Nansen Closing Net

The Nansen Closing Net is a vertical plankton net with messenger operated closing mechanism. A 70 cm diameter stainless steel ring with a 3 meter long net bag, made of Tetex (upper part), gaze of 100 µm (middle part) and gaze of 55 µm (lower part and side window of Netbucket), is operated in conjunction with a heavy net bucket frame for high towing rope speed during descent.

For easy retrieval the sample is concentrated inside a removable plastic net bucket with side window (covered with sieve gauze). The open net is brought to the greatest scheduled depth. During ascent the net can be closed in the intended depth by strangulating the net bag below the net ring. This allows for sampling defined depth layers.

The Nansen Closing Net can be used in conjunction with one Mechanical Flow Meter with back-run stop for measurements of filtered water volume.