Orcas' boat attacks raise concerns among researchers.

A group of killer whales severely damaged a sailing boat off the coast of southern Spain, adding to dozens of attacks by orcas on vessels recorded so far this year off Spanish and Portuguese coasts. The incident follows at least 20 interactions this month alone in the Strait of Gibraltar between small vessels and killer whales. Guidelines issued by the Spanish Transport Ministry stipulate that every interaction between a ship and an orca must be reported to authorities.