Secrets of the deep
SCIENCE’S NEW TOOL TO TRACE ALL FISH STOCKS
AUSSIE scientists are using cutting edge forensic techniques borrowed from crime scene investigators to determine the health of our oceans, with potentially massive implications for the global fishing industry – and even what seafood we eat.
A state-of-the-art laboratory called OceanOmics will be officially launched at the University of Western Australia this Thursday, building up a comprehensive library of the estimated 5500 fish and vertebrate species that frequent Australia’s oceans.
The lab is the latest ambitious conservation project from Andrew and Nicola Forrest’s Minderoo Foundation. While “Twiggy” earnt his reputation (and billions) from land-based enterprises, marine conservation has taken an ever-increasing focus for the mining magnate.
The OceanOmics program “aims to revolutionise ocean conservation through the development of nextgeneration genomic tools … for the monitoring and management of ocean wildlife, including endangered species,” according to the Minderoo Foundation.
The researchers are using a technique called environmental DNA (eDNA) analysis to determine what’s actually out there in the deep – and crucially, in what sort of numbers.
Currently, estimates of marine species’ health are based on observations, or catch – methods which can be unreliable. It’s been estimated that more than half the global seafood haul is from fish stocks with insufficient data to determine if they’re sustainable or not.
The Australian government monitors 477 individual fish stocks in our waters, and the latest report shows 302 of those species are sustainable. But 37 of the fish stocks are depleted, another 17 are characterised as “depleting,” 36 are recorded as “negligible catch” and for 70 there is insufficient information to make an assessment. So for
160 of the 477 monitored stocks (one in three), warning signs could or should be flashing.
On the depleted list are such favourites are blue swimmer crab, Tasmanian scallops, and several stocks of snapper.
But with 65 per cent of the seafood eaten in Australia coming from overseas, the OceanOmics research has the potential for a global impact.
Working like a sort of Crime Scene Investigation Marine Unit, the OceanOmics team will detect what species of marine life pass through a certain location based on the DNA they leave behind – fishy fingerprints, if you like. “eDNA can revolutionise how we measure, understand and ultimately protect the ocean,” OceanOmics director Dr Steve Burnell said.
The eDNA samples are collected in tubes of sea water lowered to different depths. The sea water is then run through filter paper, which collects all those telltale DNA signs of a marine species’ presence – everything from tiny corals to the big behemoths of the sea. The samples can be analysed back at OceanOmics, or on board the research vessel Pangaea, which comes equipped with its own full laboratory.
Analysis on board Pangaea, with its rapid turnaround time for results, means the crew can do additional testing in the same or nearby waters, should surprising results pop up. It also means they can monitor the real-time effects of marine heatwave events – increasingly frequent in Australian waters – to see which species suffer, which species survive, and which species change their behaviour or range as a consequence.
Currently docked at Fremantle, the Pangaea’s next expedition will take it around the Cocos Keeling Islands, one of two Australian Indian Ocean territories close to Indonesia. Satellite imagery shows the immense pressures in at play in the region: trawlers largely avoiding the exclusive economic zones around the Christmas and Cocos Keeling islands, but intensively working other areas, including a narrow strip between the zones.