More Mysterious Dark Substances Seen In Ocean Around Mauritius After Oil Spill

The giant puzzle surrounding the Mauritius oil spill keeps getting bigger almost two months on, as more pieces are added, and fewer questions are answered.

On Sunday 20 September, local kitesurf instructor, Denis Labeauté filmed a mysterious dark substance in the waters moving around the South of the island.

Based on the direction of the currents at this time of year, the substance was coming from the direction of the giant Japanese ship, the Wakashio, and the subsequent oil spill. It could also have been coming from the direction of the sunken front part of the vessel, the part of the vessel still stuck on the reef, or the cleanup operation, that continues under strict secrecy.

Given that the Wakashio was sunk in an undisclosed location and a full inventory has still not yet been disclosed of what was on the vessel, it is unclear whether the dark substance could have originated from the vessel.

Just 15 days earlier, on 5 September, a mysterious brown substance had turned the pristine blue coral lagoon of Blue Bay Marine Park into a much darker color, causing concern across the country.

Government scientists the following day said that this dark substance was algae.

Algae as a precursor to ocean deadzones

In oil spills elsewhere in the world, algae blooms have been associated with ocean deadzones.

Coral reefs require clear waters which are free from particular nutrients that could cause a harmful algae bloom. Certain cleanup operations use either organic fertilizers or chemicals to try eradicating the presence of oil. This is usually done to rapidly remove the visible trace of oil, but could cause longer term issues.

Harmful algae blooms could end up creating many more serious cascading effects on coral reefs. For example, the brown algae could be an indication that calcification of corals may be being prevented. This could be a precursor to a phase change of the corals.

US Marine toxicologist, Riki Ott, has seen her fair share of oil spills. She is the executive director of the ALERT Project which is supported by high profile US Environmental NGO, Earth Island Institute that has taken a stand against harmful oil spill clean up operations.  She expressed concern with what she is seeing in Mauritius.

“The emergence of algae following an oil spill is a worrying sign. Oil spills usually smother algae first. Then in time, fragile algae that live in clean environments are replaced by more opportunistic algae that can survive in polluted environments. When substances such as nitrogen and phosphate are added, as in bioremediation, the algae can also bloom. Algae blooms are linked with dead zones, because the algae bloom consumes the oxygen in the water.”

Asked whether the algae bloom could also be a result of the oil spill clean up operation, she said, speaking to Forbes “the presence of algae could be an attempt to accelerate biodegradation of oil by nutritional supplementation. Oil is an overdose of carbon, so oil-eating bacteria growth is limited by phosphorus and nitrogen. Products such as surface washing agents or bioremediation agents with phosphates could cause this. This would stimulate the bacteria and and also the algae, effectively acting as a fertilizer for the algae. This could be particularly damaging for coral reefs.”

Riki went on to explain her experience with the Exxon Valdez oil spill in Alaska in 1989, and the legacy of bioremediation agents there.

“What was foisted on us during the Exxon Valdez as a bioremediation agent, was actually industrial solvent 2-butoxyethanol carrying some phosphate. It interacted with oil more like a dispersant. This turned out to be really deadly for the workers. Really bad.”

150 square kilometers cordoned off

This comes a month after 32 kilometers of Mauritian coastline was cordoned off, with fishermen and tourist boats now banned from 150 square kilometers of the coral lagoon. Most of the clean up operation is happening in a restricted way around this coastline, with no independent scientific oversight, even though Mauritius has many independent scientists on the island, including a former President who is an internationally renown biodiversity scientist.

Riki Ott explains some of the pressures that are often felt during oil spills. “With oil spills, there’s always a temptation to make things appear cosmetically clean at the surface, and that apparently overwhelms common sense. The clean up officials allow these industrial solvents to dissolve oil off water surfaces or beach substrates like rocks, and then push the oily droplets underwater. The thinking is ‘out of sight, out of mind.’ The clean up teams then leave because visually, beaches look ‘clean.’ However, the locals are left with the long-term consequences of these short-term decisions. The media is usually long gone when this happens.”

With half a century of major oil spills, there are well researched and well understood guides on how to respond to an oil spill in a highly sensitive biodiversity hotspots with fragile coral reefs.

Unusual secrecy over oil spill cleanup

The concerns come amid general concern within Mauritius about how the oil spill response and clean up are being handled.

A Government of Mauritius press statement had said that the vessel insurer, Japan P&I Club, were responsible for the cleanup operation. Japan P&I club had then selected French company, Polyeco and Le Floch Depollution, and were also being advised by the IMO and oil industry group, ITOPF.

However all five international organizations have declined to reveal what technique was being used for the oil spill clean up, and open themselves to independent and transparent scientific oversight.

This is certainly not the behavior expected of international organizations that were brought in to role-model best practices on how to respond to a major oil spill.

This comes amid confusion on the role of the International Maritime Organization in Mauritius following the revelation last week that the IMO Representative left Mauritius on 4 September. This meant that there has been no IMO representation in Mauritius for almost three weeks.

None of this was disclosed by the IMO or the Government of Mauritius at the time, raising even more questions about how the oil spill response and clean up is being handled.

Since the start of this crisis on 25 July, when the Japanese-owned vessel crashed into the coral reefs of Mauritius, there has not been one unified press conference with all international representatives.

Thousands of Mauritians have been attempting to help with the oil spill response, including a large diaspora community, but these offers have been rejected for an army of international and anonymous international consultants.

An analysis by Forbes, revealed that of the 79 international consultants brought into Mauritius 100% were men. 2019 was highlighted as the year to empower women in maritime, but clear the numbers are speaking louder than the marketing.