The physics of open-water shellfish aquaculture

Aquaculture of shellfish species is expanding in many countries. Limitations on, and competition for, inshore water space is making offshore shellfish developments more attractive. Here we review issues relating to the design and mechanics of shellfish longline structures in relation to the offshore marine environment. Two main facets are explored: (i) the effect of the flow (waves and currents) on the farm and (ii) the reverse perspective of the impact of the farm on the flow. Because these systems are relatively new, we first examine similar systems, both natural (kelp beds) and man-made (floating breakwaters, fish farms). Techniques for measuring both the local oceanography and the structural response are listed along with new approaches for measuring important properties. A number of future applied research topics are identified as being a key to advancing the industry, including issues like mooring design, vertical drag coefficients, wave–current interaction, stratification and influence on fauna.