Biology Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2749
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Item Occurrence of Pharmaceuticals and Personal Care Products (PPCP) & Artificial Sweeteners (AS) in Surface Waters of Maryland's Chesapeake Bay Western Shore(2022) Gibbs, Alexandra Marie; Filoso, Solange; Gonsior, Michael; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In the United States, nutrient, personal care products (PPCP) and artificial sweeteners (AS) pollution in lakes, rivers, and estuaries is a problem that has been recognized for decades and is of special concern for many in coastal Maryland. PPCP are used on a daily basis, and include prescription analgesics, antibiotics, over-the-counter medications, fragrances, and cleansers. AS are synthetic sugar substitutes, ubiquitous in everyday food and drink, including soft drinks, baked food and dairy products. The widespread use of PPCP and AS by human populations results in their sustained contribution to surface waters via wastewater treatment. This study used 13 PPCP and 2 AS to describe their sources and temporospatial patterns in Maryland’s Western Shore. Sampling was conducted over three seasons in 2021 at 79 sites, including headwater streams, groundwater, and rivers feeding into the Chesapeake Bay. Sites were influenced by a mix of wastewater treatment plants (WWTP) and onsite wastewater treatment systems (OWTS). The detection frequency of the study compounds ranged from 2% to 100% in large catchments and 31% to 100% in headwater catchments. Six PPCP and AS were measurable at 80% or more of the sites, illustrating their ubiquitous presence throughout the study area. During the study, individual PPCP and AS concentrations were highly variable temporally, ranging from non-detectable to 6.58 μg/L. Major factors controlling concentrations were proximity to wastewater treatment, discharge and season. Four compounds—Ace-K, carbamazepine, sucralose and caffeine—were used as tracers to identify wastewater sources as they have distinct removal efficiencies during wastewater treatment and have anthropogenic origins. Caffeine to sucralose/Ace-K/carbamazepine ratios were used to identify discharges of untreated wastewater. Finally, PPCP and AS concentrations were explored in one headwater stream during storm events. Stormflow discharge was shown to impact the water quality of the receiving waters. The combination of discharge data, OWTS distribution data, an extensive suite of PPCP and AS and varied catchment types used in this thesis contributes to the understanding of human sourced wastewater pollution in coastal communities.Item ELUCIDATING RECRUITMENT STRESSORS FOR THE MARYLAND STATE ENDANGERED COMMON TERN (Sterna hirundo) THROUGH USE OF A MINIMALLY INVASIVE SURVEILLANCE SYSTEM(2018) Marban, Paul Ramon; Murrow, Jennifer L; Prosser, Diann J; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In this thesis, I monitored two breeding colonies of the Maryland state endangered common tern (Sterna hirundo) using a surveillance system composed of video cameras and temperature loggers. This system was coupled with an in-depth image analysis of Landsat scenes to quantify island loss in the Chesapeake Bay and coastal bays of Maryland and Virginia from 1986 to 2016. Incubation duration was determined through analysis of both in-nest temperature and video footage. Incubation trends varied between colonies but an overall trend of nighttime desertion was observed on Skimmer Island as a result of predator presence. Island loss was documented in the region since 1986. Area of beach habitat, key for breeding populations of this species, increased in 1996 and 2011 as a result of sand accretion on coastal islands and the construction of Poplar Island. All other habitat types declined. This thesis is the first to document island loss in the Chesapeake Bay beyond 2011 and the first to quantify the impact of Poplar Island’s construction on the region. To promote future breeding of common terns in Maryland, resources must be allocated to create new habitat islands removed from the mainland and free of nesting predators. Existing islands must also be supplemented yearly with substrate to mitigate erosion from sea level rise.Item Downscaled Climate Change Forecasting and Maryland's Forests(2011) Juchs, Stephanie; McIntosh, Marla S; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Effective planning and management of forests in a changing climate requires valid and robust predictions of future climate change that are context-specific since climate changes vary by region. Climate models are often used to predict future trends in temperature and precipitation at the global level, but are most useful if downscaled to predict change at regional levels. Monthly temperature and precipitation were predicted using three downscaled regional climate models for the 1990s and the 2050s. Comparison of the 1990's predictions to weather station data from across Maryland indicated inherent model biases affecting accurate predictions, which were used to adjust the model-projected climate variables for the 2050s. The projected daily temperatures were also used to calculate projected growing degree days and frost days. The degree of climate change in Maryland projected by these regional models for the next half-century would have profound impacts on forests across Maryland.Item BIRD COMMUNITY RESPONSE TO CONSERVATION RESERVE PROGRAM HABITAT IN MARYLAND(2010) Blank, Peter Joshua; Dively, Galen P.; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The populations of many bird species in the United States that use early-successional habitats have been substantially declining over the last 40 years. The main reason for these declines is habitat loss. Land enrolled in the U.S. Department of Agriculture's Conservation Reserve Program (CRP) often represents the only uncultivated herbaceous areas on farmland in the mid-Atlantic and therefore may be important habitat for early-successional bird species. CRP filter strips are strips of herbaceous vegetation that are planted along agricultural field margins and are usually planted with native warm-season grasses or introduced cool-season grasses. We studied the breeding and wintering bird use of CRP filter strips adjacent to wooded edges in Maryland from 2004-2007. We conducted bird and vegetation surveys in filter strips and measured landscape attributes around CRP plantings. We used 5 bird community metrics (total bird density, species richness, scrub-shrub bird density, grassland bird density, and total avian conservation value), species-specific densities and abundances, nest densities, and nest survival estimates to assess the habitat value of filter strips for birds. Bird community metrics were greater in filter strips than in field margins without filter strips, but did not differ between cool-season and warm-season grass filter strips. Most breeding bird community metrics were negatively related to the percent cover of orchardgrass (Dactylis glomerata). Several grassland birds were more common in wide filter strips (>60 m) compared to narrower filter strips (<30 m). The density of early-successional bird species was greater in filter strips with higher plant species richness and shorter and less dense grasses. Wintering bird use was significantly less in filter strips mowed in the fall than in unmowed filter strips. The abundance of northern bobwhite (Colinus virginianus), an important game bird and species of conservation concern, was positively associated with the percent cover of CRP land in the surrounding landscape. These results suggest that the CRP has created additional habitat for many early-successional bird species, but changes in the planning and management of CRP plantings may improve their habitat value for breeding and wintering birds.Item Genetic Diversity and Phytochemistry of Maryland-Grown American Ginseng (Panax quinquefolius L.)(2004-09-16) Schlag, Erin Margaret; McIntosh, Marla S; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)American ginseng (Panax quinquefolius) is a valuable medicinal herb threatened by over-harvest. Because data are insufficient, current attempts to protect diversity and improve cultivation are inadequate. Random Amplified Polymorphic DNA (RAPD) markers were used to estimate genetic diversity and high-performance liquid chromatography (HPLC) was used to characterize root ginsenoside concentrations in wild and cultivated populations of American ginseng in Maryland. Wild populations were less diverse than cultivated and highly differentiated from one another; suggesting that drift was high and gene flow low in wild populations. Exotic plants were genetically and phytochemically distinct from native plants. The main ginsenoside in exotic plants was Re versus Rg1 in native plants. Plants from at least one wild population were genetically and phytochemically similar to exotic plants, suggesting that exotic plants were introduced into wild populations. Thus, native Maryland American ginseng is unique but threatened by drift, isolation and artificial introductions.