(Photo by Patrick Sikes)
On Whitford Brook in Old Mystic, Jon Vander Werff wades in the chilly water to his waist to check a fish trap he designed to capture every alewife, blueback herring and American shad that swims upstream to spawn. The trap, made of PVC pipe and polyethylene mesh, spans the entire 30-foot expanse of the river and funnels fish into a containment area from which they can be counted and released each day.
Using a long-handled net, he scoops out a shimmering silvery alewife about 10 inches long that struggles to escape back into the fast-moving water to join its compatriots a short distance upriver.
“Just one out of 80,000 alewives makes it to adulthood to spawn, so this is one of the lucky ones,” says Vander Werff, a fisheries biologist with Save the Sound, an advocacy group for Long Island Sound and its rivers. “The odds are stacked against them, because their role in the ecosystem is to act as food for big-game fish in Long Island Sound. By getting eaten, they’re doing their job.”
For a couple of centuries, the odds were also stacked against them because of the numerous dams that had been constructed on most of the rivers stretching inland from the Connecticut coast, preventing the fish from reaching their spawning grounds in fresh water. Some of those dams are now being removed or having modern fish ladders installed to allow the fish to return. The Hyde Pond Dam on Whitford Brook was constructed around 1800. It was removed in 2016.
Daily during spawning season — late March until mid-June — Vander Werff and a team of volunteers count and release any fish captured in traps on six rivers and streams along the coast, monitor water temperature and flow levels at each site, and clear debris from the mesh. At Whitford Brook, they counted 1,287 alewives swimming upstream in 2018, but just 42 last year, when strong currents from heavy rains caused the trap to repeatedly collapse, allowing most fish to pass uncounted. This year the numbers rebounded a bit, as the trap caught 325 alewives (plus 18 blueback herring and four American shad). At Bride Brook in East Lyme, more than 200,000 alewives now swim through a culvert each year after Save the Sound led an effort to restore the culvert in 2009, three times as many as made it upstream before the restoration.
These projects to provide safe passage for anadromous fish — those that spawn in freshwater rivers but spend the rest of their lives at sea — are not just about helping those individual species. They’re about rebuilding the food web of Long Island Sound, supporting numerous saltwater fish species of commercial and recreational importance, and improving the overall health of the Sound.
“Removing dams and building fish passageways is all about making more forage fish,” explains Peter Auster, professor emeritus of fisheries at the University of Connecticut and senior research scientist at Mystic Aquarium. “By making fish passageways inland, you’re letting a species that lives in Long Island Sound reproduce and their young migrate back downstream and into the ocean. All those tiny fish, which can produce extreme abundances and very high densities as they come out of their spawning rivers, create feeding opportunities for a wide range of other species — striped bass, bluefish, sculpin, seals and lots of other marine wildlife.”
These dam-removal and fish-passageway projects are the latest strategy in the decades-long process of revitalizing the Sound and addressing emerging threats to the creatures that live there.
Before the Clean Water Act was passed in 1972, much of Long Island Sound was a toxic soup of pollutants. Millions of gallons of untreated sewage and industrial chemicals were discharged there daily. It has taken billions of dollars of investment to upgrade wastewater treatment plants and limit industrial discharge, and yet there is still much to do as climate change and other new threats force federal, state and local regulators and environmental managers to shift strategies to keep ahead of the problems.
“The Sound is in reasonably good shape right now,” says Tracy Brown, director of Save the Sound. “We’ve seen recovery from some of our bigger threats, like excessive nitrogen [from wastewater discharges] depleting oxygen in the water, but there is definitely more work to be done. In addition to continuing to fight our old foes, there are new stressors to deal with.
“The primary stressor, though, is the huge mass of humanity that lives in its watershed,” she adds, noting that the watershed extends all the way up the Connecticut River to Canada. “The health of the Sound is a mirror of how we’re living on land. We’re getting better with our behaviors and land management and stewardship, but we have a long way to go.”
