Genetic Diversity and Population Structure in Aquatic Organisms

Genetic diversity and population structure shape the resilience, adaptability and long-term viability of aquatic organisms. Genetic diversity denotes the variety of heritable variation within and among populations, reflecting mutational processes, historical demography and environmental selection. Population structure refers to the distribution of genetic variation across geographical and ecological landscapes, determined by factors such as gene flow, barriers to dispersal, reproductive behaviour and local adaptation. In aquatic systems, these processes are influenced by currents, salinity gradients, temperature regimes, hatchery or aquaculture practices and exploitation pressure. High levels of diversity can buffer populations against disease and environmental change, while distinct genetic clusters may signal the presence of evolutionarily significant units requiring targeted conservation. Integrating molecular tools with ecological data uncovers patterns of connectivity and differentiation, guiding sustainable management of fisheries, the design of marine protected areas and restoration of endangered stocks. Advances in sequencing and analytical methods now permit genome-wide surveys of diversity from plankton to fish, illuminating the interplay of neutral drift and adaptive selection in a changing aquatic world.

Research from Nature Portfolio

Recent studies employing microsatellite markers across multiple sampling sites in the Bohai Sea have revealed unexpectedly low genetic diversity in cultured populations of the swimming crab compared with wild cohorts. Analysis of allele frequencies and heterozygosity metrics identified four genetic subpopulations with weak geographical correlations, suggesting human-mediated translocations and aquaculture practices override natural dispersal patterns. Estimates of gene flow and differentiation indices indicated limited barriers to genetic exchange, underscoring the need for regionally coordinated broodstock management to prevent erosion of wild genetic resources and maintain fishery yield and ecosystem resilience.

Genetic Diversity and Population Structure in Aquatic Organisms publication trend

The graph below shows the total number of articles in genetic diversity and population structure in aquatic organisms across all publications each year (not limited to Nature Index journals).

Technical terms

Genetic diversity: The total variation in alleles and genotypes within and among populations, crucial for adaptation and evolutionary potential.

Population structure: The spatial and genetic subdivision of species into distinct groups, shaped by gene flow, selection and barriers to dispersal.

Microsatellite marker (SSR): A DNA sequence with repeating short motifs used to assess genetic variation and relationships among individuals and populations.

Single nucleotide polymorphism (SNP): A variation at a single nucleotide position across genomes, widely used for high-resolution genotyping and evolutionary inference.

Gene flow: The movement of genes among populations through dispersal or migration, influencing levels of differentiation and connectivity.

Heterozygosity: The proportion of individuals carrying two different alleles at a locus, used as an indicator of genetic variability and population health.

References

1. Microsatellite markers reveal genetic diversity and population structure of Portunus trituberculatus in the Bohai Sea, China. Scientific Reports (2023).
2. Population structure and genome-wide evolutionary signatures reveal putative climate-driven habitat change and local adaptation in the large yellow croaker. Marine Life Science & Technology (2023).
3. Evolution and genetics of bighead and silver carps: Native population conservation versus invasive species control. Evolutionary Applications (2020).