A tank for water has a bottom and a surrounding wall with an inside and an outside. In a lower portion, the wall is provided with a hatch casing positioned in a hatch opening extending through the wall for access by personnel from the outside to the inside of the tank. The hatch casing is provided with a hatch with an inside and an outside. The hatch in a closed position closes the hatch opening in a liquid-tight manner. The inside of the hatch is flush with the inside of the wall when the hatch is in the closed position. A method for giving personnel access to the tank through the hatch opening is also described.

A method of moving farmed aquatic animals from a tank containing the animals, the tank having a tank outlet and a conveyance pipe, the conveyance pipe having a conveyance pipe inlet connected to the tank outlet and a conveyance pipe outlet at an outlet elevation higher than the tank outlet, the method comprising: (i) by means of a water inflow into the tank, maintaining a water level in the tank at a level above the outlet elevation to generate a flow of water from the tank through the conveyance pipe while positioning a moveable water-permeable screen inside the tank to crowd the animals towards the tank outlet, (ii) by means of the flow of water therethrough, moving animals through the conveyance pipe.

A method of moving farmed aquatic animals from a tank containing the animals, the tank having a tank outlet and a conveyance pipe, the conveyance pipe having a conveyance pipe inlet connected to the tank outlet and a conveyance pipe outlet at an outlet elevation higher than the tank outlet, the method comprising: (i) by means of a water inflow into the tank, maintaining a water level in the tank at a level above the outlet elevation to generate a flow of water from the tank through the conveyance pipe while positioning a moveable water-permeable screen inside the tank to crowd the animals towards the tank outlet, (ii) by means of the flow of water therethrough, moving animals through the conveyance pipe.

A device for high density culture of fish larvae includes: a nursery tank, a first aerotube, a standing mesh drain pipe, and a dual-drain recirculating water treatment system. The nursery tank is a rounded corner tank or a polygonal tank without dead corners. The first aerotube is disposed around the bottom of the inner wall of the nursery tank. The standing mesh drain pipe is disposed in the center of the bottom of the nursery tank. The dual-drain recirculating water treatment system includes a first water treatment system and a second water treatment system. The first water treatment system and the second water treatment system are symmetrically disposed on both sides of the nursery tank, respectively. The first water treatment system is configured to purify upper layer water of the nursery tank, and the second water treatment system is configured to purify lower layer water of the nursery tank.

A device for high density culture of fish larvae includes: a nursery tank, a first aerotube, a standing mesh drain pipe, and a dual-drain recirculating water treatment system. The nursery tank is a rounded corner tank or a polygonal tank without dead corners. The first aerotube is disposed around the bottom of the inner wall of the nursery tank. The standing mesh drain pipe is disposed in the center of the bottom of the nursery tank. The dual-drain recirculating water treatment system includes a first water treatment system and a second water treatment system. The first water treatment system and the second water treatment system are symmetrically disposed on both sides of the nursery tank, respectively. The first water treatment system is configured to purify upper layer water of the nursery tank, and the second water treatment system is configured to purify lower layer water of the nursery tank.

Disclosed is a feedback feeding system pond recirculation with fusion of machine vision and infrared detection. Feeding strategies are provided according to the feeding behavior of fish in cooperative with machine vision technology and infrared sensing technology. The pond recirculating aquaculture is an open environment. The change of natural environment may affect the feedback signal of the fish feeding behavior provided by the machine vision due to the low visibility; or it may affect the feedback signal of the fish feeding behavior provided by the infrared detection because low temperature may decrease feeding intensity. The fusion of these two strategies can solve the problem of intelligent feeding strategies in the pond recirculating aquaculture mode.

Disclosed is a feedback feeding system pond recirculation with fusion of machine vision and infrared detection. Feeding strategies are provided according to the feeding behavior of fish in cooperative with machine vision technology and infrared sensing technology. The pond recirculating aquaculture is an open environment. The change of natural environment may affect the feedback signal of the fish feeding behavior provided by the machine vision due to the low visibility; or it may affect the feedback signal of the fish feeding behavior provided by the infrared detection because low temperature may decrease feeding intensity. The fusion of these two strategies can solve the problem of intelligent feeding strategies in the pond recirculating aquaculture mode.

The method for rearing an animal according to the present invention includes: grasping a tide-generating force; and feeding, to the animal, foods varying in fat ingredient content according to the variation level of the tide-generating force. In addition, the apparatus for rearing an animal according to the present invention is provided with a food feeding means for feeding, to the animal, foods varying in fat ingredient content according to the variation level of a tide-generating force.

The method for rearing an animal according to the present invention includes: grasping a tide-generating force; and feeding, to the animal, foods varying in fat ingredient content according to the variation level of the tide-generating force. In addition, the apparatus for rearing an animal according to the present invention is provided with a food feeding means for feeding, to the animal, foods varying in fat ingredient content according to the variation level of a tide-generating force.

Apparatus (10) for removing gases in a liquid, and/or for removing foam and particles from a liquid and/or for the transport of liquid, the device (10) comprises conduits (16) for transporting the liquid from a first location to a second location, where the conduit (16) comprises a first upstream conduit portion (16a) for receiving of liquid, a substantially horizontal conduit portion (16b), a downstream conduit portion (16c) to discharge liquid out of the conduit (16), and a venting conduit portion (16d) to discharge gases, particles and a part of liquid out of the conduit (16) via conduit portion (16e) and means (17) arranged in the upstream conduit portion (16a) and/or horizontal conduit portion (16b) for supplying microbubbles to the conduit (16), and that in the conduit (16) means (19) are provided for establishing vacuum in parts of the conduit (16), characterized in that the device (10) in the conduit portion (16b) comprises two or more venting conduit portions (16d).