Warmer waters are hurting Norway’s salmon farming industry

El Nino—a climate pattern raising temperatures across the planet—followed by colder waters and a 20-year high in jellyfish attacks have driven fish mortality to a record 16.7% so far this year, the Norwegian Veterinary Institute said.

Norwegian salmon farmers face challenges from an unusually harsh winter and the El Nino climate phenomenon which led to record fish mortality and concerns over long-term forecasts ahead of a warmer summer.