Global shipping companies have spent billions fitting vessels with “cheat devices” that will allow them to pollute water while still satisfying new emissions legislation, environmental groups have warned.

More than $12bn (£9.7bn) has been spent on the 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.

The sulphur emitted by the ships is processed by the scrubber, which in turn discharges as a liquid which contains pollutant properties which have been found to pose a risk to sea life.

The change could have a devastating effect on wildlife in British waters and around the world, experts have warned.

Coral reefs: Trying to combat climate change damage Show all 25 1 /25 Coral reefs: Trying to combat climate change damage Coral reefs: Trying to combat climate change damage Masked Butterflyfish (Chaetodon semilarvatus) swimming over a bommie reef in the Egyptian Red Sea marine reserve of Ras Mohamed, off the southern tip of the Sinai peninsula AFP/Getty Coral reefs: Trying to combat climate change damage Rising sea temperatures cause corals to bleach (go white) and die Getty/iStock Coral reefs: Trying to combat climate change damage A giant clam is seen nestled among coral reefs at the Obhor coast, 30 kms north of the Red Sea city of Jeddah AFP/Gett Coral reefs: Trying to combat climate change damage Coral reef in seychelles that has degraded After the reef has died they break up and become rubble. On this reef there is some regrowth of young corals so there is hope for recovery Getty Coral reefs: Trying to combat climate change damage Coral gardening A rabbitfish in a net H Goehlich Coral reefs: Trying to combat climate change damage A school of fish and a sea can in a healthy coral reef off the coast of Isla Mujeres, Mexico Getty/Lumix Coral reefs: Trying to combat climate change damage Sky views of great barrier reef in Australia Getty/iStock Coral reefs: Trying to combat climate change damage A fish swims among coral reefs at the Obhor coast AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving in the Red Sea AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A rope nursery Nature Seychelles Coral reefs: Trying to combat climate change damage Fish swimming off the coast of Egypt's Red Sea resort of Hurghada. The rebounding tourism sector is worrisome for the fragile marine ecosystem AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A parrotfish on the reef C Reveret Coral reefs: Trying to combat climate change damage Gorgonian sea fan on a a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage A diver swims during a Great Barrier Reef experience on Lady Elliot Island, Australia Getty/Tourism Queensland Coral reefs: Trying to combat climate change damage Jessica Bellsworthy, a PhD student conducting research on the coral reefs of the Gulf of Eilat, holds a coral in an aquarium at the Interuniversity Institute for Marine Sciences in Eilat AFP/Getty Coral reefs: Trying to combat climate change damage Coral reefs in the water off the Obhor coast, 30 kms north of the Red Sea city of Jeddah in 2008 AFP/Getty Coral reefs: Trying to combat climate change damage A diver photographs golden anthias (Pseudanthias aurulentus) on a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage FUNAFUTI, TUVALU - AUGUST 15: From the air the ocean (L) and the logoon (R) and separated by a thin stip of land on August 15, 2018 in Funafuti, Tuvalu. The small South Pacific island nation of Tuvalu is striving to mitigate the effects of climate change. Rising sea levels of 5mm per year since 1993, well above the global average, are damaging vital crops and causing flooding in the low lying nation at high tides. Sea water rises through the coral atoll on the mainland of Funafuti and inundates taro plantations, floods either side of the airport runway and affects peoples homes. The nation of 8 inhabited islands with an average elevation of only 2m above sea level is focusing on projects to help it and its people have a future. Four of the outer islands are 97% solar energy dependent and the Tuvalu Government is working to achieve 100% renewable energy from wind and solar by 2025. Tuvalu's 11,000 inhabitants see the effects of climate change in their daily life. (Photo by Fiona Goodall/Getty Images for Lumix) Fiona Goodall Getty/Lumix Coral reefs: Trying to combat climate change damage A photo taken on April 4, 2019 shows fish swimming off the coast of Egypt's Red Sea resort of Hurghada. - In dazzling turquoise waters off Egypt's Red Sea coast, scuba divers swim among delicate pink jellyfish and admire coral -- but the rebounding tourism sector is worrisome for the fragile marine ecosystem. (Photo by Mohamed el-Shahed / AFP) (Photo credit should read MOHAMED EL-SHAHED/AFP/Getty Images) MOHAMED EL-SHAHED AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A damselfish Sarah Frias-Torres Coral reefs: Trying to combat climate change damage Divers swim past a coral reef in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage A puffer fish hovering above coral in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving on June 12, 2017 in the Red Sea off Eilat. Global warming has in recent years caused colourful coral reefs to bleach and die around the world -- but not in the Gulf of Eilat, or Aqaba, part of the northern Red Sea. At the Interuniversity Institute for Marine Sciences in southern Israeli resort city Eilat, dozens of aquariums have been lined up in rows just off the Red Sea shore containing samples of local corals AFP/Getty Coral reefs: Trying to combat climate change damage This photo taken on April 21, 2017 shows an aerial shot of part of mischief reef in the disputed Spratly islands on April 21, 2017. Philippine Defence Secretary Delfin Lorenzana flew to a disputed South China Sea island on April 21, brushing off a challenge by the Chinese military while asserting Manila's territorial claim to the strategic region. / AFP PHOTO / TED ALJIBE (Photo credit should read TED ALJIBE/AFP/Getty Images) TED ALJIBE AFP/Getty Coral reefs: Trying to combat climate change damage fish swimming off the coast of Egypt's Red Sea resort of Hurghada AFP/Getty

