Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species

Authored by Emma F Young, Mark Belchier, Lorenz Hauser, Gavin J Horsburgh, Michael P Meredith, Eugene J Murphy, Sonia Pascoal, Jennifer Rock, Niklas Tysklind, Gary R Carvalho

Date Published: 2015

DOI: 10.1111/eva.12259

Sponsors: United Kingdom Natural Environment Research Council (NERC)

Platforms: R

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a seascape genetics' approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C.gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N.rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts.

Tags

Climate-change Reproductive success Marine fish Icefish champsocephalus-gunnari Pelagic larval duration Southern scotia arc Mackerel icefish Circumpolar current Seascape genetics Notothenia-rossii