Objectives:The overall goal is to develop and validate an advanced hydrodynamic modeling capability, AQUA-MIT, for predicting nonlinear sea loads and nonlinear seakeeping responses of aquaculture structures and mooring lines under severe sea conditions. Importantly, AQUA-MIT will be capable of accurately evaluating turbulent viscous drag and lift forces on net cages including biofouling and fish swimming effects. AQUA-MIT will be a powerful open-community tool to be used by the public to design and develop innovative economical netted marine facilities for offshore aquaculture farming.Methodology:A combined computational and experimental approach is adopted. We (i) develop and apply Navier-Stokes equations based direct numerical simulations (DNS) to quantify the turbulent viscous drag/lift forces on netted aquaculture cages including effects of biofouling growth on cages and fish swimming inside cages; (ii) apply the established high-order spectral (HOS) model to compute nonlinear ambient flow fields of severe seas; (iiI) compute nonlinear global motions of fishing cages by means of an established boundary element method (pFFTQBEM) coupled with the robust cable program, RISER-SIM; and (iv) conduct scaled model tests to obtain benchmark solutions for validating model predictions.Rationale:There is potential for substantially increasing seafood production by moving fishing farms to offshore areas. Harsh offshore wave and current conditions, however, pose great challenges to aquaculture farming technologies and operations. We propose to develop an advanced hydrodynamic modeling capability, AQUA-MIT, for accurately predicting nonlinear sea loads and seakeeping responses of netted aquaculture facilities under extreme sea conditions including biofouling and fishing swimming effects. AQUA-MIT will be used by the public to design and develop innovative economical offshore aquaculture structures for U.S. aquaculture farmers to expand the production capacity of domestic seafood.