Oceans: West Coast oysters facing multiple threats

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Oysters face an uncertain future.

Climate change makes young oysters more vulnerable to invasive snails

By Summit Voice

FRISCO — West Coast oysters could be facing a double whammy of global warming and invasive snails, according researchers with University of California, Davis’ Bodega Marine Laboratory.

Lab tests suggests that, as oceans become more acidic from the buildup of carbon dioxide in the atmosphere, oysters will be smaller, and invasive snails will take a bigger toll.

Specifically, invasive snails ate 20 percent more juvenile oysters when both species were raised under ocean conditions forecast for the end of this century The results highlight the dangers of multiple stressors on ecosystems, said Eric Sanford, professor of evolution and ecology at UC Davis and first author on the study. Continue reading

Study tracks natural variability of ocean acidity

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Ocean acidification will have impacts on most life in the coastal zone. bberwyn photo.

‘For vulnerable coastal marine ecosystems, this may be adding insult to injury …’

By Summit Voice

FRISCO — In addition to the long-term threat of ocean acidification resulting from increased atmospheric greenhouse gases, marine organisms also must deal with short-term spikes of increased acidity.

Those acute episodes are caused by a variety of natural factors, including temperature and algal activity, according to a new study led by researchers with Duke University, who took a close look at natural cycles of acidity in a North Carolina estuary.

“The natural short-term variability in acidity we observed over the course of one year exceeds 100-year global predictions for the ocean as a whole,” said  Zackary I. Johnson, a molecular biologists at Duke’s Nicholas School of the Environment. Continue reading

Global Warming: Some Arctic ocean organisms are unlikely to survive in increasingly acidic oceans

Some Arctic-dwelling copepods may not be able to survive increasingly acidic oceans.

Some Arctic-dwelling copepods may not be able to survive increasingly acidic oceans.

“Some marine animals may not be able to survive the impact of ocean acidification … ‘

By Bob Berwyn

FRISCO — Marine organisms with a limited natural habitat range will likely suffer the most as oceans become more acidic. Among the first to go may be tiny copepods in the Arctic Ocean living just beneath the surface. The crustaceans are a critical part of the ocean food web, helping to sustain many other animals.

“Our study found that some marine animals may not be able to survive the impact of ocean acidification, particularly the early-life stages,” said Dr, Ceri Lewis, with the University of Exeter. “This unique insight into how marine life will respond to future changes in the oceans has implications that reach far beyond the Arctic regions.”

The recent findings on ocean acidification impacts came from a research expedition conducted as part of the Catlin Arctic Survey. The study found that copepods that move large distances, migrating vertically across a wide range of pH conditions, have a better chance of surviving. Continue reading

Climate: Ocean acidification hard to swallow for some marine organisms

Research shows direct impact on sea urchin larvae

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Ocean acidification is affecting a wide range of marine organisms, from sea snails and oysters to clownfish and sea urchins. PHOTO COURTESY NICK HOBGOOD, VIA THE CREATIVE COMMONS.

By Summit Voice

*More Summit Voice coverage of ocean acidification is online here.

FRISCO — Sea urchins may be a canary in the coalmine for the impacts of ocean acidification, according to new research, which shows that the digestive function of the marine animals is impaired by acidified water.

About 25 percent of all the CO2 released into the atmosphere is absorbed by the oceans and converted to carbonic acid, making the water more acidic. Previous studies have showed that marine species and ecosystems can suffer in an acidified environment.

In one research project, scientists with the British Antarctic Survey showed how acidic water in the Southern Ocean is eating away at the shells of sea snails, and other research shows that the Arctic Ocean may be ground zero of acidification. Continue reading

Climate: Ocean acidification will have huge costs

Coral reef erosion is likely to outpace reef building this century

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The acidity of the world’s oceans could increase by 170 percent by the end of the century, as greenhouse gas emissions continue nearly unabated. bberwyn photo.

By Summit Voice

FRISCO — The legacy of historical fossil fuel emissions on ocean acidification will be felt for centuries, an international team of scientists concluded in a new report, warning that the world needs to prepare for major losses of ecosystem services.

If carbon dioxide emissions continue on their current trajectory, the acidity of the world’s oceans may increase by around 170 percent by the end of the century, the report found. People who rely on the ocean’s ecosystem services — often in developing countries — are especially vulnerable.

