These sea stars have been almost swept away – but BC researchers say that Fiords provided refuge
BC researchers discovered that the fjords of the central coast could provide refuge for the Sunflower Star in danger of extinction, a discovery that could have implications for the wider ecosystems at risk due to the heating of the seas.
Nine in 10 marine stars have been swept away since 2013 due to a star of Sea Star star, which led to a mass death of animals along the western coast of North America, from Alaska to Mexico. The star of the sunflower sea is listed as in critical danger from the International Union for the conservation of nature.
While the exact cause of the disease is unknown, scientists say that it has had serious chain effects, since the stars of the sunflower sea eat sea urchins and play an important role in keeping those populations under control. Without them, the curls have flourished and were able to do it Eat alga forestswhich further destabilizes marine ecosystems.
Now, after years of diving along the central coast of BC, the researchers have found many healthy adult colonies of sunflower starfish in the fjords there.
Alyssa Gehman, scientist of the Hakai Institute and contract professor at the University of BC, Co-author of a document on the results. What they discovered, he said, is that while the disease that loses the starfish was found in the cornflowers and the starfish died there, the mortality rate is much lower than elsewhere in the ocean.
The researchers suspect that the difference has something to do with the water temperature. In the fjords – long, narrow and deep interiors often found between high cliffs along the central and northern coasts – the ocean tends to be fresher than elsewhere.
Gehman said that the research team was notified for the first time of the large number of sunflower starfish in Fiords by the divers of the indigenous resources of the Central Coast who were looking for a Rockfish – and the two groups ended up collaborating on the final research document.
“When we looked at the oceanography … we discovered that where stars are located, it is colder,” Gehman said to Darius Mahdavi, scientific specialist of the CBC. “This is our next thing, he is trying to understand exactly what the temperature relationship is and how it works.”
Changes in the seasons
Jeff Sha, a aquarium biologist in the Vancouver Aquarium who was not involved in the study, said that scientists have evidence that the star of the starfish has thrived in warmer water.
“The higher the temperature, the more likely it is that the beginning of the disease, the more difficult it is that an infected marine star would return from that,” he said.
“Since temperatures are increasing along our coasts … we had a a pair of heat domes In the last decade, each of these events was basically another lap of devastation for the population “.
Gehman said in the fjords, the Arctic outflow conditions create cold winds in the winters, cooling the water and making the environment higher in oxygen, which is good for starfish.
“In the summer, when it’s hot, there is a glacial outflow that arrives,” he said. “And it is so fascinating, but essentially creates a small fresh water river on the surface of the cornflower.”
Sha said that seafarers don’t like fresh water, which means that they will go deeper and in the colder water.
“The researchers are assuming that this is a bit of what gives them some refuge away from the hottest temperature area and keeping them healthy from the disease for waste,” he said.
Implications for recovery efforts
Sha said the stars of the sunflower sea, in particular, are a fierce predator for sea urchins – and without them, there have been devastating effects for other species.
“The populations of sea urchins are boom on our coast, causing a decline in our algae and our algae forest, which therefore removes habitats for rocky fish and all these beautiful animals we have,” said the biologist.
Over the past ten years, the disease has killed about five billion seaside stars of sunflower, interrupting the underwateries from the Alaska to California. Now, starfish are released in nature around the islands of San Juan in the state of Washington. They are the first of their kind to have been raised in captivity by researchers from the University of Washington. Jason Hosin, a marine biologist of the University of Washington, shares more about his research.
Gehman said that some algae forests along the BC coast have been reduced to “Barrens”, where all the leafy portions of the algae were consumed by sea urchins.
The scientist said that, while the researchers try to lift the stars of the sunflower sea in the laboratory and put them back in the ocean, their work in the cornstars could be important, although it has recognized that climate change will continue to influence the fact that the fjords can remain a “refuge habitat” for the species.
“The hope of being able to potentially raise stars that would be resistant to illness,” he said. “And this suggests that we must pay attention to the temperature even when we do that job.”
