Ocean

Toxic algal blooms have been a growing problem in recent years associated with warming waters and nutrient-rich agricultural runoff in lakes, rivers, and oceans. These outbreaks can damage ecosystems, degrade water quality, and release toxins that threaten both wildlife and people. But a recent discovery suggests that nature may have found a way to fight back.

Significant blooms of the brown seaweed Sargassum in the tropical Atlantic have been taking place since 2011, impacting tourism in the Caribbean. A more general observation is that between 2003 and 2022, macroalgal mats and microalgal scum have expanded around the globe. A recent study looked at the rise of macroalgae blooms across the globe over the past two decades.

The world’s oceans just keep getting hotter. International analysis published in the journal Advances in Atmospheric Sciences finds that the oceans stored more heat in 2025 than in any year since modern measurements began.

The United States took many backward steps with respect to the environment over the past year. Elsewhere, there was some progress by governments and other organizations in efforts to protect the natural world, preserve ecosystems, and establish policies to benefit the environment.

PFAS – per- and polyfluoroalkyl substances – otherwise known as forever chemicals – are man-made chemicals known for their extreme persistence. They resist breaking down in the environment and in the human body and have led to widespread contamination in water, soil, and unfortunately in human blood. They are used in non-stick cookware, waterproof clothing, food packaging, and firefighting foams. PFAS have been linked to serious health issues like cancers, thyroid disease, and reproductive problems.

Coastal ecosystems are undergoing a process known as a coastal squeeze. Beaches face a combination of rising sea levels caused by climate change and reductions caused by expanding development in coastal zones. Between the two forces, beaches are gradually being eaten away. According to research by a marine scientist in Uruguay, almost half of the beaches in the world could disappear by the end of this century.

Each summer, vast quantities of Sargassum seaweed spread across the tropical Atlantic and foul the coasts of the Caribbean Islands, the Gulf of Mexico, and northern South America. The Sargassum is not only bad for tourism, it also disrupts ecosystems by providing massive amounts of food for many marine species, upsetting the balance of those systems.

Researchers at the King Abdullah University of Science and Technology in Saudi Arabia have found that there are marine bacteria living in all the world’s oceans that are able to consume and digest plastic – in particular polyethylene terephthalate (or PET) plastic – the plastic found in soda bottles, clothing, and many other things.

A subpolar gyre is a large-scale ocean current system located at high latitudes created by a persistent region of low atmospheric pressure. These gyres circulate water in a cyclonic direction – counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. This circular motion of water drives the upwelling of cold, nutrient-rich deep water to the surface, which plays an important role in regulating the climate in the higher latitudes as well as the nutrient cycles that sustain ocean ecosystems. Subpolar gyres influence the circulation of other ocean currents like the North Atlantic Current, the East Greenland Current, and the Labrador Current.

The Best of Our Knowledge explores topics on learning, education, and research.Seahorses are some of the most unique and beautiful creatures in the ocean.The Pygmy Seahorse is one of the most interesting looking and complex of them all.They are only 1 inch big, and due to their size were not known to exist until about 50 years ago.We will learn all about this tiny creature that comes from the depths of the ocean hidden in coral.