Category: ocean acidification

Ocean acidification seen as huge threat to Atlantic cod

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Climate change to put a big hit on cod stocks.

Fish larvae seen as highly sensitive to CO2

Staff Report

New lab experiments suggest that increasing ocean acidification could take a big bite out of the economically important cod fishery in the North Atlantic. The research suggests that the buildup of CO2 in the ocean could double the mortality of newly-hatched cod larvae.

Members of the German research network BIOACID quantified the impacts, showing that recruitment could decrease to levels of one quarter to one twelfth of the recruitment of the last decades. Cod have already been under intense fishing pressure for decades, and the new study, published in the online journal PLOS ONE, identifies climate change as an emerging new threat. Continue reading “Ocean acidification seen as huge threat to Atlantic cod”

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”

Scientists urge practical steps to combat ocean acidification

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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”

Annual atmospheric CO2 increase the biggest on record

Far, far away from 350 ppm …

Atmospheric carbon dioxide in February 2016 measured at Mauna Loa.
Atmospheric carbon dioxide in February 2016 measured at Mauna Loa.

Staff Report

The goal of limiting atmospheric carbon dioxide to 350 parts per million — considered the environmentally “safe” level, just moved a little farther away. Scientists tracking concentrations of the heat-trapping pollutant at a mountaintop lab in Hawaii said last week that CO2 concentrations jumped by the largest annual amount recorded since measurements began 56 years ago.

The reading comes from NOAA’s Mauna Loa Observatory, and researchers said the latest increase was the fourth year in a row that CO2 concentrations grew by more than 2 parts per million, according to a press release from NOAA.

“Carbon dioxide levels are increasing faster than they have in hundreds of thousands of years,” said Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network. “It’s explosive compared to natural processes.” Continue reading “Annual atmospheric CO2 increase the biggest on record”

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”

Global warming: Goodbye to sea scallops?

A northward shift of the Gulf Stream could warm waters off the New England coast significantly, according to a new NOAA study. Graphic courtesy NASA.
Rapidly warming ocean temperatures off the New England coast are affecting many marine species. Graphic courtesy NASA.

New vulnerability assessment to help guide fisheries management

Staff Report

Rapidly warming ocean temperatures off the coast of the Northeastern U.S. are likely to have a big impact on nearly all fish and other marine life in the region. Scientists with the National Oceanic and Atmospheric Administration carefully surveyed 82 species in a recent study, trying to identify which are the most vulnerable to global warming.

“Our method identifies specific attributes that influence marine fish and invertebrate resilience to the effects of a warming ocean and characterizes risks posed to individual species,” said Jon Hare, a fisheries oceanographer at NOAA Fisheries’ Northeast Fisheries Science Center (NEFSC) and lead author of the study. “This work will help us better account for the effects of warming waters on our fishery species in stock assessments and when developing fishery management measures.” Continue reading “Global warming: Goodbye to sea scallops?”