Yet despite the Act’s historical ties to pesticides—the discovery of DDT’s impacts on bald eagles was one factor that propelled lawmakers to begin protecting threatened species—officials in the pesticide office at the Environmental Protection Agency (EPA) are only now starting to figure out how to comply with the law.

In fact, last year, the EPA acknowledged that over the past five decades, it has effectively ignored its responsibility to evaluate pesticides’ impacts on at-risk plants and animals in more than 95 percent of cases.

Now, due to new leadership and a string of court decisions forcing its hand, the agency says it will reverse course as it reviews new pesticides. At the same time, it has begun tackling a backlog of evaluations so long that it could take several more decades to catch up.

“We’re finding out that pesticides are posing a major risk to endangered species, and they have been ever since they were approved,” says Nathan Donley, the Environmental Health Science Director at the Center for Biological Diversity. “The problem is that the safeguards now being put in place . . . should have been put in place 50, 40, 30 years ago.”

Time is running out: In recent years, multiple reports have identified biodiversity loss as one of the biggest threats facing humanity, alongside—and in conjunction with—climate change. One study published in February determined that total ecosystem collapse is now “inevitable” unless current trends are reversed.

Intensive pesticide use is one of many intersecting factors contributing to the crisis (alongside habitat loss due to agriculture, development, and climate change). Herbicides kill plants and destroy habitats, insecticides kill beneficial insects and deplete and contaminate food sources for larger organisms like birds, and both kinds of chemicals leach into waterways, threatening aquatic organisms.

While the EPA evaluates the basic health and environmental risks of pesticides under the country’s primary pesticide law, it weighs those risks against benefits to farmers and the security of the food supply. Under the Endangered Species Act, the agency is subject to a much stricter mandate to ensure that approving a pesticide for use doesn’t jeopardize the survival of any species on the list. As a result, the evaluations are more thorough and often require the involvement of the Fish and Wildlife Service (FWS) and the National Marine Fisheries Service.

And while the goal is to identify serious threats to specific endangered species, experts say when the evaluations do find risks, it’s safe to assume other plants and animals are also being negatively impacted. “It is a good indication there is overall harm,” Donley said. “EPA has been doing a good job of communicating that the mitigations now being put into place are not only going to protect endangered species, but they’ll have the indirect effect of protecting all species in those areas.”

As someone who spends a lot of time suing the agency, Donley is uncharacteristically optimistic about the EPA’s steps forward. However, he and other experts pointed to many factors that limit whether the agency’s plan will effectively protect biodiversity going forward.

The agency is hindered by inadequate funding, limited staff, and a complex evaluation process, and it must also rely on the partner agencies, which have their own limitations. As a result, it may be cutting corners to speed up progress.

Even when officials find pesticides that cause harm, removing them from use is almost never an option. In fact, one of the reasons officials are rushing to fix the process is because courts could walk back the approval of several pesticides if the EPA continues to ignore the law.

“Farmers don’t know if these pesticides will be suddenly taken off the market,” said Jake Li, deputy assistant administrator for pesticide programs for the office of chemical safety and pollution prevention at the EPA. “We could have a court decision any day that says, ‘Well, EPA, you’re in violation of the Endangered Species Act’ . . . and then we just have to start pulling pesticides off the shelf.”

That’s a scenario the EPA wants to avoid, Li said, because farmers need a “diversity of tools” to control weeds and pests. Instead, the EPA’s primary objective is identifying ways to minimize exposure to the chemicals, and many of their solutions rely on getting farmers, and others who apply pesticides, to closely adhere to complicated label instructions with very little—if any—enforcement. Finally, some experts say that even when the EPA does conduct evaluations, the data available is scant and the process can underestimate risks to species.

This web of bureaucratic barriers, paired with a foundational assumption that toxic pesticides are necessary and their risks can be managed with the right practices, means that the EPA’s remarkable push to finally follow the Endangered Species Act is charting a path toward an unremarkable outcome: The agency will mostly ensure the continued use of pesticides found to pose risks, albeit with new protections in place.

