Bronx River herring come home to spawn

At least six Alewife Herring have found their way back to the Bronx River. Scientists and volunteers released the fish into the river three years ago. Photo courtesy of Rocking the Boat

It’s been 400 years since an Alewife Herring left the Bronx and wriggled back, 400 years since Dutch colonists dammed the Bronx River. On Tuesday, April 7 volunteers from Rocking the Boat, a nautical non-profit, found several mature Alewife swimming in the river.

The fish are almost surely the offspring of those released in 2006. Alewife, like salmon, are “anadromous” fish. Born in freshwater, they spend years in the salty sea, but return to the river to spawn. According to scientists and elected officials, the Bronx River – once clogged with rusty cars and industrial waste – is a waterway reborn.

“This proves that the Bronx River is back,” said Jorge Santiago of the Bronx Council on Environmental Quality.

Congressman Jose E. Serrano, who helped fund the Alewife project, called April 7 “a great day for the Bronx environment.” Scientists from Lehman College and the Natural Resource Group – a Parks Department unit – partnered with the Bronx Zoo, the New York Botanical Garden and various non-profits.

“The Wildlife Conservation Society is extremely proud to be part of [the Alewife project],” executive director John Calvelli said. “With the return of a beaver to the Bronx two years ago, and now Alewife, the Bronx River is clearly on the rebound.”

Since the 1600s, dams have prevented Bronx River fish from spawning upstream. Soon, the Natural Resource Group will install fish ladders at three Bronx River dams. The Bronx River is New York City’s last free-flowing waterway. In 2007, a beaver nicknamed Jose, after the congressman, appeared on the river.

“Plenty of fish call the Bronx River home,” Natural Resource Group scientist Marit Larson said. “Perch and white sucker. The American eel.”

At least one fish ladder will boast a viewing grate. Larson was surprised when Rocking the Boat phoned on April 7. So far, she and the volunteers have identified six fish.

“We were astounded,” Larson said. “We knew the fish might return after three years. But for every million eggs, only a thousand hatch. Few make it to sea and back.”

Alewife are small and swim at night in groups. A popular baitfish, they are an important food source for egrets, herons, ospreys, raccoons, dolphins, sharks and striped bass. Although not listed as endangered or threatened, they are in decline due to lost habitat. The Alewife released into the Bronx River in 2006 were captured in Connecticut.

“The revitalized Bronx River is a symbol of the Bronx itself,” Serrano said. “Every day we receive word of a new success. We have come a long way, just like those little fish.”

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