5.0 Conclusions 
In conclusion, several promising indicative methods have been evaluated which should 
prove useful for ballast water compliance monitoring. These tools differ in their sensitivity, 
output, costs, training requirements, and processing time, all of which must be considered 
when selecting tools for ballast water compliance monitoring. Future work will be required to 
determine the accuracy of these methods at varying cell concentrations, to assess these 
methods in different types of plankton communities, and to determine if different processes for 
treatment of ballast water have effects on the analytical results of the instruments. A better 
understanding of the variability in concentration estimates due to the selection of calibration 
factors is crucial.