Skip to main content

“Potential of eDNA approaches for the monitoring of marine bivalve parasites: example of the ROME project (7035)”

Written by marina02 on . Posted in Abstracts.

Abstract

Potential of eDNA approaches for the monitoring of marine bivalve parasites: example of the ROME project

Environmental DNA approaches are increasingly used to detect microorganisms in environmental compartments, including water. They show considerable advantages to investigate and monitor microorganisms such as bivalve parasites.

An eDNA-based monitoring network named ROME (Réseau d’Observatoires de Microbiologie Environmentale intégrée, rome.ifremer.fr) piloted by Ifremer was deployed in France between 2020 and 2024 in four estuarine ecosystems that integrate oyster farms: Baie des Veys in Normandy, Rade de Brest in Brittany, Marennes Oleron in New Aquitania, and Etang de Thau in Occittania. This network aimed at evaluating the influence of river inputs on the structuration of estuarine microbiomes and the potential emergence of new microbiological risks for human, aquaculture and ecosystem health.

In the four studied ecosystems, water was collected fortnightly at both a coastline and an off-shore sampling stations. Additionally, adult oysters were collected monthly.  Nucleic acids were extracted from water samples after filtration at 20, 3 and 0.22µm and from oyster tissues. Amplification and Illumina sequencing of the V4 and V1-V2 18S rDNA regions allowed analyzing the protistome from water samples and oysters, respectively.

Sequences of taxa belonging to parasite genera infecting bivalves were detected in water and oyster samples. The geographic origin as well as the nature of samples (coastline and off-shore water, oyster) had an influence on the taxa detected. These results show the potential of such eDNA-metabarcoding approach to detect the presence of parasites but also to better understand their distribution in coastal ecosystems.  This study also highlights the need for standardization and validation of the method before its application for routine monitoring.

Authors
  1. ARZUL, ISABELLE, IFREMER, Presenter
  2. LECADET, CYRIELLE, IFREMER, Author
  3. CANIER, LYDIE, IFREMER, Author
  4. CHEVIGNON, GERMAIN, IFREMER, Author
  5. SERGHINE, JOELLE, IFREMER, Author
  6. PPARNAUDEAU, SYLVAIN, IFREMER, Author
  7. NOEL, CYRIL, IFREMER, Author
  8. SIANO, RAFFAELE, IFREMER, Author