Coastal Watershed Institute
Florida Gulf Coast University
10501 FGCU Blvd S.
Fort Myers, FL 33965-6565
Hurricanes (tropical cyclones of 32ms-1 - 74 mph or greater) are the single most costly and destructive weather disasters in the United States. In 2012, Hurricane Sandy was directly responsible for 72 deaths and estimated damage costs exceeding 50 billion dollars. Research suggests a rise in sea surface temperatures caused by anthropogenic climate change has led to an increase in the intensity of tropical cyclones over the last 40 years. This interpretation has, however, been challenged on the basis that the observational hurricane record is too short (161 years) and unreliable to reveal long-term trends in hurricane activity. Paleotempestology, a research area that uses geological proxy techniques to reconstruct hurricane frequency and strength over long periods of time (~0-7 thousand years), can address these limitations. Being a relatively new field, paleotempestology studies are confined to a few geographical locations; to date no records exist for the Southwest Florida region—a significant hurricane target zone. This project will reconstruct the hurricane history of Southwest Florida over the past five thousand years by identifying hurricane overwash deposits in back-barrier lagoons and marshes. Records will be correlated with existing paleotempestological studies to determine patterns of hurricane activity and inactivity. To understand how the El Niño Southern Oscillation (ENSO) and sea surface temperatures (SSTs) have impacted hurricane activity in the past, correlations will be made with previously published paleo-ENSO and paleo-SST studies. In addition, the study will establish a site-specific Southwest Florida hurricane database that will be used to better understand the characteristics of storms that produce overwash deposits.
To distinguish long-term patterns in tropical hurricane activity, reliable paleotempestological reconstructions that extend back before the instrumental record are needed. Our record will provide first order insights into past frequency and strength of hurricane landfalls in Southwest Florida. The project will advance the field of paleotempestology by employing a multi-site, multi-method approach in paleotempestological reconstruction and subsequent analysis for the Southwest Florida coast. We anticipate that the generated hurricane data sets will be later used in computer models. This information will aid in better understanding of long-term processes that control the formation, intensity and track of Hurricanes.
This project will provide broad socio-economic gains via the maturation in understanding of past hurricane frequency, intensity and track which may be used later in models, risk assessment, county planning and development, and student and community education. Specifically this project will provide high school, undergraduate and graduate students with the opportunity to explore science outside of the classroom and broaden their knowledge in research science. Through this mentoring and training of the next generation on climate science issues and associated societal impact, this proposal has great future impact.
Assessing the effect that community dynamics has on trophic transfer
The potential for mercury (i.e., methylmercury, MeHg) to biomagnify is well known. My laboratory has completed a number of studies on MeHg accumulation in fish, birds, panthers and, most recently, sharks. The efficiency or rate of MeHg biomagnification through different food webs is influenced by many factors including the natural variation in trophic structure among communities (e.g., food chain length, linkage strength, etc.), degree of openness (subsides of food and nutrients from other systems), primary and secondary productivity, among others. Recently, my laboratory has employed stable isotope analysis (SIA) of nitrogen as a tool to examine biomagnification integrated across the entire food web (i.e., Food Web Magnification Factor or FWMF). This approach also allows us to disentangled and assess separately variations in basal concentrations of MeHg entering the food web, either due to variations in bioavailability of the various mercury species or activity of the methylating bacteria. In effect, quantifying mercury transfer to higher trophic levels, in addition to alerting us to the risk of exposure, is now becoming another tool, complemented by d15N,to study the complexity of food webs dynamics among ecosystems. We recently completed a FWMF study in a near-coastal offshore environment, are currently investigating FWMFs along transects in two estuaries with very different land uses and wrapping up a FWMF study in a coral reef food web.
Research activities primarily address phytoplankton ecology, particularly harmful algal blooms (HABs). Most of Parsons’ HAB research focuses on the ecology of the benthic dinoflagellate, Gambierdiscus, the organism responsible for ciguatera fish poisoning. He also studies Pseudo-nitzschia, the diatom that produces the neurotoxin, domoic acid. Other topics include phytoplankton responses to riverine inputs in the northern Gulf of Mexico (the Mississippi River) and southwest Florida (the Caloosahatchee River) and phytoplankton responses to the Macondo (Deepwater Horizon) oil spill.