As concerns about the potential link between non-Hodgkin’s lymphoma and Roundup exposure continue to grow, new research suggests that, in addition to posing a risk of harm to human health, the controversial weed killer is also triggering a loss of biodiversity that could adversely affect the food chain and pose significant problems in the future. The report, published in the journal Natural Ecology and Evolution on March 2, studied experimental phytoplankton communities exposed to the “ubiquitous herbicide glyphosate” and found that the widespread use of the weed killer causes a 40% loss in biodiversity, thereby making ecosystems more vulnerable to pollution, climate change and other environmental stressors or disturbances.
Phytoplankton, also known as microalgae, are microscopic marine algae that serve as the foundation for several aquatic food webs. Food webs are made up of interconnected food chains and understanding how they work help us comprehend the effect changes to ecosystems can have on a variety of species, both directly and indirectly. For example, in a stable ecosystem, phytoplankton provide food for everything from microscopic zooplankton to whales, snails, shrimp, jellyfish and other sea creatures. Phytoplankton form the bases of aquatic food webs and changes in their biodiversity can cause a ripple effect that reverberates far up the food chain.
Glyphosate, the active ingredient in Roundup, is a broad-spectrum weed killer introduced in the 1970s by Monsanto. The weed killer has been used extensively on crops worldwide since the 1990s, when Monsanto introduced genetically modified (GMO) crop seeds that are specifically designed to be resistant to the weed killer. “Farmers spray their corn and soy fields to eliminate weeds and boost production, but this has led to glyphosate leaching into the surrounding environment,” says Andrew Gonzalez, a study author and biology professor at McGill. This new Roundup study demonstrates that fact, showing that widespread glyphosate use can have a number of unintended ecological consequences when it leaches into the environment, including freshwater sources. “Evidence is accruing that glyphosate may be having broad ecotoxicological effects on many species beyond the weeds it was designed to kill.”
In order to examine the potential ecological impact of continued Roundup use, scientists from McGill University in Canada conducted an experiment where some freshwater phytoplankton communities were exposed to low levels and extremely high levels of the herbicide. They found that while some phytoplankton populations developed a resistance to the powerful herbicide and were able to survive being exposed to lethal doses of Roundup, this came at a cost, with a 40% loss in biodiversity. “We observed significant loss of biodiversity in communities contaminated with glyphosate,” reports Gonzalez. “This could have a profound impact on the proper functioning of ecosystems and lower the chance that they can adapt to new pollutants or stressors. Moreover, the loss of phytoplankton diversity might be expected to affect the productivity and stability of the food chains that support other species in our freshwater ponds and lakes.”
Based on their findings, the McGill researchers warn that the potential for Roundup exposure to cause a loss of biodiversity could be problematic in the future. With less diversity, future environmental disruptions, “such as those arising from climate change or other forms of contamination and pollution,” could mean that these ecosystems are less resilient than they would be otherwise. This risk, paired with growing evidence that Roundup exposure can cause cancer in humans, should be carefully considered by farmers and other consumers who regularly use the weed killer on their crops, lawns and home gardens. “The growing global trend in glyphosate use because of our reliance on Roundup ready crops suggests that the ecological and evolutionary effects that we have uncovered should be added to the important health and ecotoxicological concerns that have already been raised for glyphosate,” the McGill researchers concluded.