On the condition of our planet - effects of people - how various systems are coping, or not....
Thursday, July 28, 2016
"Scientists Find Out What Killed Millions of Starfish"
"A new study shows warmer ocean temperatures are likely responsible for the mass die-off, threatening the biodiversity of marine life from Alaska to Mexico."
An epidemic swept across North America’s West Coast three years ago, but most people hardly noticed.
That’s because the disease targeted starfish—millions of starfish.
From Alaska to Baja California, starfish populations have been decimated by sea star wasting syndrome, a disease that turns the darlings of the tide pool world into heaping piles of goo within days of exposure.
Scientists have observed wasting events hitting coastal starfish populations before, but nothing like this epidemic, which researchers are calling the single largest, most geographically widespread marine disease ever recorded.
Sea stars, or starfish, are what’s known as a keystone species, important to maintaining biodiversity in marine environments. But an epidemic that swept across the West Coast killed millions of the multi-limbed animals—wiping out up to 95 percent of populations in some regions. Now, a new study is showing warming ocean temperatures might make mass die-offs more severe.
Without starfish to keep mussel populations in check, the sharp-shelled bivalves would push out other marine species, damaging the biodiversity of habitats along the West Coast.
The team analyzed water temperature records taken before, during, and after the wasting episode at locations around the San Juan Islands and Puget Sound in Washington state. They found that as water temperatures rose across the region, so did the risk of infection for sea stars. Sites where water temperatures rose the most left sea stars at highest risk of infection.
Researchers also placed sea stars in aquarium tanks set to temperatures ranging from 54 degrees to 66 degrees Fahrenheit. The hotter the tank, the more quickly starfish succumbed to wasting, Harvell said.
“That confirmed that water temperature can affect mortality,” she said.
With ocean temperatures steadily increasing thanks in part to human-induced climate change, the future of sea stars could be threatened.
The sheer size of this latest wasting event has scientists concerned. Melissa Miner, a marine biologist at the University of California, Santa Cruz, said sea star populations are still decimated across nearly all of the West Coast...
On a walk amid tide pools in Newport Beach’s Crystal Cove State Park last week, this reporter did not spot a single starfish. In October 2014, scientists found 191 starfishalong the same rocky reef. Now, there appeared to be an abundance of mussels lining the rocks—the ochre starfish’s favorite meal.
This blog has become a place where I post articles that I find related to global warming - causes and effects, as well as a few other topics - related or not.
Jellyfish are like poster-boys of global warming changes - jellyfish are one species of animal that are doing very well. The increased acidity of the oceans, warmer waters, the decrease in predators as fish and other wildlife decline have all favored jellyfish. They seem to thrive on the fertilizers that people have been washing into the seas. Most animals do not.
I also like to post discoveries - especially discoveries that are being made out in space as people are able to see farther and farther galaxies and nebulas and supernovas. Even though I don't think that people will ever go live any of those places - I just like knowing that they are out there. It's part of keeping in mind that the earth and it's inhabitants are such a small part of what is going on in the universe.
I have another blog with posts on art and artists - it's called M'S IMPRESSIONS.