Dye releases, typically of rhodamine, are used in predictive studies to assess the likely dilution and dispersion of effluents in the marine environment; or postcommissioning,to verify that outfall design criteria have been met.

Dye releases can be monitored visually, or quantitatively using in-situ or sample fluorometry.

A variety of release methods can be employed, including continuous gravity feed, continuous pumped discharge via temporary pipe [2] and batch or continuous discharge via existing outfall [1].

Contour plots [4] and composite surface plots [3], are derived from a number of transects across the dye plume, and can be used to indicate the variation in dispersion patterns throughout the tidal cycle.

Qualitative visual descriptions of plume dispersion are also used.