Much of the progress made to date can be attributed to a partnership of federal and state agencies, municipalities, scientists, nonprofit groups and others working together as part of the Long Island Sound Study, led by the U.S. Environmental Protection Agency. Initiatives undertaken as part of the study have led to significant reductions in pollution discharges, restoration of tidal wetlands and other habitats, and ongoing water quality monitoring.
“The Sound is such a core part of the culture and economy of the region,” says Dennis Deziel, the EPA’s Region 1 administrator. “It supports so many species, it’s an estuary of national significance. It’s the perfect example of what we need to get right.”
"The health of the Sound is a mirror of how we’re living on land. We’re getting better with our behaviors and land management and stewardship, but we have a long way
While the many signs of recovery are worth celebrating, water quality in some harbors and bays along the Connecticut coast is still threatened — not from direct discharges of pollutants but from the runoff of lawn fertilizers, automotive fluids, agricultural chemicals, failing septic systems and numerous other toxins from daily life that find their way into waterways and end up in Long Island Sound.
“When we have more intense rains, that’s when we see all these nonpoint sources causing hypoxic [low oxygen] zones, and those sources are starting to trend up,” says watchdog Bill Lucey, the Long Island Soundkeeper for Save the Sound. He notes that Black Rock Harbor in Bridgeport and Norwalk Harbor still occasionally experience fish kills due to low oxygen levels, and the overall diversity and abundance of fish there has declined. “To fix the Sound,” he says, “you have to fix the watershed.”
A changing Sound
While water quality continues to be a main focus of many groups working to restore the Sound, the growing issue facing marine life is climate change, which is shifting the composition of fish species that live there and altering the waters in other ways that make it challenging for wildlife to thrive.
Water temperatures in Long Island Sound have been increasing by nearly 1 degree Fahrenheit per decade — faster than 99 percent of the world’s oceans — which has made it less hospitable to many kinds of marine life that prefer cooler waters, including iconic species like lobster and winter flounder. Conversely, species from the south that prefer warmer water are becoming much more abundant in the Sound, like black sea bass, scup, summer flounder and blue crab.
“It depends on your perspective whether the warming Sound is a threat or an opportunity,” says Justin Davis, assistant director of the Connecticut Department of Energy and Environmental Protection’s Marine Fisheries Program. “If you’re a lobsterman, then for sure you see it as a threat. But if you’re a recreational fisherman or someone who runs a charter boat, the fact that some species like black sea bass have become abundant has been a great thing. It’s created a host of new opportunities.”
Davis oversees a trawl survey in the Sound that has been conducted for more than 30 years. Every April, May, June, September and October, a team of scientists tows a fishing net behind a boat at 40 different locations to sample the composition of marine life found at each site. Two of his staff have been involved for 25 years.
“They recall in the early days that they’d get baskets and baskets full of lobsters when they were towing,” he says. “Now when they get a lobster, everybody stops what they’re doing and comes over to look at it. They haven’t caught a female lobster in three years. The same is true of winter flounder. We used to get tons and tons, and now we get very few. Now we fill the nets with tons of scup, which is a stock of fish that wasn’t doing well here in the ’90s.”
Another shift in species composition is most noticeable on area beaches. Instead of seeing large numbers of blue mussel shells washed ashore after storms, beachcombers are now more likely to see the shells of slipper limpets, a sea snail that often attach themselves together in stacks. UConn’s Peter Auster says the shift in abundance of the two species is the result of the warming Sound making local plankton species grow smaller.
“Limpets can feed on smaller plankton more efficiently than blue mussels can,” he says. “In water 70 or 80 feet deep, blue mussels used to dominate those areas, and now they’re dominated by limpets.”
“It depends on your perspective whether the warming Sound is a threat or an opportunity. If you’re a lobsterman, then for sure you see it as a threat. But if you’re a recreational fisherman or someone who runs a charter boat ... it’s created a host of new opportunities.”
Blue mussels are an important food for tautog and other commercially valuable fish, and the decline of blue mussels may have implications for those fisheries. In addition, mats of blue mussels linked together on the seafloor provide a place for smaller creatures to burrow under for shelter. Limpets don’t provide a similar sheltering place for other species.
