How did shipping fuel changes affect the Great Barrier Reef?

Removing sulphur from shipping fuels reduced atmospheric shading, allowing more sunlight to reach the reef and intensifying a 2022 coral bleaching event.

What was the impact of reduced sulphur emissions on corals?

Corals on the Great Barrier Reef experienced up to 10% more heat stress due to increased solar energy penetration after sulphur reductions.

When did the Great Barrier Reef's sixth mass bleaching occur?

The sixth mass bleaching event on the Great Barrier Reef occurred in the early months of 2022, despite it being a typically cooler La Niña year.

Home / Environment / Shipping Fuel Change Worsened Coral Bleaching Event

Shipping Fuel Change Worsened Coral Bleaching Event

22 Jan

•

Summary

Removing sulphur from shipping fuel intensified coral bleaching.
Great Barrier Reef corals faced up to 10% more heat stress.
Reduced sulphur emissions allowed 5-10% more solar energy on reef.

Shipping Fuel Change Worsened Coral Bleaching Event

Regulations implemented in early 2022 to significantly reduce sulphur content in shipping fuels inadvertently amplified a major coral bleaching event on the Great Barrier Reef. The International Maritime Organization mandated a cut in fuel sulphur from 3.5% to 0.5%.

This reduction in sulphur pollution, while beneficial for human respiratory health and acid rain, also decreased the atmospheric shading effect. Research indicates that this allowed 5% to 10% more solar energy to reach the reef.

Consequently, corals experienced up to 10% greater heat stress during the 2022 bleaching, the sixth recorded mass bleaching event and notable for occurring during a typically cooler La Niña period.