Fish get a push to spawn up river
On Tuesday, April 18, the Town of Brookhaven and the Seatuck Environmental Association released about 300 adult male and female river herring into the Swan River in an effort to promote upriver spawning, marking the first time in over 200 years that the connection between the Swan River and Brookhaven’s south shore bays was restored.
Enrico Nardone, the executive director of Seatuck, explained that the herring need to reach fresh water to mate. The dam (located near Montauk Highway in East Patchogue), which was built before 1800, Brookhaven Town chief environmental analyst Anthony Graves said, created a blockage, preventing the fish from naturally migrating upstream to do so. In an effort to restore the lost numbers, Seatuck captured river herring from the Peconic River in Calverton so that they could be placed in the freshwater portion of the Swan River spillway earlier this week.
“The fish couldn’t get through to spawn; numbers were greatly reducing,” Graves said. “This was a priority.”
In addition to the fish release, the town also plans to install a fish passage on the Swan River to enable the fish to migrate upstream naturally in an overall effort to restore the river herring population in the future.
According to Graves, once all Department of Environmental Conservation approval is granted, construction will begin this fall. The cost of that project is estimated at about $375,000.
That project, Supervisor Ed Romaine said, has been funded through a state grant and is part of an overall objective to install fish passages throughout the town. He said passages would also be installed between the upper and lower lakes in Yaphank, on the Carmans River and on the Peconic River in Calverton.
“This will actually allow it to go back to the way it was in colonial times before dams were installed, where fish could swim upstream and spawn and restore the population,” said Romaine.
Eventually, the fish will spawn and juvenile river herring will be restored as an important part of the ecosystem of the Swan River. River herring, Graves explained, are important prey species that often feed trout and ospreys in Swan Lake, and once they move back out to sea they are important forage for bluefish, striped bass, dolphins, tuna and seabirds.
Swan River is one of only a few free-flowing, spring-fed streams on Long Island that have remained in a relatively natural state. Below the Swan Lake dam, Swan River currently supports anadromous fish runs for alewife and trout, and sea-run brown trout use the tidal segment of Swan River for spawning. The entire length of Swan River has been designated a Significant Coastal Fish and Wildlife Habitat (SCFWH).
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