The Future Polar Bear The Impact of the Vanishing Sea Ice on an Arctic Ecosystem

About this book

The spotlight is on the Arctic region. Crumbling glaciers, thawing permafrost and the vanishing sea ice cover are phenomena frequently discussed in the media. They are clear signs of the intense warming of the Arctic ecosystem. The dramatic decline in sea ice has consequences not only for the microorganisms, plants, animals and peoples that live there, but also for the climate at the middle latitudes. Inspired by their years of scientific research and experience in the field, the authors present unique photographic material and discuss the processes and the impact of climate warming in the polar region.

The polar bear is the symbol par excellence of the unique sea ice ecosystem. The authors explore the life, past and future of this top predator. Can this super-specialist still adapt? Is its survival threatened or not?

The Future Polar Bear provides the necessary tools to put media reports about the Arctic, climate change, sea ice and the Polar Bear into context.

Contents

About the authors 9
Foreword by Robert Christopherson 11
Acknowledgements 13

1. Introduction: The lure of the icy seascapes 17
2. The Arctic’s geography in a nutshell 23
      An ocean surrounded by land 23
      Where are the Arctic’s boundaries? 25
      The meaning of the Arctic Circle 26
      How big is the Arctic area? 27
3. The Arctic climate 31
      Less solar radiation, more reflection 31
      The radiation balance and the supply of heat 32
      The more northernly, the colder and dryer 33
      Where do we find the lowest temperatures? 35
4. Climate change in the Arctic 39
      Why is the increase in temperature more evident in the Arctic? 39
      Climate change and the Arctic people 42
      The influence of changes in the Arctic on the climate at lower latitudes 43
      Is what is happening in the Arctic really that bad? 45
5. The sea ice 49
      About water 50
      How sea water freezes 50
      From ice crystal to first-year pack ice 52
      Multi-year pack ice 53
      Movements of sea ice in space and time 57
      Temperature gradient and salt concentrations in the ice 58
      Open water amid sea ice: the polynya 60
      Freshwater mountains in the sea: icebergs 61
6. Algae and grazers in the sea ice ecosystem 65
      A piece of ice alive with all kinds of beings 65
      Single-celled life as the basis of the sea ice ecosystem 66
      The growth and production of algae in the sea ice 68
      Sea ice algae also need nutrients 69
      The ice algae bloom and their release from the melting ice 69
      Sea algae play a role in atmospheric processes 70
      The grazers of the sea ice algae 70
      Two separate algae blooms fuel the grazing animals 71
      Zooplankton as a link between algae and higher trophic levels 71
      Calanus copepods as bulk food for fish, birds, whales 72
      Copepods as food for the Little Auk 75
      A small fish with a great influence: the Polar Cod 76
      A companion to warming: the acidifcation of the ocean 79
7. How do birds and mammals cope with the cold? 83
      Stay or go 83
      Heat production and brown fat 84
      The difficult balance between heat loss and production 86
      Thermal bridges and insulation 86
      Sea mammals need a thick fat layer 87
      A heat exchanger 87
      Body volumes and surfaces 88
      The meanings of colours 89
      Hibernation? 89
8. Sea ice loss and Arctic seabirds 93
      Arctic ice-associated seabirds 93
            The Spectacled Eider 94
            Least Auklet 94
            Crested Auklet 95
            The Black Guillemots of Cooper Island 96
            Brünnich’s Guillemots 100
            The elusive Ivory Gull 101
            Ross’s Gull: the mystery of the Arctic 104
9. Impacts of declining sea ice on Arctic marine mammals 109
      Walrus: the tooth walker 109
      Lack of sea ice 111
      Ringed seals 113
      Bearded seals 115
      Harp seals 117
      Moving north? 119
      Whales of the Arctic sea ice 119
            Bowhead Whale 120
            Beluga or White Whale 121
            The Narwhal: unicorn of the ice 122
      Reduced sea ice: more assaults 122
10. Apex predator: the Polar Bear 127
      Taxonomy 128
      The early years 129
      Speciation is underway 131
      The ‘ice bear’ cometh 132
      Fossil record, classifcation and taxonomy 133
      Surviving the earlier warmer periods 137
11. Population ups, downs & whereabouts 147
      Where do Polar Bears live in this seasonal landscape? 149
      The subpopulation regions: the bears’ home ranges 151
      Roaming the regions 153
      Svalbard Archipelago in the Barents Sea 154B
      Bears of the Greenland pack ice 158
      Hudson Bay: the best-studied Polar Bears in the Arctic 159
      The Beaufort sea and the Chukchi Sea Polar Bears 166
12. Reproduction, denning & cub rearing 173
      The mating season 174
      Pregnant bears move ashore and make dens 178
      Declining and unstable pack ice 180
      Birthing and external pregnancy 184
      Leaving the den and the hunt for food 186
      Mother bear as teacher 189
13. Hunting strategies and food 197
      Top of the menu: seals 197
      Hunting methods on the ice 198
      The still hunt 199
      Stalking on the ice 201
      Aquatic stalking 203
      Sense of smell 206
      Hunt timing issues 206
      Alternative food sources 209
      Potential food trapped in the ice 211
      Bears stranded on land where living is not easy 213
      Food at a dead end 218
14. Additional assaults on the Polar Bear 223
      Contamination 223
      Why is a threatened species still harvested? 227

The Future Polar Bear: a reflection 231

References 234

Customer Reviews

Biography

Louis Beyens and Rinie van Meurs each have more than thirty years of experience in the polar regions as scientists and expedition guides. Beyens is a professor emeritus at the University of Antwerp and specializes in polar ecosystems. As an expedition leader, Van Meurs is fascinated by the animal life in the sea ice and is a passionate follower of the polar bear.