engleski

Ozone as a Treatment Process for Minimizing Invasive Species on Oil Tankers

Ships' ballast water is generally considered to be a major contributor to the introduction of invasive species. Introduced into new habitats, invasive species can cause significant adverse ecological and economical impacts on the marine environment. Non-indigenous species (NIS) can substantially disrupt the structure and function of coastal marine ecosystems. The U.S. Coast Guard estimates that NIS introductions cause approximately $6 billion in economic damage in the United States annually. Ballast water exchange (BWE) or mid-ocean exchange is currently the only management strategy available for ships to reduce the quantities of non-indigenous coastal organisms in ballast water. BWE occurs when ships replace coastal water in their ballast tanks with open ocean water to reduce the abundance of coastal NIS. Even though BWE is a management strategy that many ships can implement immediately, and which does not require retrofitting or development of new technology, it has some significant limitations and is viewed generally as a stopgap measure to reduce the risk of invasions. A number of studies are currently being conducted to develop new technologies which treat ballast water and thereby minimize the likelihood of additional invasions. Although many treatment possibilities are being explored, their evaluation is at an early stage and no alternative treatments have yet been approved by state, regional, or federal regulatory authorities. Ozone is one treatment option being considered for minimizing invasive species in ballast water. The goal of this study was to determine the efficacy of a full-scale ozone system to remove coastal organisms compared to ballast water exchange.

Ships' ballast water; ozone; invasive species

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