New virus found in Hawaiian dolphin could trigger global epidemics in marine mammals, scientists say

Biologists in hawaiiI have detected an unknown strain of cetacean before morbillivirus, a pathogen that can cause deadly infections in marine mammals around the world. The virus was detected in a solitary Fraser’s dolphin, a very social species, raising concerns that the disease could spread and wreak havoc outside the central Pacific Ocean.

This male juvenile Fraser’s dolphin (Lagenodelphis hosei) ran aground off Maui in 2018, launching a two-year investigation into her condition. Her body was in fairly good condition, but her organs and cells were showing signs of illness. Genetic analysis of cell cultures has revealed the culprit: a “new and widely divergent strain of morbillivirus” that scientists “previously ignored,” as explained by Krisi West, an associate researcher at the Institute of Marine Biology at UH Mānoa in Hawai’i. Press release.

Oonly one a handful of cetacean Morbillivirus strains are known to exist, but that’s bad news, causing deadly epidemics among marine mammals, including cetaceans (the group that includes both dolphins and whales) around the world. Other species of the genus Morbillivirus include the virus that causes human measles and the virus behind canine distemper. Details of the research are published today in Scientific Reports.

Fraser’s dolphins are very social and friendly, and they are known to mingle with other dolphins and whales. As a result, Fraser’s dolphins, an oceanic species, could bring this highly infectious pathogen to other parts of the world, forcing marine wildlife managers and environmentalists to be on their toes.

“It’s also important to us here in Hawai’i because we have many other species of dolphins and whales – about 20 species that inhabit Hawai’i – which may also be vulnerable to an outbreak of this virus,” added West. “One example is our Endangered False Island Killer Whales, where only 167 individuals are estimated to be left. If the morbillivirus were to spread through this population, it would not only be a major obstacle to the recovery of the population, but could also pose a threat of extinction. “

Indeed, this is a very serious matter. Two previous incidents involving new strains of morbillivirus have resulted in high mortality rates in dolphins off Brazil and the west coast of Australia. Brazilian Example, more than 200 dolphins in Guyana are said to have died of the disease from November to December 2017.

The authors of the new study say more research is needed to test immunity rates in dolphins and whales in the central Pacific, as this could help establish the rate of previous infections and the extent of the disease. epidemic. However, it will not be easy to bring this disease under control. The UH Health and Stranding Lab manages to recover less than 5% of cetaceans that die in Hawaiian waters. The team is asking the public to report sightings of dead and distressed marine mammals to the NOAA Marine Wildlife Hotline.

Encouragingly, a mass vaccination campaign might be possible. As the press release points out, NOAA has been working on a morbillivirus vaccination program to create herd immunity among endangered Hawaiian monk seals. It is even more encouraging to know that reluctance to vaccinate in oceanic dolphins will not be a problem.

Following: Herbicide, lead, and other poisons found in the bodies of stranded whales and dolphins.