Playing Catch-Up on Pesticide Evaluations

Since it began tackling the problem, the EPA has completed 14 biological evaluations and drafted another handful. To get a grasp of how big the backlog is, said John Stark, a professor of entomology who runs the ecotoxicology program at Washington State University, one only has to look to a class of insecticides called organophosphates.

Organophosphates are highly toxic pest killers that became widely used earlier in the 20th century. It wasn’t until 2017 that the EPA completed biological evaluations for malathion, first approved in 1956, and chlorpyrifos, approved in 1965. Use of malathion has plummeted since the 1990s, while EPA canceled its approval of chlorpyrifos last year based on its health risks.

“We’ve moved so far past a lot of [these pesticides], and they’re really hardly used anymore,” Stark said. “That tells you how far behind this process is.”

In laying out its plans to play catch-up, agency officials wrote that “Even if EPA completed this work for all of the pesticides that are currently subject to court decisions and/or ongoing litigation, that work would take until the 2040s, and even then, would represent only 5 percent of EPA’s ESA obligations.”

In the meantime, since most evaluations that need to be done are for pesticides already on the market, the agency is working on new, broader ways to reduce potential harms that don’t require waiting for each individual evaluation. In June, officials proposed restrictions and other practices that could be put in place to protect 27 of the most vulnerable species from exposure from groups of pesticides that might harm them.

Then, in July, the agency released its first Herbicide Strategy, which identifies common routes of exposure to weedkillers, like drift and runoff, and proposes broad changes to how those chemicals are used.

Li said the idea is to create frameworks that lead to label changes upfront, so that by the time an individual pesticide gets through its endangered species evaluation, the practices in place for using it—such as restrictions on when or where it can be applied—have hopefully already removed a lot of the potential risk.

“It’s much simpler, and it’s much faster,” he said. “That’s really the key.” Both new frameworks are currently in draft form and are open to public comment.

Is the EPA Cutting Corners?

Take Enlist One and Enlist Duo, two herbicides produced by Corteva Agriscience. Enlist One contains 2,4-D, while Enlist Duo combines both 2,4-D and glyphosate (the primary chemical in Roundup).

In January 2022, the EPA re-approved both products. Before doing so, it completed a biological evaluation, which found likely harm to hundreds of species. That’s a big deal, since in the past, the agency did not do that evaluation at all. But when the EPA finds “likely” harm, the law also requires it to go to the wildlife-focused agencies to have a more thorough evaluation completed before approval.

In this case, the EPA approved the herbicides first. Then, it started the process with the Fish and Wildlife Service. “They’re basically saying, ‘Well, now we did it, and we’re just going to keep moving because Fish & Wildlife isn’t keeping up,” said Kristina Sinclair, an attorney at Center for Food Safety, which is suing the EPA over the approval. As a result, the herbicides have been in use for another year and a half without a final opinion from FWS.

That’s significant because wildlife-focused agencies provide expertise the EPA doesn’t have, Stark said, and bring in additional information. “They take into account population processes and modeling,” he explained. The FWS has so far only completed one of the evaluations that the EPA has sent their way, on malathion. The National Marine Fisheries Service is further along but still far behind.

Reducing Exposure to the Most Toxic Pesticides

In some cases, the measures being proposed involve restrictions based on the locations where pesticides are being used.

For example, when the agency conducted a preliminary assessment of atrazine, a widely used herbicide, it found many plants and animals would likely be put at risk by its reapproval. So, EPA officials approached Syngenta, the company that makes atrazine, and proposed restrictions on its use in forests and along roadsides—two places that provide critical habitat for many species—which the company agreed to. Atrazine use is also banned in the state of Hawaii, which is home to a high concentration of endangered species.

Experts are less convinced by other mitigation measures the EPA has proposed. For instance, if a pesticide poses a risk to aquatic insects due to runoff into rivers and streams, the agency says a farmer might be required to choose from a list of practices, such as planting cover crops or buffers along streams, to reduce the amount of pesticides that leave the fields and end up in the water.

Stark said there’s plenty of evidence that those practices work in terms of reducing exposure, but in some cases implementing them may mean difficult choices for a farmer, like taking a section of land out of production to plant a buffer strip of bushes and trees. Before that, the person applying the pesticide would have to read the label instructions, which Li said in some cases can be 50 to 100 pages long.

