A Vanishing Breed
The Mysterious Disappearance Of River Herring
By STEVE GRANT
This is the first in an occasional series about the fish species of Connecticut — from the ever- popular striped bass to the lesser-known river herring. Some fish we like to eat; some we don't. Some are flourishing; some are not. And all are affected by vexing environmental issues.
River herring are not glamorous fish. They are not salmon, not trout, not striped bass.
They are small, often less than a foot long. In recent years, most people who sought them out — and this was a comparative handful of people — sought them not as a game fish, not as a food fish but as bait fish. They've even been used as fertilizer.
Consequently, the plight of river herring, as alewives and blueback herring are collectively known, might as well be a secret. River herring populations have crashed in many of the brooks, streams and rivers they migrate to each spring to spawn.
At the Holyoke Dam on the Connecticut River in Holyoke, Mass., 630,000 migrating blueback herring were counted in 1985. By 2006, the number counted at Holyoke fell to 21 fish, and last year it was 69 fish. This year's run is just beginning, with only a few fish counted so far.
"Entire runs have winked out," said Steve Gephard, supervising fisheries biologist with the state Department of Environmental Protection. "We need to examine a couple of streams this year to determine whether or not bluebacks still enter them. If not, it is possible that the species may qualify for listing under the state's Endangered Species Act."
While river herring may not make the cover of Field & Stream, they are hugely important fish in the great scheme of things that is ecology, and biologists like Gephard are scrambling to rescue them.
On a recent day, Gephard, who has worked for decades restoring migratory fish runs, was part of a small crew trapping alewives returning to Bride Brook in East Lyme.
Bride Brook is a tiny stream that, unlike many others along the coast, still has a healthy run of alewives. On this morning, 400 fish were taken from the trap and hauled in a tanker truck to the Saugatuck River in Westport and one of its tributaries, the Aspetuck River, to help restore an alewife run in that river system, a run that was almost destroyed by dams. Fish passageways on dams are making it possible again for migratory fish to return to former upstream spawning waters.
"This is an extremely important fish both to the marine ecosystem — Long Island Sound and beyond— and the freshwater ecosystem in our rivers and lakes and ponds," Gephard said.
"Everything eats it. It is the field mice of the ocean. It supports not only lots of other species of fish but lots of birds and mammals. Nesting ospreys absolutely have to have healthy runs of alewives to prosper."
David M. Post, an assistant professor in the department of ecology and evolutionary biology at Yale University, has studied river herring in Connecticut coastal streams and determined that the fish are pretty much genetically identical, which means that while many herring and alewives return to the river of their birth, not all do. Over time, that creates a homogenous genetic population among many streams, which allows the biologists to successfully transplant fish from one stream to another without having to worry about negatively affecting the genetic makeup of succeeding generations.
Not only do osprey feed heavily on river herring, but other species, including cormorants, take them, Post said. Cormorants alone are capable of eating perhaps 25,000 fish in a spawning area like Bride Lake, he said.
Regional Decline
Connecticut imposed a moratorium on the taking of any river herring in 2002, for any purpose. A small number of Connecticut families once netted and pickled the herring, but the biggest demand for river herring in recent years came from striped-bass anglers who wanted to catch and use them for bait.
Because alewives and blueback herring are doing poorly throughout much of their range, the problem is not likely due to coastal development destroying habitat for the fish. Alewives are found from Newfoundland through North Carolina. Blueback herring are found from Nova Scotia to Florida.
"The fact that there is this real regional decline suggests that there are other deeper underlying problems that are not going to be addressed by imposing a state-level moratorium and by providing fish passage," said Eric T. Schultz, associate professor in the University of Connecticut's department of ecology and evolutionary biology. "There is something else out there."
Climate change is a possibility, in that warmer temperatures might affect stream flows negatively and make it harder for the fish to find their spawning streams, which they are thought to identify by smell.
At the moment, there are two more likely suspects; striped bass preying on the river herring, and commercial fisherman at sea who do not actually seek out river herring, but catch them accidentally in their massive nets while fishing for other species, such as Atlantic herring, which spends its life at sea and whose populations remain viable.
