The U-Tow: A system for sampling mesozooplankton over extended spatial scales

Abstract

A new system is described for sampling mesozooplankton over extended spatial scales. This system, called the U-Tow, is small (~1 m long), can be towed at high speed (>10 knots) and collects mesozooplankton in up to 50 discrete samples on a roll of filtering mesh. The spatial resolution of samples is dictated by the advance interval of the filtering mesh, which, in turn, is software controlled. So, for example, if each sample provides an integrated catch over 20 km, a single deployment may cover up to 1000 km. The U-Tow can carry a range of sensor packages with data being stored either in an internal data logger or transferred in real time up a conducting cable to be logged on the towing ship. Additionally, the U-Tow has the capability to undulate and hence sample at a range of depths. Initial results from deployments in the NE Atlantic and Irish Sea are described.