INTEGRATING THE CULTIVATION OF MULTIPLE CROPS ON LONGLINE STRUCTURES: TRIALS WITH MUSSELS Mytilus edulis AND SUGAR KELP Saccharina latissima

Mussel (Mytilus edulis) farming and sugar kelp (Saccharina latissima )  farming have been  two rapidly expanding sectors of marine farming in the Northeastern U.S. over the past ten years. The number of mussel farms has climbed from two or three raft-based farms in Maine to more than a dozen in that state, and an additional four offshore farms in NH, MA and RI. There were no seaweed or kelp farms a decade ago, and now there are more than 40 across New England. Markets are robust for both crops and the alternatives are a dwindling and erratic wild supply or imports. Given that both these crops are individually being grown on similar longline structures, integrating the cultivation of the crops can be advantageous for several reasons; (1) better space utilization of limited permitted sites - "3D farming", (2) shared use of the capital costs of expensive anchors, lines, and buoys, (3) better business risk management via crop diversification, and (4) lower risk to protected species by using fewer vertical lines per unit of production. The additional benefits of using multiple complementary nutrient bio-extractive crops are improved ec osystem services such as improved water quality, and provision of structures resulting in nursery and foraging habitat for other species.

Our research focused on developing and demonstrating innovative gear that efficiently integrated two different cro ps into an offshore lease area by using multiple growline systems. Our engineering and  in-situ  trials developed methodologies for efficient management and harvest of a dual-crop culture system.