Federal scientists have determined that a family of widely used pesticides poses a threat to dozens of endangered and threatened species, including Pacific salmon, Atlantic sturgeon and Puget Sound orcas.

The National Marine Fisheries Service issued its new biological opinion on three organophosphate pesticides – chlorpyrifos, diazinon and malathion – after a yearslong court fight by environmental groups. 

At the urging of pesticide manufacturers, the Trump administration had sought a two-year delay of a court-ordered deadline to issue the findings by the end of 2017, but it was unsuccessful.

The exhaustive 3,700-page federal review, dated December 29, concludes that chlorpyrifos and malathion jeopardize 38 out of the 77 species under the jurisdiction of the fisheries service and that diazinon was found to jeopardize 25 of the listed species.

The report makes detailed recommendations to the Environmental Protection Agency (EPA) for new restrictions on how and where the pesticides can be sprayed to help limit the harm.

EPA Administrator Scott Pruitt in March reversed an Obama-era effort to bar the use of chlorpyrifos on fruits and vegetables after peer-reviewed academic studies found that even tiny levels of exposure could hinder the development of children’s brains.

EPA’s press office did not respond Friday to a request seeking comment about the latest federal study on the threat to protected species.

Organophosphorus gas was originally developed as a chemical weapon before World War II. Dow Chemical, based in Midland, Michigan, has been selling chlorpyrifos for spraying on citrus fruits, apples, cherries and other crops since the 1960s. It is among the most widely used agricultural pesticides in the United States, with Dow selling about five million pounds (2.3 million kilograms) domestically each year.

Dow AgroSciences, the Dow subsidiary that sells chlorpyrifos, did not respond to a request for comment Friday.

The Associated Press first reported in April that lawyers representing Dow and two other pesticide companies sent letters to three of Trump’s Cabinet secretaries saying the academic studies were flawed. Dow wrote a one-million-US-dollar check to help underwrite Trump’s inaugural festivities, and company CEO Andrew Liveris led a now-disbanded White House manufacturing working group.

CropLife America, an industry trade group that lobbies Congress and federal agencies on pesticide regulations, said it is still reviewing the final National Marine Fisheries Service opinion.

“The denial of a requested extension of time to complete the opinion resulted in a document that has the potential to create exaggerated and unfounded concerns regarding threatened and endangered species and have a negative impact on farmers as well as public health protection,” said Jay Vroom, CEO of CropLife.

A coalition of environmentalists and commercial fishermen has fought in court for more than a decade to spur the federal government to more closely examine the risk posed to humans and endangered species by organophosphates.

Studies have shown for years that even low levels of pesticides running off into streams and rivers can impair the growth, swimming ability and reproductive systems of salmon. Potentially harmful levels of the toxins then build up in the bodies of orcas, also known as killer whales, that eat salmon.

“Salmon have been waiting four decades for relief from toxic pesticides in many of our rivers,” said Glen Spain, the northwest regional director of the Pacific Coast Federation of Fishermen’s Associations. “The agencies should do their job.”