(Vancouver) Southern resident killer whales are increasingly suffering from skin diseases that leave large stains on their distinctive black and white color, according to a new study.
The research, published Thursday in the journal PLOS One, analyzed photographs of more than 18,000 killer whale sightings from 2004 to 2016 in the Salish Sea, a maritime area in the northern Pacific Ocean. Skin lesions are found to have become “surprisingly” more widespread, posing another threat to a population already facing a range of challenges.
Co-author Stephen Raverty, a veterinary pathologist at the British Columbia Animal Health Centre, said scientists observing the whales had noticed these unusual skin changes before, but they had never been assessed over time. time.
The study indicates that although the significance of the lesions was unclear, the possibility that they were linked to decreased fitness and immunity in an endangered population was a concern.
Scientists have speculated that the lesions could be an infection and an indicator of the whales’ declining ability to fend off disease.
The exact underlying cause of these skin problems was unclear, Raverty said, but they could be the result of human activities.
“We know that there are certainly consequences related to increased marine traffic, contaminant loads, increased noise in the marine environment and lack of prey, which are sort of the main elements known to impact the health of southern resident killer whales,” said Raverty.
Joseph Gaydos, chief scientist at the University of California, Davis School of Veterinary Medicine and lead author of the study, said in a statement that before reviewing the data, they had no idea that the prevalence of skin lesions was increasing so dramatically.
“It’s worrying,” he said. We must now try to isolate the potential infectious agent”.
The study involved 141 whales, 99% of which showed signs of skin lesions at some point during the study.
The most common lesion types were “grey spots” observed in 27% of whales studied, followed by “grey targets” observed in 24% of cases.
Mr Raverty said the study was a step forward in assessing the health of whales via a “non-invasive” assessment for them.
” [Cela] helps us know if these changes may indicate something happening systemically that could impact animal health,” he added.
Another co-author, Martin Haulena, chief veterinarian at the Vancouver Aquarium, said the study can help scientists recommend conservation strategies.
As a highly contaminated group of animals, killer whales are affected by the conservation of salmon species, habitat and noise, he said.
“A healthy environment, minimal disturbance: these things are very important for the recovery of whales,” Haulena said.
This dispatch was produced with the financial assistance of Meta Exchange and The Canadian Press for News.