POTENTIALLY POLLUTING WRECKS
Over 3000 ships sank in the Pacific during WWII, including about 300 oil tankers. As they rust, many of them are starting to leak oil. In 2001, a sunken warship in Micronesia started leaking oil and the US Navy eventually conducted a major salvage operation to remove about 6000 tons of oil from the wreck. Several Pacific Island communities are worried that major oil spills from other wrecks will soon devastatingly pollute the reefs and mangroves of their coasts. But very little is known about which wrecks are ticking time-bombs and which wrecks have already lost their oil…. discovering this information is the focus of our project.
Phase 1: Identify the most worrying wrecks
Working with the Pacific Regional Environment Program (an organisation of 21 governments) to implement its strategic plan on WWII wrecks, and with marine archaeologists and historians, we are researching which of the wrecks are the most potentially polluting. Methodologies exist to balance factors like location, size of the possible spill and its impact on nearby ecosystems and communities (mangroves are important fish nurseries and very easily damaged, for example)
Phase 2: Field investigation/Ground truthing
We will visit the PPWs of most concern and investigate whether they still have worrying amounts of oil in them. Working with subsea oil engineers, we have identified several methods for discovering if there is oil in a wreck and we are conducting research on the best of these methods. Our expedition ship, the RV Ocean Recovery, was built for diving support of North Sea oil rigs and is capable of supporting industrial diving operations if necessary, with a four-anchor positioning system, surface air supply, a diving bell and a decompression chamber. We will make detailed 3D models of the wrecks we visit, with ROVs (remote control mini-submarines) able to conduct this work in deeper water than human divers.
Phase 3: Preventing oil spills
When we find a wreck that will cause a dangerous spill when it breaks up, there are a number of approaches to mitigate any environmental damage.
Using a process called hot-tapping. Oil has been removed from many wrecks around the world, and although our ship could carry out such industrial operations, this work would probably need to be carried out by government entities.
This electro-chemical process is used daily in the subsea oil and gas industry and on almost all boats. A very weak electrical current not only stops the hull from rusting any further, it also stimulates marine growth on the wreck, which makes it structurally stronger. Our ship, with its four-point anchoring system, is equipped to precisely lower the giant anodes necessary to install enough protection to save the wrecks for decades to come.
Various bacteria are known to eat and breakdown oil – and this is an exciting field of bioremediation. Oil samples we have taken from old wrecks in Chuuk (Truk) lagoon in Micronesia have been analysed at Curtin University and found to contain indigenous populations of Pseudomonas Sp, a bacterium that breaks down oil. Working under a memorandum of understanding with Newcastle University, which has sponsored a PhD scholarship to work on this microbiology, we aim to discover if there is a practical way to encourage bacteria to “eat an oil slick before it happens”.
Catherine Graue from ABC Radio Australia interviews Dr Bill Jeffery about the Pacific’s potentially polluting wrecks in this interview. Find the full article here.