  Human-made structures are increasingly found in marine coastal habitats. The
aim of the present study was to explore whether urban coastal structures can
affect the genetic variation of hard-bottom species. We conducted a population
genetic analysis on the limpet Patella caerulea sampled in both natural and
artificial habitats along the Adriatic coast. Five microsatellite loci were
used to test for differences in genetic diversity and structure among samples.
Three microsatellite loci showed strong Hardy-Weinberg disequilibrium likely
linked with the presence of null alleles. Genetic diversity was significantly
higher in natural habitat than in artificial habitat. A weak but significant
differentiation over all limpet samples was observed, but not related to the
type of habitat. While the exact causes of the differences in genetic diversity
deserve further investigation, these results clearly point that the expansion
of urban structures can lead to genetic diversity loss at regional scales.
