Researchers believe herbicide may stunt ocean life
A drawing of plankton and krill from NOAA's photo library by William Scoresby. It's from his 1830 article, "An account of the Arctic regions with a history and description of the northern whale-fishery."
Researchers believe that atrazine – a widely used herbicide – might be having an unintended effect on the ocean food web.
Atrazine has been a source of controversy before this, but the U.S. Environmental Protection Agency hasn’t yet given it a thumbs down. It finds its way to coastal areas typically from agricultural runoff. Recently Marie DeLorenzo – a research ecologist in Charleston, South Carolina – and her colleagues studied the effects of atrazine on microscopic ocean plants called phytoplankton.
Marie DeLorenzo: We found that two of the five species that we tested had a decrease in the amount of carbon that they put into protein. Whereas a bluegreen species actually increased the amount that went into protein.
In other words, phytoplankton are like land plants in that they convert sunlight into proteins. And this process appears to be disrupted by atrazine. Phytoplankton have a critical place at the bottom of the ocean food web. Aquatic life that eat phytoplankton, such as clams and krill, could be affected by deficiencies in its nutrition. So, Marie DeLorenzo wants to learn more.
Marie DeLorenzo: The more realistic exposures would be in larger tanks that might have sediment and marsh plants and other species present… things that you’d find in the estuary.
Our thanks today to NOAA — the National Oceanic and Atmospheric Administration.
Our thanks to:
Marie E. DeLorenzo, Ph.D
Research Ecologist
Marine Ecotoxicology Branch
NOAA, National Ocean Service
Additional Teacher Resources
NOAA: Pesticide May Negatively Affect Estuarine Health
NOAA researchers have identified potential effects of the commonly used herbicide atrazine on phytoplankton. This article describes their research and provides an image of phytoplankton as viewed under an electron microscope.
NOAA: Exposure to Endocrine Disrupters from Long-Range Air Transport of Pesticides
Final report of a study that involved developing an atrazine emissions inventory for the U.S. and Canada. Atrazine is an herbicide and known endocrine disrupter.
