Researchers have discovered the cause of the mysterious ocean epidemic that transformed billions of ocean stars into goo along the west coast. That’s not what they expected.
Since 2013, the wasteful disease of sea stars has been killing sea stars, causing catastrophic damage to the ecosystem and is at risk of extinction of the largest sea star species. Researchers believed the virus was the cause of the disease, but after four years of investigation, they found that the bacterial strain was responsible.
The pathogenic bacteria are pecpenitidavibrio, part of the same genus that causes cholera (V. cholerae) and produces strains that devastate coral and shellfish populations, the statement said.
You might like it
Researchers, who published their findings on Monday (August 4) in the Nature Ecology and Evolution Journal, used DNA sequences to identify infected sea stars microorganisms that are not healthy individuals. Ultimately, the team focused on high levels of V. pectenicida, an infected sea star known as permeate fluid.
“When we saw the liquid-liquid liquid between exposed sea stars and healthy sea stars, there was something fundamentally different: Vibrio,” said Alyssa Gehman, a marine disease ecologist at the Hakai Institute and the University of British Columbia (UBC), in a statement. “We all had chills. We thought it was. We have it. That’s what causes waste.”
Related: “Unconcretized Head Walking Around the Sea Bed of Lips”: Scientists finally solve what a starfish is
The wasteful disease of the sea stars has infected more than 20 species, but is particularly devastating for the sunflower sea stars (Pycnopodia helianthoides). These giant sea stars, which can grow up to 39 inches (1 meter) in diameter, are now functionally extinct in most of the southern region of the US, but further north, suffer population losses of over 87%. The study found that this decline has dire consequences for the ecosystems they live in.
The sunflower sea stars are predators that keep the sea urchins in control, preventing sea urchins from eating too much kelp. However, due to the massive losses of sea stars, scientists have exploded sea urchin populations, leading to a significant reduction in kelp forests. It is a major issue as kelp forests provide habitat for thousands of species, support the local economy through fishing and tourism, are important for coastal indigenous and tribal communities, protect coastlines from storms and store carbon dioxide.
“When we lose billions of ocean stars that really change ecological dynamics,” Melanie Prentiss, an evolutionary ecologist at the Hakai Institute and UBC, said in a statement. “Losing a sea star is far beyond the loss of that single species.”
Studying unnecessary diseases
Scientists have a hard time finding the cause of wasting illness. The disease begins as a lesion in the body of a sea star, and essentially melts tissue for about two weeks afterwards, eventually reducing the sea star body to a goo. However, sea stars can present similar symptoms to other environmental stressors and illnesses, making it difficult to grasp what lies behind a particular illness. The study authors investigated many pathogens they thought were the cause of the disease waste before identifying a strain of V. pectenicida, known as FHCF-3.
Once researchers identified the strain, they created a culture of V. pecpenida from infected sea stars and fed it to healthy sea stars. The result was that almost all infected sea stars died, and studies show that FHCF-3 was blamed on a useless disease. Researchers still have much to learn about the disease, but they can now proceed to investigate its driver and how to best fight it.
“Understanding why this led to the loss of the sunflower sea star is an important step in restoring this species and all the benefits that kelp forest ecosystems offer,” said Jono Wilson, director of the Department of Marine Science at the California chapter of the nature reserve who was involved in the study, in a statement.
Source link
