The Village of Saugerties will begin running its weed harvester in May to try to get ahead of the Asian milfoil that builds up each summer. The effectiveness of the harvesting has been questioned by naturalist Leslie Surprenant, whose studies of the harvested and unharvested areas of the Esopus Creek cast doubt on whether the harvesting program over the past two years is the reason for the reduction in weed growth.
A retired marine biologist and member of the Town of Saugerties Climate Smart Task Force, the Town Conservation Advisory Commission and the Ulster County Environmental Management Council, Surprenant spoke to the Village Board at its regular meeting on April 17. She had previously briefed the Town Board at its meeting on Wednesday, April 5.
The use of the harvester began in 2019, when Zdanek Ulman (also known as “Z”) harvested a section of the Creek opposite the Village Beach. The following year, the Village bought the harvester from Ulman after he decided to concentrate on his primary business of diving.
The operation of the harvester rests primarily with the Village, but it was purchased jointly by the Village, the Town of Saugerties and John Mullen, a Saugerties-based contractor who owns land along the riverfront.
In her study of some 39 sites in 2020 and 38 in 2022, Surprenant found that there was no significant difference in the number of weeds in harvested and unharvested areas. One possible explanation is that turbulence caused by releases from New York City’s Ashokan Reservoir kept the weeds from reproducing. The turbulent water becomes very muddy, which prevents light from reaching the plants below the surface, so they can’t reproduce. Trustee Donald Hackett commented that as much as we don’t like the turbulence or the mud, it seems that they also have some positive effects.
The harvester may have contributed, Surprenant said, but the comparison of harvested versus unharvested areas indicated that it was unlikely that the harvesting program alone could explain the differences. Both the harvested areas and non-harvested areas showed a 70 to 75 percent reduction.
Further study — ideally annually, but certainly every two years — will be needed to establish how the weeds can be eliminated or controlled, Surprenant said. While she will continue to monitor many of the sites she studied in previous years, dropping some that did not have significant weed growth, Surprenant said that she will not monitor in the Village. She suggested that the Village set up its own monitoring plan, and offered to help design it. While Surprenant will continue to monitor the areas in the Town that she has been studying, the work is hard, and especially when temperatures climb into the 90s it can be difficult even to read and record the information that she is collecting. Adding the Village to the operation would be too exhausting, she said.
The Village has records of the areas where its harvester has been working, and Surprenant said that she will check with Eyal Saad, who is coordinating the Village’s efforts to remove the weeds, for his records. Murphy said that the Village would not have a problem with Surprenant looking at the weeds collected by the harvester to see what species are collected.
Harvesting can have negative effects, Surprenant noted. The chopped-up leaves can reproduce, and in late July, floating leaves break up, take root and spread the plants far and wide. Removal should best be done before that.
Village Board members and mayor Bill Murphy say that they, working with the Town and Mullen, will do whatever is necessary to keep the weeds under control. Both Town and Village officials have said they would not want to use chemicals to control the weeds, as chemicals could harm plants that the Village would like to protect along with those that are unwanted.