Blue whales threatened by ship collisions in busy Patagonia waters

Blue whales threatened by ship collisions in busy Patagonia waters

The largest mammal ever to live on the Earth, the blue whale, is under threat from boat collisions as one of its main feeding grounds in Chilean Patagonia is overrun with vessels, a new study has revealed.

The endangered whales must contend with up to 1,000 boats moving daily through an important feeding area in the eastern South Pacific, according to research published in the scientific journal Nature.

Scientists researching the feeding patterns of the largest cetacean found that 83% of daily operating vessels belonged to the extensive salmon farming industry in the area of northern Chilean Patagonia.

The blue whale – which can weigh 150 tonnes and measure as much as 30 metres in length – has made a dramatic comeback in numbers in Antarctic waters but remains endangered and was on the brink of extinction due to industrial whaling in the last century.

Satellite tracking of blue whales and vessel traffic data released by the Chilean fisheries service Sernapesca has made it possible to pinpoint where ship strikes are more likely to occur for the species.

Luis Bedrinana-Romano, lead author of the paper, said the recently published data on vessel traffic is alarming. “We know where the whales are, but we also know that their total population is very low in this area. In fact, according to our research, they could reach between 200 and 700 individuals,” he said.

“Any incident of collision [resulting in] death of these animals represents a real threat to their conservation,” he said.

When a blue whale feeds, it invests a large amount of energy to find and consume its main food, krill, said Rodrigo Hucke-Gaete, the project leader and co-author of the study.

“Field observations that we have carried out indicate that when blue whales feed, they practically only pay attention to this activity,” he said. “This makes them more prone to being hit by boats and particularly at night, when, according to other investigations, whales are on average closer to the surface as a result of their food also rising to the surface.”

The scientists are calling on the fishing industry to work with them to put in place protective measures to avoid fatal collisions for blue whales, which have already occurred in 2009, 2014 and 2017, as well as deaths from entanglement in salmon farms in 2007 and 2020.

The feeding conditions for whales can occur in several places in Chilean Patagonia, famous for its fjords and inner seas, such as the Gulf of Ancud and Reloncavi Sound, at the mouth of the Moraleda Channel, and on the western coast of Chiloe Island, an area renowned for its spectacular marine biodiversity.

Leave a Reply

Your email address will not be published. Required fields are marked *