Devices, known as open-loop scrubbers, which extract sulphur from the exhaust fumes of ships that run on heavy fuel oil.This means the vessels meet standards demanded by the International Maritime Organisation (IMO) that kick in on 1 January. However, the sulphur emitted by the ships is simply re-routed from the exhaust and expelled into the water around the ships, which not only greatly increases the volume of pollutants being pumped into the sea, but also increases carbon dioxide emissions. The change could have a devastating effect on wildlife in waters around the world, experts have warned.
A total of 3,756 ships, both in operation and under order, have already had scrubbers installed according to DNV GL, the world’s largest ship classification company. Only 23 of these vessels have had closed-loop scrubbers installed, a version of the device that does not discharge into the sea and stores the extracted sulphur in tanks before discharging it at a safe disposal facility in a port.
For every ton of fuel burned, ships using open-loop scrubbers emit approximately 45 tons of warm, acidic, contaminated washwater containing carcinogens including polycyclic aromatic hydrocarbons (PAHs) and heavy metals.
Increasing volumes of wastewater will create toxic sediment around ports and could have a devastating effect on the wildlife in British waters, according to Lucy Gilliam, a campaigner for Transport and Environment, a Brussels-based NGO.
“In the North Sea and some parts of the Channel, the water quality has already been heavily degraded,” she said. “Wildlife in these areas is likely to be far more vulnerable to the effects of having ships discharging huge volumes of acidic, polluted, warm water from scrubbers. As things stand, far too few parameters are covered by the existing IMO criteria for permitted discharge from scrubbers.”
Heavy metal pollution has been connected to damage to the central nervous system in humans and animals while PAHs have been blamed for skin, lung, bladder, liver, and stomach cancers. The increasing acidification of the world’s waters is killing coral reefs, something scientific studies have warned threatens entire oceanic food chains.
International Council on Clean Transportation (ICCT), a non-profit organisation that provides scientific analysis to environmental regulators, estimated that cruise ships with scrubbers will consume around 4 million tons of heavy fuel oil in 2020 and will discharge 180 million tons of contaminated scrubber washwater overboard.
“About half of the world’s roughly 500 cruise ships have or will soon have scrubbers installed,” said Mr Comer. “Cruise ships operate in some of the most beautiful and pristine areas on the planet, making this all the more concerning...If you are conservative and say that ships are spending about $3m (£2.4m) per ship to instal scrubbers, at 4,000 ships that’s $12bn (£9.7bn) dollars of investment in a technology that enables ships to use the world’s dirtiest fossil fuel – heavy fuel oil. Worse, scrubbers increase fuel consumption by about 2 per cent, increasing carbon dioxide emissions..."