Water management contributes to greater environmental safety in maritime navigation
Por Capitão-Tenente (RM2-T) Camila Marques de Almeida – Brasília, DF
The International Convention for the Control and Management of Ship Ballast Water and Sediments (BWM Convention) aims to prevent, minimize and eliminate the risks of introducing harmful aquatic organisms and pathogens into the aquatic environment, due to the discharge of ballast water and sediments from ships. It establishes rules for ships in operation to adopt efficient management measures, for example by installing treatment systems on board. The text of the Convention was adopted by the International Maritime Organization (IMO) in 2004, in London, and ratified by the Brazilian National Congress in 2010.
By international standards, established by the IMO, States must take all necessary measures to prevent, reduce and control pollution of the marine environment resulting from the use of technologies under their jurisdiction or control, or the intentional or accidental introduction of species, whether exotic or new, into a part of the marine environment, which may cause significant and harmful changes. To this end, since 2005, Brazil has had a legal and mandatory instrument for all ships sailing in Brazilian waters: the Norm of the Maritime Authority on water pollution caused by vessels, platforms and their support facilities, better known as NORMAM-20, which is currently in its third revision.
What is ballast water?
It is the water that primarily ensures the stability of a vessel. It is placed in tanks with the objective of guaranteeing safety, aiding propulsion, and acting as a counterweight. In the past, to achieve this stabilization, solid ballast was used, such as stones and metals. With the development of maritime transport, this was replaced by water, starting with the construction of steel ships, for reasons of efficiency, availability, and economy.
The importance of the issue lies in the fact that ballasted ships can carry invasive alien species inside the ship’s tanks. For Newton Narciso Pereira, an associate professor at the Universidade Federal Fluminense, who has a doctorate in naval and oceanic engineering from the University of São Paulo, “these species alter the local ecological balance and can cause negative impacts on fishing, aquaculture, health, and other economic activities. This occurs because in new environments these organisms tend to have no natural predators, find plenty of food, and start to form new populations. Studies indicate that, per voyage, about 3,000 to 7,000 species can be found in a ship’s ballast tank.
1 – Ballast acts as a counterweight, i.e. when the ship is empty it is ballasted.
2 – To prevent the introduction of non-native and pathogenic species, the ship must manage its ballast water. This can be done by ocean exchange or by installing a treatment system on board the ship.
3 – Upon arrival at the destination, if the ship is to receive cargo, it will de-ballast. If it leaves cargo, it will fill the ballast tanks with water.
Therefore, to control and minimize the transfer of non-native species around the world, management measures have been defined within the IMO. Still for Professor Newton Pereira, the risks of bioinvasion are a reality and there are numerous examples of exotic species transfers, whose ballast water was a vector of transmission. “For example, the golden mussel in Brazil, zebra mussel in the United States, among other species of jellyfish and algae worldwide. These invasive species can cause an imbalance in the aquatic ecosystem, as well as compromise native species, besides the economic and social impacts they generate in the places where they manage to establish themselves,” he explains.
The Head of the Environmental Department for the Coastal Zone and Brazilian Jurisdictional Waters of the Directorate of Ports and Coasts, Frigate Captain (Technical Staff) Maria Cecilia Trindade de Castro, who has a PhD in oceanography from the University of Plymouth, United Kingdom, explains that the main methods of ballast water management on board a vessel are the oceanic exchange of ballast and the treatment of the water with a view to making organisms in it unviable. “In order to comply with these, the IMO Convention stipulates that the oceanic exchange of ballast, called the D-1 standard, should take place at least 200 miles from the nearest land in places of at least 200 meters depth, or 50 miles from the nearest land in places of 200 meters depth or more.
When the ship is complying with standard D-2, called the performance standard, it is generally opted to install a treatment system on board the ship, the most common being treatment composed of the association of a filter and an ultraviolet lamp system, or the installation of a filter associated with an electrochlorination process.
In order to verify compliance with the requirements of the Ballast Water Convention and NORMAM-20, Port State Control carries out a verification of the requirements foreseen in NORMAM-20 that must be complied with by the ships. Port State Control has an International Certificate (International Ballast Water Management Certificate) in addition to other documents required from vessels to which NORMAM-20 and the Convention are applicable, such as: the vessel’s Ballast Water Management Plan, the Ballast Water Register Book and a Form with information on on-board ballast water management which is a Brazilian requirement, the model for which is provided for in NORMAM-08/DPC.
Navy News Agency *** Translated by DEFCONPress Team ***