Tag: ocean acidification

Climate: California mussel shells thinning as oceans acidify

A new study shows California mussel shells are getting thinner because of ocean acidification. @bberwyn photo.
A new study shows California mussel shells are getting thinner because of ocean acidification. @bberwyn photo.

Biologists create historic record of climate change impacts

Staff Report

The shells of California mussels have thinned dramatically in the modern era, probably as a result of ocean acidification, a direct result of increased carbon dioxide in the atmosphere resulting from fossil fuel combustion, say University of Chicago biologists who compared mussel specimens collected in the 1970s with present-day samples.

In the 70s, the shells were on average 32 percent thicker than modern specimens. Going back even farther, the researchers said shells collected by Native Americans 1,000 to 1,300 years ago were also 27 percent thicker than modern shells.

“Archival material provided by past researchers, the Makah Tribal Nation, and the Olympic National Park allowed us to document this intriguing and concerning pattern in shell thickness,” said Cathy Pfister, PhD, professor of ecology and evolution at the University of Chicago and lead author. The study was published June 15, 2016, in the Proceedings of the Royal Society B. Continue reading “Climate: California mussel shells thinning as oceans acidify”

Ocean acidification puts Dungeness crab fishery at risk

Study shows how changing ocean chemistry slows life cycle

Dungeness crab
Ocean acidification will slow the reproductive cycle of Dungeness crabs, according to a new study. Photo courtesy NOAA.

Staff Report

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”

Climate: UK public basically unaware of ocean acidification

oysters
Love oysters? Then you should be worried about ocean acidification. @bberwyn photo.

Marine life is at risk from CO2 emissions

Staff Report

The reality of global warming may be setting in for many people, but some of the more subtle and unseen impacts of climate change are not so easy to grasp.

A recent survey in the UK showed that only 20 percent of the population are aware of ocean acidification. Even fewer — just 14 percent — say they have a basic understanding of what that means, even though scientists have been reporting their findings on the topic for many years. Continue reading “Climate: UK public basically unaware of ocean acidification”

Scientists urge practical steps to combat ocean acidification

dg
The summer of 2015 saw an unprecedented bloom of algae along the West Coast. Photo courtesy NOAA.

Seeking resilience for coastal ecosystems

Staff Report

Scientists are urging resource managers along the West Coast of North America to start using adaptive strategies in the face of ocean acidification and hypoxia caused by global carbon dioxide emissions.

The report comes after a couple of years of record-warm ocean temperatures off the West Coast likely contributed to several unprecedented events, including a mass starfish die-off, a huge bloom of toxin-producing algae, a wave of sea lion pup mortality, and fin whale deaths near Alaska.

In general, scientists believe that warmer ocean temperatures will increase the prevalence of marine diseases, but there are steps that could help coastal communities meet the challenges of changing ocean chemistry, including better monitoring, and boosting natural ecosystems that can remove CO2 from water.

The 20-member panel of ocean experts said the West Coast is a hotspot for climate change impacts because of upwelling cold water that that transports nutrient-rich, low-oxygen and high carbon dioxide water from deep in the water column to the surface near the coast.

But all is not lost, the scientists said, explaining that governments in Oregon, California, Washington and British Columbia can take actions now to offset and mitigate the effects of these changes. Acting now is less expensive than waiting for the long-term impacts to play out, the panel concluded. Continue reading “Scientists urge practical steps to combat ocean acidification”

Study says ocean acidification has already slowed coral growth

A diverse coral reef in the U.S. Virgin Islands. PHOTO BY CAROLINE ROGERS/USGS.
A coral reef in the U.S. Virgin Islands. Photo by Caroline Rogers/USGS.

‘If we don’t take action … coral reefs will not survive into the next century’

Staff Report

The most dangerous effects of global warming may still be decades away, but ocean scientists say that the buildup of carbon dioxide is already slowing down the growth of coral reefs. By simulating ocean acidification on a section of the Great Barrier Reef, the researchers showed that excess C02 in the atmosphere is affecting coral reefs.

“Our work provides the first strong evidence from experiments on a natural ecosystem that ocean acidification is already causing reefs to grow more slowly than they did 100 years ago,” said study lead author Rebecca Albright, a marine biologist in Carnegie’s Department of Global Ecology in Stanford, Calif. “Ocean acidification is already taking its toll on coral reef communities. This is no longer a fear for the future; it is the reality of today.” Continue reading “Study says ocean acidification has already slowed coral growth”

CO2 could take huge toll on ocean fish by mid-century

kj
Can the world’s oceans survive the global warming era?

Not much time left to cut greenhouse gas pollution

Staff Report

Building levels of carbon dioxide in the atmosphere and oceans could have a widespread and devastating effect on many fish by 2050, Australian researchers warned in a new study.

“Our results were staggering and have massive implications for global fisheries and marine ecosystems across the planet,” said Dr. Ben McNeil, a researcher at the University of New South Wales Climate Change Research Centre. “High concentrations of carbon dioxide cause fish to become intoxicated … a phenomenon known as hypercapnia. Essentially, the fish become lost at sea. The carbon dioxide affects their brains and they lose their sense of direction and ability to find their way home. They don’t even know where their predators are,” McNeil said. Continue reading “CO2 could take huge toll on ocean fish by mid-century”

Scientists track unexpected oceanic plankton surge

Scientists working in the Gulf of Mexico are tracking BP's spilled oil as it works its way up the food web, from bacteria to plankton. PHOTO COURTESY NOAA.
Will plankton rule in a globally warming world? Photo via NOAA.

‘Something strange is happening here, and it’s happening much more quickly than we thought it should …’

Staff Report

Atmospheric carbon dioxide ending up in the world’s oceans may be fueling a population explosion of microscopic marine algae in the North Atlantic, scientists said in a new study that shows how greenhouse gases can drive dramatic ecosystem changes. Continue reading “Scientists track unexpected oceanic plankton surge”