Ocean Acidification
a writing seminar course at Duke University
Talmage, S. C., & Gobler, C. J. (2010). Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish. Proceedings of the National Academy of Sciences of the United States of America, 107(40), 17246. Retrieved from http://search.proquest.com/docview/757190173?accountid=10598
Anthropogenic CO2 has found its way into the world’s oceans, thereby decreasing pH levels. As a result, the growth of marine organisms, especially those with CaCO3 shells, is being negatively affected. The School of Marine and Atmospheric Sciences at Stony Brook University has conducted experiments that examine the effects of the ocean’s past, present, and future (21st and 22nd centuries) CO2 concentrations on the growth of larvae of two species of bivalve shellfish (Mercenaria mercenaria and Argopecten irradians). For these species, the CaCO3 shells, serving as lines of defense for larvae and providing physical stability for fragile organs, are so vital. Larvae of both species were grown under near preindustrial CO2 concentrations and modern day CO2 levels. The results show that for the former, growth and metamorphosis rates and survival and lipid accumulation rates were higher in comparison to the latter group of larvae. Thus ocean acidification during the past 200 years may be inhibiting the survival of larval shellfish.
Science 18 January 2008:
Vol. 319 no. 5861 p. 285
DOI: 10.1126/science.1151493
Economics and Climate Change
Climate change and pollution are the definitive issues of the current era. The changes to our atmosphere and ocean, such as warming by 2 degrees celcius and a foot of sea level rise in this century are minimal estimates of the consequences of current actions.
One of the questions is whether it would makes more sense committing a relatively large amount of money to try to reduce future global warming by suppressing carbon emissions or spending a smaller amount to deal with many of the problems that currently afflict humans and the environment.
Most likely the best option is a moderate plan, spending medium sums in order to regulate emissions now and build up to a reversal project with higher expenditures.
The aspect of money in combating climate change and it’s effects is an important aspect and should gain more attention.
Mar. Ecol. Prog. Ser. 388, 235-242 (2009)
Increased atmospheric CO2 concentrations may pose a greater threat to some species of fish than previously predicted because of the combined effects of ocean acidification and increased temperature.
Philip Munday at James Cook University and his colleagues tested the aerobic scope (resting and active O2 consumption) of two species of Australian coral reef fishes, Ostorhinchus doederleini and O. cyanosoma, in waters that modeled 2100 projections for temperature and pH.
In both species, aerobic scope declined over 30% in both above-average temperatures (29 to 32oC) and in acidified water (pH 7.8 and ~1000 ppm CO2). Mortality rates increased dramatically above 33oC.
Reduced aerobic capacity in tropical fish species will likely affect feeding, growth and reproduction, threatening the stability of fish populations. Compounded effects of increased temperature and increased pH on non-calcifying marine organisms had been largely unknown, but this study indicates that some fish populations could be at significant risk if carbon emissions continue at the current rate.
Marine Policy
Volume 34, Issue 3, May 2010, Pages 367-374
doi:10.1016/j.marpol.2009.08.006
How is the the world’s oceans related to economics? How can an assessment of an economy prevent unprecedented impacts and help mitigate many factors that contribute to ocean related problems? J.T Kidlow, The National Ocean Economics Program, and A. Mcllgorn, The University of new England and Southern Cross University, have researched the importance of estimating the ocean as a contributor to modern economies. Until 1990, many nations have not formally conducted an evaluation of the effects the ocean has on its economy. Kidlow conducted an evaluation of ocean industry sectors, based off APEC’s industry sectors, and concluded that the U.S.A’s GDP, is directly effected from the following ocean industries: oil and gas; fisheries/living resources; shipping; marine construction; and marine tourism. Kudlow reasearch in 2009, based off data in 2004, list that the ocean is 138billion dollar contributor to the U.S economy, not including environmental and ecosytem stocks that arent direct goods and services. Kudlow presents data that could be useful to policy makers in the determination of ocean and marine ecosystem preservation.
Long-term effect of coral transplantation: Restoration goals and the choice of species.
Journal of Theoretical Biology 280 (2011) 127–138
As the health of many coral reef ecosystems is declining, coral reef restoration is growing increasingly important. A common method of restoration is transplantation, or the transference of healthy coral to failing reef communities. However, research conducted by Soyuka Muko and Yoh Iwasa provides evidence that in some cases, transplantation can be detrimental to restoration efforts. When fast-growing coral was introduced to a population of Pocillopora, an endangered coral species with limited larvae dispersal, the native Pocillopora population was unable to recover and was replaced by the new coral species over the long-term. Such a result would lower the biodiversity of a community and make it more susceptible to collapse. Muko and Iwasa demonstrate that the benefits of a transplantation can be roughly ensured by assessing available larvae supply from existing adult specimen and by using a mathematical model to calculate an appropriate transplanted-coral density. They suggest that the potential of transplantation should be carefully evaluated case-by-case in order to avoid unwanted results.
