Canadian researchers solve the mystery of starfish disease

A team led by researchers from British Columbia has resolved the mystery of a terrible disease that has decimated billions of starfish along the Pacific Coast of North America, more than 10 years after their disappearance.

The main author of the new study, Melanie Prentice, remembers a moment when she did not really believe in it when the researchers discovered an abundant bacterial strain in sick starfish and absent in healthy starfish.

My first reaction was to say to me: “OK, I made a mistake”she said.

Melanie Prentice explains that the team had spent months trying to refute its conclusions, finally confirming that it has deciphered the disease code.

The team discovered that the bacteria Vibrio pectenicida is an obvious cause of starfish disease.

This is a question that researchers have been trying to answer for about 12 years; So we are more than delightedindicates Ms. Prentice, associate researcher at the Hakai Institute and the Department of Earth Sciences, the Ocean and the atmosphere of the University of British Columbia (UBC).

The article which details the four -year research project and its conclusions was published online on Monday in the journal Nature Ecology & Evolution.

Alyssa Gehman, who contributed to the launch of the project in 2021, described the disease asdreadfulprovoking the appearance of lesions in starfish, the loss of their arms and their disappearance in porridge About a week or two after exposure to the pathogen.

It was particularly deadly for sunflower starfish, killing about six billion of these starfish that can develop 24 arms and reach a wingspan of one meter.

Giant seas of sea are now considered functionally extinguished in a large part of their old distribution area off the continental coast of the United States, with losses exceeding 87 % in the North Shelters where they persist, according to the study.

A pillar of the ecosystem

This collapse had cascading consequences, including the massive disappearance of significant ecological, cultural and economic Varech forests.

I think we didn’t really realize their importance before losing themdeplores Ms. Prentice, describing the orange sunflower starfish, purple or brown like a species keystone having a considerable impact on their ecosystem.

Giant starfish are leading predators, inspiring fear for other invertebrates.

Almost everything that lives on the ground underwater flees when they arriveunderlines Ms. Gehman, an environmentalist specializing in marine diseases at the Hakai Institute and assistant professor at the Institute of Oceans and Fisheries of the UBC.

They control the sea urchins, thus ensuring the health of the Varech forests which provide habitat and food to many other species.

The devastation of starfish starfish caused a Total change of ecosystemsaid Melanie Prentice, transforming Varech forests rich in biodiversity into Terrible sea urchin deserts.

The bacteria responsible for the decline in the seas from the starfish had remained elusive for more than 10 years, since starfish was observed for the first time in 2013, dying in large numbers. This same bacteria is known to attack scallops.

This discovery allows researchers to focus on deeper questions, in particular the possible role of warming oceans and the possibility of raising seas of seas of captivity to promote resistance to diseases and accelerate restoration, maintains Alyssa Gehman.

The disease now seems seasonal, with epidemics occurring during the hottest months, which suggests that temperature could be a factor, she adds. The environmentalist will soon conduct temperature experiences to deepen his research.

These results could help researchers understand where starfish could face climate change in the future.

Melanie Prentice indicates that there are populations remaining starfly starfish along the coast of British Columbia, and that it is very possible that some of them are more resistant to debilitating disease.

She added that the discovery and selective breeding of seasicks more resistant to the disease could produce super Star of the sea intended to be reintroduced into the wild.

It sometimes looks like science fiction, but work is underwayshe concludes.