Date of Thesis



Rapid development of hydrofracking, particularly in the Marcellus Shale region, has greatly outpaced ecological research assessing potential impacts on aquatic ecosystems. Increased sedimentation and contamination of streams from unconventional natural gas (UNG) activity could affect stream biota, resulting in altered rates of in-stream leaf decomposition. We deployed leaf packs in seven sites representing a range of UNG activity among different land uses including forest, agriculture, and development. In addition, physical and chemical variables were measured. Summer breakdown rates for all sites, mesh sizes, and leaf species were higher in the presence of UNG activity. Fall breakdown rates demonstrated no consistent trend among land uses or UNG activity. Summer deployment had more storm events than fall, promoting more runoff into streams as well as more sediment release. This suggests that higher physical breakdown rates in UNG sites could have been caused by more disturbed land, modifying stream hydrology. However, fall measurements, under more consistent flow regimes, indicate sites with flashier hydrology are prone to faster breakdown rates due to mechanical fragmentation rather than biological decomposition. Leaf breakdown rates were not a consistent indicator of UNG impairment among our sites due to factors affecting breakdown rates caused by land uses other than UNG and physical breakdown attributed to hydrologic disturbances.


leaf decomposition, marcellus shale, natural gas, land use, aquatic ecology

Access Type

Masters Thesis

Degree Type

Master of Science



First Advisor

Matthew McTammany