A Karenia brevis red tide bloom is affecting parts of Galveston County, Texas, on September 16, 2026, after state biologists confirmed moderate to high cell concentrations, fish kills and respiratory irritation along the coast. NOAA forecasts a moderate to high risk of respiratory irritation at some beaches on Galveston Island and Bolivar Peninsula as the bloom continues.
A large marine heatwave has persisted along the U.S. West Coast since summer 2025, raising sea surface temperatures about 1.7–2.2°C (3–4°F) above average across parts of the Northeast Pacific. In a report published March 3, 2026, the National Oceanic and Atmospheric Administration (NOAA) Fisheries said this is only the third time in the observational record for the California Current ecosystem that such a large portion of coastal waters has remained anomalously warm for so long into winter without El Niño conditions.
Elevated concentrations of iodine-129 were detected in seawater samples collected recently from the West Philippine Sea during a nationwide marine radioisotope survey conducted by the University of the Philippines Marine Science Institute. The concentrations were higher than those measured in other Philippine marine areas, despite the Philippines having no active nuclear power plant or nuclear weapons program.
ENSO remains neutral, and NOAA’s Climate Prediction Center has issued a La Niña Watch, assigning a 71 % probability of La Niña development during October–December 2025.
A toxic algal bloom affecting South Australia’s coastline since March 2025 has killed more than 14 000 marine animals and spread across over 5 000 km² (1 930 mi²), prompting the state government to declare a natural disaster.
Thick accumulations of decomposing sargassum seaweed washed ashore in Dania Beach, Florida on July 23, 2025, releasing hydrogen sulfide odors and prompting cleanup efforts. The event was part of a broader seasonal trend affecting Florida’s coastlines, driven by ocean currents and wind patterns transporting offshore blooms inland.
Sargassum levels in the Atlantic basin hit a record 37.5 million metric tons in May 2025, the most recorded since monitoring began. The sharp increase has inundated coastlines, affected tourism, and raised health concerns across parts of the Caribbean.
Thousands of Velella velella, also known as by-the-wind sailors, washed ashore on beaches in Ventura County, California, from late April to early May 2025. The mass stranding, driven by onshore winds and warm ocean conditions, reflects seasonal oceanographic changes along the California coast.
Rip currents claimed one life and left two injured on Saturday, April 12, 2025, after pulling three teens into the water while swimming at Lake Worth Beach in Florida.
An international team exploring the seafloor after iceberg A-84 broke off the George VI Ice Shelf in January 2025 discovered a previously unseen ecosystem, raising questions about how life adapts to some of the harshest environments on the planet. Since the area became accessible, at least six new species have been identified in the region.
