MOHT is a type of trawl net used to collect large zooplankton, juveniles, larvae, and small fish. When attempting to collect organisms capable of swimming, if the net is towed at a faster speed than the organisms, escapement from the net mouth can be suppressed. On the other hand, when a trawl net is towed at high speed, the increased drag makes it difficult for the net to sink. The MOHT is equipped with a diving plate that increases the sinking force as the towing speed increases, so that the net does not easily float even when towed at high speed and can be towed stably at the target depth, so that it is used as a quantitative sampling device suitable for stratified sampling to investigate the stock of marine resources. This section describes the configuration of the MOHT and its observation and towing operations.
[Open Access] Oozeki at.al. (2004)
