A device mounted to a vessel for harvesting a subsurface concentration of artemia cysts. In certain embodiments, the device includes a vertically adjustable front net support, a vertically adjustable rear net support and a net having a first end secured to the front net support and a second end secured to the rear net support. A conduit can be coupled to the second end of the net whereby the concentrated artemia cysts are drawn from the second end of net to a processing destination. In certain embodiments, the net has an aspect ratio of at least approximately 4:1. The processing destination could be the vessel or some other destination. In certain embodiments, the vessels are equipped with a dewatering station to which the concentrated cysts are directed for further processing. In some embodiments, the net is secured to a frame which is in turn coupled to the front net support. The front net support can include one or more arms. In certain embodiments, the front net support includes a brace which can be attached to the vessel. The brace can include one more sleeves that correspond to the one or more arms and be hingedly attached to the vessel.

A device mounted to a vessel for harvesting a subsurface concentration of artemia cysts. In certain embodiments, the device includes a vertically adjustable front net support, a vertically adjustable rear net support and a net having a first end secured to the front net support and a second end secured to the rear net support. A conduit can be coupled to the second end of the net whereby the concentrated artemia cysts are drawn from the second end of net to a processing destination. In certain embodiments, the net has an aspect ratio of at least approximately 4:1. The processing destination could be the vessel or some other destination. In certain embodiments, the vessels are equipped with a dewatering station to which the concentrated cysts are directed for further processing. In some embodiments, the net is secured to a frame which is in turn coupled to the front net support. The front net support can include one or more arms. In certain embodiments, the front net support includes a brace which can be attached to the vessel. The brace can include one more sleeves that correspond to the one or more arms and be hingedly attached to the vessel.

A spreading device for spreading gear, including fishing gear or seismic survey gear, towed behind a vessel in water, comprising a hollow body of concavo-convex shape and made of plastics material. The body has a general mirror symmetry about a plane which is substantially mid-height and/or mid-length in the body in use. The body has a fore-and-aft to top-to-bottom aspect ratio of between 1:2 and 4:1, and an inner concave side and an outer convex side. The device has a forward towing point on the inner concave side for a tow line to the vessel and aft towing point for attachment of the gear to be towed. The plastic material of the hollow body renders the body buoyant in water and enables ballast or additional buoyancy to be added.

A spreading device for spreading gear, including fishing gear or seismic survey gear, towed behind a vessel in water, comprising a hollow body of concavo-convex shape and made of plastics material. The body has a general mirror symmetry about a plane which is substantially mid-height and/or mid-length in the body in use. The body has a fore-and-aft to top-to-bottom aspect ratio of between 1:2 and 4:1, and an inner concave side and an outer convex side. The device has a forward towing point on the inner concave side for a tow line to the vessel and aft towing point for attachment of the gear to be towed. The plastic material of the hollow body renders the body buoyant in water and enables ballast or additional buoyancy to be added.

A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.

A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.

It is provided an Antarctic Krill trawl with a centralized sinker and a self-expandable mouth structure, including a beam, an upper border rope, a lower border rope, a lateral line, a cover net, a flank net and a body net. A length of the beam is 18 to 20 meters. The beam enables the mouth to be expanded horizontally, a sinker is provided at each of two sides of a belly net at a front end of a first mouth of the body net. A component force of a sinking force by the sinker is transmitted through the lateral line and a sewing edge so as to cause the lower border rope in a tensioning state due to the transmitted force. The body net comprises a back net, a lateral net and a belly net. Taper ratios of the back net and the lateral net are 2-1.

It is provided an Antarctic Krill trawl with a centralized sinker and a self-expandable mouth structure, including a beam, an upper border rope, a lower border rope, a lateral line, a cover net, a flank net and a body net. A length of the beam is 18 to 20 meters. The beam enables the mouth to be expanded horizontally, a sinker is provided at each of two sides of a belly net at a front end of a first mouth of the body net. A component force of a sinking force by the sinker is transmitted through the lateral line and a sewing edge so as to cause the lower border rope in a tensioning state due to the transmitted force. The body net comprises a back net, a lateral net and a belly net. Taper ratios of the back net and the lateral net are 2-1.

There is provided a spreading device (100) for trawl fishing and seismic survey operations. The device has an upper frame (111), an intermediate frame (113) and a lower frame (112). There are at least two upper panels (22, 23) between the upper and intermediate frames, and at least two lower panels (22, 23) between the intermediate and lower frames. One of the upper panels and one of the lower panels adjustable in its angle of attack with respect to other panels. There is provided a manual means for adjusting the angle of attack of the adjustable panels.

There is provided a spreading device (100) for trawl fishing and seismic survey operations. The device has an upper frame (111), an intermediate frame (113) and a lower frame (112). There are at least two upper panels (22, 23) between the upper and intermediate frames, and at least two lower panels (22, 23) between the intermediate and lower frames. One of the upper panels and one of the lower panels adjustable in its angle of attack with respect to other panels. There is provided a manual means for adjusting the angle of attack of the adjustable panels.