Science Serving Maryland's Coasts

Hannah Geiser, Goshen College

Class Year: 

Project Title: 

Presence of Ammonia-Oxidizing Archaea and Bacteria along Physiochemical Gradients in Coastal Beaches and Estuaries


Coastal intertidal estuaries in California and Maryland were analyzed for the presence of ammonia-oxidizing archaea and bacteria and correlation with dissolved inorganic nitrogen removal. DNA was extracted from sediment samples and real-time polymerase chain reaction was used to quantify the presence of the amoA gene subunit, a portion of the gene that encodes for the conversion of ammonia to hydroxylamine. Ammonia-oxidizing archaea and bacteria were found with relatively more archaea in the coastal sediments. The abundance of ammonia-oxidizing bacteria appeared to correlate with dissolved oxygen. Removal of dissolved inorganic nitrogen did not appear to be limited by the abundance of microbes found in the sediment.