Ballast Water is water carried in ships ballast tanks to improve the stability, balance and trim. It is taken up or discharge when cargo is loaded or unloaded, or when the ship needs the extra stability is severe weather. When ships takes on ballast water, plants and animals that live in ocean are also picked up. Discharging this ballast releases water releases other organisms into new areas where they become marine pests
Threats due to Ballast Water :
While Ballast Water is essential for safe and efficient modern shipping operations, it may pose serious ecological, economic and health problems due to multitude of marine species carried in ships Ballast Water.
The problem of invasive species in ship’s Ballast Water is due to expanded trade and traffic volume over last few decades. The effect in many areas of world is devasting, quantitative data shows the rate of bio-invasion is continuing to increase at an alarming rate and new areas are being invaded all the time. The spread of invasive species is recognized as one the greatest threat to ecology, damage to biodiversity economics of planet. Biofouling is also considered one main vector for bioinvasion and described as the undesirable accumulation of microorganism, plants, algae and animal submerged structure.
Examples of Some Major Aquatic Bio-Invasions :
Ballast Water Management :
||Western & Northern Europe
||Displaces native aquatic life, alters habitat, ecosystem. Blocks water intake pipes, sluiches and irrigation ditches. Economic cost for USA alone from these mussels was US$750 million in 1989-2000
||Southern Australia, New Zealand
||Displaces native algae and marine life. Alters habitat and ecosystem. May affect commercial shellfish stocks through space competition and alteration of habitat.
||Various strains with broad ranges
||Southern Australia, Gulf of Mexico and other areas
||Some cholera epidemics are reported to be have been associated with ballast wate
All ships should require to implement a Ballast Water management plans. During the Convention Development Process, considerable efforts were made to formulate appropriate standards for Ballast Water management. They are the Ballast Water exchange standard and the Ballast Water performance standard. Ships performing Ballast Water exchange shall do so with an efficiency of 95 per cent volumetric exchange of Ballast Water and ships using a Ballast Water Management System (BWMS) shall meet a performance standard based on agreed numbers of organisms per unit of volume.
Anti-fouling paints are used to coat the bottoms of ships to prevent sea life such as algae and molluscs attaching themselves to hull and thereby slowing down the ship and increasing fuel consumption.