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Unlocking foraminiferal genetic diversity on estuarine mudflats with eDNA metabarcoding
David Singer1, Marie P A Fouet2, Magali Schweizer2
1Université d'Angers, Nantes Université, Le Mans Université, CNRS, Laboratoire de Planétologie et Géosciences, LPG UMR 6112, 49000 Angers, France; Changins College for Viticulture and Enology, University of Sciences and Art Western Switzerland, Route de Duillier 60, 1260 Nyon, Switzerland.
The Science of the Total Environment
|August 5, 2023
Summary
Environmental DNA surveys reveal dominant foraminifera operational taxonomic units (OTUs) in estuaries, with a significant reservoir of dormant stages. This genetic diversity is key to understanding estuarine health despite complex stressors.
Area of Science:
- Ecology
- Marine Biology
- Environmental Science
Background:
- Estuaries face complex environmental biomonitoring challenges due to multiple anthropogenic and natural stressors.
- The
- estuarine quality paradox
- highlights difficulties in detecting anthropogenic pressure amidst natural variability.
- Foraminifera are identified as promising bioindicators for estuarine health assessment.
Purpose of the Study:
- To validate molecular approaches, specifically environmental DNA (eDNA) metabarcoding, for assessing foraminifera communities in estuarine environments.
- To investigate the community composition and genetic diversity of foraminifera in estuarine mudflats.
- To explore the relationship between environmental factors and foraminifera community structure.
Main Methods:
- An environmental DNA (eDNA) survey was conducted on estuarine mudflats along the French Atlantic coast.
- A metabarcoding approach targeting foraminifera was employed.
- Statistical modeling was used to analyze the influence of physical, chemical, and climatic factors on community composition.
Main Results:
- Estuarine environments exhibit a dominance of a few active foraminifera operational taxonomic units (OTUs), alongside a substantial reservoir of dormant or propagule stages.
- Significant genetic diversity was observed, with different OTUs dominating across the studied estuaries.
- Physical, chemical, and climatic factors explained only 43% of the variance in foraminifera community composition, suggesting the influence of other factors.
Conclusions:
- Environmental DNA biomonitoring offers new perspectives for characterizing genetic diversity in estuaries.
- The substantial reservoir of dormant foraminifera stages represents a key component of estuarine genetic diversity, potentially responding to environmental variability.
- Factors beyond quantifiable environmental parameters, such as estuarine history and ecological drift, likely play significant roles in shaping community structure.
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