Fishing Method Development, Oceanographic Survey

Float-sink type farming cage

Most domestic quiet waters suitable for farming are already in use. So the technology enabling stable Bluefin tuna farming even in wavy and current open waters which were not suitable for it is required. In order to solve this problem, we have developed the world’s first “Large sink-float type farming facilities” using an HDPE (high density polyethylene) pipe. It sinks and floats while farming.

Primary features

Withstands typhoons and storm
The cage withstands from 3m or higher wave attack by sinking before the impact.
Can be used in non-use sea area
New fish farming is allowed in sea area which were not used such as out-of-bay
Various result by sinking
Avoidance from red tide and muddy water, Suppression and prevention from organisms attached to the net and parasites, Feeding in proper temperature water zones, Measures for sun protection, and Prevention from theft
Φ50m farming cage: Sinking operation
Φ30m farming cage: Floating operation

Pneumatic hauling net

The aging and labor shortage is serious problems for trap nets operation.
Nitto Seimo is developing pneumatic hauling nets to support the hauling operations.
The world’s first technology (Patent pending) of settling an entire large farming cage is also applied to trap nets, and operations leading fish to the final section of the bag net can be reduced.

Oceanographic surveys

Understanding of seabed topography is important to designing nets and increasing fish catch efficiency in installation of trap nets and fish farming nets.
Nitto Seimo is offering various surveys and support depending on customer needs.

  • ・We analyze data of fishing ground surveys and support installation of the most appropriate nets in consideration of geography, distance from adjacent fishing grounds and active fishing periods.
  • ・We create drawings of seabed topographies using fish detectors and sonar.
  • ・We judge the fishing ground by understand installation directions and current speed by placing a current meter near the net for a while because the installation angle against a current is an important element in preventing the deformation.
  • ・When any reef or rock is found by the survey, we make sure the geometry by ROV (Remotely operated vehicle).
  • ・It is possible to visually confirm an installed net and breakage of a net.
  • ・We grasp movement of school of fish around and in the net by installation of sonars.
  • ・We measure drift of the net by a net depth meter.