Essay : The varied tributaries to a Mill Pond decision
Photo courtesy of Steve Hurley
Whether — for ecological reasons — to dredge or even obliterate West Tisbury's historic Mill Pond is an issue that stirs strong emotions among the town's residents.
These feelings are so intense that one can envision — if the grist mill dam that created the pond in the 1700s were to be removed — townspeople gathering on a back porch with their guitars to conjure up a new version of an old song, the first four lines of which might be:
"Go tell Aunt Rhody,
Go tell Aunt Rhody,
Go tell Aunt Rhody
The old Mill Pond is gone."
The 2.5-acre pond was last dredged in the 1970s. Its average depth is probably less than two feet and its deepest portions less than six feet. The most downstream of the man-made ponds on Mill Brook, it has been slowly filling with silt and accumulating aquatic vegetation, particularly at its upper end.
Wild brook trout once lived in the Mill Pond and the portion of Mill Brook that is below it. This is no longer true. Throughout recent summers the temperature of the water coming over the dam has gone into the 70s and 80s, and the same temperatures existed in lower Mill Brook. Brook trout cannot survive, let alone propagate, in water that warm. During the past decade, in my watercress wanderings up and down lower Mill Brook, I have never seen a brook trout swimming or feeding.
Hence the proposal to remove the Mill Pond dam, which had its genesis in a public meeting at the West Tisbury Library last year, arranged by Prudy Burt, a member of the town's conservation commission. At that affair, Michael Hopper, president of the Sea Run Brook Trout Coalition, gave a slide show presentation of his group's successful efforts to restore sea-run brook trout in two Massachusetts coastal streams, the Quashnet River in Falmouth and Red Brook in Wareham. Both restorations included removal of dams.
I occasionally caught sea-run brook trout — also called "salters" — in lower Mill Brook until the mid-1900s. "Sea-run" is slightly misleading. Unlike the anadromous Atlantic salmon, these trout don't go to sea. They drop down out of the brooks in which they were born into bays, estuaries, and salt ponds, and return to fresh water to spawn. For a few weeks after their return, they have darker backs and lighter sides than do their fresh water counterparts. Smelt were also in lower Mill Brook when I was a boy, but I never knew whether they were of the fresh water or anadromous variety. An anadromous fish is one that is born in fresh water, goes to salt water to attain growth and maturity and returns to fresh water to spawn.
Mill Brook is about four miles long. Major ponds above the Mill Pond are Priester's Pond, Crocker Pond, and Fisher Pond (also called Woods Pond). There are also several smaller impoundments along the way, most created after WW2.
Last month, biologist Steve Hurley, who is Southeast District Fisheries Manager for the Massachusetts Division of Fisheries and Wildlife, visited Mill Brook with his backpack electrofishing survey crew. Fish are temporarily stunned by an electrical charge that emanates from the tip of a hand-held probing rod. They are then netted, identified, measured, photographed, and returned to the water with minimal handling and harm.
Mr. Hurley's survey was assisted by Prudy Burt, who made arrangements with landowners for access to the brook in various locations. Mr. Hurley and his team found wild brook trout — including young of the year — in the brook and its tributaries from its headwaters above Fisher Pond downstream to a point about a mile above the Mill Pond where their survey of the upper reaches of the brook ended. As an interesting aside, they also found large clusters of American eels, a pleasing discovery, because eel populations in Tisbury Great Pond — into which Mill Brook flows — have been declining.
The American eel is a catadromous species. Each spring, small eels, known as elvers, depart their birthplace — the Sargasso Sea — and range along the North American coast from the Gulf of Mexico to the Gulf of St. Lawrence, entering estuaries and salt ponds. The females swim up rivers and streams where they attain growth and maturity, which may take a decade. The males remain in their salty environment waiting for the females, which grow much larger than the males, to return. When that happens, they all swim back to the Sargasso, procreate and die, and a new crop of elvers repeats the cycle.
Mr. Hurley and his co-workers found no trout in lower Mill Brook even though it has several substantial cold springs flowing into its east shore.
West Tisbury residents now know that wild brook trout still survive in the upper reaches of Mill Brook, making the restoration of them — if deemed desirable — in the Mill Pond and lower Mill Brook a more attainable goal.
In a recent letter to this newspaper, Bob Woodruff, chairman of West Tisbury's Mill Pond Committee, examines the complexities of dealing with the Mill Pond dilemma. He favors dredging, but adds — erroneously, I believe — that it would not benefit trout. It seems likely that proper dredging would allow trout to also live — as they did for many years — in the Mill Pond and the brook below it. Also, of course, sea-run brook trout could once again visit lower Mill Brook.
The estimated cost of one dredging plan considered by the Pond Committee was about $400,000, and one dam removal estimate given Prudy Burt was more than $550,000.
These figures should be regarded with caution and are extremely preliminary. For example, Ms. Burt notes that in similar projects in Massachusetts, various NOAA Restoration Partnerships, the national Fish and Wildlife Foundation, and private organizations have absorbed most of the stream restoration costs. Mr. Woodruff notes that outside help for dredging is also possible and that the various dredging plans being considered by his committee vary considerably in cost.
Save for the Mill Pond and Crocker Pond (which once had a grist mill) Mill Brook and its impoundments are a vivid example of the urge to divert or dam a stream for no significant practical purpose that often possesses riparian owners, an urge to which I probably would have succumbed had I owned land with a stream flowing through it as a young man.
The Tiasquam River, the only other major stream, in addition to Mill Brook, that enters Tisbury Great Pond, has three major ponds on it, Look's and Davis, and one created in recent years by the late West Tisbury artist Stan Murphy. Look's Pond once hosted a grist mill, and Davis Pond a fulling mill. The remaining small impoundments and the Murphy pond are examples of the aforementioned riparian owner syndrome.
In observing that restoring stream habitat for sea-run brook trout is a laudable goal where "appropriate," Mr. Woodruff goes to the core of the Mill Pond problem. If the Mill Pond was seen and visited by few, eliminating it would be much less of a social and philosophical problem. For centuries, the Mill Pond has given visual and emotional sustenance to Vineyarders and its visitors. It is presently little more than a shallow mud hole, but it still pleases the eye. It is also a highly visible public treasure. I always slow down and scan its surface for otters, birds, or rising fish when I drive past, and among the memories that seize me is when, 75 years ago, I huddled in my duck blind at its upper end waiting for black ducks to drop down out of a dark December sky.
Nelson Bryant of West Tisbury was for almost 40 years the outdoor columnist for The New York Times. As a young man, he participated in the D-Day invasion with the 82nd Airborne. Later he became managing editor of the Daily Eagle in Claremont, New Hampshire, and then a dockbuilder on the Vineyard, before beginning a career as a columnist that would take him around the world and back again to the Vineyard.