The National Science Foundation recently released an audio slideshow which highlights a research group from the Bodega Marine Laboratory studying the effects of ocean acidification on Olympia oysters collected from Tomales Bay, California. Watch the slideshow below, or read the NSF press release.
Posts Tagged ‘ocean acidification’
The gravity of the situation regarding Ocean Acidification, and the need to raise public awareness on this topic cannot be overstated. New results continue to be released showing that the consequences of Ocean Acidification are likely to be more pervasive and significant than previously predicted due to interactions among several potential contributing factors. This important paper shows astonishing model predictions of ocean pH that have tremendous implications for shell-building organisms such as shellfish and coral, and consequently on marine life and humans alike. We again wish to express our gratitude to the editorial staff at Oceanography for allowing us to reprint the following article.
Ocean Acidification: Present Conditions and Future Changes in a High-CO2 World
By Richard A. Feely, Scott C. Doney, and Sarah R. Cooley
Special Issue Feature from: Oceanography, Vol.22, No.4 (December 2009)
The uptake of anthropogenic CO2 by the global ocean induces fundamental changes in seawater chemistry that could have dramatic impacts on biological ecosystems in the upper ocean. Estimates based on the Intergovernmental Panel on Climate Change (IPCC) business-as-usual emission scenarios suggest that atmospheric CO2 levels could approach 800 ppm near the end of the century. Corresponding biogeochemical models for the ocean indicate that surface water pH will drop from a pre-industrial value of about 8.2 to about 7.8 in the IPCC A2 scenario by the end of this century, increasing the ocean’s acidity by about 150% relative to the beginning of the industrial era. In contemporary ocean water, elevated CO2 will also cause substantial reductions in surface water carbonate ion concentrations, in terms of either absolute changes or fractional changes relative to pre-industrial levels. For most open-ocean surface waters, aragonite undersaturation occurs when carbonate ion concentrations drop below approximately 66 micromoles per kilogram. The model projections indicate that aragonite undersaturation will start to occur by about 2020 in the Arctic Ocean and 2050 in the Southern Ocean. By 2050, all of the Arctic will be undersaturated with respect to aragonite, and by 2095, all of the Southern Ocean and parts of the North Pacific will be undersaturated. For calcite, undersaturation occurs when carbonate ion concentration drops below 42 micromoles per kilogram. By 2095, most of the Arctic and some parts of the Bering and Chukchi seas will be undersaturated with respect to calcite. However, in most of the other ocean basins, the surface waters will still be saturated with respect to calcite, but at a level greatly reduced from the present.
Click on the below image to view the full text PDF:
Ocean Acidification is an important ocean health topic about which there was little public awareness as recently as a few years ago. Its potential impact on seawater chemistry and corresponding consequences on marine biodiversity is significant and far-reaching, and as such it is a focus area in the educational resources developed for this project. Recently, the journal Oceanography, devoted an entire issue to this critical topic, and they have generously given us permission to reprint the following article summarizing recent advances in this area.
Ocean Acidification: A Critical Emerging Problem for the Ocean Sciences
By Scott C. Doney, William M. Balch, Victoria J. Fabry, and Richard A. Feely
Special Issue Feature from: Oceanography, Vol.22, No.4 (December 2009)
Over a period of less than a decade, ocean acidification—the change in seawater chemistry due to rising atmospheric carbon dioxide (CO2) levels and subsequent impacts on marine life—has become one of the most critical and pressing issues facing the ocean research community and marine resource managers alike. The objective of this special issue of Oceanography is to provide an overview of the current scientific understanding of ocean acidification as well as to indicate the substantial gaps in our present knowledge. Papers in the special issue discuss the past, current, and future trends in seawater chemistry; highlight potential vulnerabilities to marine species, ecosystems, and marine resources to elevated CO2; and outline a roadmap toward future research directions. In this introductory article, we present a brief introduction on ocean acidification and some historical context for how it emerged so quickly and recently as a key research topic.
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January 9, 2010 – At Sea, 48º 57’S, 057º 51’W
By Herb McCormick
Late this morning, as Ocean Watch continued to gobble up the miles toward our next port of call – Port Stanley, Falkland Islands – at a prodigious rate of speed, my watch mate, Dave Logan, tilted his nose toward the sky and said, “I smell dirt.” It looked like fun: I tried it too. No, I couldn’t catch a whiff of anything (and have my doubts about Logan), but the sky did have a haze of sorts that we hadn’t detected earlier on this mostly glorious run from Mar del Plata, Argentina. Logan dove below to grab an instrument we have aboard called a Microtops Sun Photometer. We’d heard that the after effects of a dust storm in Patagonia might be drifting our way, and on behalf of scientists a half a world away, we were poised to help discover if the rumor was true.
