Earth is simmering in its hottest water temps on record, and that’s bad for fish and us

The world's oceans have reached their hottest temperatures on record, with implications for both marine life and human societies, according to a report from the European climate service Copernicus. Over the weekend, ocean temperatures hit 21.1 degrees Celsius (70 degrees Fahrenheit), narrowly surpassing the previous record set in March 2024.

This surge in heat is attributed to a growing El Nino event and human-induced climate change. Samantha Burgess, strategic climate lead for Copernicus, emphasized that the ocean is under immense pressure due to this unprecedented warmth. Jane Lubchenco, former chief of the U.S. National Oceanic and Atmospheric Administration, described the record as "very troubling," as a warmer ocean destabilizes weather patterns and threatens food security, economic prosperity, and marine life.

Warmer waters also lead to more acidic conditions, reduced oxygen levels, and altered ocean currents, amplifying the intensity of storms and heat waves. Scientists warn that the current El Nino, already as strong as recent ones, is expected to peak between November and January, potentially marking an unprecedented peak in ocean temperatures.

The loss of coral reefs, already reduced to one-fifth of their numbers from the 1990s, and the potential collapse of the Peruvian anchovy fishery could have cascading effects on global fisheries, food security, and the livelihoods of communities dependent on these resources.