Global climate change had been impacting the world's oceans since the early 1980s, although most people hadn't noticed the transformation until the mid-2010s, when the reduced surface temperatures, increased ferocity of storms, and seemingly endless blooms of toxic algae had become severe enough to make headline news. As the glaciers melted, they dumped their runoff into the deep currents that warmed much of the world. The sudden freshwater influx lowered the ocean's temperature and overall salinity even as temperatures on land continued to climb. Fish were dying. Whales and other large sea mammals were changing their ancient migration patterns, following the food into waters where they had never been seen before. Sharks were doing the same, sending scientists into tizzies and panicking the public.