Abstract 
Promising approaches for indicative analysis of ballast water samples have been 
developed that require study in the field to examine their utility for determining compliance 
with the International Convention for the Control and Management of Ships' Ballast Water and 
Sediments. To address this gap, a voyage was undertaken on board the RV Meteor, sailing the 
North Atlantic Ocean from Mindelo (Cape Verde) to Hamburg (Germany) during June 4-15, 
2015. Trials were conducted on local sea water taken up by the ship's ballast system at multiple 
locations along the trip, including open ocean, North Sea, and coastal water, to evaluate a 
number of analytic methods that measure the numeric concentration or relative biomass of 
viable organisms according to two size categories (> 50 pm in minimum dimension: 7 
techniques, > 10 pm and < 50 pm: 9 techniques). Water samples were analyzed in parallel to 
determine whether results were similar between methods and whether rapid, indicative 
methods offer comparable results to standard, time- and labor-intensive detailed methods (e.g. 
microscopy) and high-end scientific approaches (e.g. flow cytometry). Several promising 
indicative methods were identified that showed high correlation with microscopy, but allow 
much quicker processing and require less expert knowledge. This study is the first to 
concurrently use a large number of analytic tools to examine a variety of ballast water samples 
on board an operational ship in the field. Results are useful to identify the merits of each 
method and can serve as a basis for further improvement and development of tools and 
methodologies for ballast water compliance monitoring. 
Keywords: Ballast water management convention; detailed analysis; indicative analysis; invasive 
species; management; shipping; viable organisms 
Highlights: 
• Evaluated rapid, indicative analysis methods to monitor ballast water compliance 
• Trials were conducted on a variety of samples sourced across the Atlantic Ocean 
• Several rapid methods showed high correlation with traditional microscopy results