The Around the Americas expedition has always aimed to be a voyage of discovery, and a large part of that mission has been to carry forth not only scientists themselves, but also recording instruments and data-collection tools to help other scientists conduct research and experiments from their landlocked labs and classrooms in institutions across the United States. In fact, in several different iterations, it happens onboard ever day. But today, as Ocean Watch closed to within a day of the Falklands, a couple of interesting things were going on that helps cast a light on how our offshore journeys aid shore-side science.
Yesterday, oceanographer Michael Reynolds – our longest standing onboard scientist, currently taking a break to work back home in Seattle – forwarded an email from a NASA scientist, Dr. Santiago Gasso, who specializes in atmospheric aerosols and is based in Greenbelt, Maryland. Here’s a portion of Dr. Grasso’s note:
“I’ve been in contact with you before regarding my interest in dust storms in Argentina and how they advect to the ocean. So, I want to let you know that a moderate dust storm is occurring right now between the cities of Bahia Blanca and Viedma (41º S)…and there is also dust activity in the coastal city of Comodor Rivadavia (46º S). There is strong wind from the W too.
“The dust cloud should advect SE towards the general area where you are located. Since I know you have a Microtops sun photometer, you may be aware of probably increases in aerosol optical depth in the next 24-48 hours. I do not expect you to see much dust (with the) naked eye; if you do I would appreciate if you could take some photographs. I heard from local fishermen that they have seen abundant dust deposited over the water, so…proof of it would be very helpful. It would greatly help to compare with the satellite.
“Also, I’ve been watching the area from space every day and right N of the Malvinas (Falkland) Islands, there is a huge bloom of coccolithophores and it would be great if you describe it and maybe take some pictures.”
Okay, a few things are going on here. Let’s start with the aerosols and dust.
A story from www.sciencemag.org describes succinctly what we mean by aerosols: “Human activities are releasing tiny particles (aerosols) into the stratosphere. These human-made aerosols enhance scattering and absorption of solar radiation. They also produce brighter clouds that are less efficient at releasing precipitation.
“These in turn lead to large reductions in the amount of solar irradiance reaching Earth’s surface, a corresponding increase in solar heating of the atmosphere, changes in the atmospheric temperature structure, suppression of rainfall, and less efficient removal of pollutants. These aerosol effects can lead to a weaker hydrological cycle, which connects directly to availability and quality of fresh water, a major environmental issue of the 21st century.”
Dr. Gasso has specialized in dust observation in the Patagonia region and the study of the long-range transport from there into the Southern Ocean and Antarctica. “Detection of dust in this area is very difficult because dust tends to be mixed with clouds and the satellite algorithms get confused in such scenes and dust detection in this area is poorly characterized,” he writes. Readings from devices like the Sun Photometer, then, can be highly useful.
Both photographer David Thoreson and Logan spent the morning recording data. The unit itself is tricky to master, particularly on the rolling deck of a sailboat. The very general idea is to point the device skyward and pinpoint the sun in the bulls-eye of the target; it’s not unlike the old hand game where you roll little stainless-steel balls into divots in a plastic-encased toy. As Logan squinted and gave the photometer a little body English, I mentioned that kids weaned on PlayStation might be pretty good at it.
“The skills gained in video-gamesmanship could certainly apply to this scientific instrument,” he said. I was sorry I’d brought it up.
While Logan shot the sun, our current onboard scientist, Dr. Warren Buck, took cloud observations and photographs for our ongoing NASA S’COOL program. Meanwhile, our 360º Ladybug camera, erected on the aft antenna arch, continued to collect and download the tens of thousands of images it records every day.
“This might be one of the really key times for the Ladybug,” noted Michael Reynolds. And that brings us to the cocolitophore bloom.
We’d been noticing as we’ve traveled south that the water’s color has been changing constantly, and dramatically, and today was a beautiful greenish blue. We’ve also seen occasional milky patches, and the bird sightings have been off the charts. We’ve also been noting some very strange surface-water readings on our fishfinder/depthsounder. Do any or all of the above have anything to do with this algae bloom? Frankly, we’re not sure. We’ve just sent Dr. Reynolds a long list of questions of our own. But here’s what we do know, courtesy of an article sent along by the good doctor:
“Coccolithophores are single-celled algae (plankton) distinguished by special calcium carbonate plates (or scales) of uncertain function. They’re almost exclusively marine and are found globally in large numbers throughout the oceanic surface waters, the euphotic (good sunlight) zone of the ocean.”
