This has been a terrible year for the world’s freshwater fish and a lot of work needs to be done to stop thousands of species from hurtling toward extinction in 2024, researchers say. The International Union for Conservation of Nature says that about 21% of freshwater fish—3,086 out of 14,898 assessed species—are at risk of extinction because of factors including pollution, overfishing, and climate change, the latter of which affected at least 17% of threatened species. The IUCN says climate change puts pressure on fish species in several ways, including by shifting the seasons and forcing sea…