Striped bass, whose numbers once were crashing, have made a remarkable comeback over the past three decades since federal and state fisheries managers imposed highly restrictive limits on commercial and recreational taking of stripers. They are a hugely popular gamefish again.
The stripers now show up in large numbers in the Connecticut River, especially in spring, where they feed heavily on migrating river herring. There is no question striped bass eat some of the herring; the only question is how many and whether the stripers are a major reason for the decline of the herring.
Work by Schultz and his colleagues indicates that striped bass in the 28-inch to 40-inch size range — perhaps 30 percent to 40 percent of the stripers in the Connecticut River — are gulping down a herring every third day on average.
In the evening this time of year, researchers are out on the Connecticut using electro-fishing equipment to stun stripers, count and measure them. The fish are not harmed. Some of the fish also are tagged. Schultz asks that anglers who catch a tagged fish call the telephone number shown on the tag and report the tag identification number. That information will help to better determine how many stripers are in the river.
"Ultimately the number we are after is how many river herring are disappearing down the throats of striped bass in a given season," he said. Are the striped bass to blame? "I think we really don't know. We are keeping an open mind about it," Schultz said.
The role of commercial fishing fleets in coastal waters is less clear, though a number of environmental and conservation groups are convinced the fleets are a major reason for the decline of river herring.
"One of the greatest frustrations here is that we don't have good enough data, even though the law requires we do, to completely understand how much river herring is being caught out at sea in the generic herring fishery," said Peter Shelley, vice-president of the Conservation Law Foundation, speaking as a member of the Herring Alliance, a coalition of groups urging action to reduce the take of river herring at sea.
"The sense we get from very preliminary work is that some of the new fishing techniques to capture herring are also indiscriminately catching river herring at the same time. Sea herring are relatively abundant. River herring are not."
The coalition is urging regional and federal fisheries regulatory agencies, notably the National Marine Fisheries Service, to better monitor the fishery and limit the by-catch of river herring.
The industry says some river herring undoubtedly are taken as by-catch, but one spokesman says that what information is available so far does not suggest the mid-water trawl fishery is the cause of the decline.
Declines began even before the new fisheries techniques began to be used a decade ago, said Jeff Kaelin of Winterport, Maine, who represents the trawler Providian, owned by Ocean Spray Partnership. He said the company is a member of the Sustainable Fisheries Coalition and wants to work with federal and state fisheries managers to determine the best way to preserve herring stocks.
Whatever the cause, or causes, scientists already have identified signs of stress in river herring populations. Comparing information gathered in the 1960s at Bride Brook with information gleaned from recent runs, Schultz said there are dramatic changes in the fish.
The alewives returning to spawn are much younger than they used to be. In the 1960s, something like 80 percent of the fish were repeat spawning fish that were 4 or 5 years old. Today, almost all the fish are spawning for the first time. And all the fish are smaller, typically 8 or 9 inches, when, historical information suggests, they used to be 11 or 12 inches.
"Exploited fish populations do this all the time," Schultz said. "If you go and fish a population heavily, you find the fish start getting smaller and smaller and younger at maturity. Something is taking out a lot of the adults in the ocean, or when they are starting to migrate."
That makes the fish more vulnerable. In nature, sometimes conditions will be adverse one year and all but wipe out that season's reproduction. If a fish population has many different age groups, it will not be seriously affected for the long term. But with river herring populations now reduced to just young fish "it means you are in big trouble. Big trouble," Schultz said.
Meanwhile, the moratorium imposed by Connecticut in 2002 and in some other states since has not made any difference at Bride Brook, Schultz said. Fish are still young, still small, and there is no increase in the size of the run, he said.
So far, however, the transplant program is helping. Herring runs have been restored on many small coastal streams in Connecticut. At Latimer Brook in East Lyme, where alewives from Bride Brook were transplanted some years ago, a totally self-sustaining run of about 1,000 fish now migrates up the brook every year.
There are no crowds waiting to see them return, of course, unlike, say, the crowds that will gather to look at bald eagles, though the return of migratory fishes is as much a part of the arrival of spring as the leafing of the trees.
"I've been at this 30 years now and been all around the world and seen all sorts of fun things," Gephard said. "But the spectacle of alewives coming back every spring, swimming upstream, coming in and spawning you never get tired of that.
