The Driller
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • CLASSIFIEDS
  • EQUIPMENT
  • SAFETY
  • VIDEOS
  • EDUCATION
  • SOURCEBOOK
  • EVENTS
  • SUBMIT
  • ABOUT
  • SIGN UP
cart
facebook twitter linkedin youtube
  • NEWS
  • Water
  • Geothermal
  • Construction
  • Environmental
  • Mining
  • All Industry News
  • EQUIPMENT
  • Rigs & Heavy Equipment
  • Consumables
  • Pumps
  • Featured Products
  • VIDEOS
  • Newscast
  • Drill Talks
  • Ask Brock
  • Emerging Drillers
  • EDUCATION
  • Drilling Business Insights
  • Reference Desk
  • Sponsored Insights
  • EVENTS
  • Conferences & Demo Days
  • Newscast LIVE
  • SUBMIT
  • Drillers @Work
  • ABOUT
  • Contact
  • Advertise
The Driller
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
The Driller
  • NEWS
    • Water
    • Geothermal
    • Construction
    • Environmental
    • Mining
    • All Industry News
  • CLASSIFIEDS
  • EQUIPMENT
    • Rigs & Heavy Equipment
    • Consumables
    • Pumps
    • Featured Products
  • SAFETY
  • VIDEOS
    • Newscast
    • Drill Talks
    • Ask Brock
    • Emerging Drillers
  • EDUCATION
    • Drilling Business Insights
    • Reference Desk
    • Sponsored Insights
  • SOURCEBOOK
  • EVENTS
    • Conferences & Demo Days
    • Newscast LIVE
  • SUBMIT
    • Drillers @Work
  • ABOUT
    • Contact
    • Advertise
  • SIGN UP
Drilling Industry News

USGS Research Finds Contaminants May Play Role In California Amphibian Decline

February 15, 2001
More than 50 percent of adult frogs and tadpoles at Yosemite National Park had measurable levels of chlorpyrifos or diazinon, compared to only nine percent at coastal reference sites.

Scientists have confirmed agricultural contaminants may be an important factor in amphibian declines in California. According to an article recently accepted by the journal Environmental Toxicology and Chemistry, a study by scientists of the US Geological Survey (USGS) and US Department of Agriculture (USDA) indicates organophosphorus pesticides from agricultural areas, which are transported to the Sierra Nevada on prevailing summer winds, may be affecting populations of amphibians that breed in mountain ponds and streams.

Dramatic population declines in red-legged frogs, foothills yellow-legged frogs, mountain yellowlegged frogs and Yosemite toads have occurred in California over the last 10-15 years, but no single cause for these declines has been positively identified. Scientists and managers have been especially concerned because many of these declines occurred in some of the state's most seemingly pristine areas. Declines have been particularly drastic in the Sierra Nevada, which lie east of the intensely agricultural San Joaquin Valley. The red-legged frog is listed as threatened under the US Endangered Species Act, and the mountain yellow-legged frog and Yosemite toad have been proposed for listing.

"While crucial to the agriculture industry, pesticides by their very nature can result in serious harm to wildlife both by directly killing animals and through more subtle effects on reproduction, development and behavior," said Dr. Donald Sparling, a research biologist and contaminants specialist at the USGS Patuxent Wildlife Research Center in Maryland. "Unfortunately, now there appears to be a close correlation between declining populations of amphibians in the Sierra Nevada and exposure to agricultural pesticides."

The scientists found proof pesticides are being absorbed by frogs in aquatic and terrestrial systems and are suppressing an enzyme called cholinesterase, which is essential for proper functioning of the nervous system. Modern pesticides function by binding with this enzyme in animals and disrupting nervous system activity, usually causing death by respiratory failure. Decreased cholinesterase activity can indicate exposure to certain commonly used pesticides and can be harmful to animals.

The scientists collected 170 tadpole and 117 adult Pacific treefrogs, a species fairly abundant in the Sierra Nevada, from 23 sites in six locations including coastal, foothill, Lake Tahoe Basin Yosemite and Sequoia national parks; adult frogs were also collected from Lassen National Park. They found cholinesterase activity levels in tadpoles were significantly lower in mountains east of the San Joaquin Valley compared with similar sites farther north and east of the Sacramento Valley where agricultural activity is less intense. Moreover, cholinesterase activity became decreasingly lower in tadpoles from northern and southern sample sites as the sites moved in a gradient from the coast to the higher elevations. Thus, tadpole populations in the mountains had lower cholinesterase values than those along the coast. Similar but less significant trends were seen in adult frogs.

The researchers also measured concentrations of particular pesticides in the bodies of tadpoles and adults. More than 50% of adult frogs and tadpoles at Yosemite National Park had measurable levels of chlorpyrifos or diazinon, compared to only 9% at coastal reference sites. Frogs at Yosemite National Park also had a higher frequency of detection for chlorpyrifos than those on the coast. Both diazinon and chlorpyrifos degrade very rapidly in organisms, and detection of either compound indicates recent exposure to the chemicals. of the pesticides tested in related lab studies, chlorpyrifos and diazinon, commonly used organophosphates, suppressed nervous system activity and, along with endosulfan, a frequently used organochlorine pesticide, proved the most highly toxic to frogs. Diazinon has recently been targeted for a three-year phaseout by the US Environmental Protection Agency (US EPA).

"The presence of pesticides and the decrease in cholinesterase activity in Pacific treefrogs suggest that other species, which are more closely associated with water, could be even more affected," said Dr. Gary Fellers, a research biologist and amphibian specialist at the USGS Western Ecological Research Center in California. "Mountain yellow-legged frogs, for example, spend two or three years as tadpoles before they metamorphose and then spend considerable time in the water as adults. Melting of pesticide-contaminated snow could provide a pulse of toxic chemicals at a critical time in the life history of these frogs."

