FLOW-3D News: Spring 2005 - Application Note
Marine Shellfish Culture
Hardwood Island Research Raft (Maine)
Shellfish culture in Maine, began with efforts by Ed Myers (Abandoned Farms) in the early 1970’s to grow mussels using a longline system. Problems with predation by sea ducks, market price and production technology hindered the early development of the industry. However, the early efforts resulted in legislation providing the framework for further aquaculture lease development, and garnered the interest of entrepreneurs which eventually led in the growth of shellfish farming over the next three decades.
In 1978, Great Eastern Mussel Farms (GEM) tried and failed with longline culture, and began harvesting and selling high quality wild mussels based on quality control standards. GEM’s marketing efforts put mussels on the map in the U.S. and led to a strong demand for the shellfish through the 1980’s. Early yields were quite good, but by the mid-1980’s, when farm sizes and seeding densities increased, yields decreased. Samples of mussel patches from the edge and the middle of bottom culture sites demonstrated a strong density dependency on growth rates of the mussel seed, which was also affected by water current speeds in the sites studied.
In 1986, GEM received funding from the National Science Foundation (NSF) to develop a mussel growth model based on site-specific conditions and factors controlled by the mussel farmer (e.g., seed size, density, biomass, and time of year seeded). As a result of this work, annual mussel farm landings increased, but then leveled off due to a scarcity of mussel seed.
To increase yields beyond those attainable with bottom culture methods, GEM developed mussel rafts similar to those used in Spain and Scotland. GEM used rafts rather than longlines because predator nets surrounding the rafts could be used to keep sea ducks from eating the mussels, and because a large amount of mussels could be produced in a small area to reduce competition from other users of coastal waters.
In 1998, GEM received funding from the United States Department of Agriculture (USDA) to develop an aquaculture expert system for mussel raft culture. This work, which was completed in 2004, integrates the previous research on bottom culture and extends the analysis methods to three dimensions (i.e., suspension culture).
Campbell, D.E. and C.R. Newell. 1998. MUSMOD: a production model for bottom culture of the blue mussel, Mytilus edulis. J. exp. Mar. biol.ecol. 219: 171-204.
Newell, C.R. 1990. The effects of mussel (Mytilus edulis, Linnaeus, 1758) position in seeded bottom patches on growth at subtidal lease sites in Maine. J. Shellfish Res. 9: 113-118.
Newell, C.R., D.E. Campbell and S.M. Gallagher. 1998. Development of the mussel aquaculture lease site model MUSMOD: a field program to calibrate model formulations. J.exp.mar.biol.ecol. 219: 143-170.