The total tonnage of salmon that was brought aboard each mother ship exceeded 100 metric tons on some days. The reason for the small mesh size (4 1/2" )was that the Japanese were targeting sockeye going to Bristol Bay. The area they fished was in the North Pacific kind of off the end of the Aleutian chain. The gillnets fished about 25 ft deep and was about 15-20 lb mono that was a green color that was invisible in the water and caught fish in daylight. Each year I was able to spend about a week on one of the gillnetters and observe the fishing operation. Each 90 ft gillnet boat had 18 crew. The mothership were around 500 ft long and had a total crew of over 200 crew. Each mother ship had one salmon observer and one marine mammal observer. The gillnets killed some Dall's porpoise which the marine mammal observer took samples from. This fishery was legal fishery that I think ended around 1986. There was some illegal fishing afterward especially by other nations. Tug might know more about this. Steelhead had not been studied much at that time and so the range and origin of steelhead was extended because of the samples (whole fish)collected in that fishery.