This July 2019 photo provided by Peter Westley shows the carcass of a chum salmon along the shore of the Koyukuk River near Huslia, Alaska, July 2019 was the hottest month ever recorded in the state. Global warming looks like it will be a far bigger problem for the world's fish species than scientists first thought, since a study led by Dr. Flemming Dahlke released on Thursday, July 2, 2020 shows that when fish are spawning or are embryos they are far more vulnerable to hotter water. (Peter West