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 65 of these vessels have had closed-loop scrubbers installed only, 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.

The Exhaust Gas Cleaning System Association has estimated that 4,000 ships will be operating with scrubbers by the time the legislation is enforced, up from fewer than a hundred in 2013.

The ships that have been quickest to adopt the devices are the larger vessels, such as bulk carriers, container ships and oil tankers, which have the biggest engines and have historically been the worst polluters.

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, according to the International Council on Clean Transportation (ICCT), a non-profit organisation that provides scientific analysis to environmental regulators.

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.”

She added: “Scrubbers are effectively cheat devices in that they satisfy environmental legislation, while allowing ships to continue to pollute. They are legal according to IMO rules, which allows shipping companies to wash their hands of their environmental responsibilities.”

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.

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Bryan Comer, a senior researcher at ICCT, said the use of scrubbers by cruise ships is a particular concern.

The ICCT has 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.”

Scrubbers generally cost between £1.6m and £8.1m depending on the vessel – and the adoption of this technology has cost billions of dollars over recent years, according to Mr Comer.

“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.

“Imagine how far $12bn could have gone if it was applied towards developing and deploying technologies for zero-emission vessels.”

Under IMO regulations, ships are permitted to use open-loop scrubbers as what they call “equivalents”. These are defined as: “Any fitting, material, appliance or apparatus to be fitted in a ship or other procedures, alternative fuel oils, or compliance methods used as an alternative to that required.”

In statement to The Independent, the IMO said: “The intention behind that idea of equivalents is to allow for innovation.”

Though IMO member states have approved the use of open-loop scrubbers to meet the incoming sulphur cap, some regional ports have introduced rules to prevent their use.

In January, the UAE’s Port of Fujairah announced a ban on the use of open-loop scrubbers in its waters.

In July, China said it would extend a ban scrubber discharges to cover all coastal regions within 12 nautical miles from China’s territorial sea and regions near the southern island province of Hainan.

Authorities in Belgium, Germany, Ireland and the US have also implemented bans on scrubber discharge in some regions.

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In May, EU member states made a submission to the IMO’s Marine Environment Protection Committee calling for it to develop a set of “harmonised rules” on the areas and conditions under which scrubbers can discharge.

In response, the committee appointed a team to assess the available evidence relating to the environmental impact of discharges from scrubbers. This team is due to present its findings in February 2020.

In a statement issued to The Independent, the IMO said it had already “adopted strict criteria for discharge of washwater from exhaust gas cleaning systems”.

It added that it is “undertaking a review of the 2015 guidelines on exhaust gas cleaning systems. The guidelines include, among other things, washwater discharge standards.”

UPDATE (25.10.19):