Predicting Which Species Succeed in Climate-Forced Polar Seas

Simon A. Morley,David K. A. Barnes,Michael J. Dunn

doi:10.3389/fmars.2018.00507

Simon A. Morley, David K. A. Barnes + Show 1 more

Open Access

https://doi.org/10.3389/fmars.2018.00507

Copy DOI

Abstract

Understanding the mechanisms which determine the capacity of any species to adapt to changing environmental conditions is one of the foremost requirements in accurately predicting which populations, species and clades are likely to survive ongoing, rapid, climate change. The polar oceans are amongst the most rapidly changing environments on earth with reduced regional sea ice duration and extent, and their faunas expected sensitivity to warming and acidification. These changes potentially pose a significant threat to a number of polar fauna. There is, therefore, a critical need to assess the vulnerability of a wide range of species to determine the tipping points, or weak links in marine assemblages. Knowledge of the effect of multiple stressors on polar marine fauna has advanced over the last 40 years, but there are still many data gaps. This study applies ecological risk assessment techniques to the increasing knowledge of polar species’ physiological capacities to identify their exposure to climate change and their vulnerability to this exposure. This relatively rapid, semi-quantitative assessment, provides a layer of vulnerability on top of climate envelope models, until such times as more extensive physiological data sets can be produced. The risk assessment identified more species that are likely to benefit from the near future predicted change (the winners), especially predators and deposit feeders. Fewer species were scored at risk (the losers), although animals that feed on krill were consistently as under the most risk.

Highlights

Amongst the foremost scientific questions of the Anthropocene are which populations, species and clades will survive sustained, rapid climate change and which mechanisms underpin their sensitivity (Pennisi, 2005)
While climate envelope models give a measure of exposure, they need to be overlain by a layer of vulnerability based on known physiological tolerance
While many of the species living in the shallow Antarctic are eurybathic, with distributions that stretch well below these surface waters, their population densities are often at their highest in the shallowest 20 m, e.g., the limpet, Nacella concinna, the urchin, Sterechinus neumayeri and the sea cucumber, Heterocucumis steineni

Summary

Introduction

Amongst the foremost scientific questions of the Anthropocene are which populations, species and clades will survive sustained, rapid climate change and which mechanisms underpin their sensitivity (Pennisi, 2005). Previous mass extinctions have led to massive faunal shifts whereby 5–29% of the original species dominate the remaining fauna, leading to a global “biotic homogenization” (McKinney and Lockwood, 1999). The species that tend to dominate after such extinctions share features of high genetic and/or physiological diversity, broad geographic ranges, high dispersal, broad capacities and tolerances (eurytopic species), small body sizes, high fecundity, and, in the Anthropocene, a positive association with human societies (McKinney and Lockwood, 1999). The most intense and rapid climate forcing has occurred in parts of Earth’s high latitudes, many of whose fauna have few of those typical “winner” features.

Objectives

Results

Conclusion