As the dominant forage fish in the Gulf of Maine food chain and an important bait source Maine lobstermen, Atlantic herring are vitally important to the ecology and economy in the region. A 2009 cut in annual herring quota by the New England Fishery Management Council has prompted industry stakeholders to take a closer look at the role that inshore areas play in overall herring biomass.
This spring, GMRI and the Maine Lobstermen's Association launched a comprehensive investigation of these herring spawning areas. Ten lobstermen from ten different Maine communities were enlisted to participate in a fourteen week study. The project, funded through federal grants, marks the first inshore Gulf of Maine herring survey since 2006.
This summer, each participant's boat was outfitted with an ES70 echosounder, computer processor, and monitor. The ES70 uses sound frequencies to produce detailed images of the ocean floor and distinguishes individual fish species based on an identifying echo signature that each species displays.
In late August, each boat began conducting eight-hour overnight transects. The weekly data collection trips will coincide with the herring spawning season. GMRI's Demersal Ecologist Graham Sherwood and graduate student Katie Wurtzel will analyze the data from each boat to measure herring age, density, and biomass. The data will be further enhanced by actual herring samples collected by herring industry participants during the ten week period.