The data were sampled as part of the North Pacific (NORPAC) Survey, also described as the Marine Salmon Exploratory Fishing Surveys.|
Sampling Gear: Zooplankton were sampled with a plankton net (45 centimeter diameter, 2 meter length) equipment with a 330 micrometer nylon mesh net.
Towing Method: Vertical tows were lowered to 150 meters and then retrieved at 1 meter/sec or faster. Horizontal tows were towed at 2 knots for 10 minutes just below the surface.
Analysis: Organisms longer than 1.5 inches (tunicates, meduase, siphonophores) were removed before measuring. The reported wet weight therefore represents only organism < 2 inches in length.