DV-11-13 Molecular genetics and habitat characterization of juvenile cod in Frenchman Bay

Brian Tarbox
Assistant Professor in Marine Science
Southern Maine Community College
Fort Road
South Portland, ME 04106

Spawning stocks of Atlantic cod (Gadus morhua) have disappeared from downeast Maine, but juvenile cod have made regular appearances since at least 2000. The source of these juveniles and their adult grounds is unknown. While previous studies have found a segregation of eastern and western Gulf of Maine cod populations , no one has examined the molecular genetics of the eastern fish to determine the origin of these juveniles. Expanding on a study of the molecular genetics of cod from Jeffrey’s Ledge in the western Gulf of Maine (with the Mount Desert Island Biological Laboratory) Tarbox and Roger Woodman, fisherman and owner of the schooner Alert, conducted a survey of Frenchman Bay in August 2011. The purpose was to detect and trap juvenile cod for genetic analysis, map traditional cod grounds, measure temperature, salinity, pH and dissolved oxygen and conduct sonar transects to detect schools of forage fish. While no cod were found, the researchers were able to collect data to compare Frenchman Bay with productive areas of the western Gulf. Sea Grant funds supported transportation and fuel costs for the sampling trip.

Sea Grant funds: $5,000

Saving the Oceans film crew and host Carl Safina joined the researchers to film their work for an upcoming PBS documentary.