Aquaculture and Fishery Netting
topic
Aquaculture netting encompasses fish cage nets, predator exclusion nets, pond covers, and harvesting nets manufactured from HDPE, nylon (PA6, PA66), and UHMWPE fibres using raschel knitting or braiding processes. Salmon cage nets (HDPE knotless raschel, mesh size 12–25 mm, twine diameter 2–4 mm, breaking strength 80–300 N/mesh junction) are deployed at depths of 15–50 m in sea cage systems of 50–200 m circumference, containing 50,000–200,000 fish per cage. Copper alloy mesh nets (CuZn alloy, 0.5–2.0 mm wire diameter) provide inherent antifouling properties (biofouling reduction >90% versus HDPE) eliminating net cleaning costs of $50,000–150,000/cage/year in high-fouling locations. Net solidity ratio (projected area/total area) of 0.15–0.35 balances water exchange (minimum 0.15 m/s current velocity through net) with predator exclusion. Antifouling coatings (Cu₂O at 15–25% in vinyl or epoxy binder, 100–200 µm DFT) extend net cleaning intervals from 4–6 weeks to 6–12 months for HDPE nets. UHMWPE nets (Dyneema SK75, specific strength 3.5 GPa·cm³/g) reduce net weight by 40–50% versus nylon at equivalent strength for deepwater cage applications. Global aquaculture netting market exceeds $1.2 billion.
Role
Aquaculture netting is the primary containment structure for the $300 billion global aquaculture industry, with net material selection, mesh geometry, and antifouling strategy directly determining fish health, stocking density, labour costs, and profitability of salmon, sea bass, and tilapia cage farming operations.