Dr Alistair Hobday1, Dr Juan-Diego Gaitan-Espitia1,2
1CSIRO, Hobart, Australia, 2The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, China
Impacts of climate change are apparent in natural systems around the world and many species are and will continue to struggle to persist in their current location as their preferred environment changes. In many places, scientists, managers and policy makers are developing a range of intervention strategies that seek to boost population persistence in the face of these changes. These strategies are focused on two aspects that theoretically enhance species persistence – population connectivity and population size – and have been successful approaches for species conservation in the past. However, while these past successes are based on an “equilibrium” view of the environment. In contrast, climate change represents a relatively fast non-equilibrium (directional) selection pressure, producing conditions outside the historically experienced range. Novel genotypes might need to evolve, and so interventions that facilitate large, connected populations may in fact interfere with the direction of selection pressure and slow down evolutionary responses to climate change. Thus, some intervention efforts may be antagonistic to species persistence. We argue that successful interventions will require consideration of effects at genetic, individual, population and community levels. We provide advice and a conceptual framework to guide thinking about the risks with species interventions, and show that in some cases enhancing population size and increasing connectivity may not be the most appropriate options for species threatened by climate change, and may even reduce the success of their natural evolutionary responses.
Research Director at CSIRO Oceans and Atmosphere.