They use "purse seine" nets to catch the Tuna. The fast cutters lay the nets, the small boats on the back of the cutter are offloaded and they run round in a big circle dragging the end of the net back to cutter. They then close the net and the factory ship comes along side the cutter on the net side and they load the tuna into the hold of the factory ship for instant freezing. They sometimes use a small helicopter to find the schools of tuna. With the volume of fish offloaded in Manta every day, it makes you wonder if the tuna will go the way of the Atlantic cod fisheries.