It is still a thrill."
The Mysterious Disappearance Of River Herring
By STEVE GRANT
This is the first in an occasional series about the fish species of Connecticut — from the ever- popular striped bass to the lesser-known river herring. Some fish we like to eat; some we don't. Some are flourishing; some are not. And all are affected by vexing environmental issues.
River herring are not glamorous fish. They are not salmon, not trout, not striped bass.
They are small, often less than a foot long. In recent years, most people who sought them out — and this was a comparative handful of people — sought them not as a game fish, not as a food fish but as bait fish. They've even been used as fertilizer.
Consequently, the plight of river herring, as alewives and blueback herring are collectively known, might as well be a secret. River herring populations have crashed in many of the brooks, streams and rivers they migrate to each spring to spawn.
At the Holyoke Dam on the Connecticut River in Holyoke, Mass., 630,000 migrating blueback herring were counted in 1985. By 2006, the number counted at Holyoke fell to 21 fish, and last year it was 69 fish. This year's run is just beginning, with only a few fish counted so far.
"Entire runs have winked out," said Steve Gephard, supervising fisheries biologist with the state Department of Environmental Protection. "We need to examine a couple of streams this year to determine whether or not bluebacks still enter them. If not, it is possible that the species may qualify for listing under the state's Endangered Species Act."
While river herring may not make the cover of Field & Stream, they are hugely important fish in the great scheme of things that is ecology, and biologists like Gephard are scrambling to rescue them.
On a recent day, Gephard, who has worked for decades restoring migratory fish runs, was part of a small crew trapping alewives returning to Bride Brook in East Lyme.
Bride Brook is a tiny stream that, unlike many others along the coast, still has a healthy run of alewives. On this morning, 400 fish were taken from the trap and hauled in a tanker truck to the Saugatuck River in Westport and one of its tributaries, the Aspetuck River, to help restore an alewife run in that river system, a run that was almost destroyed by dams. Fish passageways on dams are making it possible again for migratory fish to return to former upstream spawning waters.
"This is an extremely important fish both to the marine ecosystem — Long Island Sound and beyond— and the freshwater ecosystem in our rivers and lakes and ponds," Gephard said.
"Everything eats it. It is the field mice of the ocean. It supports not only lots of other species of fish but lots of birds and mammals. Nesting ospreys absolutely have to have healthy runs of alewives to prosper."
David M. Post, an assistant professor in the department of ecology and evolutionary biology at Yale University, has studied river herring in Connecticut coastal streams and determined that the fish are pretty much genetically identical, which means that while many herring and alewives return to the river of their birth, not all do. Over time, that creates a homogenous genetic population among many streams, which allows the biologists to successfully transplant fish from one stream to another without having to worry about negatively affecting the genetic makeup of succeeding generations.
Not only do osprey feed heavily on river herring, but other species, including cormorants, take them, Post said. Cormorants alone are capable of eating perhaps 25,000 fish in a spawning area like Bride Lake, he said.
Regional Decline
Connecticut imposed a moratorium on the taking of any river herring in 2002, for any purpose. A small number of Connecticut families once netted and pickled the herring, but the biggest demand for river herring in recent years came from striped-bass anglers who wanted to catch and use them for bait.
Because alewives and blueback herring are doing poorly throughout much of their range, the problem is not likely due to coastal development destroying habitat for the fish. Alewives are found from Newfoundland through North Carolina. Blueback herring are found from Nova Scotia to Florida.
"The fact that there is this real regional decline suggests that there are other deeper underlying problems that are not going to be addressed by imposing a state-level moratorium and by providing fish passage," said Eric T. Schultz, associate professor in the University of Connecticut's department of ecology and evolutionary biology. "There is something else out there."
Climate change is a possibility, in that warmer temperatures might affect stream flows negatively and make it harder for the fish to find their spawning streams, which they are thought to identify by smell.
At the moment, there are two more likely suspects; striped bass preying on the river herring, and commercial fisherman at sea who do not actually seek out river herring, but catch them accidentally in their massive nets while fishing for other species, such as Atlantic herring, which spends its life at sea and whose populations remain viable.
