“This is the first study that demonstrates that larval crabs are already affected by ocean acidification in the natural environment, and builds on previous understanding of ocean acidification impacts on pteropods,” said lead author Nina Bednarsek, senior scientist with the Southern California Coastal Water Research Project. “If the crabs are affected already, we really need to make sure we start to pay much more attention to various components of the food chain before it is too late.”
The ocean absorbs carbon dioxide from the atmosphere, which reduces pH levels and concentrations of calcium carbonate, a mineral used by shellfish to calcify their shells. As more carbon is released into the atmosphere, concentrations of calcium carbonate decrease and the shells of organisms like foraminifera get thinner, a trend Osborne saw clearly in the sediment cores she examined.
“The shell thickness record instantly showed a long-term declining trend,” she said. “It was really obvious across entire record.”
As the amount of atmospheric carbon dioxide continues to rise, our oceans are playing an increasingly important role in absorbing some of this excess. In fact, it was reported recently that the global ocean annually draws down about a third… Read More ›
“We were alarmed to find that diatoms were so negatively affected, with some species likely to have diminished silica production before the end of this century,” says Dr Petrou.
Research published this week in the peer-reviewed journal Science analyzed more than 100,000 seawater samples worldwide collected from 1994 to 2007 and taken from nearly every corner and depth of ocean.
The analysis found the oceans are absorbing about 31 percent of the carbon humans are spewing into the world. For context, the weight of the carbon seeping into the ocean each year, on average for the period of study, is roughly equivalent to 2.6 billion Volkswagen Beetle cars, Feely said.
By Charmaine Coimbra Dominoes. It’s like 150 years of stacked dominoes collapsing in four directions from Rugby, North Dakota, North America’s geographical center and from every geographical center of every continent on Planet Earth—with the final dominos landing in every… Read More ›
“Across the United States, changes in our climate and our oceans are having very real and profound effects on communities, businesses, and the natural resources we depend on — including our economically valuable fisheries …” declared a NOAA Fisheries webpage updated in June. “Understanding these changes and measuring their impacts is an important part of NOAA Fisheries’ mission.”
As the Pacific Ocean acidifies—a consequence of carbon emissions—oyster farms off California, Washington State, and British Columbia have struggled to get larvae to grow into seed, the stage when young oysters’ shells have formed. Though scientists are not quite sure why, the water off Southeast Alaska hasn’t seen the same deleterious effects. Now, entrepreneurs and investors are eyeing the state, looking to turn a profit off the short-lived gains of climate change.
Another reason global warming has not been too bad yet is because the ocean absorbs most of the earth’s excess heat. But oceans are warming due to greenhouse gas emissions. According to the National Oceanic and Atmospheric Administration, half of the increase in ocean heat content since 1865 has occurred over the past two decades. Warmer water holds less oxygen, but the respiration rate of animals (except for marine mammals) increases with temperature, so they need more oxygen at the same time that less is available. A warmer ocean has less turnover (vertical water movements), which normally brings nutrient-rich water up from deep water to the plankton that photosynthesize near the surface. With fewer nutrients, they photosynthesize less and animals can’t get enough food.