-100- PLANKTON AND WATER SAMPLES by Allyn H. Seymour ve dat ow Ty eo aS . ‘e ‘ . mous 28 Miho heb NE RENpe WAie gePFTSSR, 7 AED drm MeWil . : t . ot om SHMRE oe tah Seo foemereenneg TF re tee ort, wat Teahe emgEGE AECD-3446 PLANKTON Samples of the iagoon plankton were collected by pumping the water & 4 various depths through plankton nets. This method produced quantitative sq from a known depth with a minimum ofeffort, Other samples were collected tres the ship's salt water supply, from towing small plankton nets, and from night ¢ lections using an underwater light and dip nets. Plankton collecting was a pargs time assignment for two men and was scheduled for evenings and off days for fell collections. The records of the plankton collections are presented in Table 1, The pump was mounted on the afterdeck, starboard side of the LSIL, kh @ originally intended that a pump supplied by a 2-inch rubber hose would be used, the pump placed in operation was capable of lifting 10, 000 gallons of water per ban: from a depth of 200 feet and was supplied by standard, reinforced, Navy fuellng PS a heavy, rubber-coated, 4-inch iron pipe. The intake line led over a guide welded onto the stern and afterdeck up ™@.78 3-inch reducing unit that led into the pump. From the Carver pump, Model 318, turned by a Wisconsin air-cooled motor, type AHH, the water either went through line with a meter or a line that by-passed the meter, to a cylindrical tank in whidl plankton nets were hung. The tankwas about 5-1/2 feet tall and 18inches in ¢ and was attached to the stern so that the bottom of the tank was about 2feet above” the ship's water line and the top of the tank about 2-1/2 feet above the level of afterdeck. After a net had been suspended within the tank, water was pumped . slowly through the net until the water level in the tank approached the top of the Then the valve in the outlet at the bottom of the tank was opened, and at the some time, the flow of water into the net was increased and the two adjusted 5° that 8 much of the net as possible was supported by the water, but with the water le remaining below the top of the net.