Category: ocean acidification

Ocean acidification to hit key fisheries

Study projects 55 percent increase in acidity in next 50 years

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The world’s oceans are in big trouble. @bberwyn photo.

Staff Report

There’s no stopping ocean acidification without stopping CO2 emissions, and that’s bad news for many marine species, including Dungeness crabs, according to new new research published in the journal Global Change Biology.

Tiny shell-forming organisms like pteropods and copepods are vulnerable to acidification, but will likely experience only a slight overall decline because they are prolific enough to offset much of the impact, the study found. But those impacts will cascade through ocean ecosystems to affect larger animals like crabs, that will suffer as their food sources decline. Dungeness crab fisheries are valued at about $220 million annually, and may face a strong downturn over the next 50 years. Continue reading “Ocean acidification to hit key fisheries”

Signs of serious global warming impacts piled up in 2016

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2016 is on track to be the third year in a row with a record-warm average global temperature.

There wasn’t any relief from a wave of worrisome global warming news in the spring of 2016, including a study from Harvard showing how rising temperatures will send ozone levels surging to dangerous highs across parts of the U.S.

“In the coming decades, global climate change will likely cause more heat waves during the summer, which in turn could cause a 70 to 100 percent increase in ozone episodes, depending on the region,” said Lu Shen, first author and graduate student at Harvard’s John A. Paulson School of Engineering and Applied Sciences.

Even if the president-elect follows through on his threat to cut funding for Earth observation programs, there are other international science agencies that will continue to monitor climate change impacts, including the European Space Agency. In April, data from ESA ice-observing instruments showed that the meltdown of Antactic ice shelves may be irreversible at this point. The thick shelves of ice that sit at the edge of the continent act as breaks on inland glaciers. If the ice shelves vanish, it could mark a point of no return for Antarctica’s ice, the ESA reported. Continue reading “Signs of serious global warming impacts piled up in 2016”

Sea snails showing signs of global warming wear and tear

Study helps quantify ocean acidification impacts

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Scientists estimate that pteropod shell dissolution has increased 20 to 25 percent on average in waters along the U.S. West Coast due to CO2 emitted by humans.

Staff Report

By mapping CO2 emissions and comparing that information with data on CO levels in the ocean, scientists say they can now show to what degree the build-up of heat-trapping pollution contributes to the dissolving of shells of microscopic marine sea snails called pteropods.

Other studies from the Southern Hemisphere have reached similar conclusions. Pteropods are an important food for commercially valuable fish species like salmon, sablefish and rock sole.

“This is the first time we’ve been able to tease out the percentage of human-caused carbon dioxide from natural carbon dioxide along a large portion of the West Coast and link it directly to pteropod shell dissolution,” said Richard Feely, a NOAA senior scientist who led the research. Continue reading “Sea snails showing signs of global warming wear and tear”

The Paris climate agreement is now in force

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Can the world live up to the ambitions of the Paris climate agreement? @bberwyn photo.

Now the hard work begins …

Staff Report

As the Paris climate agreement goes into effect, it’s important to remember that, so far, there’s been a lot more talk than action by the global community. Plans are one thing, action is another, and unless there are significant cuts in greenhouse gas emissions in the next few years, there’s almost no chance to limit global warming to less than 2 degrees Celsius.

Here are some sobering facts to show why immediate action is needed, starting with the latest annual greenhouse gas bulletin from the World Meteorological Organization.

Carbon dioxide, methane and nitrous oxide all reached new record high concentrations in the atmosphere in 2015. According to the analysis, CO2 levels are not 144 percent higher than in pre-industrial times; methane is 256 percent higher, and nitrous oxide is 121 percent higher. It’s likely that CO2 concentrations, as measured at Mauna Loa, will stay above 400 parts per million for all of 2016. The increase of methane from 2014 to 2015 was larger than that observed from 2013 to 2014 and that averaged over the last decade. Continue reading “The Paris climate agreement is now in force”

New surveys confirm Great Barrier Reef damage

Heat-driven coral bleaching continues to take a toll

Staff Report

A new survey of the Great Barrier Reef shows that an ocean heat wave that peaked last March killed up to 95 percent of corals in some parts of the northern reef.  And in the aftermath of the worst coral-bleaching event on record, predatory snails are now taking on toll on the remaining corals.

According to the ARC Centre of Excellence for Coral Reef Studies, researchers recently returned to 83 reefs they surveyed at the height of the bleaching event.

“Millions of corals in the north of the Great Barrier Reef died quickly from heat stress in March and since then, many more have died more slowly,” said Dr. Greg Torda whose team recently returned from re-surveying reefs near Lizard Island. Continue reading “New surveys confirm Great Barrier Reef damage”

How long can the oceans soak up CO2?

What’s the tipping point?

Researchers examine ocean acidification rates

Staff Report

For now, the world’s oceans are sucking up so much carbon dioxide that it’s helping to slow the rate of global warming. But that’s expected to change in the future, researchers warned after taking a detailed look at the rate of ocean acidification in the northeast Pacific Ocean. Continue reading “How long can the oceans soak up CO2?”

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”