FLOATING, CLOSED, SELF SUPPORTING FISH FARMING CAGE, COMPRISED OF A TUBULAR MEMBRANE MADE OF HIGH STRENGTH AND LOW BIOFOULING ADHERENCE POLYMER AND FISH FARMING CAGE SYSTEMS.
The invention relates to a closed, self-supporting cage (100) for fish-farming in the sea, aimed mainly at the fish-farming industry and/or storage centres, which adapts to the square, rectangular or circular shapes of the existing meccano-type floating metal structures (90), with perimeter passages, which comprises a tubular membrane (1) such as a bag made of a polymer with high mechanical strength and low biofouling adhesion, that ends in a conical shape at the distal end from the surface thereof, wherein said tubular membrane (1) comprises floats (2, 2') that aid the buoyancy of same in the water and which are incorporated into said actual tubular membrane (1); an upper sleeve (6) such as a sealed continuous pocket containing, on the inside thereof, a steel cable that runs along the entire upper edge of the tubular membrane (1), from which a plurality of couplings start; suction or "lift-up" means (4, 4') located centrally on the bottom and inside the tubular membrane (1); and outer perimeter rings (11) concentric with the liner of the tubular membrane (1) which basically consist of a steel cable covered with high-strength polyethylene, which serve as an exoskeleton for the tubular membrane (1). The invention further relates to a system for fish-farming in the sea, which comprises a plurality of cages and a system for supplying refreshing water to the cages (100), which comprises means for treating and recirculating water.