Environmental & human disturbance effects on global marine genetic diversity

Background/Question/Methods

Interpreting drivers of neutral genetic diversity patterns across global oceans will facilitate understanding how biodiversity is shaped across environmental gradients and enable the isolation and further study of the effects of human activity. We expect that human activity and local environmental conditions will be predictive of genetic diversity patterns. Open data practices enable us to access ocean-wide multi-species genetic data suitable for addressing these questions. We programmatically searched open data repositories collecting, georeferencing and re-purposing raw neutral microsatellite data for marine fishes – 72770 individuals from 1027 populations and 69 species, to examine global drivers of diversity patterns and the processes that shape them. We then tested for relationships between genetic diversity and primary productivity, distance to market, nearby land area, human population density, fishing effort and cumulative human impacts on genetic diversity.

Results/Conclusions

Results to date showed overall low but detectable multi-species effects across global oceans. Land area, interpreted as the effect of terrestrial nutrient and energy output on associated marine ecosystems was positively related to gene diversity. Cumulative human impacts, a measure of the sum of human caused pressures on global oceans was found to negatively affect allelic richness and gene diversity. Distance to market, a measure of market access and fishing effort, was found to have a positive effect on allelic richness showing that the further a population is from a human fishing activity center the less affected it is at the genetic level. We conclude that genetic diversity patterns linked to environmental conditions are in part driven by the influence of terrestrial nutrient and energy runoff, and that human activity has clear negative impact on global marine genetic diversity.