Ballast water has been an integral component of the ship’s stability since the steel hulled vessels have been introduced. Whether or not the ship is at sea, ballast water is carried on all seagoing vessels big or small to maintain acceptable stability conditions. A good ballast water management plan is imperative for all ships.
Ballast water reduces stresses on the vessel’s hull, balances off for the weight lost due to consumption of water and fuel, provides better maneuverability with sufficient vessel draft, including ship propeller immersion, and also helps in improving living conditions of the crew aboard by reducing vibrations and uncontrolled vessel’s movements.
Why is Ballast Water in Discussion?
While ballast water remains indispensable for safe, secure and effectual shipping operations, it has been scientifically researched and proven by expert authorities that ballast water is a significant path for the transfer of harmful and equally damaging aquatic organisms and other pathogens that pose serious ecological, economic and health problems.
The introduction of these harmful marine organisms and other similar pathogens has caused major damage to many of the worlds’ coastal regions and bio-diversities over the years. Examples of such organisms are Golden Mussels, Zebra Mussels, North American Comb Jellyfish, the Cladoceran Water Flea, and the North Pacific Seastar.
Steps taken to Reduce Hazards Associated with Ballast Water
The global community, under the administration of IMO has adopted the “International Convention for the Control and Management of Ship’s Ballast Water and Sediments, 2004”. This Convention is intended at stopping the introduction of superfluous aquatic organisms and pathogens through the discharge of ballast water and sediments.
The accountable authorities, which includes scientists, ship owners and operators as well as flag States, have determined that the method of ballast water exchange provides an effective means, to prevent the unintended transfer of these harmful marine organisms. This of course is on a temporary basis until the authorities come up with a permanent solution related to ballast water treatment systems.
What is Ballast water exchange and who’s responsible for its management?
Ballast water exchange is a process which involves the substitution of water in ship’s ballast tanks using either a sequential, flow-through, dilution or other exchange method which is recommended or made obligatory by the IMO, in order to preserve ecology in biologically rich coastal waters and similarly to those in deep oceanic waters.
Since, it has been scientifically established that those marine organisms and/or pathogens taken on in coastal waters are less likely to survive when discharged into the open ocean due to changes in the water’s chemistry, temperature and salinity, and similarly those organisms taken onboard in oceanic waters are less likely to survive in coastal waters, Ballast Water Exchange or BWE is required to be carried out during the vessel’s voyage though various zones of the seabed.
The quantity, distribution and circulation of ballast water are determined by the Master of the vessel and are based out of explicit operational and environmental conditions. The vessel’s Master and the designated “Ballast Water Management Officer” are the responsible authorities for the implementation of the Ballast Water Management Plan.
The Ballast Water Management Plan
This Ballast Water Management Plan has been developed to provide guidance and assistance to the vessel’s crew and operators in the effectual operation of the ballast water exchange system. The accomplishment of this plan enables the vessel to prepare for the steps and proceedings required when conducting ballast water exchange. Since Ballast water exchange operations are more hazardous than normal port operations, vigilant and calculated planning has to be carried out before hand.
It is the duty of the vessel’s Master and the “Ballast Water Management Officer”, usually the Chief Officer to develop detailed measures and processes related to the ballast water exchange. All concerned are to be familiar with the safety aspects of ballast water exchange and ballast water management plan, in particular with the method/s of exchange to be used on board their vessel.
The Master and crew engaged in ballast water exchange at sea should be educated in and familiar with the following, as appropriate:
i) The approved vessels loading conditions to be used during ballast water exchange
ii) The vessel’s ballast pumping and piping arrangements, positions of associated air and sounding pipes, positions of all compartment and tank suctions and pipelines connecting them to the vessel’s ballast pumps and, in the case of use of the flow-through method of ballast water exchange, the openings used for release of water from the top of the tank together with overboard discharge arrangements
iii) The means of confirming that the sounding pipes are clear and that air pipes and non-return devices are in good order
iv) The distances off the coast required to undertake the various ballast water exchange operations. This will also include the time required to complete individual tanks
v) The method/s to be used for ballast water exchange at sea, e.g. Flow-through, dilution, etc.
vi) The need to incessantly monitor ballast water exchange operations
Throughout the ballast water exchange process, the Master has to take into consideration the following:
1. The vessel’s position including traffic density.
2. Weather forecasts and sea condition.
3. Vessel’s stability and loading conditions.
4. Condition and performance of the vessel’s machinery and maneuverability.
Each procedure concerning ballast water exchange is to be fully recorded without delay in the ballast water record book (An integral part of ballast water management plan). These records are considered to be critical to the success of the ballast water management plan and dole out to provide documentation that the ballast water exchange has been properly conducted and the exchange has been completed.
Also included should be a list that identifies a representative listing of those items that may be considered for inclusion as a section of the Ballast Water Management Plan, as follows:
i) The location (Lat/Long) where ballast water exchange is to occur is to be identified.
ii) A detailed position and description of the watertight and weather tight closures (e.g., manholes, opening of vents and air pipes) which may have been opened during ballast exchange that must be re-secured.
iii) Descriptions of the procedures required to conduct ballast water exchange.
Authorized Port State Officers may inspect the ballast water record book on board the vessel as a means to determine the status of exchange completed. These officials may choose to make a copy of the entries in the record book and require the vessel’s Master to certify that the copy as a true copy. Any copy so certified may be permissible in any legal proceedings as evidence of the facts stated in the entry of ballast water management plan.