Flow tracer

[2][3] Temperature, salinity, density, and other conservative tracers are often used to track currents, circulation and water mass mixing.

The following twelve years oceanographers recorded where the ducks washed ashore, some thousands of miles from the spill site, and this data was used to calibrate and verify the circulation patterns of the North Pacific Gyre.

[5] Transient tracers change over time, such as radioactive material (Tritium and Cesium-137) and chemical concentrations (CFCs and SF6), which are used to date water masses and can also track mixing.

[citation needed] While extremely unfortunate, scientists were able to use the concentrations of anthropogenic compounds and half-lives of radioactive material to determine how old a water body is.

When these two types of water masses mix, such as the Kuroshio Current in the north Pacific, it often causes huge phytoplankton blooms, because they now how conditions they need to grow—warm temperatures and high nutrients.