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Herein, we evaluate the scientific basis for managing hull fouling of ships entering Korean ports, diagnose biological risks that may occur when in-water cleaning (IWC) systems remove hull fouling, and present a protocol for evaluating these risks (the Korean Infection Modes and Effects Analysis; K-IMEA). Protocol development included the selection of core elements and scenario design for IWC and the evaluation of regrowth experiments. The K-IMEA index was designed by considering the inoculation pathway of attaching organisms in all processes to ships that enter a port for in-water cleaning. A number of risk indices were defined: R1—Introduction/Establishment of alien species before in-water cleaning; R2—Establishment of alien species escaped during in-water cleaning; R3—Introduction/Establishment of alien species after in-water cleaning; and R4—Establishment of alien species in effluent water. K-IMEA regrowth experiments (R2 and R4) using the in-water cleaning effluent showed that the attachment and regrowth of prokaryotes, microalgae, and macroalgae were successfully detected. In particular, prokaryotes were observed in samples filtered through a 5 μm mesh of the in-water cleaning effluent, even at a low fouling rating (Levels 1–2). These experiments suggest a necessity to consider a secondary treatment method in addition to the primary filtration method for the treatment of in-water cleaning effluents. [ABSTRACT FROM AUTHOR]

Ballast water management systems (BWMSs) using active substances (AS) have been subjected to land-based tests with artificially increased dissolved organic matter (DOM) and cultured species according to the International Maritime Organization G9 guidelines before the BWMS Code revision. Therefore, data on the environment risk assessment (ERA) of disinfection by-products (DBPs) for actual port DOM and natural species are limited. This study was conducted using seawater from Jangmok Bay, South Korea, during a phytoplankton bloom. In treated water with a high biological content (Group A), the DBPs concentration increased as the initial AS concentration increased. However, in treated water with a low biological content (Group B), the DBPs concentration did not increase as the initial AS concentrations. The higher the residual AS concentration on day 5, the more the DBPs concentration increased, and the composition ratio of the DBPs was also affected. The ERA to individual DBP was evaluated as low given <1 for the ratio of the predicted environmental concentration to the predicted no-effect concentration in port environments exposed to DBPs in discharged ballast water. This result may suggest that the ERA of IMO G9 performed with cultured species and additives could substitute the outcome obtained with natural plankton assemblages. [ABSTRACT FROM AUTHOR]

Ship biofouling is recognized as a significant pathway for the introduction and spread of invasive organisms. The in-water cleaning of ship hulls generates wastewater that includes antifouling paint residues and biofouling organisms, which inevitably leak into the marine environments, resulting in substantial adverse effects on marine ecosystems. To assess the impact of hull cleaning wastewater (HCW) on microalgae, we conducted microcosm experiments using HCW including attached microalgae. The experiments consisted of a total of 12 combined trials, including the following groups: ambient seawater as a control, the 5% HCW group (HCW), and the 5% HCW + nutrient addition group (HCW+N), conducted at temperatures of 15 and 20 °C, respectively. The Chl. a concentrations in the water column in the control group exhibited maximum values on day 1 (5.24 μg L−1 at 15 °C and 12.37 μg L−1 at 20 °C), but those of the treatments were at low levels, below 2 μg L−1 at both temperatures. On the other hand, the Chl. a concentrations on plastic plates were higher in the treatments than in the control group. Specifically, the Fv/Fm ratio in the water column, which indicates photosynthetic activity, was significantly higher in the control group compared to both the HCW and HCW+N groups at 15 and 20 °C (p < 0.05). This suggests that the growth of water column phytoplankton was inhibited following HCW inoculation. However, there were no significant differences in the Fv/Fm on plastic plates between the control and HCW treatment groups, implying that the periphyton maintained a high photosynthetic capacity even in the presence of HCW treatments. The elution of particulate copper in HCW was observed, which was considered as the main reason for the growth of phytoplankton. Our study results suggest that the runoff of HCW in the marine environment has a greater negative effect on phytoplankton than on periphyton, which can lead to changes in microalgae community composition and a decrease in productivity in the marine environment. Therefore, it is crucial to manage HCW runoff based on scientific assessments to minimize the ecological risks associated with the removal of biofilm or slime from ship biofouling during in-water hull cleaning. [ABSTRACT FROM AUTHOR]