Longhuan Zhu
Research Scientist
Center for Sustainable Seafood Systems
UNH School of Marine Science and Ocean Engineering
Friday, March 28, 2025, 3:10pm
Chase 105
Abstract
With the expansion of macroalgae aquaculture in oceanic waters, particularly species of the order Laminariales, there is a growing need for optimized kelp cultivation systems suitable for exposed conditions. Kelp farm systems must be designed to withstand extreme storm events to prevent failures that could generate ghost gear while also minimizing risks to important marine resources such as whales. To address this need, we developed a high-fidelity hydrodynamic modeling technique for kelp farms by introducing equivalent kelp elements for kelp aggregates with Reynolds number-based drag coefficients derived from full scale towing tests. The model was validated with comprehensive field datasets from a single-line cultivation system with two mooring connections in Saco Bay, Maine. We then applied this model to design whale-safe kelp farms that use high density polyethylene pipe (HDPE) as the cultivation structure and fiberglass rod as a major part of the mooring line to avoid whale entanglement. Numerical simulations showed that whales have the potential to break the mooring rod and avoid entanglement. Finally, we explored the potential benefits of kelp farms for wave attenuation, suggesting that they could serve as effective nature-based coastal protection.
Bio
Longhuan Zhu joined the School of Marine Science and Ocean Engineering at the University of New Hampshire in September 2023. He is a Research Scientist in the Center for Sustainable Seafood Systems where his primary focus is developing engineering design and evaluation techniques for coastal and offshore sustainable seafood systems. He has extensive experience in numerical modeling of structural dynamics, fluid-structure interaction, regional coastal wave-current-sediment processes, and flow-vegetation interaction for coastal resilience. He holds a B.Eng. and M.Eng. in Naval Architecture and Ocean Engineering, as well as a Ph.D. in Civil Engineering.
