What is Ballast Water?

Ballast is any material used to weight and/or balance an object. Ships have carried solid ballast, in the form of rocks, sand or metal, for thousands of years. In modern times, ships use water as ballast. Ballast water is therefore water carried by ships to ensure stability, trim and structural integrity. It is much easier to load on and off a ship, and is therefore more efficient and economical than solid ballast. When a ship is empty of cargo, it fills with ballast water. When it loads cargo, the ballast water is discharged.

BWT Regulations

Ballast Water Treatment Standards

The Ballast Water problem

There are thousands of marine species that may be carried in ships' ballast water; basically anything that is small enough to pass through ships' ballast water intake port and pumps. These include bacteria and other microbes, small invertebrates and the eggs, cysts and larvae of various species. The introduction of invasive marine species into new environments by ships' ballast water exchange attached to ships' hulls and via other vectors has been identified as one of the greatest threats to the ecological balance of the world's oceans.

The spreading of harmful aquatic organisms when brought into coastal habitats via ships' ballast water may cause irreversible changes affecting human health and industries as well as the ecological balance of the seas. These problems are already experienced by a number of the world's coastal states and their effects are well documented.

The Ballast Water Convention will require all ships to implement appropriate Ballast water management plans and recording procedures - but more importantly, it defines a Ballast Water Performance Standard by which ships' must comply. The measure to be applied is that of onboard Ballast Water Treatment, introduces unique challenges to the industry. This is apparent when addressing ballast water volumes and the speed required to turnaround ships in ports.