Aug 20 (Reuters) - A U.S. judge at the urging of

environmental groups has thrown out an assessment by a federal

agency governing how endangered and threatened marine species

should be protected from oil and gas drilling in the Gulf of

Mexico.

U.S. District Judge Deborah Boardman in Greenbelt, Maryland,

on Monday ruled the U.S. National Marine Fisheries Services'

so-called "biological opinion" was flawed and did not adequately

address risks species face from oil spills and vessel strikes.

The assessment was issued in 2020 during Republican former

President Donald Trump's administration and was legally

necessary for oil and gas exploration and drilling to be

conducted.

The judge, appointed by Democratic President Joe Biden, said

the assessment violated the Endangered Species Act. She faulted

it for assuming an oil spill like the catastrophic Deepwater

Horizon one in 2010 would not occur.

Boardman gave the agency until Dec. 20 to either complete a

new opinion or "plan for the changes ahead," citing the risk

that her decision if implemented immediately would "disrupt oil

and gas activity in the Gulf without necessarily mitigating the

dangers to listed species."

The decision drew praise from environmental groups including

the Sierra Club and the Center for Biological Diversity, who in

a lawsuit filed in 2020 argued more safeguards were needed for

imperiled whales, sea turtles, and other species.

"The court's ruling affirms that the government cannot

continue to turn a blind eye to the widespread, persistent harms

that offshore oil and gas development inflicts on wildlife,"

Chris Eaton, a lawyer for the plaintiffs at Earthjustice, said

in a statement.

The fisheries service did not respond to a request for

comment.

Three oil industry trade groups, American Petroleum

Institute, the National Ocean Industries Association and the

EnerGeo Alliance, had intervened in the lawsuit to defend the

opinion alongside oil major Chevron ( CVX ).

The trade groups in a joint statement warned of "disruptive

consequences" to the U.S. economy if a new biological opinion

was not timely developed and said its issuance should be of the

"highest priority."

Biden's administration last year had sought to scale back an

oil and gas auction in the Gulf of Mexico by 6 million acres to

reduce conflicts with the endangered Rice's whale habitat. But

the oil and gas industry and the state of Louisiana successfully

sued to expand the auction.