offcourse, but it depends on the intensity of acidity of oceans

Though it has been predicted that by the year 2100, the acidification of ocean would pose serious threat to marine life and may be we are not able to see some of the magnificent organisms but I am wondering that may be its not the individual taxa that adapt and survive but definitely the communities would definitely evolve in the context of changes in diversity and dominance of variety of taxa living in the ocean.

It's indeed a good question!!!

From what I have seen, the rate of coastal ocean acidification is quick (in natural time scales), while on a large scale it moves at a slower pace. When bodies of water are connected to others around them, organisms instead of adapting to the acidity tend to migrate to the waters facing less acidification. This causes an imbalance in the localized food chain, leading finally to the death of those organisms that could not migrate from the region (mainly the plankton). These then sink and decompose, consuming what oxygen is in the water for the decomposition, further increasing the acidification in the region.

Well that depends on the rate at which seawater is acidifying. There are reports demonstrating that some marine organisms (including some foraminifera, sea urchins, algae) can survive in laboratory conditions simulating the one expected to be caused by ocean acidification. Moreover, the bulk of the reports that explained the harmful effects of seawater acidification on marine species, have focused on the impacts of future conditions on present populations, overlooking the potential effects of adaptation and acclimatization (e.g. physiological, behavioral). So there is no proper answer to this issue as of now.

Some literature:

1. http://planetearth.nerc.ac.uk/news/story.aspx?id=1421

2. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2435.2012.02061.x/abstract

3. http://www.newscientist.com/article/dn23358-sea-urchins-evolving-to-cope-with-ocean-acidification.html

It is true that there is great uncertainity about the response of marine communities with the increasing acidity over a period of time but while reading the above links, one can find some interesting insights into the relation between genetic variablity and adaptability/evolution. So, some organisms do survive those conditions because there might have accumulated great variability in their genetic material through time and thus they have more survival chance in adverse condition as in case of purple sea urchins. In one article it is well emphasized that "the changes are the result of natural selection" (Pespeni)" thus reminding of great Darwinian principles.

The literature cited above is really great!!!

As is generally the case with anthropogenic disturbances to ecosystems, ocean acidification will have winners and losers: some populations of marine organisms will adapt, while others will go extinct. A recent study by Parker et al. (2012) provides relevant evidence in this respect. They found that exposing adult oysters to elevated CO2 during reproductive conditioning had positive carry-over effects. Larvae spawned from adults exposed to elevated CO2 were larger and developed faster, but displayed similar survival compared with larvae spawned from adults exposed to ambient CO2. Importantly, this happened just across one generation, which is not enough for natural selection.

Parker LM, Ross PM, O’Connor WA, Borysko L, Raftos DA, Pörtner H (2012) Adult exposure influences offspring response to ocean acidification in oysters. Global Change Biology 18:82–92. DOI: 10.1111/j.1365-2486.2011.02520.x

First of all, we should prove this paradigm.

As we know, the ocean is predominantly alkaline and immense.

While evidence of an apparent increase of 0.1 over a period greater than 200 years(Jacobson 2005), we must pause a little to wonder about the reliability of the data and the size (and origin) of the sample is sufficient.

Thank you. I will check all the literature cited. Thank you very much.

A newly published article that you may be interested in checking out:

Kelly, MW and Hofmann, GE. 2013. Adaptation and the physiology of ocean acidification. Functional Ecology 27: 980-990.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2435.2012.02061.x/full

Evidence for adaptation during OA is very scarce. But look at:

http://rstb.royalsocietypublishing.org/content/368/1627/20120444.abstract

Also, our own studies showed OA induced evolutionary changes in a non-calcifying invertebrate, the calanoid copepod Pseudocalanus acuspes. Our lab incubations showed that OA will inflict metabolic phenotypic plasticity leading to a decrease in fecundity and an increase in metabolic rate at OA levels corresponding to 900 µatm CO2. Beyond that, at 1550 µatm CO2, P. acuspes will experience evolutionary adaptations that partly alleviate OA effects so that further loss of fecundity is avoided. Reciprocal transplant tests showed that without adaptation fecundity would have dereased twice as much. We are currently preparing the manuscript for publication

Peter, please get me a copy of the above mentioned MS as soon as it gets published.

Marine species will be affected to ocean acidification (OA) based on their physiological and structural adaptations, for example, calcifying organisms that produce aragonite form of CaCO3 (e.g. pteropods, corals, molluscs) are more vulnerable to changes in ocean acidification than those that constructed of calcite structures (e.g. planktonic algae; coralline algae, protozoans). Wittmann and Pörtner (2013) conducted sensitivities of five extant animal taxa (corals, crustaceans, molluscs, fishes and echinoderms) to a wide range of CO2 concentrations. They found that corals, echinoderms and molluscs were very sensitive to a decline in the pH value. By contrast, only higher concentrations had an impact on crustaceans such as the Atlantic spider crab or edible crab. Adult teleost (bony) fishes are thought to be relatively robust to changes in ambient pH as they are able to control their acid-base balance by bicarbonate buffering, mainly across the gills and via the kidney. Rising CO2 may enhance productivity of non-calcifying seagrasses, seaweeds as they require CO2 for photosynthesis and living, for example, photosynthetic organisms such as seagrasses showed higher growth rates, as much as five-fold or higher with acidification.

Wittmann, A.C. and Pörtner, H-O. 2013. Sensitivities of extant animal taxa to ocean acidification. Nature Climate Change. 3: 995–1001

The literature cited are very useful.

My most recently published work suggests that infaunal bivalves are able to recognize and reject more acidic sediments and disperse to more favorable habitats. Although this mitigates exposure to acidified conditions, failing to burrow can increase the vulnerability of settling clams to other sources of mortality, such as predation or entrainment.

http://www.sciencedirect.com/science/article/pii/S0022098114000033

Hi Clements,

I read your article (the abstract) with an interest. Did you carryout or planning to carry out any toxicity (lethal and sub-lethal) tests of different level sediment pH on clams as well? Can this species be a suitable indicator as a biomonitor to assess OA impacts? Thanks

Hi Golam,

We are running a 60d lab experiment this summer that may or may not include LC50 as an endpoint - I'm still in the process of determining reasonable goals for this experiment.

I'm not sure that Mya would be a suitable species to use as a biomonitor for OA. This species is highly tolerable to a wide range of environmental conditions (temperature and salinity, at least); however, we don't know much about it's pH tolerance range (something certainly to be explored).

There is certainly some work to be done in this area though! One thing I'm interested in is analyzing the burrows of juvenile and adult clams under different OA scenarios. We know that Mya can dwell within anoxic sediments by oxygenating their burrows with O2 from overlying water - it would be interesting to conduct pH analysis on these burrows under different OA conditions and see if they can buffer their burrows alongside oxygenating them.

Take-home here is that there is some work to be done before we can determine if Mya is a viable indicator of OA impacts - my preliminary thoughts are that there are better choices for biomonitoring.

Best,

Jeff

Hi Jeff , Many thanks for the update. If you can identify a species that can be used to biomonitor of OA, that would be of immense value such as bio- monitoring with mussels for trace metals, pesticides and EDCs etc

Kind regards

Golam

I think even those marine organisms dont have time to adapt but there will be another generation of those marine organisms will exist to resist those changes in ocean acidification.