OCEAN: Climate Change Intensifies Heatwaves & more – 22nd April 2025

Ahoy from BA! This is the Rorshok Ocean Update from the 22nd of April twenty twenty-five. A summary of what's going down in the 70% surface of the Earth covered in saltwater.

On Thursday the 17th, US President Donald Trump signed a proclamation reopening the Pacific Islands Heritage Marine National Monument to commercial fishing, aiming to support American Samoa’s economy, which depends heavily on tuna fishing. The new policy permits US-flagged vessels to fish up to 200 nautical miles from shore within the previously protected area. The administration said that migratory fish like tuna move beyond sanctuary borders, making strict protections less effective.

Local leaders in American Samoa supported the move, warning that earlier conservation plans threatened thousands of jobs. Environmentalists are condemning the decision, as it puts endangered species and delicate marine ecosystems at risk.

Still in the Pacific Ocean. A study published on Monday the 14th in the journal Proceedings of the National Academy of Sciences revealed that climate change has dramatically intensified heatwaves in the Pacific Ocean over the past twenty-five years. Researchers traced these changes back to nineteen forty and confirmed that human-driven global warming has lengthened and strengthened marine heatwaves. The study found that oceans now experience nearly fifty days of extreme heat per year, while in the nineteen forties it was only fifteen days, with some Pacific regions facing up to eighty days.

Scientists showed that fossil fuel emissions fanned these changes, which have disrupted marine ecosystems, triggered mass coral die-offs, and harmed fisheries and tourism. Dr. Xiangbo Feng, who led the research, warned that continued warming will make these events more frequent and damaging.

From the Pacific to the Atlantic Ocean. On Wednesday the 16th, the Guardian reported that an expedition of scientists filmed a colossal squid alive in its natural habitat for the first time during a deep-sea expedition near the South Sandwich Islands in the South Atlantic. This marked a historic moment exactly 100 years after the species’ discovery.

An international team aboard a Schmidt Ocean Institute’s vessel captured footage of the juvenile squid, measuring thirty centimeters (or twelve inches) and swimming at 600 meters (almost 2,000 feet) deep, during a thirty-five-day expedition last March. Until now, researchers had only encountered remains in predators’ stomachs or dying adults in fishing nets. This colossal squid, which can grow up to seven meters (or twenty-three feet) and weigh 500 kilos (or 1,100 pounds), holds the title of the world’s heaviest invertebrate.

Want to check out the video? Follow the link in the show notes!

In more news from the Atlantic Ocean, on Monday the 14th, crowds gathered on a North Carolina beach, in the US, to witness thirty-one Kemp’s ridley sea turtles return to the Atlantic Ocean after months of recovery from cold-stunning. These critically endangered turtles became hypothermic when sudden drops in water temperature left them immobile and stranded on beaches. Volunteers from Mass Audubon’s Wellfleet Bay Wildlife Sanctuary found the turtles and transported them to the New England Aquarium’s Sea Turtle Hospital.

Last winter, the facility treated more than 500 cold-stunned turtles. Of the thirty-one turtles released in April twenty twenty-five, volunteers recovered twenty-five in Quincy, Massachusetts, and six in the New York Marine Rescue Center. Rescue teams drove the turtles in climate-controlled vehicles to warmer waters in North Carolina.

Next up, some updates on the Arctic Ocean. On Monday the 21st, experts from Japan’s Aerospace Exploration Agency reported that Arctic sea ice reached a record low seasonal peak this year. Using data from the Shizuku satellite, researchers observed that the ice extent hit its maximum in March twenty twenty-five, at just under fourteen million square kilometers (or five million square miles), which is the smallest area recorded since tracking began in nineteen seventy-nine.

Scientists linked the decline to global climate change, pointing to unusually high air temperatures from December twenty twenty-four to February twenty twenty-five. The National Institute of Polar Research also confirmed that this winter’s average monthly ice extent ranked the lowest on record. Researchers expressed concern over the ongoing impact of shrinking ice on global weather systems and ocean ecosystems.

