There, the die-off had a clear ecological trickle-down effect, called a trophic cascade by biologists. After the sea stars died, populations of their favorite prey, green sea urchins, quadrupled. The urchins quickly gobbled up kelp, reducing by 80 percent. Undersea kelp forests are critical to near-shore ocean ecosystems, providing cover and food for many marine species.
Study shows how changing ocean chemistry slows life cycle
Ocean acidification could take a bite out of the economically important Dungeness crab fishery along the Pacific Northwest coast. As the oceans absorb more CO2 from the atmosphere, the increasingly corrosive water is likely slow development and reduce survival of the crab’s larval stages, according to new research by the NOAA Fisheries Northwest Fisheries Science Center in Seattle.
Ocean acidification is one of the most serious effects of increasing CO2 emissions from fossil fuel combustion. Based on what we know about emissions trends, the average pH of surface waters off the Pacific Northwest Coast is expected to drop to about 7.8, and even more when periodic upwelling carries deep water to the surface. Acidification has already been found to slow coral growth, impair shark feeding, and speed the spread of invasive species, among other impacts.
The study, recently published in the journal Marine Biology, shows that the crab larvae hatched at the same rate regardless of pH, but those that hatched at lower levels showed signs of slowed development. The researchers suggested that the lower pH may reduce the metabolic rate of embryos. That could extend their vulnerable larval period, or could jeopardize the timing of their development in relation to key food sources, the scientists said. Continue reading “Ocean acidification puts Dungeness crab fishery at risk”→
New study shows how to help recover endangered loggerheads
Nobody likes a dirty bedroom and sea turtles are no exception.
New research by scientists at the University of Florida shows that removing beach debris helps sea turtle nesting. At cleared beaches, the number of nests rose by as much as 200 percent, the study shows, while leaving the detritus decreased the number by nearly 50 percent.
With many sea turtle species classified as endangered or threatened, restoring nesting habitat is critical to keeping them alive, said Ikuko Fujisaki, the study’s lead author and an assistant research professor of wildlife ecology and conservation with the UF Institute of Food and Agricultural Sciences. Continue reading “Debris-free beaches aid sea turtle nesting”→
New survey results show as few as 60 remaining vaquita porpoises in the Gulf of California
The population of vaquita porpoises in the Gulf of California may be down to just 60 individuals, according to conservation advocates, who released the results of recent surveys in a press release last week.
New research offers clues on global pollution pathways
Polluted dust from Asia is cutting oxygen levels in the tropical Pacific Ocean, researchers said this week, releasing a new study that traces a chain reaction that starts with land-based industrial pollution in China and other Asian countries.
“There’s a growing awareness that oxygen levels in the ocean may be changing over time,” said Taka Ito, an associate professor at Georgia Tech’s School of Earth and Atmospheric Sciences. “One reason for that is the warming environment – warm water holds less gas. But in the tropical Pacific, the oxygen level has been falling at a much faster rate than the temperature change can explain,” Ito said.
Study shows ocean dynamics mixing microplastics deep into the water column
There’s no question that plastics pollution in the world’s oceans is a serious and growing problem. One recent study estimated that somewhere between 5 million and 13 million metric tons of plastic waste were dumped into the ocean in 2010 alone, for the sake of comparison, one metric ton is 2,200 pounds, about the weight of a small car.
Other studies focusing on the impacts of all the debris show that plastic poses a risk to sea turtles,crabs and seabirds, while research voyages have shown that the tiny microparticles are to be found nearly everywhere, including the Arctic.
And new research released in April suggests that most estimates of plastics pollution in the ocean may be far too low, because most attention has been focused on measuring the debris floating near the surface. But ocean turbulence may be mixing the plastic much deeper, beyond the reach of the surface sampling, according to University of Delaware physical oceanographer Tobias Kukulka. Continue reading “There’s more plastic debris in the oceans than we think”→