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.

An arrangement for remotely controlling the position of a trawl door (1) or deflector for seismic surveys comprises an attachment point provided on a movable part (10). The movable part (10) can be moved in relation to a body of the trawl door (1) by means of a remotely controlled actuator. The movable part (10) with the attachment point (15) for a towing line is provided at the body or at a centre rib of the body of the trawl door (1). The movable part (10) with the attachment point can be moved substantially in vertical direction and approximately at right angles in relation to the direction of movement of the trawl door (1) when operated at sea, thereby resulting in an upwards or downwards movement of the trawl door (1) and thereby providing continuous adjustment of depth at which the trawl door (1) operates in the water.

An arrangement for remotely controlling the position of a trawl door (1) or deflector for seismic surveys comprises an attachment point provided on a movable part (10). The movable part (10) can be moved in relation to a body of the trawl door (1) by means of a remotely controlled actuator. The movable part (10) with the attachment point (15) for a towing line is provided at the body or at a centre rib of the body of the trawl door (1). The movable part (10) with the attachment point can be moved substantially in vertical direction and approximately at right angles in relation to the direction of movement of the trawl door (1) when operated at sea, thereby resulting in an upwards or downwards movement of the trawl door (1) and thereby providing continuous adjustment of depth at which the trawl door (1) operates in the water.

A bridle block is for a deflector, and has a stem and a rocker arm attached to each other on a pivot axis. The stem has an attachment for a vessel towline, a forward portion of the rocker arm has an attachment for fore bridle lines of the deflector, and an aft portion of the rocker arm has an attachment for aft bridle lines of the deflector. A hydraulic cylinder has a valve, and is attached to the stem and the rocker arm to hold the stem and the rocker arm in a relative position. The valve is operated by a signal from a control unit. The valve takes an open position when a signal is missing, so there is an open fluid connection between a piston side of a piston and a reservoir or an open fluid connection between the piston-rod side of the piston and the reservoir.

A bridle block is for a deflector, and has a stem and a rocker arm attached to each other on a pivot axis. The stem has an attachment for a vessel towline, a forward portion of the rocker arm has an attachment for fore bridle lines of the deflector, and an aft portion of the rocker arm has an attachment for aft bridle lines of the deflector. A hydraulic cylinder has a valve, and is attached to the stem and the rocker arm to hold the stem and the rocker arm in a relative position. The valve is operated by a signal from a control unit. The valve takes an open position when a signal is missing, so there is an open fluid connection between a piston side of a piston and a reservoir or an open fluid connection between the piston-rod side of the piston and the reservoir.

A fishing system includes a submersible fishing implement for being received in a body of water and configured for capturing one or more fish. An implement driver is configured to drive movement of the submersible fishing implement through the body of water. A data collection system includes one or more sensors for sensing one or more fishing parameters and transmitting a fishing parameter signal representative of the one or more fishing parameters. A controller is operatively connected to the data collection system to receive the fishing parameter signal and to determine based on the fishing parameter signal a selected fishing location. The controller is further configured to transmit a navigation signal to the implement driver operative to control the implement driver to drive movement of the submersible fishing implement toward the selected fishing location.

A fishing system includes a submersible fishing implement for being received in a body of water and configured for capturing one or more fish. An implement driver is configured to drive movement of the submersible fishing implement through the body of water. A data collection system includes one or more sensors for sensing one or more fishing parameters and transmitting a fishing parameter signal representative of the one or more fishing parameters. A controller is operatively connected to the data collection system to receive the fishing parameter signal and to determine based on the fishing parameter signal a selected fishing location. The controller is further configured to transmit a navigation signal to the implement driver operative to control the implement driver to drive movement of the submersible fishing implement toward the selected fishing location.

An arrangement for remotely controlling the position of a trawl door (1) or deflector for seismic surveys comprises an attachment point provided on a movable part (10). The movable part (10) can be moved in relation to a body of the trawl door (1) by means of a remotely controlled actuator. The movable part (10) with the attachment point (15) for a towing line is provided at the body or at a centre rib of the body of the trawl door (1). The movable part (10) with the attachment point can be moved substantially in vertical direction and approximately at right angles in relation to the direction of movement of the trawl door (1) when operated at sea, thereby resulting in an upwards or downwards movement of the trawl door (1) and thereby providing continuous adjustment of depth at which the trawl door (1) operates in the water.

An arrangement for remotely controlling the position of a trawl door (1) or deflector for seismic surveys comprises an attachment point provided on a movable part (10). The movable part (10) can be moved in relation to a body of the trawl door (1) by means of a remotely controlled actuator. The movable part (10) with the attachment point (15) for a towing line is provided at the body or at a centre rib of the body of the trawl door (1). The movable part (10) with the attachment point can be moved substantially in vertical direction and approximately at right angles in relation to the direction of movement of the trawl door (1) when operated at sea, thereby resulting in an upwards or downwards movement of the trawl door (1) and thereby providing continuous adjustment of depth at which the trawl door (1) operates in the water.

A fishing system includes a submersible fishing implement for being received in a body of water and configured for capturing one or more fish. An implement driver is configured to drive movement of the submersible fishing implement through the body of water. A data collection system includes one or more sensors for sensing one or more fishing parameters and transmitting a fishing parameter signal representative of the one or more fishing parameters. A controller is operatively connected to the data collection system to receive the fishing parameter signal and to determine based on the fishing parameter signal a selected fishing location. The controller is further configured to transmit a navigation signal to the implement driver operative to control the implement driver to drive movement of the submersible fishing implement toward the selected fishing location.