Monitoring marine biodiversity is essential for ecosystems conservation and fisheries management. Traditional methods based on visual surveys and capture techniques are invasive, costly, and labour-intensive. Advances in molecular detection from water samples allow for identifying organisms that inhabit, pass through, or interact with the surrounding environment. The environmental DNA (eDNA) currently emerged as an important source of biodiversity information across different ecosystems. Here, we present four case-studies applying different eDNA sampling and screening methods to assess their effectiveness in monitoring Mediterranean elasmobranchs: 1) we tested five eDNA sampling systems, both active and passive, in a controlled mesocosm. Active samplers recovered more DNA and detected all elasmobranchs, whereas passive tools showed lower efficiency; 2) we tested passive tools associated to deep-sea longlines, detecting 78% of captured species and revealing additional biodiversity, including pelagic and mesopelagic taxa not identified by traditional methods; 3) active filtration was applied on 75 samples from 25 sites in the Central Mediterranean, collected at three depths with Niskin bottles, allowing a fine-scale assessment of depth-driven species distribution; 4) over 500 samples were collected along the Italian coasts throughout 2024 using both active and passive tools, expanding spatial coverage and providing comprehensive data on elasmobranch biodiversity shifts. All samples were analysed using eDNA metabarcoding techniques with an elasmobranch-specific marker (elas02-12S), and taxonomic assignments was performed against an improved custom 12S vertebrate reference database. Our findings confirm that eDNA can detect a broader spectrum of marine biodiversity, including elusive taxa not recovered by conventional methods. While eDNA offers insights into marine biodiversity, challenges remain in standardizing methodologies and interpreting abundance data, particularly for passive samplers in fisheries applications. Addressing these gaps will enhance eDNA’s role as cost effective marine monitoring tool in both conservation and management scenarios.
Crobe, V., Spiga, M., Ferrari, A., Tinti, F., Cariani, A. (2025). EDNA-ENABLED MONITORING OFFERS BOTH OPPORTUNITIES AND CHALLENGES FOR THE CONSERVATION OF MEDITERRANEAN ELASMOBRANCHS.
EDNA-ENABLED MONITORING OFFERS BOTH OPPORTUNITIES AND CHALLENGES FOR THE CONSERVATION OF MEDITERRANEAN ELASMOBRANCHS
VALENTINA CROBE;MARTINA SPIGA;ALICE FERRARI;FAUSTO TINTI;ALESSIA CARIANI
2025
Abstract
Monitoring marine biodiversity is essential for ecosystems conservation and fisheries management. Traditional methods based on visual surveys and capture techniques are invasive, costly, and labour-intensive. Advances in molecular detection from water samples allow for identifying organisms that inhabit, pass through, or interact with the surrounding environment. The environmental DNA (eDNA) currently emerged as an important source of biodiversity information across different ecosystems. Here, we present four case-studies applying different eDNA sampling and screening methods to assess their effectiveness in monitoring Mediterranean elasmobranchs: 1) we tested five eDNA sampling systems, both active and passive, in a controlled mesocosm. Active samplers recovered more DNA and detected all elasmobranchs, whereas passive tools showed lower efficiency; 2) we tested passive tools associated to deep-sea longlines, detecting 78% of captured species and revealing additional biodiversity, including pelagic and mesopelagic taxa not identified by traditional methods; 3) active filtration was applied on 75 samples from 25 sites in the Central Mediterranean, collected at three depths with Niskin bottles, allowing a fine-scale assessment of depth-driven species distribution; 4) over 500 samples were collected along the Italian coasts throughout 2024 using both active and passive tools, expanding spatial coverage and providing comprehensive data on elasmobranch biodiversity shifts. All samples were analysed using eDNA metabarcoding techniques with an elasmobranch-specific marker (elas02-12S), and taxonomic assignments was performed against an improved custom 12S vertebrate reference database. Our findings confirm that eDNA can detect a broader spectrum of marine biodiversity, including elusive taxa not recovered by conventional methods. While eDNA offers insights into marine biodiversity, challenges remain in standardizing methodologies and interpreting abundance data, particularly for passive samplers in fisheries applications. Addressing these gaps will enhance eDNA’s role as cost effective marine monitoring tool in both conservation and management scenarios.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
