After eight years of roaming in the ocean, salmon go back to the freshwater stream of their birth place to lay their own eggs. They jump, swim, and dive through obstacles to travel upstream. The salmon stop eating, lay their eggs, and...

Why does an egg float in salt water? Learn about density and buoyancy in this video segment adapted from ZOOM. [3:02]

In this video segment adapted from ZOOM, cast members assemble a solar still and make fresh water from saltwater, demonstrating two steps of the water cycle, evaporation and condensation. 3m 32s

Meet scientist Saundra Upchurch of the Ace Basin Reserve and learn about the marsh plants of South Carolina's "Low Country." [9:43]

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.