Rectangular Midwater Trawl (RMT) net is a marine equipment used for zooplankton sampling. The system consists of two nets that can be used independently and operated in combination with the down-wire net monitor, a custom-built electronic system that enables two-way communications between the net and controllers aboard the ship. Three types of RMT nets were used to generate data accessible from this portal:

1. British Antarctic Survey Rectangular Midwater Trawl 8 (RMT 8) has a mouth opening of 8 square meters and cod-end mesh size 5 mm. The net was typically used to catch krill and deployed to a maximum depth of 200 metres. Further information is available here.

2. British Antarctic Survey Rectangular Midwater Trawl 1+8 (RMT 1+8) A pelagic trawl system composed of a combination of RMT1 and RMT8 nets. The RMT1 net has a mouth opening 1 square meter and is best suited to catch zooplankton. The RMT8 net has a mouth opening 8 square meters and is used to catch krill. Further information is available here.

3. British Antarctic Survey Rectangular Midwater Trawl 25 (RMT 25) is a larger version of a RMT net with a mouth opening of 25 square meters and cod-end mesh size 5 mm. This type of net is mainly used to catch small fish in depth up to about 1000 metres. Further information is available here.

The mesozooplankton species composition and abundance was determined using methodology described in the resource citation below.

Dataset citation:

TBC