The Associated Press: US scientist: Ocean acidity major threat to reefs I had always thought dissolved CO{2} quickly became fixed either by photosynthesis into sugars and carbohydrates or calcium carbonates. Compared to the acid-rain we had three decades ago, this one is new to me. Any details or open papers? Bob Wilson
Plenty of detail, and nearly all papers are open, one way or another. Sulfur/nitrogen acid deposition is primarily a regional matter. Emitted somewhere, rained out within a week. CO2 emissions go global , and have reduced the ocean pH from 8.2 to 8.1 in (about) 2 or 3 decades. If CO2 emissions stay on the fast track, futher 0.3 or 0.4 pH in 21st century seems probable. The Doney et al 2009 in Annual Reviews of Marine Sciences is probably the place to start. Has been cited by 404 since according to google scholar. The only two papers that I've noticed very recently, were on the 'good news' side. Corals appear to very quite a lot in their carbonate chemistry sensitivity, suggesting both winners and losers. Fishes' otoliths (they have rocks in their heads just like us ) seemed quite sensitive to acidification, however, if you gradually reduce pH over fish generations, the offspring manage to adapt. In some way that is not yet understood. I enjoyed the latter experiment because it was 'done in the way that ecological experiments should be'. An inspiration for us all. At the century scale, this is but one factor interacting with 'ag fertilizers -> river export -> coastal dead zones' and the general depletion of commercial fisheries stocks. If nothing else, we need the ocean to continue to be a human protein supplier. This could be tricky and as usual the modeling is neither thorough nor convincing to all audiences. At the much longer scale, the paleo proxies indicate that the oceans have stood at substantially lower pH. Yet somehow we have coral reefs and fish and krill and so forth, so resilience/recovery over long timescales can scarecely be doubted. Krill? huh?? Depending on your choice of numbers the top 3 species on earth in terms of biomass are 1. Cows 2. Antarctic krill Euphasia superba 3. Humans and nothing else comes really close. Hmmm. Krill being the exception, not brought to primacy by our 'unnatural' means. It seems peculiar to me, so if I did marine stuff, I'd probably look at pH effects on krill and their major food sources.
AKAICT Lubchenco was not talking about any new 'smoking gun' research. She was in a great place, was obliged to talk about something. Perhaps also to have a nice Great Barrier Reef trip (That's what I'd do, in Cairns). Perhaps just fleeing the current warmish weather of DC Perhaps you'll forgive my picking on her. She is a top-notch marine ecologist. I suppose that even Environmental Defenders deserve a day off from time to time; not just Presidential Candidates. There - a political dig. Now I'll be banned for sure. Please Danny please?
There was a related report on the new to it about oyster growers in Puget Sound, hIgher acidity is driving them out of business! Icarus
"Oceans' rising acid levels" is incorrect. Oceans may be becoming less alkaline ,but they arent about to become acidic. Also...As the Earth warms, oceans react to warming by releasing CO2 about 800 years later. How warmer water holds more CO2 ,while its also releasing more CO2 is a bit of a contradiction .
^Do you perhaps have some citation to back up that claim? Just incase:Ocean Becoming More Acidic, Potentially Threatening Marine Life Oceans acidifying at unprecedented speed - environment - 01 March 2012 - New Scientist
Its semantic. The oceans ph have decreased to 8.1 which is alkaline, and are not projected to become acidic (<7). The reduction in alkalinity is from increased acid, carbonic acid (H2CO3) from carbon dioxide in the air. Most good papers seem to say the coral reefs are in potential danger from the heat of climate change, not the acidity, but there are always those that seem to want to say its from the acid. When ever one of these comes out, another scientist seems to comes out with a coral is acid resistant study. Coral resilience to ocean acidification and global warming through pH up-regulation : Nature Climate Change : Nature Publishing Group
I agree that the acid/alkaline terminology causes public confusion. Not for the chemists, though. You can heap blame on them for not explaining the concepts better. So I'll try to explain one. As atmospheric CO2 rises, more dissolves in sea water. The temperature effect opposes this, but the temperature changes are small compared to the CO2 changes. So, acidification (which means reduction in pH) wins. No contradictions atoll. I thought I gave a recent reading assignment on that (durable) 800-year concept. Please let me know if I remember that wrong and I'll link to it.
