Science and the Sea, Part II

Episodes 15 (Science and the Sea Part 1) and 16 (Science and the Sea Part 2) follow Duke University’s research vessel Eastward on a ten day cruise. In Episode 16, students continue observing the scientists on research vessel Eastward as they investigate the effect of pollution on ocean life. A group of marine chemists takes samples at each station to determine the levels of heavy metals and tritium. A pole sampler is used to prevent specimen contamination. Collected samples will be analyzed to determine the amounts of mercury, lead, copper and cadmium in the water. Scientists use a Nisken Bottle to collect the water required for tritium analysis, while an air sampler is used to compare the level of mercury in the air.

Students observe a Marine Biologist collecting fish and other marine life for the public aquarium on Skidaway Island. Students see the process of trawling and share the excitement of the scientists as they inspect their catch. After completing the collection of data at each station, the Eastward heads back to Beaufort. On the way, the ship detours to the waters off Cape Fear near Wilmington. There John Newton continues a project to determine the origin and map recently discovered channels carved in the ocean bottom. Mapping data is collected by creating shock waves in the water and recording the returning signals. The resulting seismic profiles are plotted and sites for bottom samples are selected. A rock dredge is then used to sample the channel bottom and walls. Because time is limited, only a portion of the mapping is completed.

Students are shown the Eastward’s precision depth recorder. The instrument sends out a sound pulse that is reflected off the ocean floor and is recorded as it returns to the surface. The result is a record of the depth and shape of the ocean floor beneath the ship. Later, these records will be combined with many others to construct oceanographic charts and other maps. The episode ends as the Eastward returns to port in Beaufort.

Note to Teachers: Episode 15, Parts 1 and 2 are not intended to teach students the concepts of oceanography but rather to offer a realistic picture of what life and work is like on an oceanographic research vessel. No two cruises are alike. The array of instruments and investigation on research vessels changes from cruise to cruise. The objective of these two episodes is the help students understand that oceanography, like many other sciences, is hard, tiring and sometimes boring work, but that it holds a particular fascination and thrill for the scientific investigators.

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