Maritime and Coastguard Agency considering theories, including whether chemical haze came from a wreck

This article is more than 3 years old

This article is more than 3 years old

Investigators trying to find the source of last Sunday’s mysterious chemical plume on the Sussex coast say they are looking into possible emissions from disturbed shipwrecks in the Channel.

Almost a week after the plume caused 150 people to seek medical treatment prompting the closure of Birling Gap beach, the source of the gas is still baffling experts.

The Maritime and Coastguard Agency (MCA), which is leading the inquiry said it was considering theories, including possible emissions from disturbed wrecks on the seabed.

One possible source is the wreck of SS Mira, a British oil tanker that hit a mine almost 100 years ago during the first world war. It went down in almost exactly the same spot where a possible plume was picked up in satellite imagery five miles (8km) off Birling Gap just hours before Sunday’s incident.

Neodaas, a facility of the UK Natural Environment Research Council that works with the Plymouth Marine Laboratory, published images of the possible plume picked up that morning.

NEODAAS (@NEODAAS) .@metoffice re #birlinggap #chemicalhaze smoke(?) in #sentinel2 image from 27/08 10:56 source 50.687N 0.142E. Know if/when it made landfall? pic.twitter.com/C04rRTKFPj

If the plume was in the water at the time it could have reached shore by about 4.30pm when beach-goers first reported streaming eyes. But if it was already in the air it is unlikely to have been the source, according to Met Office wind data.

It advised the investigation that an easterly wind direction would have pushed any airborne plume at that point down the Channel.

Ben Taylor, a remote sensing scientist at Plymouth Marine Laboratory who picked up the potential plume in the satellite image, said it could have been caused by a disturbance to the wreck. But he now thinks this is unlikely to be the source of the Sunday’s incident.

He told the Guardian: “One remaining thin possibility ... is that a plume of something was released from the wreck, carried on the tide to the south-east of Beachy Head, then released into the air and was blown on-shore.”

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But he cautioned that such a scenario would have required a “massive release” of a substance from the wreck of the Mira – unlikely after almost 100 years at the bottom on the sea.

Taylor said: “My current best guess is that the wreck of the SS Mira may have partly collapsed, and where it has settled differently on the sea bed the current is picking up sediment. This is what can be seen in the water – the plume is moving in the right direction for the tidal current. But to verify that we’d need someone who

knew the wreck to go dive on it and see if it’s changed.”

He stressed that it was probably a coincidence that the satellite picked up the possible disturbance to the wreck hours before the chemical plume.



But the coastguard confirmed it was examining records of shipwrecks as part of the investigation into the incident, as well as the satellite images published by Neodaas.

It said: “As part of our investigations we are considering a number of possibilities, such as discharges from a vessel, previously unreported lost cargo, and emissions from known shipwrecks.”

The Mira, a 3,700-tonne armed tanker, was sunk by a mine from a German submarine on 11 October 1917, four miles off Beachy Head, according to the specialist website Wrecksite.

Sussex police said a ship in the Channel was still considered the most likely source of the mystery plume.

The MCA said it had identified about 180 vessels that passed through the Channel off the coast of Eastbourne on 27 Sunday August.

“We are working with all relevant environmental and public health regulators to conclude these investigations,” it said.