A fishing device particularly designed for Asian carp fishing, which includes two fishing boats, a collection frame, a fishing net, a display mechanism with a plurality of optical sensors and optical receivers, one support mechanism for one fishing boat and one lifting mechanism for one fishing boat. The lifting mechanism includes a motor, a rotary shaft, a bait holding basket, a plurality of shaft supports and a plurality of rope units. Thus, a selected bait can be used for classification fishing. The quantity of fish catch can be determined timely through the display mechanism. The lifting mechanism allows steading lifting of the fish catch out of the water without introducing any harm to the fish catch. The number and survival rate of the fish catch can be ensured while an effective fishing can be achieved. This fishing device is particularly designed for catching Asian carp fishes.

A multipurpose portable or transportable selective fish capture system and no touch transport system is described that comprises an interconverting pontoon platform which can be adapted to include a solar and/or hydro electrical energy collection, conversion, storage and distribution system and to convert between a selective fish capture system and no touch fish transport system and an for emergency response for search and rescue or oil spill response support and oil spill collection and oil transport system.

A gate mechanism (20) is adapted for mounting within the extension (4) of a trawl net (1), the gate mechanism comprising a turbine (47/147/247) for powering rotation of the gate mechanism as it is dragged through the water within the trawl net.

A gate mechanism (20) is adapted for mounting within the extension (4) of a trawl net (1), the gate mechanism comprising a turbine (47/147/247) for powering rotation of the gate mechanism as it is dragged through the water within the trawl net.

A method of controlling position of a trawl net is provided. The method may comprise: receiving, by a processor, a control input, wherein the control input comprises: (i) a selection of one of a plurality of position control modes, and (ii) a position control setpoint for the trawl net; receiving, by the processor, sensor data indicating a sensed position of the trawl net; generating, by the processor, a first trawl position control output based on the control input and the sensor data; determining, by the processor, a rate of change of bathymetry along a travel path of the trawl net; and in response to the rate of change of bathymetry meeting a threshold condition, generating a second trawl position control output by changing the one of the plurality of position control modes to another of the plurality of position control modes.

A method of controlling position of a trawl net is provided. The method may comprise: receiving, by a processor, a control input, wherein the control input comprises: (i) a selection of one of a plurality of position control modes, and (ii) a position control setpoint for the trawl net; receiving, by the processor, sensor data indicating a sensed position of the trawl net; and generating, by the processor, a trawl position control output based on the control input, the sensor data and predicted trawl net position data. The predicted trawl net position data may be generated by: defining, by the processor, a plurality of parameters; receiving, by the processor, input data comprising vessel speed data, tow line payout data, and a candidate drag coefficient value for the trawl net; and determining, by the processor, a tow angle based on the plurality of parameters and the input data.