Electro-Shocking Boat is New Tool For Surveying Fish Population
By Anthony F. Hall
Thursday, February 16, 2017
“The food web is a key to water quality,” says RPI professor Rick Relyea, the director of the Jefferson Project.
And at the top of that web is the fish population, which shapes the size and the distribution of the organisms that sustain it.
On Lake George, the fish population has been the subject of Dr. Bill Hintz’s scrutiny since 2015.
While portions of Lake George’s fishery have been studied in the past, “this is the first robust study,” said Hintz, who was recruited by RPI and the Jefferson Project to study the Lake George fish population while working on endangered fish species on the Mississippi.
“The goal is to assess the health of the fishery, the end point being a better understanding of how pollution, invasive species and the changing climate influence freshwater ecosystems,” Hintz said last week at the Darrin Fresh Water Institute in Bolton Landing, where he was testing new equipment.
To assess the status of Lake George’s fish species, first they must be caught, and Hintz and his students have used a variety of tools – nets, mostly – to gather samples over the past two years.
“It’s a catch, measure and release system,” said Hintz. “After the fish are captured, they’re weighed and measured and then returned to the lake. We keep about 5% of the sample to analyze the contents of their diets.”
RPI now has a new tool for sample-gathering in its kit – a $70,000 boat for electro-shocking fish.
“Don’t say electrocuting; we’re not electrocuting fish,” said Rick Relyea, reprimanding a reporter for speaking imprecisely.
Electro-shocking, Relyea and Hintz emphasized, merely stuns the fish and for a brief period of time only, long enough enough for the samples to be scooped up and placed in a well before being weighed.
“It’s a much more efficient way of catching fish, one that also enables us to get into places where we couldn’t with nets, where we’re obstructed by logs and rocks,” said Relyea.
According to Hintz, electro-shocking is a common method of conducting fish surveys, used by New York State’s Department of Environmental Conservation and by natural resource agencies in most other states.
Hintz worked with the manufacturer to build a boat to his specifications so that it would be suited to the Jefferson Project and its requirements, said Relyea.
The boat will be deployed next spring, at the start of the fourth year of the Jefferson Project.
Launched in 2013 by RPI, IBM and The Fund for Lake George, the project is “making significant progress” in acquiring actionable intelligence about such things as the spread of invasives through the lake, the sources of salt and the quantity of nutrients, among other things, said Relyea.
It was recently awarded a $917,000 grant from the National Science Foundation that will allow it complete a network of smart sensor platforms.
“The smart sensor network will operate collectively as a single integrated instrument, the most powerful and comprehensive of its kind, to monitor indicators of physical, chemical, and biological activity on Lake George,” said Relyea.
Last week, researchers working with the Jefferson Project, attempting to understand the impacts of road salt on the health of aquatic ecosystems, announced they have discovered something alarming: chemicals found in de-icing road salts can alter the sex ratios in nearby frog populations, a phenomenon that could reduce the size and viability of species populations.
Relyea said it was not clear yet if other creatures were experiencing similar “sub-lethal” effects of those chemicals.
As of now, however, Lake George’s fish population is relatively healthy, said Bill Hintz.
“So far, so good,” he said.
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