As plants, they need sunlight for photosynthesis, and thus live near the surface.
“Coccolithophores have long been thought to respond to increased ocean acidity, caused by increasing CO2 levels, by becoming less calcified,” the article continues. “Scientists were recently surprised to learn that in fact the opposite can happen in at least some circumstances, with the model species E. huxleyi becoming 40% heavier and more abundant in waters of CO2 concentration.”
See the attached NASA image showing the common locations of coccolithophore blooms.
Ocean acidification is clearly a major threat to our seas, and it appears coccolithophores may be an important link in our chain of knowledge. The ongoing education of the crew of Ocean Watch, obviously, continues. We’ve certainly learned a lot on our travels Around the Americas. Along the way, we’ve been honored and privileged to perhaps help our partners in science learn a few things, too.
- Herb McCormick with photographs by David Thoreson
June 19, 2009 – Gulf of Alaska, 55 32N, 132 46W
by David Thoreson
Ocean Watch has “port” and “starboard” watches as we make our longer passages. Mark, Andy, and I make up the port watch. Dave, Herb, and Michael comprise the starboard. The watch discussions can range from the fascinating, to mundane, to not speaking at all. During a passage it is common to not see much of the other watch team and head directly to the bunk for some zzz’s when you can get them.
At 0200 this morning, Capt. Schrader lead a myopic discussion on the best-tasting Jolly Rancher candies with his blurry-eyed mates. Sometimes there is just not much to say and silence (except for the iron horse) is deafening. Throw in a confused, sloppy sea and a few hours on watch can be endless.
The 0600 watch proved the opposite. After a few grunts to and from the port watch, I fell upon a conversation Michael and Mark were having at the nav/work station. Michael had a map pulled up showing the distribution of carbon “sinks” and “sources” in the oceans and seas around the planet. Michael explained how northern, colder waters absorb more carbon from the atmosphere because of an “upwelling” of carbon low water in these regions. Atmospheric carbon flows into the “sink.” The absorbed carbon is then contained near the surface. A chemical process ensues forming carbonic acid measured in pH.
The northern Pacific extending into the Gulf of Alaska is one of the areas where carbon is absorbed at a higher rate than the world average. Ocean Watch is sailing through this area currently. Part of the equipment we have on board for monitoring is manufactured by SeaKeepers International, a non-profit organization based in Miami. Ocean Watch has a SeaKeepers pumping system that captures water into a reservoir where sensors can measure and output the data. We are believed to be the first sailboat equipped which this collection system.
A color display shows the real-time data being collected 24/7. This data is comprised of ocean salinity, turbidity, temperature and PH, amongst other more arcane measurements. pH is the measurement of interest for ocean acidity. We are currently seeing pH readings in the 7.85 range. But really, what does that mean?
OK folks, for all of us non-scientists, let’s do a quick course. How about, “pH for Dummies.” Michael assures me anyone with a hot tub will already understand. On a scale of 1-14 with 7 being neutral, the oceans have an average pH of 8.1, or slightly “basic.” An over abundance of carbon in the ocean creates carbonic acid, the driving mechanism behind ocean acidification, and lowers the number. The seas and oceans simply cannot absorb what we are putting in. Ocean ecosystems have a very fine tolerance to a lower pH and the world’s coral reef systems, with their calcium-based structures, are being ravaged by these changes.
Yesterday Herb reported quite eloquently about the reading aboard Ocean Watch and his current read which involves ocean acidification, coral reefs, and the interactive elements comprising the complex model of climate change. Ocean acidification is one of the major concerns and emphasis of education and outreach as we travel around the Americas.
Life aboard Ocean Watch is like no other voyage I have had. It is challenging in countless ways. We have a great team of quick-witted mates that are sometimes hard to keep up with. Storytelling is a wonderful gift and the experience of this crew provides no shortage of tales. Mark was musing during the wee hours that there is no “story-telling” channel amongst all the other gibberish on TV. Seems a lost art, but maybe he is on to something.
Sometimes the mundane watches lead to a spark of ideas that trigger the bigger picture of the Ocean Watch voyage. As we look now to the north and the ice, it is good to be reminded of the precious waters we are currently sailing, and how they, in turn, relate to other waters and weather cycles that drive the planet on which we live.
-David Thoreson – story and photos
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