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Ballast
Water
'Ballast'
is any material used to weight and/or balance an object. Ships have
carried solid ballast in form of rocks and/or metal for thousands
of years. Ships of modern times however use 'sea water' itself as
ballast, referred to as 'Ballast Water'.
Ballasting
helps in submergence of propeller and ruder for steerage. When a
ship is emptied of cargo at some port, it is filled with ballast
water to maintain its stability. Next time when it is to be reloaded
at another port, this ballast water is discharged at that port.
In the process the live organisms as part of the ballast water are
also released in the sea at this new port, causing marine bioinvasion.
International
seaways account to over 80% of world's commodities transportation.
According to studies done under the Global Ballast Water Management
Programme by IMO - London, shipping transfers about 10 billion tonnes
of ballast water around the globe each year. This itself is indicative
enough of the scale & pace at which this problem is multiplicating
all over the world, and especially at busy ports like ones in India.
Effects
of Ballast Water
Worldwide,
marine bioinvasion of a wide spectrum of organisms including plants
& animals have been reported. The overall impact can be broadly
categorised under three major areas;
Ecological:
Disruption & changes native in biodiversity & restucturing
of the food web. It is estimated that, every nine weeks, a new marine
specie is invading a new environment somewhere in the world.
Economical:
When fisheries, coastal industry and other commercial activities
and resources are disrupted by the invading species. They may clog
the coastal pipelines, drainage and other such places, disrupting
the operations. In the USA alone, the economic losses due to this
are estimated to be US $ 138 billion each year.
Human
Health:
When toxic organisms, diseases & pathogens are introduced through
ballast water, it spreads illness and can cause even death of affected
human beings.
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