Open Ocean Ballast Exchange: A Study On The Need For Innovative Approach To Eliminate Aquatic Invasion

Abstract

The study investigates the issues regarding Open Ocean Ballast Water Exchange (OOBWE) and propose a more innovative approach to manage ballast water. Ships are constructed and meant to carry dry or liquid bulk cargo, containers, machinery, and people and travel on the ocean. If a ship is travelling without cargo, or has discharged her cargo in one port and is en route to her next port of call, ballast may be loaded to achieve the required safe operating conditions. This ensures that the ship’s propeller and rudder operate efficiently by keeping the bow under the water, as it sails in heavy seas. The study identified that BW is a vector of thousands of species of animals, plants and microorganisms, many of which survive temporarily in the ship’s tanks and are transferred to new aquatic environment when discharged. Such species become invasive, disrupt the native ecology, and have serious impact on the economy and on human health and is one biggest threat to the world’s freshwater, coastal and marine environments. Safety is identified as the greatest challenge with the OOBWE as far as ships are concerned as potential lack of adequate stability or excessive list, longitudinal strength, dynamic loads, excessive trim, bottom slamming, propeller emergence, and poor bridge visibility which may be caused by improper planning and operation of ballast transfer or discharge. Moreover, Ghana has a number of national regulations that deal with environmental issues, but no clear existing environmental regulation that deals with ballast discharge in Ghana and this creates difficulty for the relevant institutions to sanction vessels not complying to the requirements. The study identifies onboard treatment plant, port reception and/or treatment facility, and floating barge with treatment plant on board as most innovative ballast treatment option to ensure reduction or complete mitigation of invasive aquatic organisms.