Projecting Marine Mammal Distribution in a Changing Climate

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 Silber et al.Projecting Marine Mammal Distributions 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.

Aerial surveys for Antarctic minke whales (Balaenoptera bonaerensis) reveal sea ice dependent distribution patterns

“…Our results suggest that the forecasted sea ice changes (Böning, Dispert, Visbeck, Rintoul, & Schwarzkopf, 2008;Rignot et al, 2008;Silber et al, 2017) have the potential of heavily impacting AMWs. The nature and magnitude of future responses of AMWs as a species are uncertain in novel environments as projected under climate change.…”

“…Moreover, biases in shipboard cetacean surveys in ice-covered waters may arise from the influence of the ship's presence (e.g., its noise and the noise caused by ice-breaking activities) on the detection rate of cetaceans due to behavioral reactions (Erbe & Farmer, 2000). This information, however, is crucial for assessing the species' vulnerability with regard to predicted, climate-related changes in sea ice conditions (Silber et al, 2017). This information, however, is crucial for assessing the species' vulnerability with regard to predicted, climate-related changes in sea ice conditions (Silber et al, 2017).…”

“…Consequently, reliable information on densities of AMWs in sea ice is lacking. High-latitude marine systems are among the regions responding most rapidly to changing climatic conditions, with ice-obligate species facing some of the largest changes in their habitat (Nicol, Worby, & Leaper, 2008;Silber et al, 2017). High-latitude marine systems are among the regions responding most rapidly to changing climatic conditions, with ice-obligate species facing some of the largest changes in their habitat (Nicol, Worby, & Leaper, 2008;Silber et al, 2017).…”

Whales in warming water: Assessing breeding habitat diversity and adaptability in Oceania's changing climate

“…Distribution shifts are considered the most likely response of large mobile cetaceans to climate change (Silber et al, ; Sydeman et al, ). History has shown that humpback whale distribution can change on the scale of a few decades, particularly in cases of overexploitation and local extirpation.…”

Fine‐scale habitat partitioning of Chilean and Peale's dolphins and their overlap with aquaculture

“…Sympatric species may respond differently to environmental change and anthropogenic pressures, making the identification of species-specific habitat use patterns a key requirement for effective conservation (Schaefer, Jetz, & Böhning-Gaese, 2008;Silber et al, 2017). Sympatric species may respond differently to environmental change and anthropogenic pressures, making the identification of species-specific habitat use patterns a key requirement for effective conservation (Schaefer, Jetz, & Böhning-Gaese, 2008;Silber et al, 2017).…”