Development of an oceanographic towing vehicle adapted for fishing craft: Prototype and protocol for use

Since the 1930s, the use of the Continuous Plankton Recorder (CPR) sampler has been considered one of the most important plankton collection methods using ships of opportunity, which make samples available on a wider spatial and temporal scale. With this advantage in mind, the objective of this work was to develop a device that uses a similar collection method as the CPR, but with lower construction costs, and to carry out changes in functioning that facilitate its use in fishing craft in the Southeast and South regions of Brazil, for use as a tool for generating oceanographic data applied to fisheries management. The new equipment, called the Oceanographic Towed Vehicle (Veículo Oceanográfico de Reboque —VOR), has mechanical improvements and construction alterations for combined use with a multiparameter probe. For the new design of the vehicle, the aim was to create the hydrodynamic shape of an Undulating Towed Vehicle (U-tow), but without the characteristic of undulating in the water column. Based on a prototype, three experimental trawls were carried out, to calibrate the mechanism and analyze the material collected, in a laboratory, through a stereoscopic microscope.