A fish rearing system having a water circulation system comprising: a trapping section including a particle trap 2 for capturing residual feed and fish feces contained in the water, a sediment trap 6 for accumulating a sediment in a rearing tank and separating the sediment from the water, a residual feed detecting sensor 5 interposed in a pipe 4 communicating with the particle trap 2 and the sediment trap 6, and a micro-screen filter 7; a denitrification device 12 for denitrifying a nitrogen compound dissolved and contained in the water; a bubble surfacing device 11 for generating bubbles by supplying air and/or ozone and removing surface active substances contained in the water by capturing the bubbles; an ultraviolet disinfection device 13 for disinfecting the circulating rearing water; an ammonium treatment section consisting of a immersion treatment device 15 and a non-immersion treatment device 14 and having a function of decomposing ammonium contained in the water; and an aeration device 21 for dissolving oxygen into the water; wherein the denitrification device 12 is disposed at the upstream of the bubble surfacing device 11 and includes a bypass pipe 10. Thus, the fish rearing system capable of performing water quality control at a low cost can be obtained by a rational combination of devices.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of international application PCT/JP97/02628, filed Jul. 29, 1997, which designated the United States and is now abandoned.
A method and a device for the restriction of blooms of micro-organisms in an aqueous system are described. A smaller portion of the body of water in the system is subjected to a radiation treatment, preferably a UV-treatment, whereupon the treated quantity of water is returned to the aqueous system. The UV radiation will induce activation of latent viruses, and when these are returned to the water system, micro-organisms in this system will be killed or inactivated, and new micro-organisms will not be formed.
A method and system for the inland aquaculture of marine species using water from a saline aquifer having a heavy metals content within the acceptable limits of the EPA guidelines for drinking water. The aquifer is preferably the Coconino aquifer located in Arizona and New Mexico. The system can be used to culture microalgae, macroalgae, fish, shrimp and many other marine species. Nutrients and fertilizers can be added to the water to optimize culture conditions for particular species. Useful products can be isolated from the marine species or the cultured marine species can be harvested as useful products themselves.
The invention relates to a method for improving conditions in closed circuit seafood and fish farming, comprising the following steps: a) at least part of the water from at least one of the rearing ponds (1) is recycled, whereby said water is treated one or more times and purified (3, 4, 5) before it is re-injected into said pond; b) the water recycled during the recycling path indicated in step a) is mixed with a new supply of water (10); c) all or part of the recycled water (21, 22) undergoes ozonization and, wherever applicable, the new supply of water (20) also undergoes ozonization either partially or in full before it is mixed with the re-circulated water.
A container 10 for rearing aquatic animals includes a floor portion 12 which defines a plurality of openings. A wall portion 100 bounds the floor portion 12 to form, together with the floor portion 12, a chamber for receiving the aquatic animals to be reared. A filter 105 is arranged in the openings of the floor portion 12. A closure plate 103 openably closes the openings in the floor portion 12. The invention extends also to a system which includes a plurality of the containers 10. The containers 10 are supported, in a partially immersed state in a vessel of the system. A circulating arrangement of the system circulates water through the containers 10.
A device for managing the fish-raising circulatory water includes a water-storing tank, a filter, an activated carbon filter, a critical filter, a powerful oxidizing device and an ozone sterilizing device, possible to supply raising water of the best quality according to various requirements, and able to check and test the PH value and the amount of oxygen of the fish-raising water by way of a store barrel connected to the critical filter.
