In 2006, the Maine Department of Marine Resources awarded DEI a research grant to examine regional variations in the growth of known-age lobsters. The project began in July 2006 with DEI cultured lobsters no larger than the diameter of a penny. DEI staff and lobster fishermen from six areas on the Maine coast set up field experiments and distributed the juvenile lobsters to test sites in York, Boothbay Harbor, Tenants Harbor, Stonington, Beals, and Cutler. In addition to determining if geographic location makes a difference in growth rate, the experiments are designed to examine the effects of bottom type (soft vs. hard), substrate type (crushed shell vs. no shell), and container size on lobster growth. The two-year experiment ran through the summer of 2008. At the end of the study, DEI coordinated with Dr. Sean Grace at the University of Southern Connecticut, who examined the accumulation of lipofuscin from the olfactory lobe cell mass in the brain of all live lobsters. Lipofuscin is a pigment that accumulates in lobsters and other organisms at a rate that is related to the age of the animal. Collectively, Drs. Grace and Beal provided the DMR with two, independent measures of the age of lobsters. See the Final Report from DEI here.
Upper left and middle: Stage V lobsters cultured at DEI’s shellfish hatchery in July 2006.
Upper right: University of Maine at Machias students placing lobster juveniles into flow-through containers. (July 2006)
Lower left: Bottom cages holding twelve flow-through containers (with one lobster each) being lowered into the ocean near Browney Island, 2.25 km southwest of Black Duck Cove. (July 2006)
Lower right: Sampling bottom cages off York Harbor in October 2006.