The decision requires U.S. fisheries managers to take steps to implement the plan, which calls for placing numerical limits on the “bycatch” of bottlenose dolphins, four whale species and four sea turtle species snared in swordfish gillnets.

As currently written, the regulation in question also would mandate suspension of swordfish gillnet operations altogether off Southern California if any one of the bycatch limits were exceeded.

The Pacific Fishery Management Council endorsed the plan in 2015, and it was formally proposed for implementation by the U.S. Commerce Department’s National Marine Fisheries Service the following year.

The rule was expected to gain final approval but was abruptly withdrawn instead in June 2017 under President Donald Trump, whose Commerce Department determined the cost to the commercial fishing industry outweighed conservation benefits.

The environmental group Oceana sued, accusing the Commerce Department of violating U.S. fisheries laws and the federal Administrative Procedures Act. Oceana also asked the courts to order the agency to put the bycatch limits into effect.

U.S. District Judge R. Gary Klausner declined to force the National Marine Fisheries Service to immediately implement the restrictions in a decision handed down Wednesday in Los Angeles.

But he sided with environmentalists in finding the agency’s reversal exceeded its authority and was “arbitrary, capricious or an abuse of its discretion.”