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: Early-life exposure of frogs to herbicide increases mortality from fungal disease

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

Extinctions during human era worse than thought

32 minutes ago

It's hard to comprehend how bad the current rate of species extinction around the world has become without knowing what it was before people came along. The newest estimate is that the pre-human rate was ...

Robotics to combat slimy pest

4 hours ago

One hundred years after they arrived in a sack of grain, white Italian snails are the target of beleaguered South Australian farmers who have joined forces with University of Sydney robotics experts to eradicate ...

Migratory fish scale to new heights

4 hours ago

WA scientists are the first to observe and document juvenile trout minnow (Galaxias truttaceus Valenciennes 1846) successfully negotiating a vertical weir wall by modifying their swimming technique to 'climb' ...

Frequent fire and drying climate threaten WA plants

4 hours ago

Murdoch University fire ecology experts have warned that in Western Australia's drying climate, many of the plant species which contribute to the stunning wildflower displays north of Perth may need 50 per ...

User comments : 0