Bookmark and Share
  • Text +
  • Text -

Environmental Analysis

Research Presentation Video

Watch Sasha Ponomareva '14 discuss her research project.

Marine macroinvertebrates and greenhouse gas fluxes: effects of anthropogenic nutrient and temperature stressors on coastal filter feeders

Robert E. Ventura (2014); Additional Collaborator(s): Dr. Serena Moseman-Valtierra (University of Rhode Island); Melanie Garate (University of Rhode Island); Mentor(s): Frederick Grieman

Abstract: The current global warming situation has many origins in human activity. Anthropogenic stressors such as nutrient loading in Narragansett Bay, RI have been suggested to cause coastal marshes to become sources of greenhouse gases (GHGs). Although nutrient-stressed macroinvertebrates have been seen to release GHGs in laboratory settings, emissions have not yet been studied in their natural habitat. The project was conducted using blue mussels collected from a low-nutrient area of Narragansett Bay. Initial expectations for the results were that increased stress of nitrogen loading and higher temperatures would result in a larger amount of GHG emissions. Mussels were placed in mesocosms filled with sediment and raw seawater containing different concentrations of ammonium nitrate. The mesocosms were incubated in temperature-controlled chambers at 20 or 24°C and then sealed, with gas samples being taken at various times and analyzed for nitrous oxide, methane and carbon dioxide presence using a gas chromatograph. Levels of GHGs were seen to increase over the time period that the samples were taken, although further analysis and statistical tests are required before any solid conclusions can be drawn. If results conclude that exposure to nitrogen and higher temperatures increases GHG emissions in macroinvertebrates, this project will add to the knowledge of coastal GHG fluxes, supporting legislation concerning nutrient loading in Narragansett Bay and other coastal areas worldwide.
Funding Provided by: National Science Foundation; Department of Defense; ASSURE

Hopeful Hands, Healthy Plates: The Rise of Organic Farming in Taiwan

Gideon Salzman-Gubbay (2014); Mentor(s): Char Miller

Abstract: Taiwan, a tropical island located off the southeastern coast of mainland China, is venerated for its agricultural diversity. Unfortunately, 99% of Taiwan’s agricultural industry relies on synthetic pesticides and fertilizers that contaminate the environment and are harmful to human health. There is a growing acceptance among Taiwan’s middle-aged and younger generations that these environmental costs outweigh the economic benefits associated with industrialized agriculture. Because of this, Taiwan is seeing a small—but vigorous—rise in organic agriculture. This summer, I spent ten weeks volunteering on organic farms in Pingtung County, Taiwan, researching organic agricultural production and lifestyles. I divided this time between two farms, one commercial, the other orientated toward community education. I became fully immersed in Taiwanese farming culture, learning not only about organic growing methods but also the motivations behind committing to this relatively labor-intensive form of agriculture. While in Taiwan, I observed that organic produce is making its way into large supermarkets and organic farmer’s markets. Additionally, the Taiwanese government sponsors organic education programs that teach students how to grow organic produce in their gardens for personal consumption. Additionally, there are other opportunities across Taiwan for volunteers to work on organic farms and learn more about this healthier form of agriculture.
Funding Provided by: Schulz Fund for Environmental Studies

Examining Post-Depositional Alterations in the Deep Sea Coral, Desmophyllum dianthus to Assess its Viability as a Climate Proxy

Aleksandra (Sasha) Ponomareva (2014); Mentor(s): Branwen Williams; Maria Prokopenko; Jade Star Lackey

Abstract: In order to reconstruct past climatic conditions we rely on climate proxies, especially for times prior to record-keeping. Desmophyllum dianthus, a deep sea coral, may prove to contain reliable records of past ocean productivity because of the nitrogen stored in the calcite rings of its calcium carbonate skeleton. This nitrogen comes directly from the coral’s food source and likely reflects environmental nitrogen that controls productivity. However, prior to using nitrogen in D. dianthus as a proxy we must screen for significant skeletal alterations that would prevent it from storing nitrogen isotopic values that accurately reflect the nitrogen composition of its food source. Thus, the goal of this study was to screen for post-depositional alterations, or diagenesis, in D. dianthus and determine if alterations are significant enough to invalidate this species as a proxy. The scanning electron microscope (SEM) was used to examine crystal structure and bioerosion in both modern and fossil samples. There were no significantly “altered” crystal structures in the skeleton; however there was evidence of boreholes and burrows. No significant relationships were present among a preliminary comparison of ages, boring severity and δ15N values for all samples This supports D. dianthus use as a climate proxy. In continuing this research, geochemistry and δ15N value analyses of bored and unbored areas will be done to determine if borings alter nitrogen isotopic values.
Funding Provided by: Schulz Fund for Environmental Studies