As the nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize loss of life and property from natural disasters, contribute to sound conservation, economic and physical development of the nation's natural resources, and enhance quality of life by monitoring water, biological, energy and mineral resources.

Links

  • U.S. Grological Survey

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • geotechnical drilling rig

    6 Onsite Phrases Environmental Drillers Hate

    Here are six phrases that highlight common frustrations...
    Environmental Monitoring
    By: Jeff Garby
  • Wayne Nash

    Pipe Stuck? Common Causes and Solutions for Drillers

    If you have drilled for any length of time, sooner or...
    Markets
    By: Wayne Nash
  • submersible pumps, water well pumps

    Selecting and Sizing Submersible Pump Cable

    This article helps pump installers and servicers decide...
    Equipment
    By: Bob Pelikan
You must login or register in order to post a comment.

Report Abusive Comment

Subscribe For Free!
  • eNewsletters
  • Online Registration
  • Subscription Customer Service
  • Manage My Preferences

The Driller Newscast: New York Geo Talks 2025 Conference with Hands-on Driller Education

The Driller Newscast: New York Geo Talks 2025 Conference with Hands-on Driller Education

The Driller Newscast, Episode 147: Global Geothermal Collaboration at NY-GEO 2025

The Driller Newscast, Episode 147: Global Geothermal Collaboration at NY-GEO 2025

The Driller Newscast: 21st Century Drillers | Part 1 DEMAND

The Driller Newscast: 21st Century Drillers | Part 1 DEMAND

The Driller Newscast - The Big, Not-So-Beautiful Bill: How to Lose Clean Energy and Alienate the Planet

The Driller Newscast - The Big, Not-So-Beautiful Bill: How to Lose Clean Energy and Alienate the Planet

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the The Driller audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of The Driller or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • demo of a DM450 drilling rig during a customer factory visit
    Sponsored byGeoprobe

    Built for You: Smarter Drill Rigs, Stronger Support, Bigger Opportunities

Popular Stories

MainPhotoTwoBrothers.jpg

Two Brothers' Journey Through the Drilling Industry

demo of a DM450 drilling rig during a customer factory visit

Built for You: Smarter Drill Rigs, Stronger Support, Bigger Opportunities

AI and Drought Concerns

AI’s Growing Thirst for Water and Power

The Driller Classifieds

COMPRESSORS

EAST WEST MACHINERY & DRILLING IS BUYING AND SELLING AIR COMPRESSORS, AIR BOOSTERS, AIR ENDS & PARTS
Company: East West Machinery

DRILL RIGS

LOOKING FOR LATE MODEL TOPHEADS & DRILLTECH D25'S
Company: Spikes’s Rig Sales

DRILL RIG PARTS

MEETING DRILLERS NEEDS AROUND THE WORLD
Company: East West Machinery

ELEVATORS

SEMCO INC. PIPE ELEVATORS
Company: Semco Inc.

GROUTERS

GROUTING EQUIPMENT - GROUT PUMPS & GROUT HOSE REELS
Company: Geo-Loop Inc.

PUMP HOISTS

SEMCO INC. - BASIC PUMP HOISTS
Company: Semco Inc.

WELL PACKERS

LANSAS PRODUCTS - INFLATABLE WELL PACKERS
Company: Vanderlans Lansas Products

WELL SCREENS

WELL SCREENS & SLOTTED PIPE
Company: Alloy Screen Works

Products

Water Quality Engineering: Physical / Chemical Treatment Processes

Water Quality Engineering: Physical / Chemical Treatment Processes

By carefully explaining both the underlying theory and the underlying mathematics, this text enables readers to fully grasp the fundamentals of physical and chemical treatment processes for water and wastewater.

See More Products

Subscribe to The Driller Newscast

Related Articles

  • Research Finds Fracking Mobilizes Uranium in Marcellus Shale

    See More
  • Drilling May Have Affected Water Tests, DOE Finds

    See More
  • Construction Jobs Decline in 2009

    See More

Related Products

See More Products
  • drilling.jpg

    Clay Science in Drilling and Drilling Fluids

  • M:\General Shared\__AEC Store Katie Z\AEC Store\Images\ND\new site\in-too-deep.gif

    In Too Deep: BP and the Drilling Race That Took it Down

  • fundamentals.jpg

    Fundamentals of Sustainable Drilling Engineering

See More Products
×

Dig deeper into the drilling and water supply industry!

Build your knowledge with The Driller, covering the people, equipment and technologies across drilling markets.

SIGN UP NOW
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
    • Classifieds
  • SIGN UP TODAY
    • Create Account
    • eNewsletters
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing

The Driller
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
The Driller
  • NEWS
    • Water
    • Geothermal
    • Construction
    • Environmental
    • Mining
    • All Industry News
  • CLASSIFIEDS
  • EQUIPMENT
    • Rigs & Heavy Equipment
    • Consumables
    • Pumps
    • Featured Products
  • SAFETY
  • VIDEOS
    • Newscast
    • Drill Talks
    • Ask Brock
    • Emerging Drillers
  • EDUCATION
    • Drilling Business Insights
    • Reference Desk
    • Sponsored Insights
  • SOURCEBOOK
  • EVENTS
    • Conferences & Demo Days
    • Newscast LIVE
  • SUBMIT
    • Drillers @Work
  • ABOUT
    • Contact
    • Advertise
  • SIGN UP