All of Connecticut's Spawning River Herring Seem to be in the Mianus River

Now that spring spawning season is here for anadromous fish (or diadromous, as they seem to be called now), two things are incredible:

1. there are so few river herring left in Connecticut that it is illegal to fish for them.

2 the Mianus River continues to get thousands of spawning river herring -- 33,000 last year (click here and scroll almost all the way down).

Alewives...

... in the Mianus River.

Looking for Alewives

This email I received the other day is mainly about the South Shore of Long Island but, if I had time and it was closer, it would make for interesting volunteer work:

"Volunteers are needed to participate in an observational survey of alewife (a.k.a. river herring) spawning migrations in the rivers and creeks of Long Island. 



"Fishes that split their life cycle between marine and freshwater ecosystems provide many important economic and ecological benefits. Many of these `diadromous' species are fishing targets, either as food fish, baitfish, or sport fish. Perhaps more importantly, many are key forage fish, feeding larger predators further up the food chain such as striped bass, bluefish, ospreys, and marine mammals. Among the most common of these species is the alewife (Alosa pseudoharengus), a species of herring native to our region. Alewives, like all diadromous species, are threatened by impacts to freshwater habitats, including blockage of migratory pathways, habitat degradation, and declining water quality.



"Little is known about the current status of alewife spawning runs in the creeks and rivers on Long Island and collectively provide a vast area of critical spawning, feeding and nursery habitats. Documenting these spawning runs is an important step in understanding diadromous fish habitat use, and for guiding future projects to restore their populations on Long Island. This study was initiated in 2006 in the South Shore Estuary Reserve and we are looking to expand our coverage area this year to include tributaries to Long Island Sound. 



"The South Shore Estuary Reserve and Seatuck Environmental Association are seeking volunteers to watch for alewives during their upcoming spawning season, April 1 to May 31. Individuals from observer teams will take turns looking for alewives for just 15 minutes a day in a river or stream near them. Volunteer training workshops will be held on March 17th and March 22nd. 

More information on the survey and links to past reports can be found on the South Shore Estuary Reserve Website (http://www.estuary.cog.ny.us/council-priorities/living-resources/alewife_survey/alewife_survey.htm )



"Interested in helping? 



Contact:

Brian Kelder

Fisheries Scientist

Environmental Defense Fund Puleston Fellow 

Seatuck Environmental Association
Islip,
NY
Phone: 631.626.1269

Email: bkelder@seatuck.org 
www.seatuck.org
"

Conecticut, by the way, had helped build 44 passageways on blocked rivers for alewives and blueback herring. The most successful seems to be on the Mianus River, where Greenwich has been getting counts of upwards of 90,000 fish climbing their ladder.

I've never seen alewives referred to as diadromous rather than anadromous, by the way, as Mr. Kelderdid in his email.

The Fish Are Spawning in the Mianus in Greenwich Again This Year

About 90,000 anadromous fish -- alewives, mainly, but blueback herring as well -- made it over the fish ladder on the Mianus River in Greenwich in the spring of 2007. That number amazed fisheries biologists, because river herring populations have been dropping all over, and it's illegal to catch them in Connecticut.

Back in March, at the Long Island Sound Citizens Summit conference in Bridgeport, Steve Gephard, the director of inland fisheries for the Connecticut DEP, made a presentation and said that there were 44 fishways -- passages to help spawning fish make it over dams -- in Connecticut, and a 45th being built in Darien.

By coincidence he sat down next to me after his talk, and I asked him about Greenwich. He said the incredible number of fish on the Mianus was an eyebrow-raiser but that for reasons they don't understand it might also be an anomaly, a one-time surge that they can't explain.

But that does not seem to be the case. The Greenwich Time ran a Q&A with Brian Eltz, an assistant in Greenwich's conservation department whose job it is to coordinate the river herring count. Here's an excerpt:

What's been going on over at the fishway?

At the fishway, we've had a tremendous herring run this year. We've passed about 82,000 river herring so far and about 77,000 of the alewives and the bluebacks just started coming out. We have about 20 volunteers there who have been helping, so we've been able to collect good data.

How is our fishway unique?

Well, it's got the best run in the state of herring at a fishway.

What does that mean?

We have the highest number. What it is is that we have a lot of good habitat like the pond and being so close to the coast. It's good access for fish to come in and spawn in that habitat.

So it's not an anomaly. But it's still hard to explain.

Help Fish Spawn in Greenwich

The number of fish that swim upstream to spawn in Long Island Sound's watershed is ridiculously low. Every stream -- literally -- used to have a spring run, but dams have blocked them off. To compensate (we're always trying to compensate for our environmental mistakes; we never seem to recognize them ahead of time and avoid them), a number of towns have worked with the Connecticut DEP to build fish ladders and passageways.

One of the best and most active is on the Mianus River, in Greenwich. If I lived near closer, I'd volunteer to do this.

Spawning Help in North Branford and Success in Greenwich

Who knows why the number of spawning alewives and blueback herring in local rivers and streams has fallen so low? One theory is that striped bass restoration efforts have been so successful that the big fish (the stripers) are eating the little fish (the herring). Throughout Connecticut, the two most popular solutions are to remove dams or build fish ladders, to ease the upstream passage. And apparently it's working, at least in some locations:

This spring, in Greenwich, the Mianus River passageway saw a 12-fold increase in river herring — about 90,000 fish. News of the record migration spread rapidly along the shoreline.

Kim Martineau of the Hartford Courant dropped that nugget into the bottom of an interesting story (here) about a family in North Branford that, with state and Trust for Public Land help, is building a fish ladder on the part of the Farm River that passes through their property.

Migrating Eels

On the Mianus River, in Greenwich, people are working not only to help alewives swim upstream to spawn, but to help eels get downstream the Long Island Sound and then the Atlantic Ocean to spawn (American eels are catadromous, the opposite of anadromous alewives, shad, etc.) But what could the Greenwich Time reporter possibly mean when he writes this:

The Mianus River Dam, where alewives reach freshwater each April, also plays a crucial role in the lives of the Western hemisphere's only freshwater eels.

At first I thought he was saying the only freshwater eels were in the Mianus. But more likely he means American eels are the only freshwater eels in the Western Hemisphere. In any case, here's more about the eel situation:

A net hanging over the dam serves as a ladder that baby, or "glass," eels use to climb back into the freshwater. The eels remain for about 10 years in the Mianus Pond, then head out of the Long Island Sound to the Atlantic Ocean once they're mature enough to spawn.

Threatened by overfishing, hydropower plants, dams and other obstructions, the American eel recently came under consideration by the federal Fish and Wildlife Service for endangered species status.

"We're seeing fewer in Connecticut and throughout the entire (northeast) range," said Rick Jacobson, assistant director of the Connecticut Department of Environmental Protection's Inland Fisheries Division. "The concern is manmade dams and other barriers to fish passage, both in terms of moving upstream and downstream. Because of their migratory pathways, they frequently go through turbines or filter systems into water supply reservoirs. That, and overall degradation of habitat."

Nets are a primary way that conservation officials help eels circumnavigate barriers such as dams.