A seine net includes a net body having a woven net, an upper rope, a lower rope, a left wing net and a right wing net. The woven net has a division rope disposed between the upper rope and the lower rope, upper mesh areas woven between the upper rope and the division rope and horizontally juxtaposed, and lower mesh areas woven between the lower rope and the division rope and horizontally juxtaposed. Each upper mesh area has multiple first diamond meshes. Each lower mesh area has multiple second diamond meshes. The first diamond meshes are reversely arranged relative to the second diamond meshes. The first diamond meshes and the second diamond meshes gradually decrease in size from the left and right wing nets toward the net middle.

A seine net includes a net body having a woven net, an upper rope, a lower rope, a left wing net and a right wing net. The woven net has a division rope disposed between the upper rope and the lower rope, upper mesh areas woven between the upper rope and the division rope and horizontally juxtaposed, and lower mesh areas woven between the lower rope and the division rope and horizontally juxtaposed. Each upper mesh area has multiple first diamond meshes. Each lower mesh area has multiple second diamond meshes. The first diamond meshes are reversely arranged relative to the second diamond meshes. The first diamond meshes and the second diamond meshes gradually decrease in size from the left and right wing nets toward the net middle.

A seine net includes a net body having a woven net, an upper rope, a lower rope, a left wing net and a right wing net. The woven net has a division rope disposed between the upper rope and the lower rope, upper mesh areas woven between the upper rope and the division rope and horizontally juxtaposed, and lower mesh areas woven between the lower rope and the division rope and horizontally juxtaposed. Each upper mesh area has multiple first diamond meshes. Each lower mesh area has multiple second diamond meshes. The first diamond meshes are reversely arranged relative to the second diamond meshes. The first diamond meshes and the second diamond meshes gradually decrease in size from the left and right wing nets toward the net middle.

A mort trap assembly includes an upper ramp with a top end, a first bottom end, and an outer edge that is fixedly attached to an inner edge of a slide. A retaining chamber is located below the upper ramp and includes a first entry port located below the first bottom end of the upper ramp. A lower ramp has a top end spaced away from the upper ramp, and a first bottom end located at a bottom of the first entry port of the retaining chamber, and a purge pipe fluidly connected to the retaining chamber. The upper ramp is configured to receive morts from the slide, and the lower ramp is configured to receive the morts from the upper ramp and to direct the received morts into the first entry port.

A seine net assembly utilizes buoyant seine net purse rings that float above the leadline and therefore reduce the risk of the purse rings getting snagged on the bottom of the body of water. An exemplary buoyant purse ring may have a specific gravity less than 1.0 and preferably, between 0.08 and 0.96. It is desirable that the purse rings float but not be so buoyant that they cause the leadline and therefore the leadline end of the net to float. An exemplary purse ring is made out of a polymeric material such as polyethylene and most preferably ultra-high molecular weight polyethylene (UHMWPE). A polymeric purse ring may have a ring wall with a rectangular shape designed for durability and tighter packing. The width of the ring wall may be greater than the thickness.

A seine net assembly utilizes buoyant seine net purse rings that float above the leadline and therefore reduce the risk of the purse rings getting snagged on the bottom of the body of water. An exemplary buoyant purse ring may have a specific gravity less than 1.0 and preferably, between 0.08 and 0.96. It is desirable that the purse rings float but not be so buoyant that they cause the leadline and therefore the leadline end of the net to float. An exemplary purse ring is made out of a polymeric material such as polyethylene and most preferably ultra-high molecular weight polyethylene (UHMWPE). A polymeric purse ring may have a ring wall with a rectangular shape designed for durability and tighter packing. The width of the ring wall may be greater than the thickness.

A net assembly used for purse seine fishery, which is mounted on a first vessel, dropped into seawater from the first vessel, and towed by a second vessel to surround and pull fish to capture fish. The net assembly includes a plurality of floats floating on a surface of seawater to provide buoyancy to the net assembly, and coupled to one another in a spaced manner in a lengthwise direction of the net assembly; a net combination of a plurality of nets disposed under the floats in an inter-coupled state, and sunken and deployed from the surface of seawater to surround and capture fish; a weight body extending along a lower end of the net combination to provide a sinking force by means of gravity to sink the net combination; and a purse wire extending along the net combination while being spaced apart from the weight body in a downward direction, and tightened by the first vessel to allow the net assembly to form a closed space below the surface of seawater.

A net assembly used for purse seine fishery, which is mounted on a first vessel, dropped into seawater from the first vessel, and towed by a second vessel to surround and pull fish to capture fish. The net assembly includes a plurality of floats floating on a surface of seawater to provide buoyancy to the net assembly, and coupled to one another in a spaced manner in a lengthwise direction of the net assembly; a net combination of a plurality of nets disposed under the floats in an inter-coupled state, and sunken and deployed from the surface of seawater to surround and capture fish; a weight body extending along a lower end of the net combination to provide a sinking force by means of gravity to sink the net combination; and a purse wire extending along the net combination while being spaced apart from the weight body in a downward direction, and tightened by the first vessel to allow the net assembly to form a closed space below the surface of seawater.

A mort trap assembly includes an upper ramp with a top end, a first bottom end, and an outer edge that is fixedly attached to an inner edge of a slide. A retaining chamber is located below the upper ramp and includes a first entry port located below the first bottom end of the upper ramp. A lower ramp has a top end spaced away from the upper ramp, and a first bottom end located at a bottom of the first entry port of the retaining chamber, and a purge pipe fluidly connected to the retaining chamber. The upper ramp is configured to receive morts from the slide, and the lower ramp is configured to receive the morts from the upper ramp and to direct the received morts into the first entry port.

A system and method for automatically harvesting fish from an aquaculture cage is provided. Underwater robotic rovers draw out a large net from a protective enclosure. The net is manipulated to corral or concentrate the fish into a smaller volume. Transponders installed at strategic locations throughout the cage facilitate navigation of the rovers.