Coupled Multi-Scale, Multi-Disciplinary Modeling of Fish Aquaculture Farms: From Fish Biomechanics to Cage Hydrodynamics

Lead PI: Dick Yue, Massachusetts Institute of Technology

Objectives
To develop a coupled multi-physics model of offshore cage-based aquaculture in order to understand and optimize the design and feed management of floating fish farms, as well as their impact on the environment. The coupled multi-physics model of the aquaculture cage captures the behavior of the cage and the fish school in a realistic environment, and it is based on hydrodynamic, biomechanic and social interaction submodels. The project will provide critical knowledge on the offshore cagebased aquaculture that can offer competitive advantages for  the local aquaculture industry.

Methodology
Given the complexity of the overall system, we aim to develop models that are as simple as possible, while still capturing the relevant physics. We will leverage simple, but complete theoretical and computational models of individual fish biomechanics and hydrodynamics (“fishlets”), and fast O(N) computational methods for hydrodynamic interactions among hundreds of fish to obtain realistic models of fish schools. We will extend existing social interaction models of fish schooling to include confinement-induced effects. We will employ our state-of-the-art computational hydrodynamic algorithms to model the effect of waves and currents on the fish cage and the fish contained in it.

Rationale
Understanding the response and the loads on a floating cage in an ocean environment is an important and complex problem. The presence of caged fish significantly impacts the cage behavior and vice versa. Fish can increase drag forces on the cage, and the cage affects fish behavior and leads to suboptimal feeding, decreased health of the fish stock and increased environmental impact. Only by considering the coupled cage-fish problem we can develop aquaculture systems where cage design and feed management work in conjunction to result in healthy fish stock with minimum wasted feed and minimum environmental impact.