Genetic barcoding system scans marine species for pests

Genetic barcoding system scans marine species for pests
A suite of biofouling species on the broken end of a wooden jetty pylon. The white organism is invasive species Didemnum perlucidum. Credit: Department of Fisheries

A reference collection of potential invasive marine species in WA, which forms part of a system for identifying pests via their genetic material, has been hailed as a marine biosecurity world first.

Department of Fisheries biosecurity unit scientists Drs Michael Snow, Justin McDonald and Joana Dias have accumulated 73 of the 79 exotic species on the WA Prevention List for Introduced Marine Pests into the reference collection as part of a wider pilot project.

Assembling the catalogue has allowed the researchers to determine the species' unique genetic barcodes and develop sensitive DNA-based methods to support their early detection.

Introduced marine pests hitchhike into WA waters in ballast water and on hulls, ropes and anchors, and have the potential to devastate fishing, aquaculture and tourism industries by displacing native species.

It is impossible or very expensive to eradicate invasive marine pests once they become established, Dr Snow says, so innovative lines of defence and detection are crucial.

The DNA-based detection technology has been incorporated into settlement arrays deployed at Albany, Barrow Island and Hillary's in August and September as part of the project.

The devices, which provide habitat for marine organisms to settle on, will be retrieved and analysed at various intervals before the project ends in January.

This system means WA Fisheries staff can detect, identify and monitor introduced marine pests much more efficiently in the future.

Genetic barcoding system scans marine species for pests
Invasive species such as the algae Undaria pinnatifida can completely dominate once introduced. Here it smothers mussel lines in New Zealand. Credit: Department of Fisheries.

"We have a list of pests from around the world we are worried about getting into WA and (by) genetically profiling them we can be confident of identifying them in the future if they arrive," Dr Snow says.

"It is hoped that by linking a next generation sequencing approach to existing sampling technologies, such as settlement arrays, it will increase the sensitivity and timeliness of detection and identification of marine pests at an early and potentially manageable stage of their invasion process," Dr Snow says.

The researchers are working with Curtin University's Trace and Environmental DNA laboratory scientists Professor Mike Bunce and Dr Michael Stat to develop the cutting-edge metabarcoding tools.

Genetic barcoding system scans marine species for pests
Dr Michael Stat filters sea water onto a membrane filter to capture environmental DNA present in the sample for extraction and analysis. Credit: Curtin Uni

Metabarcoding is a method of biodiversity assessment which uses the simultaneous determination of all DNA barcode sequences in a sample to confirm the presence or absence of particular species.

Dr Snow says moving from detecting and identifying a single to multiple organisms simultaneously, such as taking a mixed environmental sample from a settlement array or pylon, is an exciting biosecurity advancement.

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Provided by Science Network WA

This article first appeared on ScienceNetwork Western Australia a science news website based at Scitech.

Citation: Genetic barcoding system scans marine species for pests (2015, November 18) retrieved 17 August 2019 from
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