The Case of the Disappearing Blue Crab

Research Experience:

During the summer of 2008 Ms. Clark worked with Dr. Eric Schott and his assistant Holly Bowers on the Hematodinium dinoflagellate spp. and the Blue Crab (Callinectes sapidus) project at the Center of Marine Biotechnology in Baltimore, MD, now known as the Institute of Marine and Environmental Technology (IMET), http://www.umces.edu/imet. Currently, Ms. Clark is a STAT resource teacher for Baltimore County Public Schools.Since the 1940's there has been a dramatic decline in C. sapidus harvests due to over fishing, habitat destruction, environmental pollutants, and disease. Hematodinium is a parasitic dinoflagellate that attacks the hemolymph of the blue crab which causes fatigue and ultimately, death. Our research in the lab primarily focused on collecting water, sediment, and crab hemolymph samples from known "hot spots" and analyzing them for Hematodinium. The goals of our efforts were to determine if the organism had any environmental preferences, to identify possible reservoirs, and to establish a method of transmission from the environment to the crab. Samples were analyzed for the presence of Hematodinium DNA by quantitative PCR, end-point PCR, and Gel Electrophoresis. While the data that I collected was not conclusive, it is believed through continued research efforts at COMB and other institutions that Hematodinium outbreaks occur from late summer to mid-fall because of a high water temperature and salinity preference.