OSU review details negative impact of pesticides and fertilizers on amphibians

Nov 13, 2013
Bullfrogs and other amphibians are especially vulnerable to agrochemicals because they live in both water and on land at different life stages. Credit: Lynn Ketchum.

Common pesticides and fertilizers can damage both the development and survival of amphibians to varying degrees, according to a new analysis by Oregon State University.

The new meta-analysis marks the first attempt at a large-scale summary on the negative effects of specific chemical classes on amphibians, said Tiffany Garcia, a co-author of the study and an associate professor of wildlife science within OSU's College of Agricultural Sciences. Researchers reviewed more than 150 scientific studies detailing the impacts of and fertilizers on amphibians.

Around 30 percent of amphibian species are now extinct or endangered due to a range of factors, including habitat loss, disease, and exposure to contaminants, including pesticides and fertilizers, according to Garcia.

"Billions of tons of agrochemicals are used in farming every year," said Garcia, an expert in aquatic ecology. "Any disruption to frog, toad and salamander communities has clear negative impacts on biodiversity and can also set off a domino effect throughout the ecosystem by damaging the food base for amphibian predators, including birds, snakes and fish."

Amphibians are also valuable to the environment as grazers, herbivores and predators of pests, such as mosquitos, she added.

Four classes of common agrochemicals significantly reduce survival, the researchers say: chloropyridinyls; inorganic fertilizers; carbamates, which are common in insecticides; and triazines, used in herbicides. Two others both kill and inhibit animal growth: phosphonoglycines and organophosphates, standard ingredients in many pesticides.

Agrochemicals are most damaging to amphibians in the egg and larval stages, decreasing survivorship and making individuals more susceptible to predation and also hindering the production of offspring later in life. Amphibians are especially vulnerable to pesticides and fertilizers since they live on land and in water and can come into contact with agrochemicals by both direct exposure and runoff into aquatic systems.

To reduce the effects of pesticides and on amphibians, timing is critical.

"Farmers can be, and often are, the best naturalists we have," Garcia said. "Mixing agricultural production with wildlife management is vital to the survival of amphibians, especially with agricultural intensity growing to feed our booming global human population."

"Spring, for example, is a time with heavy agricultural application, and it's also when amphibians lay eggs and develop as larvae and tadpoles," she added. "By modifying application schedules, growers can limit contact between sensitive wildlife species and harmful chemicals."

Explore further: Amphibians living close to farm fields are more resistant to common insecticides

add to favorites email to friend print save as pdf

Related Stories

Pesticides contaminate frogs from Californian National Parks

Jul 26, 2013

Pesticides commonly used in California's Central Valley, one of the world's most productive agricultural regions, have been found in remote frog species miles from farmland. Writing in Environmental Toxicology and Chemistry, resear ...

How pesticides change the environment

Aug 16, 2013

The number of humans on the planet has almost doubled in the past 50 years ‒ and so has global food production. As a result, the use of pesticides and their effect on humans, animals and plants have become ...

Recommended for you

Plants with dormant seeds give rise to more species

Apr 18, 2014

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Scientists tether lionfish to Cayman reefs

Apr 18, 2014

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

User comments : 0

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.