Ballast water management systems (BWMS) Type approval: A new application for flow imaging microscopy (FlowCAM)

Ballast water is a well-known vector for non-indigenous organisms’ introduction, causing harm to ecology, economy, and human health. Following International Maritime Organization (IMO) regulations, all vessels should use an approved ballast water management system (BWMS) to reduce the transfer of organisms. As a result, rapid and accurate methods are needed for effective ballast water management. In this paper, we examined the applicability of a flow imaging microscopy (FlowCAM) for detecting phytoplankton in land-based and shipboard BWMS tests. The results showed that FlowCAM failed to recognize and tended to underestimate the abundance of some species in comparison to a fluorescence microscope. However, the abundance of many other species or genera estimated by the two methods was similar. Generally speaking, although some discrepancies were observed, considering the efficiency of FlowCAM in capturing images and measuring the abundance of particles, FlowCAM may become a promising technology in BWMS Type Approval.