A method for external fish parasite monitoring in aquaculture, comprising the steps of: submerging a camera (52) in a sea pen containing fish, the camera having a field of view; capturing images of the fish with the camera (52); and identifying external fish parasite on the fish by analyzing the captured images, characterized in that a target region within the field of view of the camera (52) is illuminated from above and below with light of different intensities and/or spectral compositions.

A method for external fish parasite monitoring in aquaculture, comprising the steps of: submerging a camera (52) in a sea pen containing fish, the camera having a field of view; capturing images of the fish with the camera (52); and identifying external fish parasite on the fish by analyzing the captured images, characterized in that a target region within the field of view of the camera (52) is illuminated from above and below with light of different intensities and/or spectral compositions.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for obtaining initial parameters for ultrasonic transducers around a calibration target. The calibration target can include a fish-shaped structure, sensors placed at different locations of the fish-shaped structure, a processor that receives sensor values from the sensors, and a transmitter that outputs sensor data from the calibration target based on the sensor values. The calibration target can be fixed at a particular position relative to the ultrasonic transducers by a filament coupled to both the calibration target and a support structure. Sensor data can be obtained from the calibration target at the particular position relative to the ultrasonic transducers, and relative locations of the sensors can be determined. Parameters for the ultrasonic transducers around the calibration target can be adjusted based on the sensor data and the respective locations of the sensors.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for obtaining initial parameters for ultrasonic transducers around a calibration target. The calibration target can include a fish-shaped structure, sensors placed at different locations of the fish-shaped structure, a processor that receives sensor values from the sensors, and a transmitter that outputs sensor data from the calibration target based on the sensor values. The calibration target can be fixed at a particular position relative to the ultrasonic transducers by a filament coupled to both the calibration target and a support structure. Sensor data can be obtained from the calibration target at the particular position relative to the ultrasonic transducers, and relative locations of the sensors can be determined. Parameters for the ultrasonic transducers around the calibration target can be adjusted based on the sensor data and the respective locations of the sensors.

A controllable semi-open mariculture cabin system is provided, including a mariculture cabin, a water inlet mechanism, a filtering mechanism, and a fish outlet pipe. The water inlet mechanism includes a water inlet pipe and a plurality of high-pressure water inlet pipes. The water inlet pipe is located on one side of an upper part of the mariculture cabin. The plurality of high-pressure water inlet pipes are distributed in a circumferential direction of a top of the mariculture cabin. Tail ends of the high-pressure water inlet pipes are connected to jet pipes extending into the mariculture cabin. The filtering mechanism is arranged at the bottom of the mariculture cabin. An outlet end of the filtering mechanism is located in sea water outside. The fish outlet pipe is provided on a cabin wall of the mariculture cabin. A gate valve capable of opening and closing is mounted on the fish outlet pipe.

A roof cover for a fish farm, in which solar cells may be arranged on the roof cover to collect solar energy, and where the roof cover is resistant to weather conditions, and where the roof cover provides a controlled environment for fish farming by protecting it from wind and weather.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for self-calibrating ultrasonic removal of sea lice. In some implementations, a method includes generating, by transducers distributed in a sea lice treatment station, a first set of ultrasonic signals, detecting a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water, determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected, obtaining an image of a sea louse on a fish in the sea lice treatment station, determining, from the image, a location of the sea louse in the sea lice treatment station, and generating a third set of ultrasonic signals that focuses energy at the sea louse.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for self-calibrating ultrasonic removal of sea lice. In some implementations, a method includes generating, by transducers distributed in a sea lice treatment station, a first set of ultrasonic signals, detecting a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water, determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected, obtaining an image of a sea louse on a fish in the sea lice treatment station, determining, from the image, a location of the sea louse in the sea lice treatment station, and generating a third set of ultrasonic signals that focuses energy at the sea louse.

The invention relates to a diffusor for adding of gases into water, said diffusor comprising a perforated tube (1) and at least one supply tube (2), said the at least one supply tube (2) is at one end coupled to a source for supplying gas and at the other end in fluid communication with the perforated tube (1), the gas is supplied to the perforated tube (1) through at least one inner supply tube (4; 5; 15) extending from the supply tube (2) to the perforated tube (1). The invention is distinctive in that at the least one inner supply tube (4; 5; 15) is a non-perforating tube and has at least one outlet (4a, 5a, 15a) situated at a free end of the at least one inner supply tube (4, 5, 15), said gas is adapted to be distributed into the perforated tube (1) through the at least one outlet (4a, 5a, 15a).

A composition and a method with active agents to inactivate or kill parasites that attack fish and to loosen parasites that are fastened to the fish are described. The composition can be used for the prevention of and treatment of infestations or infections from parasites on fish.