Greg Gerritt: Menhaden -- foundational species

Atlantic menhaden.

Atlantic menhaden.

 

Via ecoRI News (ecori.org)

PROVIDENCE

I went for a walk on a recent morning in one of my favorite places, on the very old path along the Seekonk River at the edge of Swan Point Cemetery, on the East Side of Providence. I have been walking there for 21 years, ever since I moved to the city. It’s called a river, but it’s really the northernmost extension of Narragansett Bay, with a dredged channel for boats heading up to Pawtucket, and a wide mudflat on the Providence side of the water.

The East Providence side is dominated by a sewage-treatment plant and an old landfill. The Providence side is one of the most majestic forests in New England, a mile along the river of steep bluff filled with 170-year-old hardwoods. Even cooler is that when the old trees fall down, they leave them there. I often sit on a log that likely fell into the water just before I moved here. It’s seriously decaying, lost all its branches a decade ago, but the trunk leaning down from the stone wall protecting the path from high tide, except in big storms, into the sea will still support me when I sit on it, on dry days. Like today.

The spring after I moved here, I saw my first Rhode Island osprey from that fallen tree, and I have even seen a small flatfish swim under me once. Later that same year, I saw my first menhaden and was amazed. For nine months I had been looking into the water every day as I walked the river and saw little life in it, but come August I saw endless streams of 3-inch fish swimming by, almost rivers of fish. I eventually learned what they were. I also started seeing menhaden in August and September downtown in the Providence, Woonasquatucket and Moshassuck rivers.

I started Friends of the Moshassuck shortly after that, as that little river surely needed friends after its 300-plus-year industrial history. I walk by almost every day. Eventually, Friends of the Moshassuck developed a video project on urban wildlife in the watershed. The focus is mostly on breeding toads and the restoration of breeding habitat a ways upstream, but come August and September, I walk along the Canal Street and South Water Street waterfront with video camera in hand, because menhaden continue to fascinate and are the one giant flash of wildlife we see each year in the city.

But I want to return us to the Seekonk River waterfront. On the morning I write of, it was 60 degrees, sunny, calm and the tide was in, lapping the stone wall. And walking along the path for the half-mile I covered, almost everywhere were very young menhaden. From 1.5 to 3 inches, with of course the majority, the great majority, being the smallest size class. A few times I saw menhaden jumping offshore, larger ones from the size of the splashes, which means they are being hunted from below. And below an osprey’s favorite perch, there were the quite stinky remnants of adult menhaden all over the place.

Between the stinky adults, the jumpers offshore, and the rivers of tiny ones below, I could only think of what else happens during menhaden season along the Seekonk River. The osprey have a nest on a platform at the Bucklin Point sewage-treatment plant. This year, for the second straight, they seem to have three youngsters, as I occasionally catch glimpses of five hunting at one time.   All summer we have been seeing one or two, but come August, when the flow of menhaden is at its peak, its time to fledge the osprey chicks, and teach them to hunt. And menhaden is what they learn on, in numbers that even a beginning hunter can make a living on.

But is is not just the osprey. Cormorants are seen year-round, but during this time of year they are found in flotillas. Blue heron numbers multiply in August and September, and one seldom sees egrets except in late summer. Kingfishers are darting everywhere. Even the gulls are fishing. Gulls are not really designed to hunt mobile prey like menhaden; they scavenge and pick up stranded crabs. But this time of year you see gulls sitting on the water trying to catch little fish in the water. I have never seen a gull catch a fish, but clearly it must be a worthwhile source of food as the behavior persists, and one can only think that it works because it is directed at a prey so numerous that even a clumsy gull can catch its fill of prey that swims just below the surface eating plankton.

It was that eating of plankton that drew me to an analogy. I went to Yellowstone a few years ago, and there is one place in Yellowstone in which it is easy to see bison, the Madison River Valley. You look over the valley and there are bison everywhere. Bison need to drink pretty regularly, so they need to stay close to rivers. And then you realize that at one time, 200 years ago, there were herds of bison along almost every river in the grasslands of North America. And now there is one river valley that has a free-ranging herd and you remember what we have lost when you see what we still have.

Menhaden are the keystone species of the coastal estuaries in eastern North America. Osprey have returned since we stopped using DDT, but their continued recovery depends very much on menhaden. Eagles eat many as well, and the return of bald eagles to Rhode Island is an ongoing wonder. Three kinds of herons, egrets and kingfishers all rely upon menhaden to build up a little fat before the hard times of winter.

Seals have returned to Rhode Island, and stripped bass and bluefish make fishermen happy; they all depend upon schools of menhaden. One way you know this is true is because the schools of little ones always vastly outnumber the schools of big ones. Many die to keep the circle of life flowing.

Straying a bit from the bison analogy, we can’t afford to have menhaden in just a few places, and even more than bison, menhaden need the whole sea to do their work, to be food for all things great and small. No park could contain a school. What we have to do is protect the entire species, make sure that when people take some for our needs, that we leave enough for everything else. We must manage menhaden based on ecosystems needs, not human greed.

I strongly urge you to support menhaden management based on leaving enough in the sea for the circle of life to flow abundantly along our coasts.

Greg Gerritt is the founder/watershed steward for the Providence-based Friends of the Moshassuck.

The Seekonk River.

The Seekonk River.