US government scientists issue dire warnings about historic coral bleaching in the Pacific Ocean.

Welcome to VOA Asia Weekly. I'm Chris Casquejo in Washington.

That story is coming up, but first, making headlines:

Top U.S. diplomat Antony Blinken said Tuesday the United States will come to the defense of the Philippines amid rising tensions with China over the South China Sea. Blinken issued the pledge shortly after arriving in Manila for talks with Philippine Foreign Minister Enrique Manalo.

“We stand together in our determination to uphold international law.”

Blinken also visited Seoul, which hosted the third Summit for Democracy, an initiative of U.S. President Joe Biden.

North Korean leader Kim Jong Un oversaw firing drills by artillery units involving "newly-equipped super-large" multiple rocket launchers, state media KCNA said on Tuesday. The drills came a day after South Korea and Japan reported North Korea's launch of several short-range ballistic missiles into the sea while Blinken was in Seoul.

The Hong Kong legislature approved a new national security law on Tuesday. It grants the government expanded powers to silence dissent. The bill covers treason, sabotage, sedition, the theft of state secrets, and espionage. Convictions under the new law carry sentences up to life imprisonment. The chamber unanimously approved the new law with a 90-0 vote, and it will take effect on March 23.

Shohei Ohtani, the Los Angeles Dodgers superstar, has been the focus of attention from baseball fans in South Korea and Japan. The beloved Japanese athlete arrived in South Korea last week for the Major League Baseball opener on Wednesday in Seoul against the San Diego Padres featuring Korean star Kim Ha-seong. This week, positive vibes are emerging between South Korea and Japan, as they come together around an American game.

Residents of the Northern Mariana Islands have cast their ballots to select party candidates for the 2024 presidential election. President Joe Biden won the Democratic primary. Former President Donald Trump won the Republican caucuses. Because the Marianas are a US territory, residents have the right to vote in party events like these but not in the general elections.

Pacific leaders are on high alert after U.S. scientists warned that the world is nearing a historic mass coral bleaching brought on by high water temperatures fueled by climate change. VOA’s Jessica Stone reports.

Australia’s Great Barrier Reef – typically an underwater rainbow of color … now parts of it are a spotted canvas of white.

It’s called a coral bleach – a symptom of soaring ocean temperatures that can lead to the death of a reef and the species who live there.

“Marine heat waves are unfortunately increasing in frequency, magnitude and severity. This is directly due to climate change and global warming."

The high levels of heat stress mapped in 2023 prompted the United States' National Oceanographic and Atmospheric Administration, or NOAA, to update its coral bleaching alert maps. In December, NOAA added three new levels to its bleaching alert levels, with Level 5 predicting “near complete mortality” for reefs.

Marine ecologist Manzello says that the world is on the brink of a historic coral mass bleaching event, the fourth in history.

Species like tuna – a key food source and top export here in American Samoa. Manzello says he’s already helping the U.S. territory monitor the worst-hit reefs in their waters.

"Coral reefs provide a lot of protein, in particular for places like the Pacific Islands where you have whole communities that are wholly dependent on the fisheries.”

Palau’s President, Surangel Whipps Jr., though, says the situation isn’t hopeless and that corals can be resilient.

"Every time we’ve had a coral bleaching event, some of those species have come back, and we’re just hoping that this event is not too widespread and destructive.”

Alan Friedlander, the chief scientist at National Geographic’s Pristine Seas project, says Palau, the Marshall Islands and parts of Kirabati possess what’s called super reefs – corals that recover more quickly from bleaching than other reefs.

"These quote unquote super reefs are areas that should be set aside for protection because they can be the seed bank for other places that have been impacted."

Absent that, they say, it can take between 12 and 15 years for these ecological treasures to return to health.

Jessica Stone, VOA News.

Visit voanews.com for the most up-to-date stories.

I’m Chris Casquejo.

Finally, as winter turns to spring, DC’s famous cherry blossoms reached peak bloom this week. Tourists flocked to the nation's capital for hanami, or flower watching. This year marks the second-earliest peak bloom for the cherry trees since March 15, 1990. They were a gift from Japan in 1912.

Thanks for watching VOA Asia Weekly.