Fighting West Nile Virus With Native Fish

Much of the debate over preventing the West Nile virus has focused on when and how to use pesticides to get rid of the mosquitoes that transmit the disease. But one community is trying another approach: increasing stocks of mosquito-eating fish. The Great Lakes Radio Consortium’s Lisa Phillips reports:

Transcript

Much of the debate over preventing the West Nile virus has focused on when and how to use
pesticides to get rid of the mosquitoes that transmit the disease. But one community is trying
another approach – increasing stocks of mosquito-eating fish. The Great Lakes Radio
Consortium’s Lisa Phillips reports:


When Greg Wier was a kid, he spent hours playing in the woods next to his family’s vegetable
farm in Guilderland, New York. He was too busy having fun to pay much attention to
mosquitoes.


“You got woods, you’re a kid. We had trails and forts and everything back here.”


Wier, who now has kids of his own, still lives on the family farm. But a lot has changed. The
woods have been replaced by a subdivision. The mosquitoes he once thought fairly harmless are
now potential carriers of the sometimes-deadly West Nile virus. Wier, the town highway
foreman, is the man in charge of Guilderland’s latest effort to combat the disease. He’s taking a
different approach: stocking ponds with fish that eat mosquito larvae. The effort started in the
subdivision’s drainage pond. On this hot afternoon, Wier watches a few sunfish and tadpoles dart
around the pond’s edge:


“I grew up here. I know this area quite well, and to see something like this happening naturally
instead of chemically is good for me.”


For the past four years, Wier has stocked the pond with several native fish species, including
pumpkin seed sunfish and golden shiner, a type of minnow. Both have a healthy appetite for
mosquito larvae. The town also puts bacterial larvicides, known as “dunks,” in smaller pools of
water, but there has been no pesticide spraying since the 1980’s. Ward Stone heads the Wildlife
Pathology Unit of the New York State Department of Environmental Conservation. He is a big
fan of the Guilderland approach, especially as evidence of West Nile mounts:


“We’re in high danger right now. We’ve had mosquitoes, we’ve had a wet summer. Predictions
are that the United States will have the most severe year for West Nile virus. We need to have a
vaccine and control. This is a little bit of that overall war that the town of Guilderland is waging
and doing it very soundly and ecologically.”


Using fish to fight mosquitoes is not a new idea. But using native fish is different from what’s
been done in the past. Michael Kaufman is an entomologist at Michigan State University. He
says gambusia, a non-native species known as “mosquito fish,” has been used in the American
West and parts of Asia.


“Lots of people, myself included, think it is an unwise idea to use them indiscriminately. There is
an issue with mosquito fish eating the eggs of native species or amphibians. They’ll eat frogs or
salamander eggs. That’s obviously a sensitive issue there, too.”


Guilderland has taken no official steps to research how well the program is working, though there
have been fewer complaints about mosquitoes in the neighborhood near the drainage pond. The
question is whether other communities should follow the town’s lead. Entomologist Michael
Kaufman says there are benefits to doing so – but there are also limits.


“Anything a community can do to reduce mosquitoes coming off any breeding site is a good
thing. The problem is, many mosquitoes don’t breed in ponds that are permanent. There are a
large number of mosquitoes that breed in smaller bodies of water, temporary ponds, very polluted
areas. Things like sewage lagoons.”


In other words, places mosquito-eating native fish are unlikely to thrive. Guilderland Highway
Foreman Greg Wier is well aware that his strategy is no magic bullet against West Nile virus. He
just sees it as one part of an effort everyone has to make.


“By a town taking care of a pond like this, we’re taking care of our own backyard. If everyone else
takes care of their own backyard, cleans the gutters, birdbaths, or empties a tire, that alone will
help control the mosquito population. If every house in the area does it that will be more of an
answer to West Nile virus, I believe.”


Because the fish program is so cheap to implement, Wier has already expanded it to a pond in a
new town park. If all goes well, in a few years there could be another benefit to Guilderland’s
mosquito prevention scheme: a place for anglers to go fishing – perhaps without having to cover
themselves with quite so much bug repellant.


For the Great Lakes Radio Consortium, I’m Lisa Phillips.

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FIGHTING WEST NILE VIRUS WITH NATIVE FISH (Short Version)

With the rapid spread of West Nile, more communities are faced with the question of whether to use pesticides to control mosquitoes, which carry the virus. One town is trying a new approach: fish. The Great Lakes Radio Consortium’s Lisa Phillips reports:

Transcript

With the rapid spread of West Nile, more communities are faced with the question of whether to
use pesticides to control mosquitoes, which carry the virus. One town is trying a new approach –
fish. The Great Lakes Radio Consortium’s Lisa Phillips reports:


Non-native “mosquito fish,” also known as gambusia, have been used for years as a weapon
against the insect in parts of Asia and the American West. One town in upstate New York,
Guilderland, is trying something a little different: stocking a town pond with native species such
as sunfish and golden shiner.


Ward Stone is New York State’s Wildlife Pathologist. He says more communities should
consider doing the same.


“West Nile’s going to be around, and by lowering the mosquito population it makes it a little bit
safer. And they’re not applying any pesticides to it. We should encourage that.”


Stone says the fish program is limited because mosquitoes often breed in pools of water too small
for fish. But complaints about mosquitoes have decreased in the neighborhood near the pond,
and the town has decided to expand the program.


For the Great Lakes Radio Consortium, I’m Lisa Phillips.

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Return of the Elms

Nearly every American city has an Elm Street. That’s because the elm was once one of the most abundant species of trees in North America. It was beloved for its distinctive shape and crown of limbs that arched over city streets. Unfortunately, starting in the 1930’s, at least a hundred million elms are estimated to have been wiped out by Dutch Elm disease. Relatively few elms managed to survive the epidemic. But now, Cincinnati is in the vanguard of a movement to bring back the elm. The Great Lakes Radio Consortium’s Steve Hirschberg reports: