Oil spill lessons come full circle
When the Exxon Valdez ran aground on Bligh Reef on 24 March 1989, spilling the equivalent of 17 Olympic-sized swimming pools of oil into the Gulf of Alaska, aspects of the response did more harm than good to some of the sea creatures that live along the rugged shoreline of the Alaska Peninsula.
The oil was so sticky that the response team used high pressure hoses to pump hot water—above 60oC—to blast it off the rocks. Clams, seaweed and other organisms were effectively cooked.
In Australia, the science-based guidelines for managing oil spills, published in 2003, have now been revamped, with a view to mitigating the risk of environmental damage.
The Oil Spill Monitoring Handbook, published by CSIRO and officially launched in October, offers guidance to state governments, shipping companies and port/terminal authorities on how to respond to an oil spill and assess any environmental damage. Offshore oil and gas companies may also find it useful, though the guidelines are for surface spills, not sub-surface spills.
CSIRO ecotoxicologist Dr Sharon Hook is a member of the multidisciplinary team of chemists, geologists, biologists and oceanographers who co-wrote and co-edited the handbook with representatives from the Australian Maritime Safety Authority and Victoria EPA.
“One thing lacking in previous advice” says Dr Hook “was guidance on monitoring the recovery phase to determine what damage has been done and how the ecosystem has recovered. The handbook places more emphasis on environmental monitoring.
“We’re hoping people will use it for preparedness so that, before a spill, they have baseline data and their plans in place for monitoring.
“Australia is a large island; everything comes by ship and as the population grows we can expect more shipping. We need to be prepared to cope with the increased risk. And if we’re going to be increasingly using ocean resources for oil and gas resource development, we hope the handbook will help people measure any impact that could be occurring and help them mitigate risk.
“By being well prepared it is possible to mitigate environmental damage.”
Response and recovery
The process of dealing with an oil spill has two phases, explains Dr Hook: “The response phase is where you do the cleaning up immediately to mitigate environmental damage. For example, you might use booms, a shoreline cleanup or chemical dispersants. You are also looking at where the oil is going and seeing what resources could be impacted.
“The recovery phase is where you monitor the ecosystems to see if any damage has been done. For example, a small spill might not cause any damage. This phase might also include remediation and shoreline cleanup.”
It’s important that the two phases overlap, she says, to avoid situations like the Exxon Valdez spill where aspects of the response did more damage to the environment than the spill.
Paul Irving is a man who knows his oils. The senior scientific coordinator with the Australian Maritime Safety Authority says that with the new handbook AMSA and their national plan partners are better equipped to respond to oil spills.
“The oil that goes into a ship is not the oil that comes out of the ship and is not the oil that we respond to hours later,” he explains. “It changes over time—we call it weathering. Oils just ain’t oils.
“If you spill petrol, you are probably most worried about the explosive vapour, as it is very volatile, so an hour later you can’t find it. Diesel is very toxic very quickly, but will mostly evaporate over hours, whereas crude or fuel oil may smother everything and stick around for a long time. An hour later, it is heavier and stickier as its volatile components evaporate. It may have changed density and now, instead of floating on the surface, it can be floating just below the surface. So instead of sending out just human eyeballs, we may need to fly over it with electronic remote sensing equipment just to see it. It may break up into droplets, sink into the water and disappear for hours or days before turning up somewhere else.”
Crude oil is sometimes explosive, sometimes flammable, sometimes toxic, he adds. Predicting where it’s going to go and how it’s going to change is crucial for the safety of the response team.
“You need to know what you’re sending people into. People who do this infrequently don’t always understand the safety issues of doing science when you’re surrounded by hydrocarbons.”
Deciding what techniques to use requires flexibility and judgement, something which the handbook explains really well, he adds.
“This handbook is not just about the science; it’s not a cookbook. It provides context about the nature of the event people are going into. There is nothing else like it in the world in terms of the response phase. I’ve never seen anything like it. It’s exceptional.”
Smart sensors and genomics
The handbook also gave the team an opportunity to showcase CSIRO innovation.
For example, the sensors deployed in the water to monitor the efficacy of a dispersant are a recently developed ship-based technology. They collect data in real-time so the monitoring team know at any time whether the dispersant is working.
Genomics also comes into play. One example is using oil-degrading bacteria to measure the zone of impact and the progress of remediation efforts.
“Oil is a natural product and, like any natural product, it can be broken down by bacteria,” explains Dr Hook. “Following a spill, you typically see an increase in abundance of those bacteria that can break down oil. So measuring changes in bacterial abundance is a way of measuring environmental impact.”
Genomics approaches could be used in measuring the microbial response of these bacteria to the oil spill/response technology. It could also be used to monitor changes in organism health following the oil spill/response technology. “That’s just one example; there are lots more,“ says Dr Hook.
Interest is high at home and abroad
The handbook has already generated a lot of interest among Australian state and federal government agencies, oil companies and the shipping industry. According to Dr Hook, the Northern Territory Government has already used the guidance in managing a recent small spill.
Phil Koloi, Incident Response Coordinator with the Great Barrier Reef Marine Park Authority (GBRMPA), sees it as “the benchmark for best practice” in oil spill monitoring and response.
“Having a copy of the handbook on my desk is like having the scientists on my shoulder co-authoring updates to GBRMPA procedures,” he says. “The SOPs [standard operating procedures] are awesome.”
The contemporary response examples used in the book are applicable to an event that could occur on the Reef at any time, he adds.
“It is Australia focused, with tropical examples that include corals and seagrass, which are rarely addressed in other monitoring tomes.
“It is the sort of book that you read from cover to cover to get the broad knowledge ‘in the bank’, but also regularly flick through and use it as a doorway to the current literature.”
Internationally, Dr Hook has fielded requests from New Zealand, the US and Asia.
Before the official launch, the team presented the handbook at a workshop run by the Australian Maritime Safety Authority. Exxon Mobil representatives in attendance requested ‘rush deliveries’ of the handbook for their regional training exercises. The lessons learnt 27 years ago on the Alaska Peninsula have come full circle.