“What we can now say with high levels of confidence about ocean acidification sends a clear message,” said Ulf Riebesell, of the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany. “Globally we have to be prepared for significant economic and ecosystem service losses. But we also know that reducing the rate of carbon dioxide emissions will slow acidification. That has to be the major message for the COP19 meeting.” Continue reading

Climate: Can a lawsuit stop ocean acidification?

Conservation group eyes Clean Water Act as tool in climate fight

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Sea shells will not fare well as oceans absorb CO2. bberwyn photo.

By Summit Voice

FRISCO — It’s not clear if anything — besides massive cuts in carbon dioxide emissions — can stop the acidification of oceans, but the Center for Biological Diversity would at least like to see the EPA try to water quality standards as a way to tackle the problem.

The conservation group last week filed a lawsuit against the EPA for failing to address ocean acidification that may already be killing oysters in Oregon and Washington and threatening a wide range of other sea life. The lawsuit challenges the EPA’s decision that seawaters in those two states meet water-quality standards meant to protect marine life despite disturbing increases in acidity. Continue reading

No corner of the ocean safe from global warming

Widespread impacts expected by the end of the century

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A rapidly melting glacier on Deception Island, near Antarctica, pours fresh water into the ocean. bberwyn photo.

By Summit Voice

FRISCO — A warming climate will fundamentally change nearly all the world’s oceans by the end of the century, researchers warned this week. In addition to oft-discussed impacts of warmer water temperatures and ocean acidification, climate change will also deplete dissolved oxygen and lower the overall productivity of marine ecosystems.

“When you look at the world ocean, there are few places that will be free of changes; most will suffer the simultaneous effects of warming, acidification, and reductions in oxygen and productivity,” said lead author Camilo Mora, assistant professor at the Department of Geography in the College of Social Sciences at the University of Hawai’i at Manoa.

The study described the full chain of events by which ocean biogeochemical changes triggered by manmade greenhouse gas emissions may cascade through marine habitats and organisms, penetrating to the deep ocean and eventually influencing humans. Continue reading

Feds see more threats to Caribbean corals

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Elkhorn corals in the Caribbean are feeling the heat of global warming. Photo courtesy NOAA.

Fisheries Service gets deadline for recovery plan under court settlement

By Summit Voice

FRISCO — Two key coral species around Florida need even more TLC than previously thought, according to the National Marine Fisheries Service, which wants to reclassify elkhorn and staghorn corals from “threatened” to the even more serious category of “endangered” because of their rapid decline.

The agency also agree to speed up finalization of a recovery plan under a court settlement that sets a 2014 deadline. These corals were protected under the Endangered Species Act in 2006 because of threats from global warming and ocean acidification but, before today’s settlement agreement, had still not received the legally required recovery plan needed to save them from extinction. Continue reading

Global warming: Tiniest plankton to thrive with increased CO2, upsetting ocean carbon cycle

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Evidence is growing that increasing levels of CO2 are going to have a fundamental impact on ocean plankton.

Changes likely to reduce oceans’ capacity to absorb carbon dioxide

By Summit Voice

FRISCO — In the great global warming experiment there will be winners and losers, and it looks like some of the tiniest plankton species will be among the winners — probably at the expense of larger species higher up the food chain.

Research off the coast of Svalbard, Norway in 2010 showed that the smallest plankton groups thrive at elevated carbon dioxide levels.

This could cause an imbalance in the food web as well as a decrease ocean CO2 uptake, an important regulator of global climate. The results of the study have been published in Biogeosciences, a journal of the European Geosciences Union. Continue reading

Climate: Researchers report startling rate of acidification in parts of the Arctic Ocean

‘Nowhere on Earth have we documented such large scale, rapid ocean acidification’

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Researchers with the NASA-funded ICESCAPE Mission explore freshwater melt ponds in the Arctic. Photo courtesy NASA Earth Observatory.

By Summit Voice

FRISCO — The steady decline of Arctic sea is speeding ocean acidification, researchers reported this week in PLoS One, describing their findings after extensive water sampling in the region.

“A remarkable 20 percent of the Canadian Basin has become more corrosive to carbonate minerals in an unprecedented short period of time. Nowhere on Earth have we documented such large scale, rapid ocean acidification,” said lead researcher and ocean acidification project chief, U.S. Geological Survey oceanographer Lisa Robbins.

The research showed that the rapid pace of sea ice decline may be contributing directly to increasing acidification by exposing more of the ocean to atmospheric carbon dioxide. The impacts are intensified further by the diluting effect of melting ice. The freshwater further lowers pH levels and reducing the concentrations of calcium and carbonate, which may impact the growth of organisms that many species rely on for food. Continue reading

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