04/09/2010 - The groundhog may be able to predict the coming of spring, but the herring is the one to confirm it.
Like clockwork each year, these anadromous fish find their way back to Falmouth from the ocean, swimming against the river current in a series of runs as old as the rocks. They return by the thousands to spawn in the freshwater lakes and ponds where they first hatched, eating algae and plankton, and in turn, being eaten by birds, seals, and bass.
But this quintessential harbinger of spring has come under threat over the past decade. Sharp declines in the once-abundant fishery led several Atlantic states to impose a moratorium on the taking of river herring in January 2006. The ban was extended through 2011 by the Division of Marine Fisheries (DMF) in October 2008. Now in the fifth season of the moratorium, fish and wildlife managers are still hoping to see evidence of change in the downward trend.
"After the moratorium first started, the numbers were still tumbling. Everyone was concerned," said R. Charles Martinsen III, assistant director of the Department of Natural Resources. "It's too early to tell when we'll start to see a comeback."
River herring-also known as alewives or bluebacks-were first sighted in Trunk River on March 4 this year, said Mr. Martinsen. Slowly but surely, more and more of the small, silvery fish have been seen making their way up the eight runs in Falmouth.
The warmer-than-usual weather could have prompted the fish to return to Coonamessett River sooner than usual this year, Mr. Martinsen said, or it could be possible evidence of a larger population spilling over into the shoulder season. Herring instinctively know the path back to their natal spawning grounds, but do not lay eggs until the water temperatures are 51 to 57 degrees, according to the Buzzards Bay National Estuary Program website.
"These fish are the most valuable. They're the ones that were strong enough to make it back, ready to spawn," he said. Only about one percent of juvenile herring make it back to their birthplace every three years. Herring were once staples of the Wampanoag diet, and were also eaten smoked and pickled by European settlers. Generations of New Englanders have relied on herring for bait and fertilizer, and used their scales as buttons. In 1938, the Waquoit Herring River Company did a tidy business. Herring roe was a commonly found item in local fish markets.
As the fishing industry developed, so did the number of farms and houses along the herring runs. Though researchers do not single out any one source, a variety of man-made factors may be responsible for the precipitous decline in the river herring population over the last century. Limits on the number of fish that could be taken from runs were imposed by the DMF in 1989, but the populations continued to falter, hitting an all-time low in Massachusetts in 2003.
Some groups say that the moratorium only prevents fishermen on land from catching herring, and that the real culprit is the by-catch netted by mid-ocean trawlers.
"If fishermen are prevented from catching fish on land, and at the same time, thousands are being taken at sea, the moratorium isn't going to help," said John Crawford of the Pew Environment Group in Boston.
Working with the National Marine Fisheries Council, the organization has pushed for increased video monitoring aboard fishing vessels and restrictions on fishing near shore when herring are running. But lacking funds, Mr. Crawford said that progress has been slow. "As you look at the pattern of action around this, there's been an enormous amount of public input, but not enough real progress," he said.
Both Mr. Crawford and Mr. Martinsen said there is no smoking gun to explain the steady and rapid decline in herring populations, and say that a number of factors need to be addressed in order to bring them back. "Herring die from a hundred different stab wounds," Mr. Martinsen said. "Pair trawlers take out thousands in one whack. They're also preyed on by birds, striped bass, and poachers. There are water quality issues in the spawning grounds. It's not just one thing."
Water quality and land use change are the subjects of Rita O. Monteiro's doctoral research through the State University of New York at Syracuse. Ms. Monteiro, a Portuguese biologist who is based at the Marine Biological Laboratory's Ecosystems Center, has spent the past two years sampling adult herring from eight watersheds on the Cape and comparing them to the herring in more pristine waters in Maine and New Hampshire.
Ms. Monteiro's research focuses on the effects of urbanization on herring-evidenced by increased levels of nitrogen from wastewater in their habitat. In an initial phase of her research, Ms. Monteiro found that fish with poor health also had elevated levels of nitrogen in their muscle tissue.
While Ms. Monteiro's results are preliminary, her research could serve to inform conservation policies on what kinds of land use are appropriate near herring spawning grounds and runs. "If watershed inputs are in fact influencing alewife success, this could affect management strategies such as habitat restoration, water quality protection, establishment of reserves, control of harvest, and so on," she said.
One of the difficulties in determining the effect of the moratorium is a lack of precise data on how many herring return-and how many spawn each year. Even before the moratorium came into effect, bands of citizen observers have gone out to count the herring in local runs, every evening from mid-April through mid-June.
Louis C. Turner of Oyster Pond Road has organized a crew of volunteers at the Coonamessett River run for the past six years. He said that last year was the first season that the numbers started to increase, from about 9,000 in 2008, to around 17,000.
While the latest figures are encouraging, Mr. Turner said he will not be happy unless the group counts over 20,000 this year. "Historic runs were a million or so. In the past, people had a sense that when [the herring] were running, they could walk on the backs of fish," he said.
For the past two years, members of the Oyster Pond Environmental Trust have been monitoring the run at Trunk River, which feeds Oyster Pond. So far, the volunteers have counted more than 600 fish in that run, Mr. Martinsen said.
From 7 to 10 PM each night, volunteers at Coonamessett and Trunk rivers count the herring in two five-minute intervals each half hour as they go through the run. Using data sheets downloaded from the DMF website and stationary thermometers, the volunteers record the number of herring they see, in addition to any muskrats, crabs, or birds, and the water and air temperature.
"All you need is a flashlight, a kitchen timer, and the ability to count," Mr. Turner said.
Mr. Turner, who lives near Oyster Pond, also keeps track of the baby herring, or fry, as they exit the culvert under Surf Drive. Knowing how many fry leave the pond may provide some clues as to how many adults can be expected to return, he said.
Having only counted the fry for the past two years, Mr. Turner said the numbers do not yet reveal a trend. In 2008, he said that 4,000 herring were counted in the Trunk River run, and 200,000 fry went out by September. In 2009, 1,000 herring entered the pond, but 400,000 fry spawned.
"They're really prolific creatures, but there's also lots of predation. I'll be very disappointed if that number continues to go down," said Mr. Turner. However, he noted that with smaller populations, the annual changes will also be small.
"At this point, we're not positive the moratorium will be effective; only if we see consistent numbers, we'll know we have found the source," he said. "But when the growth starts, the hope is that it will be exponential."
This story is provided courtesy of The Enterprise of Falmouth