Tangier

Seaweed native to the northwest Pacific is invading the rich marine waters of the Strait of Gibraltar and the brown algae is clogging up fishermen's nets and endangering their way of life.

Greg Blackburn's boat was being tossed around by "heavy weather" in a notorious stretch of water. Two large orcas, otherwise known as killer whales, were responsible for the ramming but Blackburn said four more would join in - causing extensive damage to the boat. 

Scientists think a traumatized orca initiated the assault on boats after a "critical moment of agony" and that the behavior is spreading among the population through social learning.