The increase in global population has heightened the demand for fish as a crucial and cost-effective source of nutrition. To meet this demand, the aquaculture industry has significantly expanded, surpassing natural capture production worldwide. Despite this growth, research and design in this field remain limited, offering opportunities for further exploration. This study aims to optimize fish production and profitability through the implementation of a grid system. It numerically analyzes offshore fish cages configured in single, two-cage, and four-cage layouts. The single cage, with dimensions of 30m × 30m × 30m, is positioned at a water depth of 150m using nonlinear catenary mooring lines. Similar mooring specifications are applied to the bridle lines for the two and four-cage arrangements. Numerical simulations using ANSYS AQWA investigate hydrodynamic parameters under irregular waves (JONSWAP Spectrum - Hs) with varying periods (7s–20s) and incident angles (0°–90°), as well as current velocities (0.1m/s to 0.5m/s). Wave conditions representing the Off-Mangalore coast with return periods of 10, 50, and 100 years are used. Results show that the single cage exhibits the highest motion responses, with reductions of 15%–20% in multi-cage setups due to leeward shielding. The four-cage layout proves effective across tested conditions, suggesting its potential in optimizing offshore aquaculture performance.
The shift towards aquaculture production surpassing capture fisheries in recent years has opened up significant opportunities for innovative designs within the aquaculture industry. Initially, research efforts were concentrated on inland and nearshore cage designs tailored for sheltered regions. However, meeting the global demand for fish production necessitates large-scale farming operations, a task that can only be achieved through offshore aquaculture. Offshore environments present formidable challenges, demanding structures designed to withstand harsh sea conditions. Several researchers have conducted detailed reviews of both nearshore and offshore aquaculture, highlighting the complexities and potentials of these systems (Guo et al. 2020; Huguenin 1997; Klebert et al. 2013; Shaik and Thuvanismail 2024; Silva and Phillips 2007; Xu and Qin 2020).
