End-of-century habitat model forecasts suggest potential redistributions of marine predators in the Southern Ocean
Dr Ryan Reisinger1, Dr Stuart Corney2,3, Dr Ben Raymond4,2,3, Prof. Mark Hindell2,3, Dr Pierre Pistorius5
1Centre d’Etudes Biologiques de Chizé, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France, 2Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 3Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia, 4Australian Antarctic Division, Kingston, Australia, 5DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, Department of Zoology and Coastal and Marine Research Institute, Nelson Mandela University, Port Elizabeth, South Africa
The redistribution of biodiversity is occurring rapidly in marine systems. Marine predators integrate environmental signals into their behaviour and demography and play an important functional role in ecosystems. Projections of the future distribution of these predators can: indicate future potential biodiversity patterns and rearrangements, such as changes in community structure; form the basis for hypotheses about the future structure and functioning of communities; and generate spatial scenarios for conservation and management planning. We used tracking data from 14 species to model the habitat use of predators around the Prince Edward Islands, southern Indian Ocean. We also present preliminary circumpolar analyses of 17 species. Using ensembles of machine learning algorithms, we modelled habitat preference as a response to environmental covariates from 8 IPCC-class climate models. To forecast the potential distribution of the predators in 2070-2099, we used the climate model projections that assume the ‘business as usual’ greenhouse gas emissions scenario RCP8.5. Analogous climates are projected to predominantly shift to the south-east and south-west. Species potential range shifts varied in direction and magnitude, but overall shifted slightly to the south-west. Cluster analyses indicated potential changes in community composition. Overlap scores – indicating areas of common use among the predators – were higher and more concentrated at ~47° S. This means that marine predator biodiversity will likely be redistributed, but that some areas might be more intensively utilised by multiple predator species in the future. This would affect ecological processes that require consideration in terms of conservation management and marine spatial planning.
Biography:
Dr Reisinger is a post-doc at the CNRS in France, but he grew up right here in the Kruger National Park. However, by a twist of fate, his research focuses on the ecology of marine predators, particularly their foraging, movement and distribution in relation to their environment.