Maryland Sea Grant Research Experiences for Undergraduates Final Student Papers Summer 2013 Edited by Mike Allen and Jenna Clark Sponsored by Maryland Sea Grant Maryland Sea Grant College Publication number UM-SG-TS-2014-01 Copies of this publication are available from: Maryland Sea Grant College Program 4321 Hartwick Road, Suite 300 College Park, MD 20740 ___________________________________ For more information, visit the Maryland Sea Grant web site: http://www.mdsg.umd.edu/ ___________________________________ This publication, produced by the Maryland Sea Grant College Program, is a compilation of the final REU student fellow papers produced for summer 2013. This report was prepared under award NA10OAR4170072 from Maryland Sea Grant, National Oceanic and Atmospheric Administration, U.S. Department of Commerce. The statements, findings, conclusions and recommendations are those of the author(s) and do not necessarily reflect the views of Maryland Sea Grant, the National Oceanic and Atmospheric Administration or U.S. Department of Commerce. Contents Chesapeake Biological Laboratory 4 Measured Responses of Gray Tree Frog (Hyla versicolor) Tadpoles to Selenomethionine and Selenium Dioxide .................................................................................................................... 5 Chloe Anderson, REU Fellow Mentor: Dr. Christopher Rowe, Associate Professor The Effects of Nutrients on the Biomechanics of Spartina alterniflora on Poplar Island......... 17 Jade Bowins, REU Fellow Mentor: Dr. Lora Harris, Assistant Professor The Microbial Effects of the Addition of Oil to the Anoxic Layers of Benthic Sediments from the Chesapeake Bay ............................................................................................................ 30 Gene Patrick Geronimo, REU Fellow Mentor: Dr. Laura Lapham, Assistant Professor Bioaccumulation of Synthetic Musk Fragrances in Northern Diamondback Terrapins (Malaclemys terrapin terrapin) of Jamaica Bay, New York, USA ........................................... 55 Lisa McBride, REU Fellow Mentor: Dr. Andrew Heyes, Associate Professor Modeling of Blue Crab Catchability in Chesapeake Bay Using Winter Dredge Surveys ........ 71 Andrew Mealor, REU Fellow Mentor: Dr. Michael Wilberg, Associate Professor Calibration of Modern Coral Climate Signals to Ensure Accuracy of Paleoclimate Determinations in Anegada, British Virgin Islands ................................................................. 88 Sean Pearson, REU Fellow Mentor: Dr. K. Halimeda Kilbourne, Research Assistant Professor Marine Chromophoric Dissolved Organic Matter Distribution in the Atlantic Ocean .............. 99 Sandra Pittelli, REU Fellow Mentor: Dr. Michael Gonsior, Assistant Professor Levels of PAHs in Marine Biofouling Organisms Attached to Oil Rigs in the Gulf of Mexico 113 Zach Watkins, REU Fellow Mentor: Dr. Carys Mitchelmore, Associate Professor Quantifying Growth Variation of Juvenile Blue Crab (Callinectes sapidus) using RNA:DNA in Response to Elevated Water Temperature and Nutritional Rations .................................... 127 Arthur Williams, REU Fellow Mentor: Dr. Thomas Miller, Director and Professor 1 Horn Point Laboratory 143 Factors Affecting Cyanobacterial Ecology in a Restoration Wetland on Poplar Island, Chesapeake Bay ................................................................................................................ 144 Austin Boardman, REU Fellow Mentor: Dr. Judy O’Neil, Research Assistant Professor Characterizing Flow at the Susquehanna Flats ................................................................... 164 Angela Cole, REU Fellow Mentor: Dr. Lawrence Sanford, Professor Wind-induced Lateral Circulation and Mixing in the Chesapeake Bay................................. 176 Jenessa Duncombe, REU Fellow Mentor: Dr. William Boicourt, Professor Effects of N:P Ratio Variation on Feeding of Dinoflagellate K. veneficum on Cryptophyte Rhodomonas sp. ................................................................................................................ 188 Chrissie Schalkoff, REU Fellow Mentor: Dr. Patricia Glibert, Professor The Evaluation of Basic Calculations Concerning the Effects of Non-storm Waves on Offshore Sediment at Jefferson-Patterson Park, MD ......................................................................... 200 Nick Taylor, REU Fellow Mentor: Dr. Cindy Palinkas, Associate Professor Hypoxic Impacts on Egg Respiration Rates of the Copepod Acartia tonsa ......................... 