Wildlife & Nature

Dams Gone But Obstacles Remain for River Herring


River herring, which are vital to the health of southern New England’s rivers and streams, are often caught as bycatch at sea by midwater trawlers. (Herring Alliance)

Both Massachusetts and Rhode Island have spent considerable time and taxpayer money restoring thousands of river miles. This restoration work is important on many levels, but none of the benefits are likely more important than allowing anadromous fish, such as river herring, to again make their way up southern New England’s coastal rivers to spawn.

Many of the inland routes taken by these migratory fish were cut off by dams and other impediments during the Industrial Revolution. Prior to the emergence of large-scale manufacturing, a river herring run existed in almost every coastal town in Massachusetts and Rhode Island. Today, some historically important spawning grounds have been out of reach for as long as two centuries.

Progress, however, is slowly being made to undam rivers, build fish ladders, and clean rivers, streams and brooks in both states. This recent work, being done by public/private collaboratives, is already having a profound effect on many ecosystems. The Hopewell Mills dam in Taunton, Mass., was removed last year and already sea-run fish such as river herring are returning to the Mill River watershed.

This past spring the first river herring in nearly 200 years was spotted upstream of the former Hopewell Mills dam site. Sea-run fish play a major role in the ecology of Narragansett Bay, and restoring the connections between these saltwater and freshwater ecosystems will bring benefits throughout the region, according to Alison Bowden, director of freshwater conservation for The Nature Conservancy.

Whittenton Dam, just downstream from the Hopewell Mills dam site, was removed three months ago. These efforts to restore fish passage on the Mill River, a major Taunton River tributary, will continue to improve water quality, protect habitat health and make the entire ecosystem more resilient. This work also will enhance recreational and commercial fishing, both inland and at sea.

The Taunton River is one of the only free-flowing rivers in New England, and restoring fish passage to its tributaries will have a significant impact on the river’s famed herring run, which is already one of the largest in southern New England. With improved fish passage in rivers such as the Mill, Pawcatuck and Woonasquatucket, more fish will eventually return to Narragansett Bay, where they will feed the predator fish that are so critical to New England’s commercial fishing industry and culture.

In fact, during all life stages, river herring contribute greatly to the dynamics of food chains in freshwater, estuarine and marine habitats, according to a 2009 report by the Atlantic States Fisheries Commission.

“The health of Narragansett Bay depends on the health of our major tributaries,” said Rachel Calabro, community advocate at Providence-based Save The Bay. “Restoring habitat for fish in the Mill River watershed will benefit predator species and improve recreational fishing in the bay.”

Trouble at sea
While millions are being spent to remove river dams and culverts to, among other things, improve river herring runs, these important fish are finding life at sea tough as a result of unsustainable commercial fishing practices.

This at-sea problem has frustrated and angered those working to improve fish habitat inland. “We can take down dams and improve the habitat, but we can’t protect them at sea,” said Pine duBois, executive director of the Kingston, Mass.-based Jones River Watershed Association. “All of the work being done inland is being wasted at sea by poor fishing practices. We need commercial fishing practices that are less wasteful.”

The demise of river herring up and down the East Coast began in the late 1970s with the emergence of foreign-flagged factory ships. By the mid-1990s, U.S. trawlers were having an enormous impact on New England’s river herring population.

These vessels haul small-mesh nets that can be as long or wide as football fields. The nets’ mesh is so small little can escape, although the nets are designed to be selective. Trawlers often fish in pairs, dragging one of these nets between them. Caught up in those nets can be marine species not being targeted, such as river herring, and evidence shows that river herring bycatch is a significant problem.

Industrial trawlers have been reported to catch hundreds of thousands of river herring in a single net tow, according to the Boston-based Herring Alliance.

Alex Mansfield, ecology program director for the Jones River Watershed Association, said dumping these important fish — a favorite of striped bass, bluefin, yellowfin, cod, bluefish, weakfish and other predators — back into the ocean dead as bycatch waste is troubling.

