Population Genetics and Conservation of Mediterranean Freshwater Fishes

The freshwater ichthyofauna of the Mediterranean Basin represents one of the world’s richest yet most threatened regional faunas. Centuries of river regulation, habitat fragmentation and water abstraction have isolated populations, exacerbating genetic erosion and inbreeding. Recent advances in molecular methods—from microsatellites to genome-wide single-nucleotide polymorphisms—have illuminated patterns of genetic structuring, revealing glacial refugia, corridors of historical connectivity and zones of secondary contact. Conservation strategies increasingly rely on delineating evolutionarily significant and operational conservation units to prioritise management actions. Evidence from phylogeography, demographic history and landscape genetics demonstrates that both contemporary factors (habitat connectivity, local environmental pressures) and Quaternary events have shaped current diversity. To safeguard adaptive potential under climate change, integrated approaches now combine genetic monitoring with habitat restoration, supportive breeding and translocation, balancing demographic stability against risks of outbreeding depression. This synthesis underscores the need for targeted, genetics-informed interventions to preserve the unique evolutionary heritage of Mediterranean freshwater fishes.

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Population Genetics and Conservation of Mediterranean Freshwater Fishes publication trend

The graph below shows the total number of articles in population genetics and conservation of mediterranean freshwater fishes across all publications each year (not limited to Nature Index journals).

Technical terms

Effective population size: The number of individuals contributing genes to the next generation, influencing genetic drift and inbreeding.

Genetic drift: Random fluctuations in allele frequencies that can reduce genetic diversity in small populations.

Gene flow: Movement of genes between populations, counteracting divergence and inbreeding.

Operational Conservation Unit (OCU): A management unit defined by genetic distinctiveness warranting specific conservation actions.

Single-nucleotide polymorphism (SNP): A DNA sequence variation at a single nucleotide position used for high-resolution genetic analyses.

References

1. Genomic population structure and diversity of the endangered Aphanius iberus: strategies for killifish conservation. Conservation Genetics (2024).
2. Quaternary geomorphological and climatic changes associated with the diversification of Iberian freshwater fishes: The case of the genus Cobitis (Cypriniformes, Cobitidae). Ecology and Evolution (2022).
3. A conservation genetics perspective on supportive breeding: A case study of the common nase (Chondrostoma nasus). Aquatic Conservation Marine and Freshwater Ecosystems (2022).