Short article with good graphics and 3 short videos. Describes how scientists are not certain how changes in salinity impact the ocean, and that they continue to use NASA satellites to monitor and study variations in ocean salinity.  Most relevant section is "Density-Driven Circulation" which has brief text and a good video.

Recommend for middle school and up.

Fun video (<3 min) showing a water density experiment. Compares water that is salty, cold, room temperature and hot. 

Recommend for middle school and up.

Scroll through this "Storymap"  for a variety of graphics that explain why it is important to monitor salinity of water along the coast. Good to skim for an overview. 

Recommend for middle school and up.