And even that label doesn’t provide enough space to communicate everything the user needs to know. The EPA is now using an online system called Bulletins Live! Two (fun fact: internally, agency officials call the system “BLT”) to communicate restrictions that involve endangered species in specific areas.

At this point, according to Li, most farmers likely don’t even know about the system. The EPA is working on outreach and trainings and is collaborating with the USDA to try to change that. But the EPA won’t have boots on the ground monitoring whether the mitigation measures are being put in place, since states are in charge of enforcing pesticide laws. Li said the agency is in “active discussion with state agencies” about enforcement, however.

In the end, it will likely be some time before anyone knows if the mitigation measures are having an impact, Donley said. “With this pick-list approach, I really hope EPA is following up and making sure that there is high compliance. And when there is compliance, making sure that it’s reducing levels of atrazine or glyphosate or whatever the pesticide in nearby streams, maybe doing some monitoring, and following up to make sure those mitigations are having the intended effect.”

Next Steps for Pesticide Registrations

Today, neonic-coated seeds are planted on close to 100 percent of commodity corn acres across the country, where chemical dust from the seeds drifts into the air, soil, and water, threatening pollinators and many other animals that haven’t made it onto the endangered species list.

In June 2022, to meet a court deadline, EPA finally completed its first biological evaluations of the three most common neonics: clothianidin, imidacloprid, and thiamethoxam. Its evaluations found that each of the insecticides was likely to harm two-thirds to three-quarters of endangered species, including the Karner blue butterfly, Chinook salmon, the whooping crane, and the California red-legged frog.

One year later, the American Bird Conservancy released a review of the past decade of research on neonicotinoids’ impacts on birds. In the report, scientist Pierre Mineau filled more than 100 pages with alarming evidence. And he specifically pointed to the EPA’s evaluation as having “greatly underestimated the extent of the risk, for birds and probably other species as well,” because he determined the EPA was not fully considering the extent of exposure caused by coated seeds.

Even with that underestimation, he emphasized that the agency has found that hundreds of threatened species are at risk and more than 30 critical habitats are in jeopardy.

“We are now at the point where the onus of proof should switch from having to demonstrate the link between neonicotinoid use and bird populations losses, to showing why the continued profligate use of neonics is essential to human welfare in light of such environmental impacts,” Mineau said in a press release.

And it’s not clear that they are essential: Recent reports show that while some fruit and vegetable farmers depend on neonics to control pests, coated seeds on commodity corn fields—the largest use by far—often do not lead to higher yields for farmers.

No matter how much the process is improved, the EPA’s process of evaluating the risks of pesticides on species that may soon cease to exist will always be limited. Assessments prioritize acute risks, like poisoning, over long-term harms and are filled with categories of plants and animals on which no studies have been done, so “surrogate species” are used to estimate risk. Perhaps most importantly, researchers evaluate each chemical’s risks independently. At this point, it’s unknown what exposure to the growing mix means for any species.

“I like to call our waterways ‘pollutant soup,’ because it’s never one chemical,” Stark said. “I’m talking everything from every pharmaceutical you’ve ever heard of to industrial pollutants, et cetera. They’re in low concentrations, but we don’t know how those chemicals synergize with each other.”

But larger conversations about preserving biodiversity don’t often influence the bureaucratic process. Now that the EPA completed its biological evaluations of the three neonics, it is consulting with the wildlife agencies to identify practices it can put in place to reduce risks. Li said those proposed mitigation measures should be released later this year. At the same time, the wildlife agencies will continue to work on their biological opinions, which could take years.

If the mitigation is successful by the EPA’s measures, the number of endangered plants and animals exposed to neonics will be somewhat reduced. Given the larger impacts neonics are having across the landscape, is that a better outcome than if a court stopped their use entirely until the agency completed the full review process?

Donley worries that the process could legitimize the continued use of chemicals everyone would be better off without, but—given the options—he believes that risk is worth taking.

“It’s certainly not perfect, and some of their biological evaluations and mitigation plans are not even coming close to what’s needed,” Donley said. “But we’ve got to figure out what we can reasonably achieve here.”