Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)

Ivan P. Y. LAM; Yik-Hei SUNG; Jonathan J. FONG

doi:10.1371/journal.pone.0262015

Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)

Ivan P. Y. LAM, Yik-Hei SUNG, Jonathan J. FONG^*

^*Corresponding author for this work

Science Unit

Research output: Journal Publications › Journal Article (refereed) › peer-review

17 Citations (Scopus)

Abstract

We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.

Original language	English
Article number	e0262015
Journal	PLoS ONE
Volume	17
Issue number	2
Early online date	7 Feb 2022
DOIs	https://doi.org/10.1371/journal.pone.0262015
Publication status	Published - 7 Feb 2022

Bibliographical note

Publisher Copyright:
© 2022 Lam et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding

The sources of funding of the work submitted are as follows: 1. Research Grants Council of Hong Kong (Early Career Scheme #23100216), from The Government of Hong Kong Special Administrative Region; received by J.J.F. (URL: https://www.ugc.edu.hk/eng/rgc/) 2.Environment and Conservation Fund (#ECF2017-04), from The Government of Hong Kong Special Administrative Region; received by Y.H.S. (URL: https://www.ecf.gov.hk/en/home/index.html) 3.Ocean Park Conservation Foundation Conservation Fund (#RP01.1718), from Ocean Park Conservation Fundation Hong Kong; received by Y.H.S. (URL: https://www.opcf.org.hk/en/) 4. Croucher Foundation Chinese Visitorship (#870026), from Croucher Foundation; received by J.J.F.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1371/journal.pone.0262015Licence: CC BY

https://dx.plos.org/10.1371/journal.pone.0262015

Cite this

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title = "Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)",

abstract = "We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.",

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AU - FONG, Jonathan J.

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N2 - We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.

AB - We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.

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Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)

Abstract

Bibliographical note

Funding

UN SDGs

Access to Document

Other files and links

Fingerprint

Environmental DNA (eDNA) & Captive breeding of Beal's eyed turtle (Sacalia bealei) (Visitor: LIN Liu, Hainan Normal University)

Developing Environmental DNA Approaches to Study the Ecology and Conservation of Endangered Hong Kong Turtles (利用環境DNA技術研究香港瀕危龜類的生態及其保育)

Cite this

Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)

Abstract

Bibliographical note

Funding

UN SDGs

Access to Document

Other files and links

Fingerprint

Projects

Environmental DNA (eDNA) & Captive breeding of Beal's eyed turtle (Sacalia bealei) (Visitor: LIN Liu, Hainan Normal University)

Developing Environmental DNA Approaches to Study the Ecology and Conservation of Endangered Hong Kong Turtles (利用環境DNA技術研究香港瀕危龜類的生態及其保育)

Cite this