Feasibility study of ocean color remote sensing for detecting ballast water

The paper describes the feasibility of ballast water detection with SeaWiFS-derived diffuse attenuation coefficients and the corresponding number of in situ plankton cell density along the ship's routes. Onboard sampling of the ballast water have been carried out by the LNG carrier of 110,000 gross tons during the six cruises between Japan and Qatar from May 2002 to July 2003. SeaWiFS images of the ballast water exchange areas along the ship's route were acquired and processed by using SeaDAS. Based on the plankton analysis of the sampled ballast water, phytoplankton and zooplankton species were identified and their numbers of cell were counted for each ballast water exchange. It is found out that the observed cell density is highly correlated with the corresponding SeaWiFS-derived diffuse attenuation coefficient at 490 nm (K(490)). By using this correlation the criterion of 10 cells/ml imposed by IMO regulations corresponds to 0.24 m−1 of K(490). It is expected that this value of K(490) will be the criterion of future satellite-based ballast water quality standard.