From one Pole to the other. Researchers recently explored the use of environmental DNA (or eDNA) to monitor Antarctic krill distribution in the Southern Ocean. By collecting eDNA samples from both surface and seafloor waters, they aimed to understand krill habitat and biomass. They measured krill eDNA abundance and identified species.

The study, published on Friday the 18th in the journal Frontiers, found that eDNA concentrations were highest above krill swarms, and these concentrations decreased with distance from the swarms. The eDNA method showed promise in detecting krill at depths up to 4,300 meters (or 14,000 feet). The findings revealed that Antarctic krill was the dominant species.

In other news, a 6.6-magnitude earthquake struck the Indian Ocean off the coast of southwest Australia on Wednesday the 16th. The quake's epicenter was located 2,070 kilometers (or 1,300 miles) southwest of Albany, Western Australia, at a depth of ten kilometers (around six miles).

Despite the powerful tremor, the Joint Australian Tsunami Warning Center confirmed that no tsunami threat was issued for either Australia or Antarctica.

More about the Indian Ocean as on Monday the 21st, French President Emmanuel Macron began a five-day tour of Indian Ocean territories by visiting Mayotte, four months after a cyclone caused forty deaths and almost four billion US dollars in damage. He praised the resilience of locals and reviewed recovery efforts. Despite the restoration of utilities, residents expressed frustration over delays in reconstruction. Macron brought a new programming bill targeting illegal immigration, poor housing, and economic development to the parliament during a special Council of Ministers meeting.

Macron will also visit Réunion, Madagascar, and Mauritius. In Réunion, he will address cyclone recovery and a chikungunya outbreak. In Madagascar, he will attend the Indian Ocean Commission summit, where Mayotte’s membership and regional issues will be discussed. In Mauritius, he will focus on food security and marine conservation.

Let’s sail to the Suez Canal. On Thursday, the 17th, Angelina Eichhorst, the EU Ambassador, visited Ismailia, Egypt, for the first time to celebrate the Suez Canal Authority’s Excellence Day. She met with the Egyptian Prime Minister, the Ismailia Governor, and the Suez Canal Authority Chairman. Alongside EU Member State ambassadors, Eichhorst explored investment and cooperation opportunities between the EU and the Suez Canal Authority.

The event featured the signing of agreements and memoranda of understanding focused on sustainability and the green transition, particularly involving companies from Spain and Greece.

Representatives from numerous EU countries attended the ceremony.

From the Suez to the Panama Canal. On Tuesday the 15th, US President Donald Trump criticized China’s influence over the Panama Canal and warned trade partners that they may need to align with either the US or China. He shared his dissatisfaction with the canal’s current management, indicating plans for more aggressive trade talks.

He announced plans to pressure over seventy nations to limit Chinese trade routes and reject cheap Chinese imports. At the same time, Trump praised trade talks with Vietnam, which seeks closer economic and military ties with the US. Meanwhile, China, facing increasing tariffs and economic strain, began reshuffling negotiators and reaching out to allies to counter US pressure.

Closing with updates from the Black Sea, on Tuesday, the 15th, Ukrainian President Zelensky announced that Ukraine, Turkey, the UK, and France have begun talks in Ankara to strengthen Black Sea security. During a press conference with Mark Rutte, NATO’s Secretary General in Odesa, Zelensky emphasized that the discussions focus on post-war stability rather than ending the current conflict. He stressed the need for a foreign military presence to protect key coastal cities like Odesa and Mykolaiv and highlighted Turkey’s potential leadership role in future maritime security arrangements.

Turkey maintains diplomatic ties with both Russia and Ukraine and has played a crucial role in facilitating grain export agreements and ceasefire talks. Even though Ukraine accepted a US-backed ceasefire plan in March, Russia initially rejected it and only later agreed to a limited truce focused on the Black Sea and energy infrastructure.

Aaand that’s it for this week! Thank you for joining us!

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See you next week!