Woodside gas project triggers call to protect rare sea snake on WA's Scott Reef
The dusky sea snake is only found at a handful of coral reefs far from the Kimberley coastline. (Supplied: Chris Malam)
The dusky sea snake is an enigma, dwelling in some of the most remote reaches of the Timor Sea.
But this marine species, known by scientists as Aipysurus fuscus, is now only found at a handful of reefs off Australia's remote north-west coast, and experts are calling for its urgent protection.
During a recent consultation, the federal government received advice that the animal should be included on the national threatened species list as endangered, and its remaining habitat be preserved.
The submission, prepared by federal government staff with input from sea snake scientists, also recommended a review of all fossil fuel activities in the Browse Basin north of Broome, the location of the three remaining reefs that are home to the dusky.
But the proposed protection of the sea snake may come too late to be considered in the environmental impact of Australia's largest undeveloped conventional gas project.
A decision on the animal's conservation listing is not due until October. But environmental approvals are already being sought by Woodside to drill for gas as close to 3 kilometres from Scott Reef, which is key habitat for the sea snake.
The company’s $29 billion Browse Joint Venture is slated to begin in 2030 and run up to 44 years in the Torosa gas field.
And it’s a prospect which has conservationists concerned on two fronts.
One is the unlikely but potentially catastrophic consequences for the reef's diverse marine life from an oil and hydrocarbon spill in the event of a production well blowout.
The second is the contribution the project will make towards climate change and warming oceans that drive coral bleaching.
A remote reef
Scott Reef is about 260km north of the Kimberley coast.
It actually consists of two main reefs: a circular reef to the north, and a horseshoe-shaped southern section, with a big lagoon between them ranging from about 30 to 70 metres in depth.
Close to 900 fish species and more than 1,500 species of invertebrates, including corals and sponges, are found at Scott Reef.
There are also dolphins, sea birds and a genetically unique stock of green sea turtles that only nest at two spots in the Browse Basin.
Endangered pygmy blue whales migrate past Scott Reef and are believed to stop there to feed.
[pygmy whales map]
The reef is also home to at least six species of sea snake, including the dusky.
University of Adelaide sea snake expert Kate Sanders provided input to the new conservation advice, and said the reef was an amazing place to see the reptile.
There may also be other places the dusky existed that had not been picked up on surveys, but Scott Reef could be the last stronghold for the species, Dr Sanders said.
"Scott Reef is an extensive area of habitat that's important for duskies."
Scott Reef is much larger than the two other dusky sea snake habitats — Seringapatam Reef, which is about 20km from Scott Reef and Heywood Shoal, about 230km away — and is considered to have a stronger population.
However, advice to government was to designate all three reefs as critical habitat for the sea snake, something that has only happened for five other species in the 24-year history of the national environmental protection law.
The dusky sea snake was added to the international threatened species list as endangered in 2009, but the designation has no legal effect until Australia adds it to its list.
And even if the federal government does make the listing, this will have no bearing on Woodside's environmental assessment, which has already been lodged.
A Department of Climate Change, Energy, the Environment and Water spokesperson said, however, that given the project was in a Commonwealth marine area, potential impacts on species there would still need to be considered.
Greenpeace Australia Pacific climate and energy head Joe Rafalowicz said it "beggared belief" Woodside was proposing a gas drilling platform near one of the dusky sea snake's few remaining habitats.
"The point of designating the dusky sea snake as 'threatened' is to avoid actions which moves them closer to extinction," he said.
"Woodside wants to drill right near the Scott Reef, risking a catastrophic oil spill."
[torosa gas map]
A Woodside spokesperson said no drilling would occur at the reef itself, its lagoons, or the channel between them.
"No physical contact to Scott Reef, above the 75-metre contour, is expected, this being the area which incorporates the shallow reef habitats preferred by sea snakes," they said.
The spokesperson added there had been no recorded impacts from exploration wells they drilled at the reef since its discovery in 1971, according to long-term studies by the Australian Institute of Marine Science (AIMS).
