place referred to as “Old Inlet,” a place name derived from the fact that an inlet had formed there once before. And, true to form, the cry went up to “fill the breach!” Chief among the concerns was the fear that the new inlet and increased tidal flow in Great South Bay might increase the inner bay’s water level and result in flooding problems along the bay’s heavily developed northern shore.

High water levels did occur on two occasions after Sandy, with the March 2013 event registering the greatest flood levels in the Bellport area. Many pointed to the new inlet as the culprit. But Charlie Flagg’s research revealed that the March flood levels were recorded all along the Eastern Seaboard, from Woods Hole, Massachusetts, south to the Chesapeake Bay, a span of 600 miles. This was related to a large coastal storm system, not the new inlet.

Fortunately, the National Park Service did not yield to public pressure to close the breach, and researchers beefed up their efforts to monitor the situation.

The new inlet has shifted westward, pushed in that direction by the strong easterlies and net littoral currents. A large shoal has formed offshore, a result of the ebb tide depositing sand, and the classic flood tide shoals have formed just inside the bay. Salinity levels in a significant portion of the Great South Bay, particularly the portion known as Bellport Bay, have risen, and nitrogen levels have dropped. Reports are that 2013 witnessed unusually large growth rings on clam shells.

En route to the new inlet, Mike Bilecki pointed out large areas where Sandy leveled the primary dune, pushing dune sands clear across the barrier island and into the salt marsh and bay. The park service is monitoring the re-vegetation of these overwash areas, as well as the natural dune rebuilding process. Deer exclosures have been constructed to document the impact of deer browsing on the process of ecological succession there.

On the return hike, naturalist Eric Powers led us to the spot where he had caught sight of one of the most majestic birds that visits here during the winter months. There, from a safe distance where we weren’t disturbing the royal creature, we watched a snowy owl perched on a large piece of driftwood on an open expanse of salt marsh.

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