Prevention and control of Karenia brevis blooms

With the recurrent and potentially severe impacts of Karenia brevis blooms in the Gulf of Mexico, new management approaches have been examined to potentially prevent and control these blooms. This paper summarizes past and present research and strategies for the prevention and control of K. brevis blooms. Prevention presumes a certain level of understanding about the cause or causes of these blooms. This may not yet be available, however, for K. brevis in the Gulf of Mexico. Some efforts to synthesize the current understanding of bloom dynamics for the region were recommended. The earliest attempts to control K. brevis blooms in the field used copper sulfate minerals seeded from ships and crop-dusting planes. Although effective for short term applications, the method was abandoned as it provided only temporary relief at a high cost with unknown collateral damage to the ecosystem. Results from chemical screenings and ozone treatments were also presented. Algicidal bacteria have shown some promise in controlling K. brevis in laboratory experiments, either through direct contact or release of algicidal compounds. Finally, the state of the research into the use of natural clays was presented, beginning with laboratory and mesocosm tests, to larger-scale experiments and flume studies. Several impacts studies were reviewed. While much progress has been made in examining control methods in recent years, more research in the field is needed to fully evaluate the efficacy and impacts of these strategies. Furthermore, the social and human dimensions of this potentially controversial area of research may have to be explored more fully to gauge the receptiveness of the public to these management approaches.