Report on 14 Large Whales That Died due to Ship Strikes off the Coast of Sri Lanka, 2010–2014

Abstract

The greatest threat to cetaceans in Sri Lankan waters was considered to be the direct take of small- and medium-sized cetaceans using harpoons and/or as bycatch until recently. However, ship strikes have probably been occurring for years but have not been recognized for what they were. For the current study, only animals with visible and prominent injuries related to collisions were evaluated. Data gathered between 2010 and 2014 included the species, morphometry, location, and date; tissue samples were collected for genetic analysis. When possible, a complete necropsy was conducted; otherwise, partial necropsies were conducted. The study confirmed 14 reports of ship strikes between whales and vessels out of all the strandings reported from 2010 to 2014. Most strikes (n=09, 64%) involved blue whales (Balaenoptera musculus), although three other species were also documented, one Cuvier’s beaked whale, two great sperm whales, and one Bryde’s whale, as well as one unidentified baleen whale. Collision hotspots such as the southern waters of Sri Lanka are areas that warrant special attention in the form of vessel routing measures or speed limits, research on cetacean ecology, distribution, daily and seasonal movements, public service announcements, increased law enforcement presence, and other measures.