“Because these fish school together, these big pair trawlers can easily snag an entire river’s run of herring,” Mansfield said. “This practice is destroying the river herring.”

Signs of decline
River herring spawn in rivers, but live most of their lives at sea. A lethal threesome of dams, river pollution and wasteful fishing practices has pushed their populations to historic lows. In fact, during the past two decades some river herring runs along the Atlantic Coast have declined by 95 percent or more, according to the Herring Alliance.

Many river herring runs have declined along the Atlantic Coast to such a degree that the collapse of the coast-wide stock is feared to be underway, according to a 2010 study entitled “Developing Alternatives to Mitigate River Herring Bycatch at Sea.”

Much of the river herring caught as bycatch in federal waters off southern New England is by trawlers targeting Atlantic herring. In 2006 and 2009, NOAA Fisheries listed river herring as a “species of concern,” and last year the National Resources Defense Council submitted a petition to list river herring under the Endangered Species Act.

Midwater trawlers are quite large, with holds that can store about a million pounds of fish. They also employ sophisticated electronics to pinpoint and can trap entire schools. Thus a single tow in the wrong place at the wrong time could wipe out an entire run of river herring.

Dam removal, fish ladders and other ecosystem improvements have helped restore river habitat in Massachusetts and Rhode Island, but river herring numbers have remained low, in part because at-sea losses hadn’t been addressed until very recently.

Ocean protection
Rhode Island banned fishing for river herring in 2006 because of drastic declines in spawning stock size, increases in mortality rates and decreases in percentage of repeat spawners, according to Phil Edwards, of the state Department of Environmental Management’s Division of Fish & Wildlife.

He noted that between 2000 and 2005, the Gilbert Stuart Brook (North Kingstown) run size decreased from 290,814 to 7,776 and the Nonquit Pond (Tiverton) run size decreased from 230,853 to 25,417.

To help protect dwindling river herring populations, Rhode Island and Massachusetts, along with Connecticut, North Carolina and Virginia, have banned harvests of river herring with zero-tolerance policies for recreational and commercial fishing.

In Rhode Island, preliminary results have shown there has been some improvement since the zero-tolerance policy was enacted seven years ago, but current run sizes are still below historical averages, Edwards said.

“For years there were no fish,” he said. “But the runs are improving because of major habitat restoration projects that have been done on the Pawtuxet, Saugatucket, Woonasquatucket and Ten Mile River.”

The problem remains at sea, but work is being done to address the issue. The New England Fishery Management Council recently voted to limit and reduce the amount of river herring and shad that can be caught at sea. In a unanimous vote Sept. 26, the council approved the first cap on the amount of river herring and shad killed by industrial trawlers targeting Atlantic herring. These trawlers are among the largest fishing vessels on the East Coast, and all too often they snag schools of alewives and blueback herring.

This catch cap will reduce the wasteful bycatch produced by trawlers and will push the Atlantic herring fishing industry to avoid areas and times with the greatest likelihood of killing river herring and shad, according to the Herring Alliance.

The cap will be implemented in zones covering the Gulf of Maine, Cape Cod and southern New England, and will apply to midwater trawl vessels in all areas and bottom trawl gear in southern New England. When a catch cap is reached in a zone, fishing for Atlantic herring will be closed.

This recent action comes on the heels of a similar move by the fishery managers in the Mid-Atlantic region. In June, the Delaware-based Mid-Atlantic Fishery Management Council limited the river herring and shad that can be killed by vessels targeting Atlantic mackerel.

Both of these recent measures means that there are now methods in place to limit the at-sea catch of river herring from South Carolina to Maine.

“We are working with fishermen to address this problem,” Edwards said. “A lot of work is being done to determine hot spots for bycatch. The genetic study of river herring is being done to determine in the bycatch what river system or region the river herring are coming from.”


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