Student Involvement

Amy Adams, Biology major, supervised by Ely Klar and Mike Newbrey, is examining the occurrence of male feminization (intersex, feminization of male testes) of Largemouth bass in the Chattahoochee River and some of its tributaries. Amy is examining the relationship between season and the density of female oocytes in male gonads. Largemouth bass are a very popular sport fish in the region. The occurrence of intersex suggest that less fit males will be spawning in the river and that the river or tributaries are potentially poor and polluted environments for these fish. Reduced natural recruitment will mean the GA DNR will have to stock more Largemouth bass into the Chattahoochee River.

Brandon Furnish, Environmental Science major, supervised by Troy Keller, is examining Algae based wastewater treatment and the role of dissolved inorganic carbon (DIC) in algae production. Algae can be used to treat wastewater, removing more nutrients such as phosphorus and nitrogen than chemicals can alone. In return, the algae can be harvested and used as a renewable resource. In algae treatment systems the pH of the water can increase to as high as 9 which may inhibit algae production and growth. It has been observed that adding carbon dioxide via compressed CO2 pumped into the water can increase algal growth, and therefore nutrient uptake. What is unknown, is if the increase in algae production is due to the carbon dioxide lowering the pH of the water down to optimal levels, or if in eutrophic waters where phosphorus is not limited, carbon may become limited, and adding carbon dioxide to the waters introduces a new carbon source to the algae which increases production. The experiment will be to observe/record algae growth/biomass, and record nutrient levels, temperature and pH of the wastewater being treated. Some of the flumes containing the wastewater and algae will receive carbon dioxide while others will remain untreated as a control. Other carbon sources and pH modifiers will possibly be introduced to the system later to determine which may affect algae production the most in wastewater treatment systems.

Frances Woolfolk, Accounting major and Honors student, supervised by Mike Newbrey and Hugo Martín-Abad (a European ichthyologist), is studying the age and growth of the critically endangered, marine, coelacanth, Latimaria chalumnae. Very little work has been done to understand how long coelacanths can live, how fast they grow, and when they become sexually mature. We need to understand aspects of age and growth if we are to properly manage a critically endangered population of fish. Currently there is only one, very small dataset, on age and growth of coelacanths, yet three competing hypotheses on how long these rare fishes live: A) 20 years, B) 40-50 years, and C) 100+ years. Frances will have to travel to Paris, France to study preserved museum specimens to collect enough data to test the hypotheses.

Jeramy Belt, Biology major, supervised by Ely Klar and Mike Newbrey, is examining the occurrence of male feminization (intersex, feminization of male testes) of Largemouth bass in the Chattahoochee River and some of its tributaries. Jeramy is examining the relationship between age and the severity of intersex. Largemouth bass are a very popular sport fish in the region. The occurrence of intersex suggests that less fit males will be spawning in the river and that the river or tributaries are potentially poor and polluted environments for these fish. Reduced natural recruitment will mean the GA DNR will have to stock more Largemouth bass into the Chattahoochee River.

Kerstin Motsch, Environmental Science major, supervised by Troy Keller, is looking into water quality throughout the Cape Coral canal system in Florida. Fresh and salt-water bodies worldwide face constant degradation. Throughout Florida, contributing factors attributing to this deterioration in quality range from urban development and runoff, to agriculture and natural habitat loss. The Cape Coral canal system located in Lee County, FL is no exception to these anthropogenic stressors placed on water quality. The growth of beach front real estate/access throughout the city coupled with the desire for greener lawns has had a devastating effect on water quality throughout the canal system. As runoff saturated with nutrients enters the canals harmful algal blooms become more prominent leading to undesirable aesthetic and ecological ramifications. It is my hope to find a spatial -and perhaps- temporal pattern in water quality throughout the system, through the use and comparison of high resolution aerial imagery and water quality data. If a pattern can be found it can help identify effects on ecosystem services as well as shed light on future water resource management concerns.

Paul Arnold, Biology major, supervised by Mike Newbrey, is examining the rare occurrences of marine Bull sharks in freshwater rivers and lakes. Bull sharks, the most dangerous sharks to humans, will swim up major rivers all over the world to feed. They have been documented to navigate rivers and stream structures for over a thousand miles! There have been many occurrences of bull sharks in freshwater situations but no one has compiled a thorough analysis of occurrence, examined the effects of elevational changes and barriers on distribution, or thermal tolerances in freshwater. Many fisheries biologists perceive the occurrence of Bull sharks in freshwater situations as anomalous visitors, but Bull sharks should be considered indicators of healthy river systems.

Rob Monfort, Health Sciences major and Honors student, supervised by Mike Newbrey, is examining the relationships between Redbreast sunfish and various aspects of their physical habitat from pristine and polluted streams. This study will provide greater understanding of role that vegetation, boulders, sand, cutbanks, submerged wood, etc. has on the distribution of these beautiful panfish. In addition, two types of streams will be compared; highly altered, polluted, urbanized streams and more pristine, rural streams.

Taylor Ledford, supervised by Clifton Ruehl, studied the introduction of the apple snail that poses threats to freshwater biodiversity and agricultural crops like rice. Apple snails have been introduced throughout the southeast and have spread rapidly. In Georgia, they occur as far north and Albany and appear to be spreading north. He is observing the l ength-mass regressions for estimating biomass (g), standing stock (g/m2) and production (g/m2/d) of species for comparative purposes among ecosystems. These measures are important for assessing population size structure, calculating energy flux among trophic levels, estimating ecosystem health, and supporting conservation efforts. For example, estimating standing stock of introduced species facilitates understanding their impact on native flora and fauna. In this study, he established length-mass regressions using multiple shell metrics of size and mass for the apple snail, Pomacea maculata, (island apple snail) that has been introduced throughout the southeastern United States. He developed separate regressions for males and females which provide an important tool for quantifying the effect of apple snails in ecosystems where they have been introduced.