Using habitat models for chinstrap penguins Pygoscelis antarctica to advise krill fisheries management during the penguin breeding season

Victoria Warwick‐Evans,Louise Ireland,Fabrizio Manco,Harriet L Clewlow,Philip N Trathan,Norman Ratcliffe,Andrew D Lowther,Lucy Hawkes

doi:10.1111/ddi.12817

Victoria Warwick‐Evans, Louise Ireland + Show 6 more

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https://doi.org/10.1111/ddi.12817

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Abstract

AbstractAimTo predict the at‐sea distribution of chinstrap penguins across the South Orkney Islands and to quantify the overlap with the Southern Ocean krill fishery.LocationSouth Orkney Islands, Antarctica.MethodsPenguins from four colonies across the South Orkney Islands were tracked using global positioning systems (GPSs) and time depth recorders (TDRs). Relationships between a variety of environmental and geometric variables and the at‐sea distribution of penguins were investigated using general additive models for the three main phases of the breeding season. Subsequently, the final models were extrapolated across the South Orkney archipelago to predict the at‐sea distribution of penguins from colonies where no tracking data are available. Finally, the overlap between areas used by chinstrap penguins and the krill fishery was quantified.ResultsThe foraging distribution of chinstrap penguins can be predicted using two simple and static variables: the distance from the colony and the direction of travel towards the shelf‐edge, while avoiding high densities of Pygoscelis penguins from other colonies. Additionally, we find that the chinstrap penguins breeding on the South Orkney Islands use areas which overlap with frequently used krill fishing areas and that this overlap is most prominent during the brood and crèche phases of the breeding season.Main conclusionsThis is the first step in understanding the potential impacts of the krill fishery, for all colonies including those where no empirical tracking data are available. However, with the available data, it is not currently possible to infer an impact of the krill fisheries on penguins. With this in mind, we recommend the implementation of monitoring schemes to investigate the effects of prey depletion on predator populations and to ensure that management continues to follow a precautionary approach and is addressed at spatial and temporal scales relevant to ecosystem operation.

Highlights

There is a widespread concern and a growing understanding of threats facing marine systems across the globe (Halpern et al, 2012)
Southern Ocean ecosystems are facing a number of significant challenges (Gutt et al, 2015; Trathan & Agnew, 2010), especially at those locations where some of the fastest rates of warming on our planet have been recorded (Gille, 2002, 2008; Hauck, Hoppema, Bellerby, Völker, & Wolf-Gladrow, 2010; Turner et al, 2009)
Our study develops a series of habitat preference models for one of the most abundant CCAMLR Ecosystem Monitoring Programme (CEMP)-monitored avian species breeding in the Atlantic sector of the Southern Ocean, the chinstrap penguin (Pygoscelis antarctica)

Summary

Introduction

There is a widespread concern and a growing understanding of threats facing marine systems across the globe (Halpern et al, 2012). Southern Ocean ecosystems are facing a number of significant challenges (Gutt et al, 2015; Trathan & Agnew, 2010), especially at those locations where some of the fastest rates of warming on our planet have been recorded (Gille, 2002, 2008; Hauck, Hoppema, Bellerby, Völker, & Wolf-Gladrow, 2010; Turner et al, 2009) In addition to these signals of regional climate change, there is growing interest in the commercial harvesting of Antarctic krill (Euphausia superba), a species which is prey for many Antarctic marine predators and potentially one of the last major underdeveloped sources of marine protein. Understanding the factors that influence the distribution of marine predators is fundamental to mitigate these potential impacts (Louzao et al, 2011; Manly, McDonald, Thomas, McDonald, & Erickson, 2002)

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