Ocean

The Best of Our Knowledge explores topics on learning, education, and research.On this episode, we’ll learn how an unusual fossil offered scientists a new glimpse into the evolutionary history of some of Earth’s earliest animals.And we’ll learn how pirate gold helped dispel a centuries-old rumor among seafaring European traders.

The Best of Our Knowledge explores topics on learning, education, and research.On this episode, we’ll learn how an unusual fossil offered scientists a new glimpse into the evolutionary history of some of Earth’s earliest animals.And we’ll learn how pirate gold helped dispel a centuries-old rumor among seafaring European traders.

The oceans are home to a quarter million species that have been catalogued and undoubtedly a far greater number undocumented, hosting over 80% of global biodiversity. Oceans are the planet’s primary life-support system, producing at least half of its oxygen.

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.