210 Cristina Villalobos, REU Fellow Mentor: Dr. Jamie Pierson, Research Assistant Professor 2 Blank 3 UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE Chesapeake Biological Laboratory 4 Measured Responses of Gray Tree Frog (Hyla versicolor) Tadpoles to Selenomethionine and Selenium Dioxide Chloe Anderson, REU Fellow Maryland Sea Grant Dr. Christopher Rowe, Associate Professor Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science Dr. Andrew Heyes, Research Associate Professor Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science Abstract Selenium (Se) is a contaminant of concern in areas affected by coal ash disposal and runoff from seleniferous soils, and may occur in inorganic or organic forms. To quantify the different effects of organic and inorganic selenium, we dosed the food of gray tree frog (Hyla versicolor) tadpoles with selenium dioxide at concentrations of 16.27 and 34.2 ug g-1 Se dw and selenomethionine (SeMet) concentrations of 14.23 and 32.8 ug g-1 Se dw. As tadpoles accumulated Se throughout metamorphosis, we measured biological endpoints including metabolic rate, survival, and growth. A behavioral test was also administered. Chemical analyses on total accumulated Se and mercury (Hg) have yet to be completed. Analysis of food was done via chemical digestion and mass spectrometry. Midpoint respirometry analysis -1 -1 showed that SeMet high tadpoles had significantly higher metabolic rates in µl O2 g min , with a mean of 3.26, than control (mean=2.20, p=0.0024), SeO2 low (mean=2.52, p=0.0337), and SeMet low (mean=2.66, p=0.0176) tadpoles. No further significance was found regarding respirometry, growth, survival, or behavior. However, survival to the end of the study was lowest for SeMet high and SeMet low tadpoles, suggesting organic Se had more toxic effects. SeO2 did not appear to be toxic, but because of the possibility of conversion to an organic form in a natural ecosystem, efforts to restrict release of Se rich wastes are warranted. Keywords Selenium, amphibian, coal ash, metabolic rate Introduction Aquatic pollution by contaminants such as pesticides, industrial chemicals, heavy metals, and air pollutants has historically received greater attention than pollution by trace elements such as selenium (Se) (Lemly 2004). However, Se has the potential to affect aquatic environments on a much broader scale than many other contaminants, and has been singled out as the trace element of primary concern in some contaminated sites (Hamilton 2004). This is principally because Se is known to bioaccumulate in food chains, and small increases in Se 5 concentrations have the potential to be toxic and lethal (Lemly 2004; Thomas et al. 2013). The margin between the essentiality and toxicity of Se is very narrow, with an additional 2.0 µg g-1 in food sources potentially causing detrimental effects to certain fish species (Thomas et al. 2013). Additionally, because Se is a trace element, it does not break down into less toxic counterparts, retaining its toxicity for decades (Lemly 2004). This toxicity has had negative impacts on many forms of wildlife, but much investigation is still needed, especially in regards to amphibians. 2- 2- Selenium enters an ecosystem as either inorganic selenate (SeO4 ) or selenite (SeO3 ) from various sources, including but not limited to agricultural drain water, sewage sludge, fly ash from coal-fired power plants, oil refineries, and mining of phosphates and metal ores (Chapman et al. 2010). Because Se introduction is associated with such varied activities, it has the propensity to be an environmental concern worldwide (Lemly 2004). After its initial introduction, Se most likely follows a biogeochemical cycle similar to that of sulfur (Lockard et al. 2013). Although inorganic Se may not pose health threats at low concentrations, it can be converted to organic forms such as selenomethionine (SeMet) by primary producers as it passes through the food chain, which allows a greater bioaccumulative potential and possibility for trophic transfer (Thomas et al. 2013). Studies as early as 1985 reported SeMet to be more toxic to fish than selenite (Hamilton 2004), but this still has not been thoroughly investigated in amphibians. Figure 1 demonstrates how Se may enter an ecosystem in the inorganic form and later convert to a more hazardous organic form as it moves up the food web during trophic transfer (Chapman et al. 2010). Although excessive SeMet may not be toxic to primary producers and invertebrates, extensive documentation of its side effects has been reported for mammals, birds, fish, reptiles, and amphibians. For example, SeMet is known to cause problems during fatty acid synthesis in mammals (Mueller et al. 2008). Mortality and reproductive problems were observed in aquatic birds by Ohlendorf et al. (2010) and Hothem and Ohlendorf (1989) in the Kesterson Reservoir, where Se concentrations in aquatic biota were up to 64 times that of the minimum concentration