Sunday, June 30, 2019
LET FISH RUN UPSTREAM
A lot of the fish that, in one way or another, are important to anglers in New England and the Mid-Atlantic are what biologists call “diadromous,”fish that must travel between salt and fresh waters as part of theirreproductive strategy.
Striped bass are the first such fish that comes to mind, for as we all know, while they spend most of their lives in salt water, every spring they run up certain rivers, including the Hudson, Delaware and various tributaries of Chesapeake Bay, in order to spawn.
If the bass are to spawn successfully, the water that they spawn in must have certain characteristics. The most recent benchmark stock assessment states that
“Striped bass spawning areas are characteristically turbid and fresh, with significant current velocities due to normal fluvial transport or tidal action…
“Striped bass spawn at temperatures between 10 and 23oC, but seldom at temperatures below 13 to 14oC. Peak spawning activity occurs at about 18oC and declines rapidly thereafter…
“Newly hatched bass larvae remain in fresh or slightly brackish water until they are about 12 to 15 mm long. At that time, they move in small schools toward shallow protected shorelines, where they remain until fall. Over the winter, the young concentrate in deep water of rivers. Those nursery grounds appear to include that part of the estuarine zone with salinities less than 3.2o/oo.”
A river that lacks such characteristics won’t be able to support striped bass reproduction.
Yet even if a river contains suitable striped bass spawning grounds, the bass might not be able to reach them. Ever since European settlers arrived in North America, they have been building dams and creating impoundments for various purposes, often to power grist mills or, later, other industrial enterprises. Such dams alter the basic characteristics of rivers, and deny fish access to spawning grounds.
However, dams can be removed, and dams fail. The removal of failing, no longer needed dams can, in the end, be the most cost-effective solution to both fishery and watershed issues.
Maine’s Kennebec River historically supported a small spawning population of striped bass. Construction of the Edwards Dam in the 1837, and the resultant industrial activity, degraded the river and ultimately destroyed its native striped bass spawning population. Striped bass from New York were later reintroduced in the river, and a spawning population, that struggled to survive below the dam, was restored. However, that population’s future wasn’t assured until 1999, after the Federal Energy Regulatory Commission refused to renew the dam’s hydropower license due to its negative impact on fisheries, and the dam was removed.
Striped bass are not the only fish that benefit from dam removal, and not the only diadromous fish important to striped bass anglers.
Not too many years ago, the run of river herring—a collective term that includes both alewives and river herring—into northeastern rivers heralded the first good striped bass bite of the year. Whether you just called them “herring,” as we did in Connecticut, or “buckeyes” up in Massachusetts, the silver shoals of river herring running upstream brought stripers with them. Anglers fishing from sod banks and shorelines, and boaters in the estuaries, caught more than their share of striped bass either livelining herring or fishing herring-imitating lures.
As dams clogged the herring’s natal streams, the runsdeclined, and in most places, river herring can no longer be caught for use as bait, and bass no longer clog river mouths in pursuit of a baitfish that is no longer there.
Yet, once again, there is hope. On many rivers, old, obsolete dams are being removed, and when dams must, for whatever reason, remain in place, more and more state and municipal governments are installing fishways that allow herring to get around the dams and continue their swim upstream.
Again, one of the greatest examples comes from the State of Maine, where a combination of dams, closed fishways (ironically, closed to protect the river’s population of invasive smallmouth bass) and past pollution had caused the St. Croix River’s alewife run to drop to a mere 900 fish as recently as 2002.
The state allowed the fishways to reopen in 2013, and in just the few years since, the river’s alewife run has swollen from just 900 returning fish to about half a million. That’s a big increase, but is still just 5% of the river’s possible carrying capacity, so there’s still a long way to go.
And then there are eels. Eels don’t trigger striped bass blitzes, but they are one of the striped bass fishermen’s favorite baits. And they are in trouble, with dams and loss of access to upstream habitat one of the factors in their decline. While the American eel population is suffering from a number of causes, there is little doubt that better access to upstream waters, where females spend almost all of their adult lives (males tend to remain in estuaries and the rivers’ lower reaches) would alleviate one stress on the population, and so impact eel abundance.
Then there are the species that anglers don’t even think about anymore.
During the Colonial period, Atlantic salmon were present in most, if not all, major New England rivers, until dams and pollution denied them access to upstream spawning grounds. Now, they only maintain a tenuous hold in a few Maine rivers, and all of Maine’s salmon runs are listed under the Endangered Species Act. Yet there are signs that even the salmon will respond to improved upstream access.
On Maine’s Penobscot River, dams have been removed, making Milford Dam the first obstacle to the salmon’s upstream passage. And a fish lift installed at Milford Dam helps keep the salmon swimming upstream. Just a few days ago, on June 20, 107 salmon, an all-time record number, were captured at the fish lift and helped on their travels upstream. Given that only about 750 fish migrated up the Penobscot in all of 2018, seeing 107 salmon in a single day was very good news.
While biologists believe that it will take 75 years to get Maine’s Atlantic salmon off the Endangered Species List, this year’s run at Milford, at the least, gives reason to hope that delisting might, one day, occur.
A number of other species, ranging from tiny rainbow smelt and sea-run “salter” brook trout to the huge Atlantic sturgeon, have been hurt by dammed rivers, and benefit when dams are removed.
So far, I’ve written about good things happening with fish passage in Maine, but readers should rest assured that opportunities for dam removal and other fish passage improvements exist in just about every coastal state.
Anyone who cares about maintaining and increasing native populations of diadromous fish need only do a little research, perhaps contacting organizations such as Trout Unlimited, American Rivers or local conservation groups, and see what they can do to help out their home waters.
Having said that, I’ll close with a message to my fellow Long Islanders.
Sometimes, opportunities for improving fish passage don’t involve years of work and planning.
Sometimes, they drop into your lap.
That has just happened out in Oakdale, where some old, watersoaked boards in a weir on West Brook have recently rotted through and collapsed, draining the impoundment behind the low dam and allowing the river to resume something resembling its natural course. If you ever drive east on Sunrise Highway you know the place; West Brook drains out of Connetquot State Park just west of the park entrance and, until the weir collapsed, backed up into the shallow, warm, weed-choked swan pond that spread out just south of the road.
The State Parks is considering rebuilding the weir, and flooding the pond’s basin again; a fish ladder might be a part of any such rebuild, but no fish ladder functions as well as a free-flowing stream.
Undammed, West Brook could again host spawning runs of river herring, and would be more attractive to eels. If the flow could be effectively maintained, and water temperatures kept appropriately cool, there is even a chance--perhaps remote, but a chance--that it might again host a small population of native brook trout.
Dammed, it will again be a warm, weedy, shallow pond that might host a few eels, and whatever alewives manage to get around the new weir, but it will not be anything resembling a healthy river, and will not provide habitat for the same species that require a cooler waters and steadier flow.
Thus, I’m asking that you take a few minutes to contact
George Gorman, Long Island Regional Director
New York State Office of Parks and Recreation
625 Belmont Avenue
West Babylon, NY 11704
and tell him that the best way to save taxpayer dollars that would otherwise be spent on dam and pond maintenance, and more importantly, to preserve native habitat and native species, is to let West Brook run free.