“You can see the ecosystem change from one day to the next – especially with hydrilla. You’ll see a normal pond, and by the end of the growing season it will be completely filled with hydrilla,” said Nicole White, founder of the company Little Teddy Bear environmental protection advicewhich often works with city and state officials to combat invasive species. “Nothing else can survive there. It’s clogged.”
White has worked with other organizations, including the Department of Environmental Protection eradicate hydrilla in the Croton River in 2018–2022. Of the 449 sites initially sampled, hydrilla was present in 40 percent.
They ultimately managed to eradicate hydrilla from a three-mile radius downstream by applying herbicides at very low concentrations for five seasons, but the impact of hydrilla on the river ecosystem was so severe that by the end of the project, White had to replant many native plants. aquatic plants in the Croton River.
According to Taylor, hydrilla still remains in the New Croton Reservoir. To change this, the Department of Environmental Protection also uses herbicides.
The presence of hydrilla in a reservoir can affect not only the marine ecosystem, but also the water quality and the survival of local birds. It is also known that hydrilla is a habitat for cyanobacteria that can turn into a toxin –Aetocthonos hydrillicola. This type of harmful algae can kill waterfowl and bald eagles and may also harm human health.
“It’s a neurotoxin, so in places where Aetoktonos occurs on hydrilla, a lot of wildlife has died from brain damage,” White said. “So the fish died out, the reptiles died out, just like the turtles, the hydrilla-eating waterfowl died out, and then the predators of those waterfowl also died out.”
Climate change is leading to warmer weather in the fall and more extreme rainfall, which shifts sediment in the water column. This creates better conditions for the spread of hydrilla, cyanobacterial blooms and, indirectly, these toxins. Their presence has not been confirmed in New York State, although the Department of Environmental Protection collects samples for this purpose.
Water flea – a looming threat
Last year, a hooked water flea was found in the tank. The novelty of its appearance means that Department of Environmental Protection officials have not yet observed adverse effects on the marine ecosystem, and its wider consequences on the food chain are unknown. The water flea can affect water quality by eating large amounts of zooplankton, which creates better conditions for harmful algal blooms to grow. Taylor believes it was probably spread by fishing equipment because water flea eggs can survive drying for a long time.
As with zebra mussels, it is virtually impossible to completely rid the water of water fleas once they become established. For many scientists, the most essential thing is often stopping their spread into recent waterways – about 40 percent of Novel York’s freshwater is connected to canals, making it much easier for species to move.