Ballast water samples that have been adequately processed in regard to the applied analytical method may be analyzed by the classical method of incubation on special agars across the time span of 24/48 hours. After incubation the colony forming units on the agar plate are counted. This method generates qualitative (species) and quantitative (abundance) data.
The ballast water sample may be analyzed by a dip-test, for which a slide covered with specific agar is dipped into the sample and incubated for the time span of 24 hours. This method generates qualitative data (species) as well as numerical data on the level of orders of magnitude.
The Fluorescence-in-situ-hybridisation (FISH) uses gene probes to qualitatively (species) and quantitatively (abundance) mark the bacteria in the ballast water sample. The marked bacteria exhibit species specific fluorescence when examined under the fluorescence microscope. Under optimal conditions the FISH method generates qualitative numerical data of viable bacteria in less than 10 hours.
The further development of the Fluorescein-diacetate fluorometry and the Adenosin-triphosphate fluorometry may allow for the transfer of concentration data into numerical data for all viable plankton organisms in the sample. However, these methods do not generate any qualitative (species) data.