Orcas in the Pacific Northwest are battling an unknown skin disease, new research shows this week. The breedYou have found it photographic evidence that these orcas have developed increasingly mysterious lesions over the years. It’s not yet clear how damaging this trend could be, but it’s the latest potential threat to the region’s already vulnerable population.
killer whales (Orcinus orca), also known as killer whales, are found in all oceans of the world. But these marine mammals form tight-knit communities that differ significantly from one another and are led by matriarchs who can live for decades. Such a community is the southerner, a population of exclusively fish-eating orcas in the Pacific Northwest. The Southern Residents are the smallest group in the region, made up of three groups that spend most of their time in the waters of the Salish Sea off British Columbia in Canada and Washington and Oregon in the United States
The Center for Whale Research in Washington has been tracking southern killer whales since 1976. Occasionally scientists have noticed one strange lesions or patches of skin on the orcas sometimes left behind. However, no one has attempted to quantify the prevalence and frequency of these skin diseases in the population.
This new study published Wednesday in PLOS-ONE was led by researchers from the University of California, Davis School of Veterinary Medicine. They reviewed photos collected by the Center for Whale Research between 2004 and 2016, covering nearly 20,000 individual whale sightings.
From the photos, the researchers identified six different types of lesions on the orcas, with the two most common types being gray patches or targets. About 99% of the whales developed one or both of these lesions at some point, and the total number of lesions found on the whales increased over the years in all three groups. The team ruled out possible factors for the lesions, such as: B. changes in water temperature or salinity, and therefore suspected that some kind of germ was the likely culprit.
“Before we looked at the data, we had no idea that the prevalence of these skin lesions was increasing so dramatically,” said study author Joseph Gaydos, veterinarian and scientific director of the SeaDoc Society, a program at UC Davis opinion from the university. “It’s worrying. Now we have to try to isolate the potential infectious agent.”
The only bright spot is that the researchers found no link between the occurrence of these lesions and an increased risk of death in the orcas. But the lesions could still harm the orcas or be a sign of other problems, such as a weakened immune system. Therefore, more research needs to be done to understand the impact of these skin conditions on their health.
It was not a good time for the orcas living in the south in particular. They have been explained endangered by the US in 2005, but their numbers have continued to decline and it is estimated that fewer than 75 individuals reside in the community today. Human activities such as pollution and the loud noise made by boats are thought to be the biggest contributors to this decline.