Here is a meta-analysis, with all the good and bad that may be implied thereby: Vulnerability of marine biodiversity to ocean acidification: A meta-analysis I.E. Hendriks, C.M. Duarte, M. Alvarez Estuarine, Coastal and Shelf Science 86 (2010) 157–164 Relatively recent and free to download. It does not particularly support Austingreen's that thermal bleaching outweighs pH effects, which are balled up in the mysterious term 'aragonite saturation index'. My 'beef' with much coral research was alluded to in my #2 here. The timing of the experimental water-chemstry changes are done very quickly compared to real-world changes. I really don't see the cure, because decadal-scale experiments are rarely funded and not timed to inform the ongoing policy debate. So once again, we are a obliged to choose: trust the scientists, performing imperfect experiments, or trust to luck. It might be that oceans, under a 800-ppm CO2 atmosphere, will continue to provide the ecosystem services that we all know and love. Primarily, trapping carbon and feeding us with fish. Feeling lucky?
It may be the prejudice of a diver observing the effects. NOAA’s global coral bleaching prediction and monitoring get major upgrades Since I have seen bleaching related to temperature, and recovery even as ph falls, I've got to ask for strong evidence to over come my observations and NOAAs predictive model. My second area of prejudice, is running, training my body to function with more acidic (though still alkaline) blood. So when I read this in the meta-analysis, I may be more likely to discount those studies showing potential ph damage, compared to those that do not. Even if the reefs adapt to the slow lowering of ph, we do have greater chance of reefs dying under warmer water temperatures.
AustinG adds reference to the McCulloch, which was one of the 2 papers I had in mind in #2, as good news. Quoting further from the abstract would have got us to the 'winners and losers' part, but not a big deal because it is free online. Here, for corals, there still might be concerns that the metabolic magic some are doing would persist. But if decadal-scale experiments are off the table, we are just going to have to go with it. Detecting some degree of interest in this topic here I'll offer a couple more, related to the big dogs of marine carbon sequestration, the coccolithophores. www.biogeosciences.net/6/2121/2009/ describes quite usefully how to set up your water chemistry, and using "R" to perform the (painful) chemical calculations. doi: 10.3354/meps07776 looks like a good overview of the state of the science, and indeed includes good news about two of the biggest of the big dogs. The coccolithophores are tiny and fast growing, so we can dispense with my earlier stated concerns about fast-change experiments on slow-growing corals. So get cracking with your seawater aquaria, PC scientists! It is interesting that so much is new in this field since IPCC AR4. Hoping that a lot of it gets into AR5.
Quite frankly the reefs are a comparitively minor issue in my limited knowledge. My worry is the increase release if CO2 as a result of increased acidity. Icarus
The acidity is the result of sequestration of the CO2 in the air. The oceans can not sequester as much as they warm up though, at least the physics of them can't. We don't know if the sea life will sequester more or less as they heat up, but most projections are less. Without coral sea life diversity goes down, IMHO that's a bad thing.
AustinG, I hope that the AR5 authors are smarter than both of us! And delve into the literature much more than I have done here. Glad you mentioned blood also. It is actively regulated to an extremely narrow pH range. I hope you do not train yourself down to pH 7.3! There be dragons...
Icarus, the coccolithophores are sequestering marine carbonate, and then gracefully dying and sinking in out of the biosphere. 100 million years later, some reappears as volcanic CO2. And that, dear friends, is a Wilson cycle. Not named after our thread starter! Again, that article I referred to by DOI quoted research on apparently benign responses of two very important species. Just one more, then I really, really gotta go. DOI: 10.1073/pnas.0813291106 An overview writtten at the layman's level. Sort of.
I'm sure they will. I just hope that we don't have bleaching events like '98 for them to study for a while. I hit 7.31 in the lab,but a doctor wasn't available, so I couldn't go all out. I'm sure I've gone lower in races. I have a friend that didn't get a professorship, so has been doing reasearch in isreal this year. She posted that she still must be conditioned from texas, because she went running at at 33C (about 91 F) and remarked to her friends how cool the night was. They looked at her like she was crazy.
