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Once inhabited sea stars disappear due to hot water and disease



VANCOUVER – Hot water and infectious diseases have been identified as causes of extinction of sunflower starfish along the Pacific coast, says a recent study.

Sunflower sea stars are among the largest stars in the world and come in different light colors, including purple and orange. Some of them grow to more than one meter and are so fast that "literally cross the sea landscape," says Joseph Gaydos, senior author of the study.

"But when that illness happens, it's like a zombie apocalypse," said Gaydos, who is from the SeaDoc Society of the University of California, Davis.

"It can have 24 hands and suddenly walk and hands just fall. Then suddenly the whole body just dissolves. "

So what once was a "big, beautiful sea star," rough about five pounds, resembles a pile of calcified parts within a few days, he said.

"It's a really ugly and quick disease for these sunflower sea stars."

In 2013, scientists began to notice that species populations dropped between 80 and 100 percent in deep and shallow waters from Alaska and British Columbia to California. Population information was gathered by divers and deep brakes.

Sunflower sea stars are found in waters of hundreds of meters to just three meters.

Diego Montecino-Latorre, co-author of the study, and also from the University of California, Davis, said scientists found a connection between increased water temperature and smaller marine stars.

Gaydos said the water temperature increase was not the same in all areas.

Oceans are not like "dropping" with consistent temperature, he said, adding that in some places in California there was a rise of about 4 ° C, while in Washington, a rise of 2.5 ° C.

One of the theories suggested by scientists is that rising temperatures make sea stars more susceptible to a disease already present, especially because sea stars do not have a complex immune system, he said.

Co-author of Drew Harvell, professor of ecology and evolutionary biology at Cornell University, said that the wave of hot in the oceans caused by global warming makes the sea star lose disease and swiftly kill the star.

Gaydos said the sunflowers of the sea star are devastating predators, and when the number of seaweeds decreases, they may increase.

Such outbreaks of illness can have big consequences on the entire ecosystem, he said.

"Urchins can melt the kelpa forests and then when you lose sea algae lose biodiversity," he said. "Kelp is the place where fish can hide, seaweed is food for other animals."

Beds with malt have already been tortured, he added.

"Kelp also does not go well when ocean temperatures increase, so it's like one or two holes for seaweed."

One of the chapel options is selective seafood harvesting, which is tested in California, Gaydos said.

And the ability to help the sun starfish starfish population is breeding in captivity where animals that are more resistant to the virus can be selected.

Gaydos said it was extinction calling for awakening.

"It's hard to keep track of what's going on in the ocean, but we have to pay attention because it happened in a very short time," he said. "That the whole species is almost gone, that's not good."


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