Extreme Marine Heat Waves Hit Multiple Regions Around the World

The World Meteorological Organization has updated its global marine heatwave and red tide warnings. Sea surface temperatures in the Mediterranean, the North Atlantic, and off the coast of Australia have repeatedly broken records for this time of year. High temperatures can increase the toxicity of land-based wastewater, and the risk of red tides in North Africa and eastern Spain is at its peak, making it highly likely that oxygen-depleted “dead zones” will form. At the same time, ocean acidification is accelerating coral bleaching and reducing deep-sea fish catches, prompting many countries to issue warnings of declining fisheries yields.