Follow a stream or river on Long Island and you will undoubtedly run across a dam or two. Beaver Lake is a result of a dam. Two streams run into Beaver Lake: Kaintuck Creek and Beaver Brook. Kaintuck has at least two dams on it of which I am aware. There are probably more. On Beaver Brook there is one at Frost Mill Road (Lower Francis Pond), the dam at Upper Francis Pond, and one more at the intersection of Oyster Bay Road and Beaver Brook. Among the tiny tributaries that feed into Beaver Brook within the Shu Swamp Nature Preserve there are three and possibly more that are on private property. So that’s a grand total of nine dams for a fairly small watershed! Now think about not just one watershed on Long Island, but the entire island, and even further, the entire US:
A few months I wrote a post (A Dysfunctional Chain of Being: Swans, Canada Geese, Snapping Turtles and Raccoons) that was in part about the invasive swan controversy. I have been sympathetic to the recent efforts to eliminate swans from New York due to their potential to cause serious harm to aquatic habitats and their aggressive nature towards other nesting aquatic waterfowl. You see, my opinion is shaped by a scientific consideration of the facts, unlike those people who are guided by an emotional attachment to a beautiful animal, right?
Well I came face to face with my superior sense of rationality yesterday when I discovered a very sick cygnet at Shu Swamp.
Cygnet at Shu Swamp
Right before catching the swan
I transported the swan in a cooler to Volunteers for Wildlife.
I had just finished changing the batteries at the LIRR bridge antenna and was on my way back when I spied the distressed swan. I had seen the parents leave the pond just moments ago, which I found odd since as far as I know swan parents don’t leave their babies. When I approached the cygnet it was clear that something was wrong, although I could see no visible wounds. It was just so listless.
Whatever my feelings about general ecological destructiveness of swans, I wasn’t going to let this helpless animal suffer. Fortunately, Volunteers for Wildlife, a wildlife rehabilitation center, is located at nearby Bailey Arboretum. With the help of a family visiting the preserve, I threw a rain poncho over the cygnet and then picked it up and placed it in a cooler I had in my car. Five minutes later I dropped him off at Bailey. I found out today that the swan has a deep laceration in its foot (although I never saw any blood) and is on its way to the vet to have it checked out. Whatever happens I am sure the Volunteers will do the right thing and at the very least this poor creature won’t suffer.
So far things are going quite well. All four tags are still attached to their respective trout – a very unlikely outcome with the hatchery-reared fish we have released (over half of fish can’t be tracked beyond 2 weeks). Furthermore, they have moved very little if at all from their original release sites, anywhere from 100 meter maximum to as little as 1 meter. All three trout have stayed very close to the location at which they were captured. In fact three of the trout were originally PIT-tagged in our March electrofishing survey and have shown remarkable fidelty to the sites of capure back then.
As a basis of comparison here are the results of radiotracking of five hatchery-reared brook trout of similar size we released last spring and summer:
View Larger Map
Note the increase in scale in this map. Only one of the trout (101) managed to retain its tag (or possibly die) the life of the tag. You can easily see how these fish moved a lot more. 101 moved all the way to the Beaver Lake spillway before running way back upstream and settling down.
A few weeks ago, while radiotracking trout I ran into this guy hogging the trail. If you listen carefully you can hear every 20 seconds the chirp of a radiotag. One of our wild trout is only a few feet away.
I cautiously got a little closer and notice these appetizing hitchhikers on the snapper’s carapace.
Three juicy leeches
At least I assume they are just along for the ride. It’s hard to believe a leech could rasp its way through a turtle shell. Later that day, I ran into a muskrat couple frolicking at the upstream footbridge (actually they were doing more than that but this is a family website). I took video as they were amazingly unconcerned by my presence. but unfortunately the quality is terrible. Instead I leave you with this classic, and one of my personal all time unfavorite songs, “Muskrat Love” by Captain and Tennille . It’s well worth watching though if only because of the dancing muskrat puppets, Captain’s amazing muskrat chirps piano solo, and Toni Tennille’s fashionable (for the time) Dorothy Hamill hair.
I have updated the water temperature page under environmental data with the most recent temperature data. Seven temperature data loggers have been in place since May 2012. I added temperature profile graphs for each season such as this one showing summer 2012 temperatures:
Last Friday (5/16) the four tagged wild brook trout were released back where they had been caught. The videos show the release of two of the four. Brian’s doing the releases and Maryanne is doing the camera work. In the first video showing the release of trout #106 (named for the radiotag code), you can actually see the thin wire of the antenna trailing from the fish. Towards the end of the second video, the trout (I think this is #107) darts back to its original release location.
We have been tracking the four for a week. Thus far, unlike the hatchery trout, these guys have generally stayed put. Yesterday I used my GoPro camera o try to locate the whereabouts of a tagged fish once we had pinned down their location using the radiotracking receiver. In the video below you can see on the bottom right two, possibly three, trout hanging out just above the sandy bottom. Presumably one of these trout is #106 located about 30 meters upstream from its release site. At the same time I was filming this, Maryanne saw two more trout a few meters upstream.
