Toxic oil spill will harm corals, expert warns

As the operation begins to salvage the grounded Chinese coal carrier Shen Neng 1 – shipwrecked off Douglas Shoal, east of Rockhampton – the impact of oil as well as chemical oil dispersants on the reef is likely to cause further environmental damage, a Southern Cross University coral expert has warned.

Professor Peter Harrison, director of Marine Studies at Southern Cross University and director of the Southern Cross University Marine Ecology Research Centre, has been working on the effects of oil pollution and other stressors on Great Barrier Reef corals for about 30 years.

"The key issues are that oil stresses corals in both a physical and chemical manner,” Professor Harrison said.

“The oil can coat the coral tissues and kill the polyps, and the toxic oil compounds that leach into seawater also stress corals.

“The oil dispersants used to break up the oil slicks are also harmful to corals, and in some cases the combination of oil and dispersant have increased toxic synergistic effects.

“This highlights the importance of trapping the oil in booms and physically removing any spilled oil, rather than relying on dispersants.

“If the oil becomes embedded in the coral reef and sand, it will have long-lasting effects as it can be mobilised by tides and wave action and create chronic long-term pollution on the affected areas of the reef.

“This could have negative effects on coral spawning later this year at this reef, as my research has clearly shown that oils and dispersants significantly reduce coral fertilisation and larval settlement – in other words it reduces coral reproductive success."

The difficult task of transferring 900 tonnes of oil threatening to spill from the ship is scheduled to begin today or tomorrow, if the weather permits.

The Pacific Responder, a dedicated salvage and response vessel from north Queensland, will today reach the Shen Neng 1. The vessel has specialised boom equipment that will be placed in a V-shape around the Shen Neng 1 to capture any potential additional oil spill, so the oil slick can be captured before it spreads into the World Heritage-listed Great Barrier Reef area.

Professor Harrison said the incident was a timely reminder that the increased shipping traffic in the Great Barrier Reef posed significant environmental risks.

“It is fortunate that more oil has not been spilled, but the risks of a major oil spill from large vessels or oil tankers continue to grow, and highlight the need for compulsory piloting of large vessels using the Great Barrier Reef shipping routes,” he said.

Photo: A staghorn coral from the Great Barrier Reef releasing strings of mucus and expelling its symbiotic algae (bleaching) in response to stress effects from oil pollution and dispersants. (This image was not taken from the reef where the ship is grounded.) (Photo: Peter Harrison, Southern Cross University.) High resolution image available on request.

Media contact, Zoe Satherley, Southern Cross University acting communications manager, 02 6620 3144, 0439 132 095. Professor Harrison is happy to speak directly with media and can be contacted on 0407 456 249.