Urbanisation Is Associated With Reduced Genetic Diversity in Marine Fish Populations.

Area of Science:

• Marine biology
• Population genetics
• Conservation science

Background:

• Coastal cities significantly impact marine ecosystems through various human activities.
• Urbanization's effects on marine wildlife are less understood compared to terrestrial systems.

Purpose of the Study:

• To investigate the consequences of marine urbanization on fish population genetics.
• To assess the impact of human population density on marine fish genetic diversity and population size.

Main Methods:

• Compiled a global database of genotypic data from 75,361 marine fish individuals across 73 species and 1085 sites.
• Utilized microsatellite data from published research on marine fish population genetics.
• Analyzed genetic diversity and effective population sizes in relation to human population density.

Main Results:

• Significantly lower genetic diversity and effective population sizes were observed at sites near denser human populations.
• Reduced genetic diversity indicates that habitats near human settlements support smaller populations.
• Small effective population sizes near urban areas may reduce the efficiency of natural selection.

Conclusions:

• Marine urbanization leads to a loss of genetic diversity in fish populations.
• This genetic erosion poses risks to marine ecosystem function and the sustainability of fisheries.
• Mitigating human impacts through sustainable urban planning and resource management is crucial for marine biodiversity conservation.