Engineering Structures for Offshore Macroalgae Farmingar System)

This project continues our development of innovative systems for farming macroalgae on the high seas. We will identify suitable sites in Nantucket Sound to demonstrate our system and determine the associated environmental parameters including depths, currents, and waves. By combining that information with load and acceleration data from our Phase I wave-basin tests, we will refine the structural details of a two-transverse-truss array for fabrication and deployment. This 33m x 67m, instrumented, array in will support 36 seeded longlines of sugar kelp, Saccharina latissimi. We will monitor the performance of the system and the growth of the kelp at variable longline spacing from November 2017 to May 2018. We will harvest the kelp and determine optimal longline spacing based on the goal of maximizing production per unit area. A second season of kelp farming will then be used to measure optimized growth per unit area. Using data collected from these instrumented sea trials, we will design a 100m x 200m array that supports the culture of 2 ha of macroalgae longlines. Based on the projected system cost and the productivity of our test crops, we will refine our profit/loss models for 2 ha array modules and refine our business plan.