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- Earth is simmering in its hottest water temps on record, and that’s bad for fish and us (apnews.com)
The world’s oceans reached their highest temperatures ever recorded this past weekend, with experts warning that waters are likely to grow even warmer in the coming months. This alarming trend, driven by an unusually strong El Niño event coupled with ongoing human-induced climate change, is putting immense pressure on marine ecosystems and coastal communities alike.
According to the European climate service Copernicus, ocean temperatures peaked at 21.1 degrees Celsius (70 degrees Fahrenheit) on Friday and Saturday, slightly surpassing the previous record set in March 2024. Samantha Burgess, Copernicus’ strategic climate lead, emphasized the gravity of the situation: “This is yet another sign of our climate system under strain and the ocean under immense pressure.”
Jane Lubchenco, an oceanographer and former head of the U.S. National Oceanic and Atmospheric Administration, described the record as “very troubling.”
She noted that warmer oceans disrupt weather patterns and threaten vital resources such as food supplies, economic stability, and marine biodiversity. “A warmer ocean is not our friend,” she warned.
Rising ocean temperatures have wide-reaching effects. As waters warm, they become more acidic and lose oxygen, harming fisheries and aquaculture industries.
Changes in ocean currents and weather patterns can fuel more intense storms, increase rainfall, and amplify storm surges. Burgess explained that warmer seas also exacerbate heatwaves by reducing cooling nighttime sea breezes, particularly noticeable in Europe this summer.
Typically, global sea surface temperatures peak in March or April, following the Southern Hemisphere’s summer. However, this year’s record occurred in August, signaling that the oceans will continue heating until the peak of the current El Niño event, expected between November and January. This El Niño is already one of the largest on record and is anticipated to reach unprecedented intensity.
Boris Worm, a biology professor at Dalhousie University in Canada, expressed deep concern over the early onset and abnormal intensity of ocean warming. “The ocean is not supposed to do this,” he said. “It’s just that there is no normal anymore.”
The impact on marine life is severe. John Bruno, a marine ecologist at the University of North Carolina, pointed out that sensitive coral populations have plummeted to about one-fifth of their 1990s levels.
While some “weedy” coral species show signs of adaptation, iconic corals like staghorn remain vulnerable. Both Bruno and Worm warned of potential collapses in fisheries and resulting food shortages.
Of particular concern is the Peruvian anchovy fishery, the world’s largest, which typically collapses during El Niño events. Hotter waters hinder anchovy reproduction and survival, disrupting the broader food web that supports larger fish, marine mammals, seabirds, and human communities. Worm highlighted that while larger marine animals can migrate to cooler waters, anchovies cannot, making them especially susceptible.
These disruptions ripple through ecosystems and economies alike. “It’s like when you pull the rug out from underneath an economy – the whole thing collapses,” Worm explained. “Some sectors may do a little better, but overall, everybody suffers.”
Warmer waters are also contributing to increases in jellyfish populations, as noted by Burgess and Bruno. Jellyfish tend to thrive in warmer conditions, potentially impacting fisheries and coastal recreation, including along the U.S. East Coast.
Rick Spinrad, another former NOAA chief, underscored the critical role of oceans as Earth’s thermostat. He cautioned that these record-breaking sea surface temperatures foreshadow even greater environmental and societal challenges ahead. “As long as we depend on a healthy ocean for our safety, prosperity, and wellbeing, these trends are deeply concerning,” Spinrad said.
The escalating ocean heat highlights the urgent need for global action to address climate change and protect vulnerable marine ecosystems, emphasizing that the health of the oceans is inextricably linked to the well-being of people worldwide.