Herring back in promising numbers

Being a herring is no piece of cake, either. Bowing to nature’s imperative, the fish migrate in the spring from the ocean back to their birthplaces in freshwater ponds up and down the East Coast - a course studded with such obstacles as hungry striped bass and cormorants, low water, trawlers’ nets, human poachers, manmade dams, and pollution.

“It certainly is a gantlet they have to run through,’’ said John Sheppard of the state Department of Marine Fisheries. “It’s almost like a war of attrition just to get to the spawning grounds.’’

This year, however, the herring are winning that battle, with record numbers of counters reporting thousands of fish.

At Weymouth’s herring run in Jackson Square, for example, the count was up to 200,000 as of April 20, and the season has weeks to go, according to town Herring Warden George Loring.

While far lower than the peak of 860,000 fish recorded in 1995, the count is on track to overtake last year’s approximately 260,000, he said. And that number was up from 80,000 in 2005.

“There have been some spectacular pulses of fish coming through [in Weymouth]. It’s just been shoulder-to-shoulder fish, if fish had shoulders,’’ said Scott Dowd, a freshwater biologist at New England Aquarium and member of the Weymouth Herring Committee.

The high numbers in Weymouth and elsewhere along the coast south of Boston are welcome news to those who have been watching the river herring population dwindle in years past.

While there have been some fluctuations, the number of herring declined so much that the state has banned river herring fishing and sales since 2006 to allow the stock to rebuild, according to Sheppard.

“The recovery hasn’t occurred as quickly as we would like,’’ he said.

The numbers are important to more than biologists. River herring are a key food of many other species, particularly bluefish and striped bass, but also cod, haddock, and halibut. Seals and whales also eat the river herring, whose well-being is tied to the creatures eating them higher up the food chain.

The ecological and economic implications are large, Dowd said. The herring play “a critical role in the whole Gulf of Maine ecosystem [and its] whole fishing industry. The whole whale-watching industry is connected, too,’’ he said.

That’s one reason Weymouth officials acted so quickly when a pipe broke at a pumping plant on April 17 and poured sewage into the Back River near the spot where herring wait to go up a ladder on their way to spawn in Whitman’s Pond.

While it was unclear how many, if any, fish were killed by the sewage, or dissuaded from heading up the river, “it’s definitely not a good thing,’’ Dowd said. “I liken it to the [Boston] marathoners in the heat. We know it stresses them at a really critical time in their lives.’’

The typical life of a river herring starts in fresh water - streams, ponds, or lakes - where they spend a few months until they’re big enough to head out to sea, according to Sheppard. The herring usually live at sea for three to five years before they mature and come back to the same place they were born to spawn. The journey lasts about five weeks, and the adult fish swim back out to sea a week or two later.

“They’re capable of living up to 10 years and they’re capable of spawning several times,’’ he said.

River herring make the migration in more than 100 coastal rivers and streams in Massachusetts. Volunteers are conducting formal counts this year at about 30 sites, Sheppard said, including the Back River in Weymouth, South River in Marshfield, Jones River in Kingston, Herring Brook in Pembroke, First Herring Brook in Scituate, Town Brook in Plymouth, Nemasket River in Middleborough, and Island Creek in Duxbury.

Officials in Braintree hope to be able to count river herring in the Monatiquot River someday, as well. Some of the town’s earliest records involve the battle between industrialists who built dams for their mills and those who wanted the herring to move freely. The industrialists won, but the town has been working with the state Division of Marine Fisheries to restore herring to the river by building fish ladders, according to Kelly Phelan in the town Planning Department.

The state also is working to restore herring to the Neponset River, where dams have blocked the way since the late 1700s, according to Gary Nelson of the state Division of Marine Fisheries.

Plans call for building a “fishway’’ at Baker Dam near the old chocolate factory at the Milton-Dorchester line. “It involves taking down about a third of the dam and building a rock ramp - almost like a handicap ramp for the fish - which would gently slope up and create a natural rapids,’’ Nelson said.

Farther up the river at the Milton-Mattapan border, the state plans to remove a dam, a process that Nelson said involves getting “pretty much every permit known to man. It’s actually easier to build a dam than remove one.’’

When the work is done, though, the herring “would get access to 17 miles of spawning habitat all the way up to Walpole. It’s one of the more significant [herring] restoration opportunities. It also would be beneficial to the American shad, a big brother of the herring and in much more trouble,’’ he said.

Last year, the state helped rebuild the fish ladder at the dam on Upper Mill Pond in Pembroke. Before the ladder was finished, the state also caught and carried the herring by tanker trunk to the next stop on their 17-mile migration, with the help of volunteers from the North and South Rivers Watershed Association.

This year, about 70 volunteers are helping count herring at spots in Pembroke, Scituate, and Marshfield, according to coordinator Sara Grady. She trained the volunteers to watch the top of the fish ladders for 10 minutes a day, check the “waiting area’’ below the ladder, and record their findings in notebooks kept in plastic boxes at each site.

She also cautioned counters at Upper Mill Pond to stay away from the nesting swans, who can be territorial. The book at Upper Mill Pond is filled with notations, with numbers ranging from zero to 278 fish counted in a single 10-minute time frame.

“It’s a very Zen experience,’’ Grady said. “It’s nice because you take 10 minutes to just sit or stand and listen to the gurgle of the water, and maybe see a fish.’’

Johanna Seltz can be reached at seltzjohanna@gmail.com.