“On this World Ocean Day, I’m encouraged by global progress in protecting and conserving our ocean,” Blinken said. “In 2022, the United States launched the Ocean Conservation Pledge, joined by 19 countries, committing to conserve 30% of our ocean by 2030.”

The advocacy group Oceana in late May singled out Los Angeles, San Diego and New York City for banning single-use plastics, which are a growing source of toxicity in the world’s oceans. Legislation moving through the state governments of Oregon and Washington, meanwhile, call for a phase-out of plastics that can take more than a hundred years to degrade.

“It is possible to combat plastic pollution — one of the ocean’s greatest threats,” the conservation group said. “Putting in place local, state, and national policies to reduce plastics at the source will help protect the oceans, communities, and climate.”

Elsewhere, April was the warmest month on record for the average ocean energy temperature. A marine heat wave is unfolding on a global scale that is setting records that have stood for decades, and forecasters say it could get worse in the coming months as El Niño takes hold in the Pacific Ocean.

Underwater heat waves occur when water temperatures in parts of the ocean are well above historical averages. Alone, these events are not uncommon, but the nature of multiple, widespread events across the world’s oceans is alarming to scientists.

Blinken added Thursday that the U.S. government is working toward a sustainable and “blue” economy that protects the world’s oceans.

“We will continue to build upon this global momentum to protect our ocean for all those who depend on it and for all to enjoy,” he said.