Editor’s note: This commentary is by David Deen, a Democratic state representative from Westminster and the chair of the House Natural Resources, Fish and Wildlife Committee. He a board member of the Connecticut River Valley Chapter of Trout Unlimited and an honorary trustee and former river steward of the Connecticut River Conservancy, formerly the Connecticut River Watershed Council.
[I]n springtime, we cheer on our Connecticut River migrating fish including salmon, shad, American eel, sea lamprey, shortnose sturgeon and blueback herring. They are all on our idols list. Some of us go to viewing windows at the fish ladders and we read newspaper or magazines articles about the spring migration. We celebrate or bemoan the numbers reported in those stories. Spring migration is the aquatic equivalent of maple sugaring, both signaling the earth’s annual reawakening from winter.
The problem is that those springtime events are only half the story and somehow, we do not in equal measure pay attention to the important fall migrations out of our river into the salt water and most are unaware that many of our purely freshwater fish now embark on their migrations to upstream spawning locations.
Here are some brief thumbnails about the species that use our Connecticut River aquatic highway to migrate down river to salt water every fall.
Thousands upon thousands of 3- to 4-inch American shad juveniles spawned in the spring head out to the ocean and spend four to five years maturing into adults while repeat spawners await the next spring freshet that signals them to return to the river to spawn again.
Like the shad, blueback herring and alewife juveniles born in the watershed head out to sea to reach maturity before they return to their natal headwater streams.
American eel adults that have spent 20 years maturing upriver head out to sea for their 1,000-mile perilous swim to spawning grounds in the Sargasso Sea found south beyond Bermuda. These 3- to 4-foot long adults have never migrated there before and little is known of how the springtime returning glass eels find the river where they will grow since they have never been there either, yet find it they do.
Mud dwelling sea lamprey juveniles are 5-inch-long diatom and detritus eating worm-like larva. After five to 10 years as larvae they become transformers migrating down the river and to the sea to reach maturity in salt water. They hopscotch from muddy bottom to muddy bottom until they transform into a swimming fish. Lamprey do not attack other fish until they reach salt water and to complete the story, once they re-enter fresh water they do not feed at all. This is the case in a true fresh to salt and back to fresh water migratory run as in our Connecticut River.
Atlantic salmon adults migrate to the sea in fall after spawning with some adult fish if they are in a natural setting holding over staying in place until the following spring. This is a small migration now that the Salmon Restoration Program is in hiatus.
The river’s shortnose sturgeon with its territory separated into two parts, one above and one below Holyoke Dam, do not go to the sea, but migrate both up and downriver to wintering grounds. Those below the dam move to the estuary area while the upriver population moves up toward the Turners Falls dam.
There are fish in the lower reaches not found up river in Vermont and New Hampshire that are also part of this fall migration. They are sea run trout and the ubiquitous striped bass where both adults and juveniles move down river to wintering grounds in the estuary and Long Island Sound.
These migrations are all affected by the hydroelectric dams. As relicensing now underway moves forward, more efficient and less threatening means of moving these fish past the dams alive and undamaged are part of the ongoing negotiations. It is important to note that when the dams were first licensed we knew little of what is needed for safe passage and quite honestly, as a society we did not care about safe passage either. Times have changed over the ensuing half century and we hope those earlier unenlightened times will never come back.
The species that use the salt water as part of their life cycle are the long trip travelers of the fish world but even fresh water fish migrate just as predictably just not as far.
Fresh water brook and brown trout are fall spawners and their preferred spawning locations usually lie in upriver reaches in small streams. These locations offer the proper flow of water, the proper gravel bottom into which to dig their redd/nest that will hold the eggs in place overwinter and offer the juveniles hiding crevasses within the gravel until they can swim efficiently.
Once the juveniles are mature enough they will migrate to rearing areas with better food sources and larger habitats downstream. Biologists have tracked migrating fresh water trout as far as 26 miles from rearing to spawning locations. Obviously, a dam or perched culvert along the way places impassable barriers in the way of this migration. We are just starting to pay attention to this problem with landowners, NGOs, municipalities and states beginning to remove useless deadbeat dams to open these fresh water back roads for successful migrations.
So, there may be less ballyhoo for the fall migration and there are no viewing windows for it and few stories about it but it is the vital second half of nature’s cycle of aquatic life. So, let’s give a hip hip hurrah for the fall migrations.
