Learn a little about salinity differences in the estuary and watch a really cool but simple experiment to demonstrate salinity stratification. You can try this at home! [9:33]

Learn how students can use classroom tools to measure estuarine water quality. Students sample ocean, estuary and tap water for salinity using the Hydrometer. [5:09]

Learn how to properly make a coral reef aquarium. Joseph Yaiullo, co-founder of Atlantis Marine World in Riverhead, N.Y. and the curator of the aquarium's 20,000-gallon tank, shares salt water tank tips.