Ocean Acidification can Mediate Biodiversity Shifts by changing Biogenic Habitat

by Elizabeth Rodarte

Ocean acidification is the process in which the pH of the world’s oceans decreases due to the production of atmospheric CO2. The increase of CO2 and decrease in pH leads to changes in calcification, growth, and abundance of species such as coral reefs, mussels, seagrass, and macroalgae. Habitats experience the indirect effects of such CO2 increases. They must remain resistant to sudden changes in pH and CO2 in order to benefit the organisms they support. By modeling the effects of lowering pH in habitats with corals, mussels, seagrass, and microalgae, we can determine the costs to these species. Coral reefs and mussels are calcifying organisms that are negatively affected by the pH which limits survival and stunts, or even stops, growth and development. Lower pH decreases the species complexity of corals and mussels and ultimately the species richness in habitats. Mytilus mussels, for example, require specific pH to function. The species of mussels, other than Mytilus, that survive decreases in pH lack “structural complexity” to support dense surrounding vegetation. Therefore, the loss of Mytilus mussels due to ocean acidification allows for a more stable yet less diverse habitat. Continue reading

Is the IPCC as Interdisciplinary as it Should Be?

by Emil Morhardt

Sibling 2011 scientiometric (bibliometric) analyses of the IPCC Third Assessment Report (TAR) (Bjurström and Polk 2011a, b) ask questions about how interdisciplinary—as opposed to how multidisciplinary—the IPCC is in considering the state of climate change research, and the degree to which consideration of the natural scientific evidence and its economic consequences outweighs any other considerations. If each chapter were confined to a single discipline, say ice core analysis, but there were many chapters covering different types of studies, that would be perfect multidisciplinarity—at least over the range of disciplines covered—and zero interdisciplinarity. After characterizing the disciplinary content of 96 journals that were each cited 12 times or more (a total of 6417 technical papers were involved), the authors concluded that this was more-or less the case. Each chapter stayed well within its disciplinary constraints. The scientists in each discipline have their noses to the grindstone and are leaving the research in other disciplines to others. Furthermore, except for a smattering of economics, there is not much other than natural science under consideration (although medicine and energy, both of which received significant coverage might be considered as outside the realm of the natural sciences.) The only fields that looked as though they might be interdisciplinary, based on the dispersion of topics in individual journals, were in journals with the words “environmental”, “ecological”, or “policy” in their titles. Since these journals are specifically trying to attract papers that cross two disciplines, it is good that at least some of them received at least 12 citations. Continue reading

Behavior Alterations in Temperate Fish with Elevated-CO2

by Jennifer Fields

Anthropogenic CO2 emissions are causing an increase in dissolution of CO2 into the oceans resulting in ocean acidification. Teleost fish have been thought to have a high tolerance to ocean acidification because their specialized gills allow them to regulate the pH of their blood. However, recent studies have reported strong behavioral effects of ocean acidification in tropical coral reef species. The studies found that there was a diminishment of risk-assessment, learning, lateralization, and prey detection with increased dissolved CO2. But, little is known about the behavioral changes of temperate fish under the same conditions. Jutfelt et al. (2013) observed behavioral disturbances in boldness, exploratory behavior, lateralization, and learning in temperate fish under end of century ocean acidification conditions. The findings suggest that behavioral changes from increased CO2 are not limited to sensitive tropical species and could affect fish on a global scale by the end of the century. Continue reading