A year ago Sacandaga Lake was added to a growing list of New York State waterbodies infested with a new invader, the Spiny Water Flea. The Spiny Water Flea hitchhiked from Eurasia to Lake Huron in 1984 in ship ballast water, and since then, has spread to Lake Erie, Lake Ontario, the Great Sacandaga Lake, Peck Lake, and Stewarts Bridge Reservoir, threatening aquatic ecosystems, fishing, and tourism. The Hamilton County Soil and Water Conservation District is taking action to combat this tiny critter that could mean big changes for our lakes.
Topping out at half an inch in length, this invasive crustacean is not harmful to humans or pets, but could cause significant changes to the lakes it invades. Spiny Water Fleas gobble up enormous quantities of zooplankton that small fish such as young perch and minnows depend on for food. Studies indicate that the growth and survivorship of small fish are adversely impacted by fleas that are in direct competition with fish for food. Changes at the lower levels of the food chain are felt in the upper levels because larger game fish such as trout, pike and walleye prey on small fish.

Anglers beware because fleas clog rod eyelets and inhibit fish from being landed. They collect on trolling lines by the hundreds, and people resort to cutting their line when the heavy build-up makes reeling impossible.

The Darren Fresh Water Institute reported that in 2009, native zooplankton significantly decreased in the Great Sacandaga Lake compared to 2003 and 2004, and the culprit may be the fleas. The District’s Conservation Educator Caitlin Stewart said, “U.S. Geological Survey research suggests that fleas in Lake Huron may be responsible for food web changes including a decline in zooplankton that adversely impacts fish and results in lost tourism revenue. Only time will tell how this new infestation will affect Sacandaga Lake, but for a county whose economy depends on tourism, this confirmation is scary.”

Every two weeks during the summer months, fleas produce ten young, resulting in explosive populations. Eggs withstand freezing, drying, and being eaten and excreted by predators; are hardy enough to overwinter; and may lie dormant for years before they hatch. Tail spines prevent small fish from swallowing the fleas, and can puncture the mouths and stomach linings of larger fish that do eat them.

Spiny Water Fleas easily hitchhike to new lakes. “Adult fleas and eggs stick to fishing line, downrigger cables, and anchor ropes, and make their way into bait buckets and bilge water” explained Stewart. “Invasive species do not adhere to municipal or state boundaries and hitchhike many miles away from the initial infestation site. Recreationists enjoying an outing on an infested lake could unknowingly harbor Spiny Water Flea eggs or adults in their gear and watercraft and transport this deadly invader to un-infested lakes. ”

This summer, District staff amped up efforts to stop the spread of yet another invader. Educational outreach efforts included presentations to lake associations and civic organizations as well as the dissemination of posters and identification cards to campgrounds, bait shops, and businesses. Sacandaga Lake is one of twenty one lakes monitored yearly by the District for physical and chemical parameters in June, July, and August. Spread prevention includes disinfecting monitoring equipment and the anchor rope with a 5% bleach solution before leaving the boat launch. A visual inspection of the boat and trailer occurs before and after launching at every lake, and plants, mud, and organisms are removed. The aquatic invasive plants Eurasian and Variable Leaf Milfoil are established in 7 of the lakes we monitor including Fourth through Seventh Lakes, Long Lake, Raquette Lake, and Lake Algonquin, and these infested lakes in addition to Sacandaga Lake are monitored on the last day of the rotation to prevent their spread. The boat and trailer are washed at the District office after all lakes are monitored for the month.

You can help stop the spread of Spiny Water Flea and other invaders by remembering to check, clean, drain, and dry your equipment, watercraft, and trailer. Invasive species sightings should be reported. To learn more, visit our website at www.hamiltoncountyswcd.com.

Photo: Fleas collect on fishing line by the hundreds, preventing fish from being landed and making reeling impossible. Photo by J. Gunderson.