This study focuses on the structural analysis of a sustainable Integrated Multi-Trophic Aquaculture system (IMTA), designed by the University of New Hampshire (UNH) for deployment in the Gulf of Mexico. Building on the IMTA system at UNH [1], this new system is intended for the growth of 4,000 red drum (Sciaenops ocellatus) as the fed species, alongside eastern oysters (Crassostrea virginica) and graceful red seaweed (Gracilaria tikvahiae) as the extractive species.
The floating structure utilizes 0.32-meter diameter high-density polyethylene (HDPE) pipes as concentric squares, forming two fish containment sections with a submerged volume of approximately 136 m³ each. Flotation is provided by the HDPE pipe with fitted expanded polystyrene (EPS) foam billets. The structure also includes transverse HDPE and longitudinal fiberglass beams, and support decking plates and stanchions. The design features an above-surface “jump net” (PET monofilament) and a submerged fish containment copper alloy mesh.
The mooring attachment loads were estimated using a dynamic, fluid-structure interaction software called Hydro-FE integrated with the Hexagon Marc solver [2]. Input parameters included waves and currents, associated with regular service and extreme hurricane conditions. The structural model was validated by comparing the results of the SolidWorks finite element analysis and Marc simulations for a reduced order model. The simulation results are being used to evaluate system stresses, appropriate safety factor values and to estimate the structure’s design life.
[1] Chambers, M., Coogan, M., Doherty, M., & Howell, H., 2024. Integrated multi-trophic aquaculture of steelhead trout, blue mussel and sugar kelp from a floating ocean platform. Aquaculture, 582, 740540.
[2] Knysh, A., Coyle, J., DeCew, J., Drach, A., Swift, M.R., & Tsukrov, I., 2021. Floating protective barriers: evaluation of seaworthiness through physical testing, numerical simulations and field deployment. Ocean Engineering 227, 108707.