Preliminary information on cod and haddock production in submerged cages off the coast of New Hampshire, USA

The University of New Hampshire's Open Ocean Aquaculture project is intended to evaluate the potential development of offshore aquaculture in the northeastern United States. As part of this project, both cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) were raised in submerged cages at an exposed location 14 km off the coast of New Hampshire, USA. In September 2003, at a mean weight of 45 g, 30 000 cod were transferred offshore into a 200-m3 nursery net located inside a 3000-m3 cage submerged 12 m below the surface. Cod were later released into the main cage at a mean weight of 90 g and are intended to be grown to a market size of 2–3 kg. As of February 2005, the cod averaged 652 g, had a 92% survival rate, an FCR of 1.49, and an SGR of 0.49% d−1. Haddock research was initiated in mid-September 2002, when 3000 haddock (16 g mean weight) were transferred to a 35-m3 inshore nursery pen. By mid-December 2002, their mean weight had increased to 78 g, and the fish were transferred to an offshore cage. As of February 2005, the haddock had a survival rate of 92%, mean weight of 1360 g, FCR of 2.36, and SGR of 0.35% d−1.