“The engineering effect that mussels have in terms of creating habitat is significantly reduced,” Auster says. “We don’t entirely understand the cascading effect of these changes through the ecosystem and up to fish populations, but it’s relatively widespread in Long Island Sound.”
Auster notes that the warming waters have also reduced kelp populations in the region, as well as two small, little-known species — the Atlantic seasnail and a fish called the radiated shanny — both of which were previously common. Now, he says, “their existence in Long Island Sound is in question.”
In addition to warming the Sound, climate change is also causing sea level to rise, which erodes coastlines and floods salt marshes that are vital nurseries for juvenile fish. The rising seas are also forcing many communities to consider armoring their shorelines to protect homes and infrastructure, which inevitably results in the destruction of habitat for coastal wildlife.
The increasing levels of carbon dioxide being absorbed into the water from the atmosphere also leads to ocean acidification, a decrease in the pH of seawater. That phenomenon makes it more difficult for shellfish, crustaceans, corals and other organisms to grow or maintain their shells and exoskeletons. It’s an issue that is already affecting shellfish in some parts of the West Coast, and one that is being watched closely in Long Island Sound, especially by shellfishermen and aquaculturists.
“There’s been a lot of talk about ocean acidification and problems with shell development,” says Jean Paul Vellotti, an oyster farmer with Copps Island Oysters in Norwalk. “Our oysters are doing fine so far; we haven’t seen any impacts yet. But we’re going to start measuring pH to get a baseline and then keep monitoring it. It’s something we’re definitely thinking about.”
Other emerging threats
Factors related to the changing climate aren’t the only issues facing marine life in Long Island Sound, however. Invasive species are always a concern, even though none have had significant negative impacts in recent years. The one exception may be Asian shore crabs, which were first documented in the Sound in 1993 and may be outcompeting native crabs.
“Most animals that end up here and don’t belong here don’t manage to establish themselves,” Davis says. “But we’re always worried about that one thing that shows up and ends up having an outsize impact on the ecosystem.”
“Invasives often invade very slowly, and it takes a long time before you see their negative impacts,” Soundkeeper Lucey adds. “And then they’re everywhere and they’ve completely altered the ecosystem.”
Lucey is also worried about what he calls ghost traps, abandoned lobster traps that have been sitting on the bottom of the Sound for years and are still catching marine life of all kinds, most of which die in the traps. Cornell University researchers estimate there may be 800,000 to 1.2 million ghost traps scattered around the Sound. About 20,000 have been recovered by Cornell, and commercial fishermen regularly haul others up in their nets.
Plastics pollution and marine debris is an emerging issue globally, and the Sound isn’t immune. It’s a problem to which the EPA and the Long Island Sound Study are paying close attention. “It’s a very visible pollutant and one that has economic consequences for boaters and beachgoers,” says Mark Tedesco, who directs the study. “It can also have a negative impact on living resources when that plastic material breaks down into smaller pieces and is consumed by shellfish or eaten by turtles and other species.”
Despite all of these threats, however, the Sound is still far healthier than it was 40 years ago, and it’s continuing to improve in many ways. Millions of dollars are spent every year monitoring water quality, upgrading wastewater treatment, installing green infrastructure to reduce runoff, restoring coastal habitats, and improving migratory fish passageways, among many other projects.
On the Farm River in North Branford, for example, the dam at Page’s Millpond is a local landmark and not a candidate for removal, so a modern fish ladder is being installed to allow anadromous fish to reach their spawning grounds upstream. It even has what Save the Sound’s Alex Krofta calls an “eel-evator,” enabling eels to scale the dam as well. The concrete and aluminum fish ladder, featuring a resting pool halfway up, was completed in May, just in time for the peak of the spawning season for alewives and blueback herring. “This was a key priority after the dam downstream had a fish ladder installed,” says Krofta, who manages the project. “This is the next and last barrier for this river system. Fish will now have access to 5 miles of river upstream of this dam.”
