Around this time last year, Dean Grubbs and his colleagues were celebrating a conservation success story.The star of the show was the smalltooth sawfish, a large ray with a saw-like snout lined with tiny teeth. Victim of coastal development and bycatch, in 2003 it became the first saltwater fish to receive federal protection under the Endangered Species Act. By 2023, Florida's population will be the last sawfish in the US, and it's on the rise. “We were excited. We were seeing the population start to bounce back,” says Grubbs, a marine ecologist at Florida State University.
Then disaster struck. In January, a sawfish was found dead, thrashing about in shallow waters, spinning like crazy. This was after months of the smaller fish exhibiting similar behavior. Suddenly, Grubbs and his team were spending their days pulling dead sawfish from the water. After months of research and testing, the culprit finally emerged: ocean heat. A record-breaking heatwave brought “hot tub” water temperatures to Florida's coast in 2023, setting off a chain reaction that appears to have devastated the vulnerable sawfish population.
This is just one cautionary tale: something is wrong with the world's oceans. From orange algae blooms in the North Sea to outbreaks of gelatinous Bombay duckfish off the coast of China to the disappearance of Antarctic “bottom waters,” evidence is mounting that extreme temperatures are wreaking havoc on our oceans. After years of acting as silent sinks for excess human-made heat, the oceans are beginning to creak under the pressure. And we're finally starting to realize just how worried we should be.
About 90 percent of the excess is…
Source: www.newscientist.com
