Ocean acidification due to CO2 increase affect bio calcification. We can suppose that the same effect can be found in fresh water. However I did not found any research about the effect of CO2 on pound and lac. This is probably because it is negligible in such a limited amount of water. Do you have any knowledges about the atmospheric/pound physiochemical exchanges and the effect of CO2 increase?
To precise a little bit more: a endangered crayfish seems to be limited by the current PH of the system and a future PH increase may impact definitively the last population.
See: Maberly, S. C. (1996). Diel, episodic and seasonal changes in pH and concentrations of inorganic carbon in a productive lake. Freshwater Biology, 35(3), 579-598.
CO2 dissolution will acidify not just seawater but also freshwater, the same way soda water is produced. But lakewater pH is also under the (stronger) influence of land and sediment such that atmospheric CO2 plays a relatively minor role. Also, we need to consider that marine organisms have adapted to a stable pH for centuries; it becomes a challenge for them to cope with the recent rapid (relatively speaking) acidification of the ocean.
As discribed in the last reference, air-quality.org.uk, suiphur acidification plays a major role. Chimneys of UK and Germany polluted the scandinavian lakes heaviliy, unless desulphurized later in the last century.
This following website may help.
http://news.sciencemag.org/climate/2015/06/freshwater-fish-threatened-acidification
regards,
aida
More information would be helpful - the earlier answers are quite good- as noted early in this string, the watershed chemistry is also critical - there could be subsoil buffering capacity.
The exchange of CO2 between the atmosphere and the pond will likely depend on its surface/volume ratio rather than on the amount of water. In many ponds this exchange is much slower than the diurnal variation caused by the uptake/release of dissolved CO2 by algae. In essentially eutrophic ponds, this can cause wild diurnal variations in dissolved oxygen and pH (7.5 - 9) during summer blooms (at which time the organisms may have depleted the water of nutrients such as nitrate).
Bill Schlesinger's Blog on ocean acidity (please see URL below) may be of interest. Other aspects of global environmental change are included in his Blogs which are well documented. You may know Bill's excellent book Biogeochemistry: An Analysis of Global Change, 3rd Edition. Bill is in the National Academy of Sciences, and was Dean of the Nicholas School of the Environment at Duke University and later President of the Cary Institute of Ecosystem Studies before retirement. I find his Blogs to be most informative and often on topics I follow.
http://blogs.nicholas.duke.edu/citizenscientist/ocean-acidity/