Measurement of warp loads of bongo plankton samplers

• We measured warp loads of typical bongo samplers using a flume tank.
• Warp loads of bongo samplers were less than 85 kg.
• There was no evidence of flow being deflected from mouth of net.
• Quantitative data can be used to design winches.

We measured warp loads of a bongo sampler in a flume tank over a range of water velocities (0–1.05 m s−1) to estimate the payload on a winch during deployment. We used standard bongo setups comprising two mesh sizes: 500 μm and 333 μm. Warp load of a bongo sampler was less than 85 kg at maximum towing velocity. There was no evidence of the flow being deflected outside the net mouth for velocities above 0.5 m s−1.