The Influence of Spatial Distance and Environment on Small-Scale Genetic Variability in Eelgrass and Its Application...

Area of Science:

• Marine Biology
• Conservation Genetics
• Restoration Ecology

Background:

• Successful restoration relies on identifying optimal donor sites to minimize negative impacts.
• Debates in restoration genomics focus on donor site characteristics like phenotype, genetic diversity, and adaptive alleles.
• The optimal strategy, single vs. mixed provenance, and the spatial scale for sourcing donor material remain debated.

Purpose of the Study:

• To investigate micro-habitat differences and genetic variation among local eelgrass meadows.
• To determine the influence of local environment and geographic distance on genetic variation.
• To assess the adaptive potential and growth differences of eelgrass from various donor sites.

Main Methods:

• Genotyping of 10 eelgrass meadows using 1689 single nucleotide polymorphisms (SNPs).
• Assessment of micro-habitat differences, including temperature regimes.
• Common-garden mesocosm experiments simulating ambient and heatwave/freshening conditions.

Main Results:

• Substantial differences in temperature, genetic differentiation, and diversity were observed among meadows.
• Local environment, geographic distance, and genetic differentiation explained 10% of genetic variation.
• Putative adaptive loci were identified, and significant differences in growth were detected under varying conditions.

Conclusions:

• Significant variation in genetic diversity, local adaptation, and growth potential exists even at small spatial scales in eelgrass meadows.
• These factors are critical for selecting effective donor material for restoration.
• A donor registry is proposed to guide the selection of optimal donor meadows for enhanced restoration success.