A Net-Changing Mechanism for the Lowestoft Multipurpose Sampler

Abstract

A net-changing device for use with the Lowestoft multipurpose sampler is described. The unit consists of four nets mounted on stainless steel rods which are spring loaded and slide between stainless steel runners. The nets are held by metal “fingers” when not fishing, and by operating an electric motor they can be released instantaneously to the fishing position. Water enters the net through a standard nose cone via a trumpet-insert of fibreglass. The amount of water filtered is registered by an electric flowmeter mounted in the nose cone, and the depth at which the sample is taken is recorded by a pressure transducer. Nets can be selected by depressing a switch on the control unit, and the flow, depth and number of the net fishing register on meters mounted in the same unit. The underwater electronic equipment is connected to the console in the deck laboratory by a stainless steel multi-core electric cable via the slip rings of the winch. Results are given from a typical haul.