Striped bass, whose numbers once were crashing, have made a remarkable comeback over the past three decades since federal and state fisheries managers imposed highly restrictive limits on commercial and recreational taking of stripers. They are a hugely popular gamefish again.
The stripers now show up in large numbers in the Connecticut River, especially in spring, where they feed heavily on migrating river herring. There is no question striped bass eat some of the herring; the only question is how many and whether the stripers are a major reason for the decline of the herring.
Work by Schultz and his colleagues indicates that striped bass in the 28-inch to 40-inch size range — perhaps 30 percent to 40 percent of the stripers in the Connecticut River — are gulping down a herring every third day on average.
In the evening this time of year, researchers are out on the Connecticut using electro-fishing equipment to stun stripers, count and measure them. The fish are not harmed. Some of the fish also are tagged. Schultz asks that anglers who catch a tagged fish call the telephone number shown on the tag and report the tag identification number. That information will help to better determine how many stripers are in the river.
"Ultimately the number we are after is how many river herring are disappearing down the throats of striped bass in a given season," he said. Are the striped bass to blame? "I think we really don't know. We are keeping an open mind about it," Schultz said.
The role of commercial fishing fleets in coastal waters is less clear, though a number of environmental and conservation groups are convinced the fleets are a major reason for the decline of river herring.
"One of the greatest frustrations here is that we don't have good enough data, even though the law requires we do, to completely understand how much river herring is being caught out at sea in the generic herring fishery," said Peter Shelley, vice-president of the Conservation Law Foundation, speaking as a member of the Herring Alliance, a coalition of groups urging action to reduce the take of river herring at sea.
"The sense we get from very preliminary work is that some of the new fishing techniques to capture herring are also indiscriminately catching river herring at the same time. Sea herring are relatively abundant. River herring are not."
The coalition is urging regional and federal fisheries regulatory agencies, notably the National Marine Fisheries Service, to better monitor the fishery and limit the by-catch of river herring.
The industry says some river herring undoubtedly are taken as by-catch, but one spokesman says that what information is available so far does not suggest the mid-water trawl fishery is the cause of the decline.
Declines began even before the new fisheries techniques began to be used a decade ago, said Jeff Kaelin of Winterport, Maine, who represents the trawler Providian, owned by Ocean Spray Partnership. He said the company is a member of the Sustainable Fisheries Coalition and wants to work with federal and state fisheries managers to determine the best way to preserve herring stocks.
Whatever the cause, or causes, scientists already have identified signs of stress in river herring populations. Comparing information gathered in the 1960s at Bride Brook with information gleaned from recent runs, Schultz said there are dramatic changes in the fish.
The alewives returning to spawn are much younger than they used to be. In the 1960s, something like 80 percent of the fish were repeat spawning fish that were 4 or 5 years old. Today, almost all the fish are spawning for the first time. And all the fish are smaller, typically 8 or 9 inches, when, historical information suggests, they used to be 11 or 12 inches.
"Exploited fish populations do this all the time," Schultz said. "If you go and fish a population heavily, you find the fish start getting smaller and smaller and younger at maturity. Something is taking out a lot of the adults in the ocean, or when they are starting to migrate."
That makes the fish more vulnerable. In nature, sometimes conditions will be adverse one year and all but wipe out that season's reproduction. If a fish population has many different age groups, it will not be seriously affected for the long term. But with river herring populations now reduced to just young fish "it means you are in big trouble. Big trouble," Schultz said.
Meanwhile, the moratorium imposed by Connecticut in 2002 and in some other states since has not made any difference at Bride Brook, Schultz said. Fish are still young, still small, and there is no increase in the size of the run, he said.
So far, however, the transplant program is helping. Herring runs have been restored on many small coastal streams in Connecticut. At Latimer Brook in East Lyme, where alewives from Bride Brook were transplanted some years ago, a totally self-sustaining run of about 1,000 fish now migrates up the brook every year.
There are no crowds waiting to see them return, of course, unlike, say, the crowds that will gather to look at bald eagles, though the return of migratory fishes is as much a part of the arrival of spring as the leafing of the trees.
"I've been at this 30 years now and been all around the world and seen all sorts of fun things," Gephard said. "But the spectacle of alewives coming back every spring, swimming upstream, coming in and spawning you never get tired of that.
It is still a thrill."