Application of environmental DNA to detect an endangered marine skate species in the wild.

Kay Weltz,Jessica A T Morgan,Jennifer Ovenden,Jayson M Semmens,David A Moreno,Jeremy M Lyle,Hideyuki Doi

doi:10.1371/journal.pone.0178124

Kay Weltz, Jessica A T Morgan + Show 5 more

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https://doi.org/10.1371/journal.pone.0178124

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Abstract

Environmental DNA (eDNA) techniques have only recently been applied in the marine environment to detect the presence of marine species. Species-specific primers and probes were designed to detect the eDNA of the endangered Maugean skate (Zearaja maugeana) from as little as 1 L of water collected at depth (10–15 m) in Macquarie Harbour (MH), Tasmania. The identity of the eDNA was confirmed as Z. maugeana by sequencing the qPCR products and aligning these with the target sequence for a 100% match. This result has validated the use of this eDNA technique for detecting a rare species, Z. maugeana, in the wild. Being able to investigate the presence, and possibly the abundance, of Z. maugeana in MH and Bathurst harbour (BH), would be addressing a conservation imperative for the endangered Z. maugeana. For future application of this technique in the field, the rate of decay was determined for Z. maugeana eDNA under ambient dissolved oxygen (DO) levels (55% saturation) and lower DO (20% saturation) levels, revealing that the eDNA can be detected for 4 and 16 hours respectively, after which eDNA concentration drops below the detection threshold of the assay. With the rate of decay being influenced by starting eDNA concentrations, it is recommended that samples be filtered as soon as possible after collection to minimize further loss of eDNA prior to and during sample processing.

Highlights

IntroductionDetermining the presence of endangered marine species within an area that is heavily impacted by anthropogenic processes (e.g. fish farming or commercial and recreational fishing), is important for the implementation of effective management strategies to minimize such impacts on the particular population [1]
Determining the presence of endangered marine species within an area that is heavily impacted by anthropogenic processes, is important for the implementation of effective management strategies to minimize such impacts on the particular population [1]
With dissolved oxygen (DO) levels showing a decrease in Macquarie Harbour (MH), this study investigated the affect of low DO on the degradation rate of Environmental DNA (eDNA) in that water samples [27,29,30,31]

Summary

Introduction

Determining the presence of endangered marine species within an area that is heavily impacted by anthropogenic processes (e.g. fish farming or commercial and recreational fishing), is important for the implementation of effective management strategies to minimize such impacts on the particular population [1]. Confirming presence relies on locating the animals, which can prove challenging for species with low population numbers [2]. Environmental DNA (eDNA) detects endangered elasmobranch environment-grants). No individuals employed or contracted by the funders (other than the named authors) played any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

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