A decade ago, Tunisian fisherman Ahmed Chelli's nets bulged with fish and octopus that he sold at the local market in the Kerkennah islands. Today, he pulls up only "ISIS" — the name locals have given to the blue crabs that have invaded their fishing grounds in the fast-warming waters of the Mediterranean.
"The fisherman ... instead of finding fish to provide an income, he finds something that cuts his nets," Chelli complained.
For more than 70 days this summer, a marine heat wave cooked the waters of the western Mediterranean.