Projecting Marine Mammal Distribution in a Changing Climate

Gregory K Silber,Kathleen M Stafford,Daniel Howell,Roger B Griffis,Peter O Thomas,Karin A Forney,Robin S Waples,Jarrod A Santora,Dorothy M Dick,Alistair J Hobday,Elizabeth A Becker,Jason D Baker,Jonathan A Hare,Kristin L Laidre,Matthew D Lettrich,Jaume Forcada,William J Sydeman ,Charles A Stock ,Peter L Boveng ,Mark F Baumgartner ,N J Mantua ,Paul D Spencer ,Lori T Quakenbush ,Kyle S Van Houtan ,Jérôme Fiechter

doi:10.3389/fmars.2017.00413

Abstract

Climate-related shifts in marine mammal range and distribution have been observed in some populations; however, the nature and magnitude of future responses are uncertain in novel environments projected under climate change. This poses a challenge for agencies charged with management and conservation of these species. Specialized diets, restricted ranges, or reliance on specific substrates or sites (e.g., for pupping) make many marine mammal populations particularly vulnerable to climate change. High-latitude, predominantly ice-obligate, species have experienced some of the largest changes in habitat and distribution and these are expected to continue. Efforts to predict and project marine mammal distributions to date have emphasized data-driven statistical habitat models. These have proven successful for short time-scale (e.g., seasonal) management activities, but confidence that such relationships will hold for multi-decade projections and novel environments is limited. Recent advances in mechanistic modeling of marine mammals (i.e., models that rely on robust physiological and ecological principles expected to hold under climate change) may address this limitation. The success of such approaches rests on continued advances in marine mammal ecology, behavior, and physiology together with improved regional climate projections. The broad scope of this challenge suggests initial priorities be placed on vulnerable species or populations (those already experiencing declines or projected to undergo ecological shifts resulting from climate changes that are consistent across climate projections) and species or populations for which ample data already exist (with the hope that these may inform climate change sensitivities in less well observed species or populations elsewhere). The sustained monitoring networks, novel observations, and modeling advances required to more confidently project marine mammal distributions in a changing climate will ultimately benefit management decisions across time-scales, further promoting the resilience of marine mammal populations.

Highlights

Marine mammals are exposed to a variety of threats and habitat perturbations from human activities on regional and global scales
Predictions and projections for future states of drivers of marine resource abundance and distribution are generally derived from global climate and earth system models (Stock et al, 2011; Hobday et al, 2016; Tommasi et al, 2017a)
Climate variability, which present-day models suggest has limited predictability beyond a year for all but a few regions of the ocean (Meehl et al, 2014), will continue to contribute uncertainty to future climate states (e.g., Deser et al, 2012). These results suggest that some gains in the accuracy and precision of regional climate change projections are likely, but progress will be difficult

Summary

Introduction

Marine mammals are exposed to a variety of threats and habitat perturbations from human activities (e.g., by-catch incidental to commercial fisheries, industrial noise, ship-strike) on regional and global scales. Predictions and projections for future states of drivers of marine resource abundance and distribution are generally derived from global climate and earth system models (Stock et al, 2011; Hobday et al, 2016; Tommasi et al, 2017a).

Results

Conclusion