It reads like something from a Disney movie script.

Dolphins, sometimes in pods by the thousands, speed through an expanse of blue ocean that humans have agreed to protect in its pristine state. They are joined by fin whales, rare blue and beaked whales, and endangered sperm whales. Sea turtles, some as old as our country, munch on algae.

Far below, the ocean bottom rises and falls dramatically, splashed with deep-sea corals, an undersea Grand Canyon formed by ancient volcanic activity. These depths hold sea life yet undiscovered by scientists.

Cue the ominous music, because faraway the antagonist in this story has decided this place will no longer be protected, that it will again be open to commercial fishing and factory ships, large vessels with on-board processing and freezing facilities.

And the day picked for this fateful decision? That would be June 5, World Environment Day, of course.

But this is no Disney movie.

On June 5, in a meeting with fishing industry officials, President Donald Trump announced he was reopening the Northeast Canyons and Seamounts Marine National Monument to commercial fishing. The conservation area covers 5,000 square miles east of Cape Cod.

President Barack Obama announced the designation in 2016, with universal support from the Connecticut delegation, and backing from environmental and marine research organizations, including the Mystic Aquarium. The aquarium issued a statement that it was “stunned and dismayed” by Trump’s decision.

It is the first national marine monument in the Atlantic Ocean and one of five such designations.

The designation remains, but allowing commercial fishing defeats the purpose, which was to “set aside (areas) so that we can see nature as it was before we exploited it and understand the true impact of fishing,” said Enric Sala, a marine biologist and founder of the National Geographic’s Pristine Seas program.

The monument area had remained open to sportfishing and the lobster and red crab fisheries.

Trump, who apparently has never seen a natural resource he didn’t want to exploit, and seems fixated in undoing anything Obama accomplished, is on shaky legal ground.

Obama acted under the authority granted him by the Antiquities Act of 1906, passed by Congress under the leadership of the great conservationist President Teddy Roosevelt. While it gives presidents the power to establish protected national monuments, nowhere does it have a provision for a president to undo them. That, it would appear, is up to Congress.

But that hasn’t stopped Trump. He announced in 2017 that he was drastically shrinking two national monuments in Utah, Grand Staircase-Escalante designated by President Bill Clinton and Bears Ears designated by Obama. The Trump administration wants to open the lands to drilling and mining. Native American tribes and environmentalists have challenged in federal court the legality of Trump’s order and have cited the natural, cultural and religious significance of the strikingly beautiful and ecologically fragile landscapes.

Environmental advocates say they will likewise challenge Trump’s order concerning the Atlantic Ocean monument.

Trump’s premise for reopening the area to large-scale commercial fishing — that the industry has been severely hurt by Obama’s designation — appears dubious. The New England Aquarium, based in Boston, notes that despite being forced out of the monument area, landings of economically significant species by commercial fleets have increased since 2016, not decreased.

The November election could settle all this long before a court decision, with Trump and his anti-environmental agenda voted out of office. Isn’t that how the Disney movie ends? The villain gets his comeuppance. Either that or he has a conversion. But that may be too far-fetched even for a Disney script.

Paul Choiniere is the editorial page editor.