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 in 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,” said Vander Werff, a fisheries biologist with Save the Sound. “The odds are stacked against them, because their role in the ecosystem is to act as food for big gamefish in Long Island Sound. By getting eaten, they’re doing their job.”
For a couple 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
preventing the fish from reaching their spawning grounds in fresh water. Many
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.
|Jon Vander Werff at Whitford Brook (Brian Pounds)|
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 trap caught about 30 fish per day through mid-April. 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 restoring the Sound to health.
“Removing dams and building fish passageways is all about making more forage fish,” explained Peter Auster, emeritus professor 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 being employed 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,” said 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 added, 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, non-profit groups and others working together as part of the Long Island Sound Study, led by...
Read the rest of the story in the August 2020 issue of Connecticut Magazine.