“The big payoff for the alewives is the pond above the dam, because that’s where they spawn,” adds Lindsay Suter, who owns the dam and adjacent house, a former grist mill. “The herring like faster water upstream, so that’s where they go to listen to Barry White and spawn.”
Looking ahead, most of those involved in projects such as this agree that there are many reasons to feel optimistic about the future of Long Island Sound and the wildlife that lives there. For DEEP’s Justin Davis, it’s the people of Connecticut that keep him hopeful.
“Policy makers and the public are highly aware of the issues that face the Sound — like climate and the impact of land development — and there are a lot of smart people thinking about it,” he says. “Connecticut is being forward thinking, we’ve developed a plan, and while there are challenges ahead, I’m optimistic that Long Island Sound is in good hands.”
It’s believed there are more than 4,400 dams in Connecticut, most of which are privately owned and no longer serve any purpose now that the age of the industrial New England mill has long passed. In fact, their presence creates a number of problems, including preventing silt and other materials from flowing downstream, and the chance of failing and bringing harm to populations and property. Dams also limit breeding opportunities for fish species that spawn in fresh water and live in Long Island Sound, ultimately having a detrimental effect on the biodiversity of the Sound. Many of the dams are quite small, only a foot or more high, but even that small rise is impassable for some species. Only several dozen dams have been removed in the last two decades. But the pace has quickened recently, with organizations such as Save the Sound, the Nature Conservancy, and the Connecticut River Conservancy, as well as the Connecticut Department of Energy and Environmental Protection, leading removal efforts. Above, a section of the Cannondale Dam on the Norwalk River in Wilton is opened in 2018.
Leading threats to marine life in the Sound
Water quality: Pollution has long been the primary driver of the health of the Sound, though the source of that pollution has changed through the years. In the 1900s, the worst pollution came from the discharge of untreated sewage and industrial chemicals, but after passage of the Clean Water Act, those discharges were reduced significantly. Now the most worrisome pollutants come from the runoff of terrestrial contaminants like automotive fluids and lawn fertilizers.
Warming water: As temperatures increase due to the changing climate, those species that prefer cold water are disappearing from the Sound. Popular native species like lobsters and winter flounder have shifted their ranges northward, so their populations are no longer as robust in the Sound as they once were. But new species from the south like black sea bass have moved into the area to take the place of those that have left.
Ocean acidification: Increasing amounts of carbon dioxide are being absorbed into the oceans as a result of emissions from power plants, automobiles and other sources, which reduces the pH of seawater. The increasingly acidic waters will make it difficult for shelled animals like oysters, crabs and snails to grow and maintain their shells, which could have serious repercussions on shellfish populations and those species that depend on them.
Microplastics: It’s a global problem, but plastics pollution is a growing threat to local waters as well. While larger plastics are an eyesore on beaches and other coastal environments around the region, microscopic pieces of plastic can harm marine life that unintentionally consumes it, from fish and shellfish to seals and sharks. Microplastics are even being found in the seafood consumers purchase at markets and order at restaurants.
Ebb & Flow
The changes taking place in Long Island Sound due to climate change and other factors are providing a boost to some species, while others are declining.
Black sea bass prefer warmer waters and were previously most abundant off Virginia and the Carolinas. Today, its center of abundance is in the waters of southern New England.
Scup, also called porgy, are appearing in the Sound in massive numbers as the waters warm. It has become a top recreational sportfish.
Osprey, a fish-eating hawk that declined precipitously in the 1960s due to the pesticide DDT, have experienced a dramatic comeback thanks in part to the increasing availability of forage fish in the Sound.
Smooth dogfish has become the most common shark species in the Sound as waters have warmed.
Lobsters used to play a large role in Connecticut’s fishing economy, but their preference for cold water has made them all but disappear from the Sound.
Saltmarsh sparrows (shown here) build their nests low in marsh grasses, but rising sea levels are flooding their nests. Scientists predict they will go extinct within 30 years.
Winter flounder prefer colder water and struggle to reproduce in the increasingly warm waters of the Sound.
Mummichogs, silversides and other minnows that rely on saltmarshes for their development are losing habitat as marshes erode from extreme storms and rising seas.