Guy Middleton, Upper Saranac Foundation’s lake manager, and Erin Vennie-Vollrath, Aquatic Invasive Species project coordinator from the Adirondack Park Invasive Plant Program, joined forces this summer to survey the waters of Upper Saranac Lake for Spiny Water Flea. Fortunately, only native zooplankton was found (free-floating aquatic microorganisms).

While Milfoil is currently present and of most concern for the lake, the Upper Saranac Foundation is always looking to prevent future infestations of other Aquatic Invasive Species, including the Spiny Water Flea.

Spiny Water Flea is a carnivorous zooplankton that is not digested by native fish populations, yet voraciously consumes native zooplankton. Zooplankton are organisms that are hard to see with the naked eye and they are an important part of the diet of young fish.

Spiny Water Flea, like most of our other invasive threats, arrived in North America by way of the Great Lakes, transported on transoceanic ships. Although the full extent of the Water Flea’s impact is not clear, it is likely to have an influence on the ecosystems and harm the native fish population. Fishery Biologists fear it could devastate the Adirondack Park’s fisheries.

Using a specialized filtering net, Guy and Erin conducted plankton tows in the deepest, coldest parts of the Lake, where zooplankton and Spiny Water Fleas would thrive. The tows retrieved plenty of native zooplankton (daphnia, phantom midge and water mite), but no Spiny Water Fleas — good news for Upper Saranac Lake.

Spiny Water Fleas move between water bodies on boats, fishing tackle or other aquatic gear. In warmer water temperatures, they can hatch, grow to maturity, and lay eggs in as little as two weeks.

It is very important that boaters, anglers, and other recreational enthusiasts take precautions to avoid transporting this and other invasive species, particularly after leaving waters known to have any Aquatic Invasive Species. Currently, there are no practical means to eradicate Spiny Water Fleas. Limiting their spread is the only way to prevent their impact on native aquatic communities.