Dr. Claude Renaud, an expert on lampreys, set off in early September on a week-long collecting expedition in New York State. In his first blog, Claude outlined why it was important for him to search for American Brook Lamprey along the Hudson River. In Part Two, Claude and research assistant Noel Alfonso battle poison ivy, logjams and polluted rivers… and no lampreys in sight!
Our next three localities down the Hudson River had very similar names: Saw Kill River, Sawkill Creek and Saw Mill River. This reflects the enormous importance of the forest industry in New York State. Sixty-three percent of the state is forested and provides employment to over 60,000 people. Much of this land is privately owned and managed for wood or pulp.
Saw Kill River is very near Bard College where our good friend Dr. Bob Schmidt worked for many years. A single lamprey was collected at the mouth of the river in 1974. However, Bob advised against sampling at that precise locality because the water is too deep to wade in, the current is strong and it’s simply too dangerous. Bob told us that in all the years he sampled the river, often with an electrofishing apparatus, he never saw a lamprey anywhere along its length.
However, if we were going to try anyway, he pointed out where we could find good habitat. We electrofished extensively in that area and saw no lamprey larvae despite an abundance of ideal habitat (i.e., an appropriate mix of silty and sandy sediment). There were a lot of frogs and racoon tracks all around though. Bob was right!
The next place we tried was the mouth of Sawkill Creek, a direct tributary to Esopus Creek. Access to the water was a little tricky as poison ivy (Toxicodendron radicans) was everywhere! From then onwards, we treated our chest waders as if they had been contaminated and were extra careful in handling them. Here again, the habitat was ideal but there was not a trace of any lamprey larvae. As in the previous locality, the only lamprey ever caught in Sawkill Creek was taken in 1974.
Our final two localities were down in the New York City area. The first one we attempted was the Saw Mill River in Yonkers. This river has an interesting history. The last 600 metres of the river was covered in the 1920s by the United States Army Corps of Engineers. Joni Mitchell even mentioned this in a song with the lyrics, “They paved paradise to put up a parking lot.” In 2011, and again this year, sections were “daylighted” by removing the parking lot that covered it.
However, our sampling sites were further upstream along the river. Surprisingly, the problem that we faced here was neither access to the river, nor the lack of suitable habitat. The problem was logjams, debris and garbage. We tried at a place where there was suitable habitat and the result was once again negative.
Then we went to the place where one specimen of American Brook Lamprey was reported caught in 1956. What we found there was death and desolation. We saw one sucker (Catostomus sp.) gasping its last few breaths and at least four more that were floating belly up. Two sunfishes, one of which was a Bluegill (Lepomis macrochirus) were also seen dead, lying on their side. Remarkably, we saw schools of three to six large Common Carp (Cyprinus carpio) swimming up and down the current with seemingly no ill effect.
Our last locality was Tibbetts Brook where American Brook Lamprey had been documented between 1897 and 1909. We were met on the Yonkers side of the brook by Melissa Cohen, Regional Fisheries Manager, New York State Department of Environmental Conservation (NYSDEC) and three of her staff: James MacDonald, Annie Murphy and Steven Wong.
They brought their own electrofishing apparatus and the six of us spent a morning working the partly channelized brook. We saw dozens of crayfish, and a couple of Goldfish (Carassius auratus) one that had the bright orange color familiar to aquarists and the other that had reverted to the wild coloration, a drab greenish color. We also had to negotiate the inevitable logjam.
We parted with the New York biologists and made our way to Van Cortlandt Park in order to access Tibbetts Brook from the Bronx side. Van Cortlandt Park is a 464-hectare oasis of greenery in the middle of the Bronx. Tibbetts Brook flows through it and into Van Cortlandt Lake.
There is a large golf course in the park and we proceeded to the golf clubhouse to ask permission to rent a golf cart to help us reach the brook. The people there were very pleasant but told us that we couldn’t gain access to the brook from the golf course because the course edge was fenced. What a disappointment!
Luckily, we had a chance that morning to thoroughly examine the upper course of the brook on the Yonkers side or else this would have been extremely discouraging.
Our fieldwork was not in vain. We learned that in all likelihood the American Brook Lamprey has become extirpated from the Hudson River Basin. It was probably never abundant to begin with as indicated by the few collections made since its discovery in 1842. Fortunately, I have some material from the Lake Champlain Basin in Vermont that I can use to compare with the other material collected in the Northwest Territories in 2012.