Tom Sevick, an environmental science major at Loyola University New Orleans, was recently awarded $2,500 from the Louisiana Sea Grant Undergraduate Research Opportunities Program to conduct collaborative research with Dr. Frank Jordan, Professor of Biological Sciences. The main objective of this research is to compare diversity and abundance of fishes in marshes of the Mississippi River delta after the Deepwater Horizon Oil Spill to historic data that were collected by Dr. Jordan and his students during the period 1999-2004. We hypothesize that diversity and abundance will be lower in areas affected by the spill because oil contamination has a negative effect on reproduction, growth, and survival of many species of marsh fishes. Marsh fishes are important components of wetland food webs because they rapidly convert detritus, bacteria, and smaller prey organisms into biomass that is more readily available to wading birds, sport fishes, and various other top predators. Marsh fishes also facilitate transfer of contaminants up to higher trophic levels in wetland food webs. Their central role in wetland food webs makes marsh fishes ideal indicator taxa to evaluate cumulative and integrated effects of contaminants such as the mixture of polycyclic aromatic hydrocarbons associated with the oil spill. In addition to advancing our understanding of the effects of contaminants on coastal wetlands, this research also provides a unique opportunity to increase recruitment and retention of undergraduates into the Science, Technology, Engineering, and Mathematics (STEM) pipeline.