Proceedings of the National Academy of Sciences of the United States of America 107. 47 (Nov 23, 2010)
Peter Köhler and Dieter A. Wolf-Gladrow from the Alfred Wegener Institute for Polar and Marine Research and Jens Hartmann from the Institute for Biogeochemistry and Marine Chemistry conducted research on the effects of olivine (Mg2SiO4) on ocean acidity. It was already accepted that the addition of olivine to the ocean could reduce carbon dioxide concentration. The olivine reacts with carbon dioxide and water to form, among other products, bicarbonate ions, lowering the concentration of carbon dioxide. The ideal locations for olivine weathering are humid and tropic areas. This study, however, found that various factors in the oceans could lower the proposed efficiency of the reaction by 20%. Such factors include the preexisting concentrations of silicate and carbonates and the size of the olivine particles. Another newly-discovered potential deterrent of this tactic is the potential effect on ocean alkalinity. The tactic is still considered effective compared to alternatives, but further research is necessary.
B. Dalsøren, M. S. Eide, Ø. Endresen, A. Mjelde, G. Gravir, and I. S. A. Isaksen, ”Update on emissions and environmental impacts from the international fleet of ships: the contribution from major ship types and ports” Atmos. Chem. Phys., 9, 2171–2194 (2009) Received: 30 June 2008, Discuss.: 21 October 2008, Revised: 12 February 2009, Accepted: 5 March 2009, Published: 24 March 2009
It is necessary for policy makers to possess an accurate, up-to-date ship emission inventory at their disposal. The Chemical Transport Model takes place at global ports, taking into account ship size and and ship category. This model was developed to measure emission inventories for various greenhouse gases, such as CO2, NO2, CO, VOC, Black Carbon, and Organic Carbon. These emissions were found highly concentrated off of the coasts of major cities where population was dense around North America and Europe. Ships “contribute 11% to nitrate wet deposition and 4.5% to sulphur wet deposition globally. In certain coastal regions, the contributions may be in the range 15–50%.”
The report found that “ship emissions have a large impact on acidic deposition and surface ozone in Western North America, Scandinavia, Western Europe, western North Africa and Malaysia/Indonesia.” NO2 and SO2 specifically were found in high concentrations, sometimes exceeding 10% in highly concentrated ports. These results are necessary for policy makers to analyze to further implement stricter regulations to minimize the impact of ships on our oceans and planet.
SW4
Glacial-interglacial atmospheric CO2 change: a possible “standingvolume” effect on deep-ocean carbon sequestration
Climate of the Past, Vol. 5, 537-550
Research by L. C. Skinner done for the Godwin Laboratory for Palaeoclimate Research in the Department of Earth Sciences at the University of Cambridge points away from dynamic methods, such as equilibration or variable mixing, and towards a new method as a cure to ocean acidification, one where we ourselves can physically change the volume or temperature of water to promote solubility and biological changes. This study highlights the difference between the solubility of carbon dioxide in colder and normal glacial waters, specifically that carbon dioxide is much more soluble in a colder glacial ocean. Two further implications of the method beyond the simple proposal for changing the volume of water are sustaining this “standing volume effect” and increasing the total nutrient concentration in the ocean. The study ends with a disclaimer that its purpose is not to give an answer to ocean CO2 levels, but rather to explain the distinction between the distribution and the rate of circulation of water in the ocean.
Skinner, L. C. “Glacial-interglacial Atmospheric CO2 Change: a Possible “standing Volume” Effect on Deep-ocean Carbon Sequestration.” Climate of the Past 5 (2009): 537-50. Www.clim-past.net/5/537/2009/. Author(s), 30 Sept. 2009. Web.
Marine Biology. 156.3 “Predicted Impact of Ocean Acidification on a Marine Invertebrate: Elevated CO(2) Alters Response to Thermal Stress in Sea Urchin Larvae.” (2009): 439-46.
The slow increase in acidity of our ocean’s waters may mean danger to sea urchin (Srongylocentrotus franciscanus) larvae. Ocean acidification added with other stressors such as temperature change may lead to synergistic effects on these larvae.
Michael O’Donnell from the University of California and his colleagues placed sea urchin larvae in different levels of CO2.They were placed under optimistic conditions (~540 ppm CO2), expected conditions (~970 ppm CO2), or control levels (~380ppm CO2). After 93 hours, the temperature of the water was then raised to test the larvae’s ability to mount a physiological response to thermal stress. In order to test this response, the scientists measured the activation of the gene hsp70, which is controlled by a “temperature sensitive promoter”.
It was found that higher CO2 levels impaired the larvae’s development to properly respond to thermal changes in their environment. The mechanism by which this occurs, however, is unknown and O’Donnell suggests that this needs to be researched further.
Unanticipated consequences of ocean acidification: A noisier ocean at lower pH
Geophys. Res. Lett. doi:10.1029/2008GL034913 (2008)
Ocean acidification is changing not only the chemical properties of seawater, but its geophysical properties as well. As CO2 levels in the ocean rise, carbonic acid is formed, decreasing ocean pH. This increase in acidity causes the concentration of sound-absorbing chemicals such as borate to drop, resulting in a decline in ocean sound absorption.
CO2 data from several ocean sections during both pre-industrial and industrial periods was utilized to compute the change in pH and thus sound absorption due to ocean acidification. The 0.12 decline in pH lowered low-frequency sound absorption by 12% with a predicted decrease of almost 40% by 2050.
The increase in ambient noise caused by ocean acidification could pose significant problems for marine organisms that depend on signaling to navigate.
The study by Keith C Hester et al. at the Monterrey Bay Research Institute demonstrates that ocean acidification is a far-reaching problem affecting many unexpected aspects of marine life. H. E.