Stepping stones to isolation: Impacts of a changing climate on the connectivity of fragmented fish populations

• DOI: 10.1111/eva.12613
• Publication Date: 2018-02-14T13:42:33Z
• Authors: Emma F. Young; Niklas Tysklind; Michael P. Meredith; Mark de Bruyn; Mark Belchier; Eugene J. Murphy; Gary R. Carvalho
• Keywords: Isolation by distance; Peninsula

Abstract In the marine environment, understanding biophysical mechanisms that drive variability in larval dispersal and population connectivity is essential for estimating potential impacts of climate change on resilience genetic structure populations. Species whose populations are small, isolated discontinuous distribution will differ fundamentally their response to environmental stress, compared with species broadly distributed, abundant frequently exchange conspecifics. Here, we use an individual‐based modelling approach, combined a genetics projection model, consider warming two contrasting Antarctic fish species, Notothenia rossii Champsocephalus gunnari . Focussing Scotia Sea region, sea surface temperatures predicted increase significantly by end 21st century, resulting reduced planktonic duration increased egg mortality. With shorter durations, results our study predict both across Sea, from Peninsula sites islands north east, among neighbouring sites, such as around Peninsula. Increased mortality modified magnitude but had little effect overall patterns. Whilst changes impact projected regional N. , which remained genetically homogeneous within distances ~1,500 km, isolation C. northern was rising temperatures. Our highlights island world, implications ability adapt ongoing change, matter high relevance fisheries ecosystem‐level management.