How Does Motor Vehicle Pollution in the York College Creek Crossing Impact Fish? Victoria Tsang Department of Biological Science, York College of Pennsylvania Methods Three individual trials: Trial 1 – 3 replicates Trial 2 – 4 replicates Trial 3 – 3 replicates Results There is no difference in mortality rate of zebrafish larvae exposed to different low-level concentrations of motor oil; exposure to different concentrations of motor oil does not impact the day of hatching for zebrafish There is a difference in activity rate of zebrafish embryos exposed to different low-level concentrations of motor oil: zebrafish exposed to motor oil concentrations higher than mL oil/1.0 L water exhibit a significant decrease in activity level; implications on predator-prey interactions There is no difference in zebrafish embryo development when exposed to different low-level concentrations of motor oil Conclusion Overall, little impact was seen from exposure to low-level concentrations of oil However, the decrease in activity level may indicate underlying physiological problems More research is necessary to confirm whether or not motor vehicle pollution severely impacts the creek environment; it is necessary to consider other sources of contamination: o Other pollutants in Tyler Run – animal wastes, algae growth, and other motor vehicle pollution such as anti-freeze and gasoline – need to be tested individually o Pollution from other areas of York County from upstream: sewage waste, contaminated water runoffs, and paper mill waste, etc. Literature Cited Logan, D Perspectives on ecotoxicology of PAHs to fish. Human and Ecological Risk Management 13: Short, Rice, Heintz, Carls, and Moles Long-term effects of crude oil on developing fish: lessons from the Exxon Valdez Oil Spill. Energy Sources 25: Acknowledgements I would like to thank the entire Biological Sciences Department at York College, specifically my mentor Dr. Jessica Nolan, as well as Dr. Wendy Boehlmer and Dr. Karl Kleiner for all their help in assisting me with my project. Introduction Background Although it’s always fun to drive as fast as you can through the YCP creek crossing just to see how high of a wave you can make, you might wonder, just exactly how are the local fish affected by constant low-level motor oil exposure? Research has placed a major emphasis on oil spills (high level exposure) in marine environment, rather than exploring the direct impacts of low-level oil exposure on freshwater fish. This is what I’ve set out to discover! Motor Oil  Cars can introduce many types of pollutants into the water system, but motor oil is one of the more harmful pollutants that can be added.  How is petroleum-based motor oil harmful? o Aromatic hydrocarbons and PAHs (polyaromatic hydrocarbons) are the most abundant and researched component o Bioaccumulation of PAH dependent upon individual fish metabolism, ability to eliminate toxins, and life stage o Evidence shows that chronic exposure at the embryonic stage increases mutation and/or mortality rate (Logan 2007, Short et al. 2002) Test subject: Zebrafish (Danio rereio)  This experiment was set-up in-laboratory rather than directly in the creek to eliminate other factors in the environment that could impact the outcome. It focused on the early stages of development, when the most impact on fish health can be seen.  Why zebrafish? o Wild minnows, the natural inhabitants of the creek, are very difficult to breed in captivity o Key characteristics of zebrafish  Well understood laboratory model  They have quick reproduction  Short embryo stage  Clear bodies Hypothesis  Mortality H 0 : There will be no difference in the mortality rate of zebrafish embryos exposed to different low-level concentrations of motor oil  Activity H 0 : There will be no difference in the activity level of zebrafish larvae exposed to different low-level concentrations of motor oil  Development H 0 : There will be no difference in zebrafish embryo development when exposed to different low-level concentrations of motor oil Figure 2. Comparison of percent hatched per day. Data was transformed using arcsin(square root). Analysis using a two- way ANOVA show that there is no significant difference among treatments, but there is a significant difference over time. Figure 3. Comparison of activity level for each experimental group on day 7 of testing. Activity was measured using the active swim test in which the number of times each fish crossed the line in one minute was documented. Error bars represent one standard error of the mean and “a” indicates a significant difference exists between the 1:10,000 and the control group from “b”, all other experimental groups. Results were analyzed using a one-way ANOVA (p<0.0001). Figure 1. Comparative analysis of the percent of zebrafish larval mortality over the period of seven day for all experimental groups. Data was transformed using arcsin(square root). There are no significant differences among experimental groups as determined with a two-way ANOVA. There is a significant difference in percent alive over period of time for all experimental groups. Synthesize Weathered Motor Oil Create Stock Conc. (1:1) 16.6 mL oil/ 1.0 L water Breed Zebrafish Collect embryos Create Ten-fold Dilutions: 1:10, 1:100, 1:1000,1:10,000 Set-up Experimental Groups on 6-well plates Incubate at 27  C for 7 days Recorded Results Observe mortality, number of eggs hatched, development/deformities on daily basis Record activity level on day 7 VS Larval Adult Larva embryo