What are the risks of an oil and gas spill?
The last major blowout in Australian waters was in the Timor Sea in 2009 and involved a rig operated by Thailand's state-owned company PTT.
Hydrocarbons ran from the Montara well for 75 days before it was plugged.
The spill went as far as Ashmore Reef and covered about 6,000 square kilometres.
Survey flights for birds and marine animals were held about 39 days after the spill.
One dead sea snake was found during post-spill surveys along with several lethargic live specimens, in thick oil, which could not dive.
The true cost of the spill to the environment is uncertain as a broad scientific monitoring program was not put in place until about 50 days after the incident.
East Timor seaweed farmers received compensation payments for loss of work from the spill.
Woodside says the frequency of a deepwater blowout is about 0.25 per 1,000 wells drilled, based on information from the SINTEF offshore blowout database.
The company states in its environmental documents such a blowout is highly unlikely after engineering improvements in the industry following the 2010 BP oil spill in the Gulf of Mexico.
Woodside has modelled a 77-day spill event from a well 15km from the reef, which would release 142,154 cubic metres of oil and condensate. It would lead to the death of marine animals and cover the shoreline of Sandy Islet, a turtle nesting area near the south of Scott Reef.
But the company says it would aim to have emergency well-capping technology deployed within 13 days, which could limit the spill to 24,000 cubic metres.
Woodside claims this is an environmental impact the reef could recover from, based on previous findings that the ecosystem bounced back 10 years after severe coral bleaching.
More bleaching expected
But the reef might also have less chance of recovering from a shock like an oil spill given the impacts of climate change.
Scott Reef has had major bleaching in 1998 and 2016 with additional heat stress events in 2017, 2019 and 2020. More frequent coral bleaching events are anticipated in the years to come.
Woodside has funded most of the marine research undertaken at Scott Reef by the AIMS and other organisations over the past 53 years.
AIMS coral reef ecologist James Gilmour said Scott Reef appeared to have been the most impacted in WA from ocean warming in the past two decades.
"There's some signs of reefs adapting to this heat stress, but they're not adapting as fast as the heat stress is increasing," he said.
Dr Gilmour said all reefs faced a fairly bleak future until carbon emissions could be addressed.
"So some other impact on a reef combined with coral bleaching is going to speed the degradation, and the faster it happens, the less able we are to adapt, manage, intervene," he said.
Company plans carbon capture
Woodside is planning to use carbon capture and storage to sequester 47 per cent of its direct greenhouse gas emissions, which is estimated to total about 59 million tonnes of carbon dioxide equivalent emissions.
Project emissions not produced by Woodside, but by others — for example, those who buy and burn the gas — would be between 995 and 1,330 million tonnes of carbon dioxide equivalent emissions.
The responsibility for keeping these "Scope 3" emissions from the Browse venture within global climate change targets, to limit warming temperatures, will fall to countries buying the gas like Japan.
A Woodside spokesperson said the project could contribute to energy security in WA and the Asia Pacific region.
"With production capacity of 11.4 million tonnes per year [of LNG, LPG and domestic gas], Browse domestic gas could help address the forecasted shortfall of domestic gas in WA from 2030," they said.
"In addition, the Browse project has the potential to provide valuable employment, contracting and social investment opportunities during the construction and operations phases."
Woodside has faced lengthy delays in trying to get the Browse venture started.
The company proposed a controversial onshore processing facility at Broome before abandoning the idea in 2013.
Since lodging new plans in 2018, Woodside has been frustrated by the length of the environmental approvals process and appeals against permits.
The chief executive of energy research company EnergyQuest, Rick Wilkinson, said he didn't think the project would get started until at least 2032.
"Its long distance from infrastructure and deep water depth have made it a challenging project to develop," he said.
"The additional requirements of managing carbon dioxide and changing environmental regulations have added more costs to a difficult project.
"Environmental or other anti-project campaigns, whether based on facts or not, add to the uncertainty of securing regulatory approvals, and any delays add costs to the project."