Various shots of infra-red thermometer being placed aboard Royal Canadian Air Force Research plane at Comox Station, British Columbia. MCSs of man cutting open ocean perch to check sex and remove earstone. CU of earstone used to determine age of fish. Various shots of laboratory technician taking microphotographs of fish scales. Microphoto CUs of fish scales. Shots of bathy thermograph on deck being lowered into ocean to measure temperature of deep water, of thermograph being raised from water, of temperature reading being taken. Interior CS of radiation thermometer, graph in operation. Various shots of vertical plankton catcher being lowered into ocean, being raised, of young man looking at sample jar of plankton caught. Shots of high speed plankton catcher being lowered into ocean and towed along beside ship. MCSs of man pouring fish eggs into funnel full of liquid, of propeller agitating eggs in funnel. MCS and CSs of man feeding whales teeth into computing machine, of computer reading whale's age from teeth. Several shots of scientist cutting open fish in parasitology laboratory, removing stomach, placing stomach into solution, pouring solution into litre jar. MCS of scientist examining something under microscope.