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The Sea Change

Ballast water from Japan—the latest scare

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The Sea Change
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  • There’s fear that ballast water from ships arriving from Japanese ports may be radioactive. Ballast tanks are laden to stabilise ships.
  • Goa’s pollution control board has asked Mormugao port not to let any ship shed ballast water
  • One ship was quarantined and released after radioactivity tests
  • Another fear is that alien organisms in ballast water may interfere with local ecosystems

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Is radioactive seawater from off Japan reaching India? It’s a far-fetched fear, but it has gained ground in at least one Indian port, Mormugao, as cargo ships return and offload ballast water—seawater admitted into tanks at the bottom of a ship to stabilise it for the high seas.

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After the near-meltdown at the Fukushima nuclear plant, caused by the March 11 temblor and tsunami, some 57 million litres of seawater has been used to cool the crippled reactors and drained back into the Pacific as radioactive waste. The Goa State Pollution Control Board (GSPCB), it seems, was so worried that it ordered the Mormugao Port Trust (MPT) to ensure that no ship—not just those that had touched Japan—empties ballast tanks at the port. “The south Goa collector received some reliable information that two ships that had touched Japanese ports recently were likely to visit MPT,” says GSPCB chairman S.N. de Sousa. One of these ships—the MV Azul Integra—was on arrival held in quarantine for ten days and examined by experts from the Bhabha Atomic Research Centre, who said radiation levels were within permissible limits. “The ship’s agents claimed it had already de-ballasted in the South China Sea and in Colombo,” says de Sousa. There’s no word yet on the second ship, but the order stands as a precautionary measure.

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From Goa, as from other ports in India, ships laden with consignments such as iron ore set sail for destinations across the world. They fill up their ballast tanks for the unladen journey back and pump out the seawater on returning. Bans on deballasting haven’t been reported from other ports in the country, but the GSPCB order has set environmentalists and the authorities thinking about how to prevent the unsolicited entry of dangerous waste and alien organisms through the country’s ports. For, beyond the threat of bringing in radioactivity from Japanese shores, ballast water is also under scrutiny for bearing alien species into Indian waters, upsetting local ecosystems.

A.C. Anil, a scientist with the National Institute for Oceanography (NIO), Dona Paola, has listed several organisms that may have come into Indian waters through ballast water. These include black-stripped mussel, a native of the Atlantic Ocean, now spotted around Mumbai and Visakhapatnam. Some species of barnacles native to the east coast of Africa and the Persian Gulf have been found on India’s west coast.

Organisms transported via ballast water have also been blamed for pernicious algal blooms, occurring when certain harmful species of phytoplankton multiply rapidly in a limited area. Experts have suggested measures such as filtration, thermal shock and ozonisation of ballast water before discharge to prevent such eventualities.

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NIO has announced a ballast water management programme at eight of India’s major ports. This includes a baseline study to document local marine species and the likely impact invasive species from ballast water could have.

In four years, the ports are expected to have an electronic monitoring facility to help them keep track of any shedding of ballast water. “But the responsibility to ensure that ships either carry out a mid-ocean exchange or have the required treatment technologies for treating ballast water before discharging lies with the ports, according to the International Maritime Organisation,” says Anil.

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