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PLANKTON DATA
- Overview
- Zooplankton samples were collected with a NORPAC net. The net was conical (45 cm in diameter, 180 cm
long), made of GG54 net cloth (0.33 mm mesh). Vertical hauls with a NORPAC net were made from 150 m
depth estimated by wire angle to the surface at each hydrographic station. When the bottom depth is
shallower than 150 m depth on the continental shelf, the net was hauled from near the bottom to the
surface. The net was lowered to the predetermined depth, then hauled up at a speed of 1 m/sec,
immediately after the net reaching there.
A flowmeter was mounted at the center of the mouth of net to estimated the volume of water filtered
through the net. This flowmeter was calibrated some times during the cruise.
The wet weight of the samples was determined by an electoronic balance after eliminating as much as
surrounding water as possible. The water in a sample was eliminated by vacuum filtration with a small
vacuum pump or aspiration filtering apparatus. Samples containing high concentration of phytoplankton
were excluded from the measurement of wet weight. Large gelatinous zooplankton ( e.g., hydromedusae
and salps larger than 3 cm in body size) and nekton such as lantern fish were removed prior to weighing.
The value is expressed in mg/m3.
Samplings and measurement of wet weight of the samples were conducuted by officers and/or staffs of the
Plankton Laboratory, Hokkaido University.
- Data format
- Microsoft Excel file format