Check out any river on Long Island and chances are you will find a series of dams running its length. Thus virtually every river on Long Island has compromised to completely blocked fish passage resulting in the virtual elimination of anadromous fish from our waters. The Shu Swamp/Beaver Lake watershed is impacted by four dams. About the only LI stream I can think of that doesn’t have at least one dam is Alewife Creek in Southamptom, famous for its huge alewife run in March and April, and considered an “ecosystem rarity” by New York Department of Environmental Conservation.
Nature Conservancy and its partners meeting with engineers for Fuss and O’Neill at the Beaver Lake Spillway May 19.
This past fall the Nature Conservancy was awarded Long Island Sound Future Fund money towards fish passage plan development and implementation for three sites in Connecticut and New York. The site in New York is the spillway on Beaver Lake that impedes passage to and from the brackish Mill Creek. The grant provides money to develop plans for a fish ladder and apply for the necessary construction permits. I am a matching partner on the grant, providing data on water levels below the spillway as well as observations on river herring approaching the spillway. This Monday we had a “project kickoff” meeting at the spillway in which the various partners and supporters of the project met with Josh Wilson the engineer from Fuss and O’Neill, the environmental engineering firm contracted by Nature Conservancy. As you can see, there was a pretty good crowd in attendance including Sally Harold of the Nature Conservancy, director of the project, other members of the Nature Conservancy, and representatives from the Town of Mill Neck, New York DEC, North Shore Wildlife Sanctuary, North Shore Land Alliance, USGS, Trout Unlimited, and Friends of the Bay.
It seems like the engineer is leaning towards installing a steeppass ladder, which I think is similar to this one:
Alaska steeppass ladder
The engineer hopes to have a completed “permit-ready” design by August. And assuming funds can be found and the permits are approved in a timely manner, installation may occur as early as next Spring!
So that will solve one big problem for anadromous river herring and brook trout by allowing easier passage through the Oyster Bay estuary up into Shu Swamp. I hope to document an improvement in passage through PIT-tagging studies. But we have one other really big problem. Namely, if you don’t have fish it doesn’t matter how easy it is to pass! For the past three years I have been monitoring the herring spawning runs at the spillway. The previous two years I witnessed at best a handful of alewives attempting to enter the lake (see my post from last May). This year I have yet to see a single alewife. Lifelong residents of the area report seeing hundreds perhaps thousands of alewives entering the lake, and as one person told me “backing up” in Beaver Lake like it was a traffic jam. This occurred in spite of a dam with minimal passage! What happened and how are we going to bring them back? One thought we tossed around was bringing in some spawning alewives from one of the successful runs elsewhere on Long Island. These would be used to “seed” the swamp and lake with babies imprinted to the watershed and likely to return as spawning adults in three years. This strategy may have shown some success when applied at other places such as the Bronx River.
According to Lehman College Professor Joseph Rachelin featured in the video, adult progeny of the spawning alewives released into the Bronx River in 2006 returned in 2009 indicating success. However, Queens College Professor John Waldman, reports in his excellent book, Running Silver, that the returning alewives were too old to have been progeny of the 2006 spawning alewives and were more likely native alewives, which is quite a suprise since everyone thought they had been eradicated long ago.
I think a big step forward was taken this week at Beaver Lake. Improving fish passage has been kicked around for a long time but finally people are acting. Given the amount of collaborative interest I am optimistic.
The plan yesterday was to test the swimming performance of the 4 wild brook trout we caught electrofishing. The reason we want to do this is based on the results we are getting from our radiotelemetry studies on hatchery trout released into Shu Swamp. We see a lot of downstream movement right after release. We believe that one factor that may influence movement patterns of hatchery trout released is that they are not in top physical condition. We notice a lot of fin damage due to the high density conditions in the hatchery.
Hatchery trout showing damage to the caudal fin, oen pectroal fin, and a deformed opercular plate.
Furthermore hatchery fish may not get all that much exercise since the flow rates in the hatchery are much lower than they are in a stream. To test this we determine the water speed necessary to cause swimming fatigue (called critical swim velocity). In the lab this is done by placing the fish in a special swim tank similar to an Endless Pool” for people. The fish swim upstream against the flow and the flow can be gradually increased until fatigue is observed. This video, using a juvenile brook trout, shows what should happen. Fatigue occurs when the fish rests its tail against the downstream grid and stops swimming.
Unfortunately when we tried to determine swim performance in the wild trout, they would not cooperate. They just rested against the downstream grid even at very low speeds. We tried a number of approaches to get them to swim but to no avail. The fish we are using are pretty big – 8 to 10″. On the other hand there has been no problem testing swim performance in smaller 5-6″ fish. For now it’s back to the drawing board.
After giving up for now on swim performance tests, we moved on to tagging. In short order Brian had radiotagged the 4 fish and they were groggily recovering in their temporary holding tanks. Each fish received a PIT tag (if it didn’t have one already) and a radiotag. In the figure on the right you can see the incision in the abdominal cavity where the tag is implanted. The antenna leaves the body through a small puncture above 2 inches posterior to the incision. The trout will be released today. These tags should last about 160-180 days. They emit a individually coded radio pulse once every 20 sec. To extend the battery life we have the tag active for 12 hours during daylight.