A device for sampling marine plankton, comprising a screen of silk gauze that is wound from a storage spool, across a second spool, and on to a take-up spool contained in a tank of formalin. The screen mechanism is enclosed in a torpedo-shaped cylinder with stabilizing fins, which is towed behind a vessel at a known speed and depth and powered by a turbine turned by the flow of water. Water enters through an aperture at the forward end of the casing, flows through the moving screen, which collects and stores the plankton, and leaves through an exit aperture at the rear. The device was invented by Sir Alister Hardy.
Subjects: Ecology and Conservation.