Coastal and Freshwater news

Rare encounter with a Pygmy sperm whale in the vicinity of an oil rig. Photo: Deanna Elvines for OMW
18 November 2016

DNA technique moves from fish to oil

A groundbreaking DNA research technique first developed for use in aquaculture could soon be used to monitor oil rigs’ activities on the environment.

In 2013, Cawthron scientists Dr’s Xavier Pochon, Susie Wood, and Nigel Keeley together with University of Geneva Professor Jan Pawlowski, developed DNA-based techniques for environmental biomonitoring of marine farms.

Referred to as environmental DNA (eDNA) metabarcoding, the technique involves the analysis of DNA fragments extracted from sediment samples to characterize the presence of microscopic single-celled organisms such as bacteria and protists.

“Once fully validated, this technique could halve the cost of analysis and reduce processing time,” Dr Pochon says. “This means industry will be able to respond rapidly to unwanted negative impacts, while allowing more frequent and better monitoring of seabed”

eDNA metabarcoding has now been endorsed by the Norwegian Aquaculture Stewardship Council (ASC) as an acceptable complementary technique to measure benthic biodiversity and effects of salmon farming.

Soon, eDNA metabarcoding could be applied to oil rigs too. Currently, assessing the benthic impacts of drilling and production activities is expensive and time consuming, focusing on larger species (over 0.3 mm) and ignoring the smaller creatures that have a lot to say about the health of their environment.

An exploration of its applicability with eDNA was published in the journal Marine Environmental Research this year by an international team of scientists, including University of Auckland Olivier Laroche and Cawthron’s Susie Wood, Louis Tremblay, Javier Atalah, and Xavier Pochon.

The team: Louis Tremblay, Susie Wood, Xavier Pochon, Javier Atalah and Olivier Laroche

Co-funded by the Cawthron Institute Internal Investment Fund, the Fonds de Recherche du Quebec - Natures et Technologies and Swiss National Science Foundation grants, this study analysed sediment samples collected from two oil drilling sites off the coast of Taranaki in 2014.

The results showed that eDNA metabarcoding was an effective tool to provide complementary information of the sea floors’ health near offshore oil and gas platforms.

The demand for oil is expected to increase by 18.7 million barrels per day over the next 25 years, with the gas sector becoming the predominant source of energy beyond 2040. This means that despite higher cost and operating risks, offshore and deep-water oil and gas activities should rise significantly over the years. Metabarcoding provides a great option to assess and monitor these challenging environments, where organisms in the sediments are more scarce and patchily distributed.