A news stream provided by the Ocean Acidification International Coordination Centre (OA-ICC)
Credit: Flickr, Christian Gloor.
Human activity such as carbon emissions and pollution are threatening coral colonies across the globe. Some believe that at this rate, the world’s coral reefs will collapse within a couple of decades. But that’s assuming all coral are the same, which is not true. Some coral species are more resilient than others, and some — such as those growing in Hawaii’s Kāne’ohe Bay — are so tolerant to warm and acidic waters that scientists are calling them “supercorals”.
An egg mop of D. pealeii, found in shallow waters. Each egg capsule contains between 50-200 eggs. Ceridwen, (2009), geograph.org.uk. Bottom: An adult D. pealeii; the species is semelparous, meaning it only reproduces once before dying. It is a critical organism to the ecology of the North Atlantic Ocean. Clyde F.E. Roper, tolweb.org.
It’s approaching summertime in the northern hemsiphere. Dip beneath the waves rolling over the continental shelf of the northwestern Atlantic and you’ll notice something new along the sea floor in addition to sand and rocks: clusters of gelatinous tubes, forming something resembling mop heads. Upon closer inspection you’d find dozens of eggs within each tube or sac, and (depending on the stage of development) hundreds of eyes staring out into the blue. Meet the longfin inshore squid, Doryteuthis pealeii, as it gets ready to hatch from its anchored egg capsule and take its place, center stage, in the coastal habitat.
You may have never given squids much thought, beyond their suitability as a calamari appetizer, but these animals are tremendously important within the marine ecosystem. Not only are they food for us, they are tasty meals for other large marine organisms, as well as voracious predators of smaller prey. Because of this central role of squid in the environment, scientists have grown concerned over how environmental stressors will affect these species, especially throughout different life stages. Of particular concern has been stress induced by ocean acidification (OA).
Continue reading ‘Ocean acidification and baby “squidlife” crises?’
About 55 million years ago, Earth underwent a period of global warming known as the Paleocene-Eocene Thermal Maximum (PETM). Atmospheric carbon dioxide levels rose, temperatures climbed, and myriad seafloor organisms went extinct. Today, scientists study the PETM to gain insights into the potential effects of ongoing climate change. Still, several aspects of this ancient warming event remain mysterious.
In a new study, Ilyina and Heinze address a key PETM mystery: why ocean acidification appears to have occurred to a greater degree in the Atlantic than in the Pacific Ocean. Ocean acidification happens when carbon dioxide builds up in Earth’s atmosphere, forcing the oceans to absorb more of the greenhouse gas than usual. The resulting chemical reactions make seawater more acidic while also reducing the amount of carbonate ions available for building shells, corals, and other organic structures.
Continue reading ‘Explaining ocean acidification patterns during ancient warming’
The control site for the Japan research shows high biodiversity comprising tropical scleractinian corals and temperate macroalgae. (Credit: Ben Harvey)
Ocean acidification could have serious consequences for the millions of people globally whose lives depend on coastal protection, fisheries and aquaculture, a new publication suggests.
Writing in Emerging Topics in Life Sciences, scientists say that only significant cuts in fossil fuel emissions will prevent the changes already evident in areas with projected future carbon dioxide levels becoming more widespread.
They also call for a binding international agreement that builds on the United Nations Sustainable Development Goals to minimise and address the impacts of ocean acidification.
Continue reading ‘Ocean acidification ‘could have consequences for millions’’
Ocean acidification and warming may be an unhealthy combination for lobsters, say University of Maine scientists.
The heart rates of lobsters (Homarus americanus) who lived 60 days in water with predicted end-century ocean pH levels became erratic significantly sooner during an abrupt warming event than those of lobsters in ocean water with current pH levels.
The findings could be “likened to putting people on a treadmill and finding that people exposed to ocean acidification fell off the treadmill from exhaustion much sooner than those not exposed,” says Heather Hamlin, a reproductive endocrinologist and associate professor in the School of Marine Sciences.
This map shows how carbon dioxide from land flows out across Monterey Bay with morning land breezes. Base image: Google Earth
MBARI researchers recently measured high concentrations of carbon dioxide in air blowing out to sea from cities and agricultural areas, including Silicon Valley. In a new paper in PLOS ONE, they calculate that this previously undocumented process could increase the amount of carbon dioxide dissolving into coastal ocean waters by about 20 percent.
Extending their calculations to coastal areas around the world, the researchers estimate that this process could add 25 million additional tons of carbon dioxide to the ocean each year, which would account for roughly one percent of the ocean’s total annual carbon dioxide uptake. This effect is not currently included in calculations of how much carbon dioxide is entering the ocean because of the burning of fossil fuels.
Continue reading ‘Carbon dioxide from Silicon Valley affects the chemistry of Monterey Bay’
Dr. Emma Cross from the Baumann Lab just published her latest paper about brachiopod resilience to future ocean acidification in Environmental Science & Technology. The project involved long-term culturing of a polar and a temperate brachiopod under future ocean acidification and warming conditions during Emma’s PhD-research with the British Antarctic Survey. Substantial shell dissolution posed a threat to both species under ocean acidification, with more extensive dissolution occurring in the polar species.
Unexpectedly, however, the authors also discovered that brachiopods thicken their shell from the inner shell surface when extensive dissolution occurs at the outer shell surface under ocean acidification. This important finding furthers our understanding how predicted vulnerable marine calcifiers might cope under future environmental change.
Continue reading ‘DMS post-doctoral researcher Emma Cross publishes new brachiopod research’
