Dr Laetitia Mathon1,2, Dr Florian Baletaud1,3,4, Dr Laurent Vigliola1
1ENTROPIE, IRD, CNRS, Ifremer, Université de la Réunion, Université de la Nouvelle-Calédonie, Nouméa, New Caledonia, France, 2CEFE, Univ. Montpellier, CNRS, EPHE-PSL University, IRD, Montpellier, France, 3MARBEC, Univ. Montpellier, CNRS, Ifremer, IRD, Montpellier, France, 4Soproner, groupe GINGER, Nouméa, New Caledonia
Biography:
Laetitia Mathon is a young researcher, currently working in French Overseas Territories. Her work focuses on using eDNA to study coastal fish communities in various environments and degrees of disturbances. Her work demonstrated the advantages of eDNA compared to other conventional methods to describe fish communities, and the interest of integrating eDNA modeling data into conservation planning frameworks.
Abstract:
Accelerating rate of human impact and environmental change severely affects marine biodiversity, underscoring the urgency to implement the Convention on Biological Diversity (CBD) 30×30 plan for conserving 30% of marine areas by 2030. Identifying area-based conservation targets in the three-dimensional (3D) ocean, especially around deep-sea features like seamounts, is complex due to the challenging methodologies required at great depths. However, emerging technologies such as environmental DNA (eDNA) and advanced modeling frameworks present innovative solutions to these challenges.
In this study, we collected eDNA, echosounder acoustic, and video data to analyze fish biodiversity at 15 seamounts and deep slopes in the Coral Sea. We modeled seven fish community metrics and the abundance of 45 individual species and molecular taxonomic units (MOTUs) in benthic and pelagic waters down to 600 meters. These models allowed us to predict biodiversity metrics for other seamounts and deep slopes across New Caledonian waters.
By integrating these diverse data, we prioritized conservation units in 3D space, to protect at least 30% of the spatial domain, focusing on areas of high biodiversity. Our findings revealed a linear relationship between biodiversity protection targets and the spatial area protected. The scenario protecting 30% of each biodiversity metric successfully preserved 30% of the spatial domain while accounting for the 3D distribution of biodiversity.
This study underscores the value of eDNA for deep-sea biodiversity surveys, the importance of integrating diverse data collection methods to enhance 3D marine biodiversity estimates, and the effectiveness of using biodiversity targets to meet area-based international conservation goals.