Antarctic Ecosystems

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Antarctic Ecosystems

Erniogical Studies 175-R .--a-- -.\.Antarctic EcosystemsEnvironmental Contamination,Climate Change, and Human lmpact


*ContentsAntarctica: Geomorphology and ClimateTrends ...... 1Introduction ........................... 1Physical Characteristics .................... 2Geology and Mineral Resources ................ 5Geology ............................. 5Geochemical Anomalies and Mineral Resources ....... 9The Antarctic Climate and Its Rolein the Global Climate System .................. 11The Antarctic Climate ...................... 11Solar Radiation ......................... 14Temperature ........................... 17Clouds and Precipitation .................... 19Wind Regime .......................... 22Atmospheric Interactions of Antarcticawith Lower Latitudes ...................... 24Global Warming and Climate Variations in Antarctica .... 26ClimateVariability and Changes Dueto Human Activities . 26Trends of Surface Air Temperature in Antarctica ....... 31Extending Spatio-Temporal Temperature Trends ...... 34Moisture and Precipitation Trend ............... 36Summary ............................. 40Glacial. TerrestrialandFreshwaterEcosystems ....... 43Introduction ........................... 43Glacial Systems ......................... 44Antarctic Ice Sheets ....................... 47Ice Core Records of Climate and Environmental Change . . 53


XIIContentsIce Shelves ............................ 56Life in Snow and Ice ....................... 58Ice-Free Areas and Terrestrial Habitats ............ 60Antarctic Soils .......................... 64Terrestrial Ecosystems ..................... 66Freshwater Ecosystems ..................... 70Antarctic Ecosystems as Indicators of Change ........ 75Climate-Change Indications .................. 76Future Research in Antarctic Periglacial Areas ........ 79Summary ............................. 803 The Southern Ocean Environment: Anthropogenic Impactand Climate Change ...................... 83Introduction ...........................The Southern Ocean ......................Water Masses and Circulation Patterns ............Air-Sea Exchanges .......................Sea Ice ..............................Antarctic Sea Ice and the Global Climate System .......Biogeochemical Cycles of C. Fe. S and Other Elements in theSouthern Ocean .........................Pelagic Ecosystems .......................Primary Productivity ......................Effects of UV-B on Phytoplankton and Primary ProductionThe Ecological Role of Sea Ice .................Ice-Edge Processes and Communities .............Krill and Pelagic Food Webs ..................Benthic and Epibenthic Organisms ..............AntarcticMarine Food Webs and the Impactof Human Activity ........................Summary .............................4 Persistent Contaminants in the Antarctic Atmosphere ... 1254.1 Introduction ........................... 1254.2 The Atmosphere of the Southern Hemisphere ........ 1274.2.1 Trace Gases ........................... 1294.2.2 The Impact of Biomass Burning ................ 1324.2.3 Aerosols ............................. 1324.2.4 Volcanic Emissions ....................... 137


Contents4.34.3.14.3.24.3.34.3.44.44.5Persistent Contaminants in the Antarctic Atmosphere .... 140The Mercury Cold Trap ..................... 142Trace Elements in Antarctic Aerosol .............. 146Radionuclides .......................... 151Persistent Organic Pollutants (POPs) ............. 153Antarctic Scientific Stations as Sourcesof Atmospheric Contaminants ................. 158Summa ry ............................. 16055.15.25.2.15.2.25.35.3.15.3.25.3.35.3.45.3.55.45.55.65.6.15.6.25.75.8Persistent Contaminants in Snow. Terrestrial Ecosystemsand Inland Waters ........................ 163Introduction ........................... 163Atmospheric Contaminant Depositionand Their Incorporation into Ice ................ 164Dry. Wet and Occult Deposition in Polar Regions ...... 165Air-Snow Interactions and Post-Depositional Processes . . 169Snow and Ice Core Records of Airborne Trace Metals .... 171Lead as a Paradigm of Hemispheric-ScaleAnthropogenic Impact ..................... 172Natural and Anthropogenic Inputs of Leadto Antarctic Snow ........................ 175Copper. Cadmium and Zinc .................. 178Mercury and Other Trace Metals ................ 183Persistent Organic Contaminants ............... 186Monitoring of Persistent ContaminantsAround Scientific Stations Through Snow .......... 189Contaminants in Antarctic Soils ................ 191Cryptogamic Organisms as Biomonitorsof Atmospheric Contaminants ................. 196Accumulation of Persistent Contaminantsin Antarctic Lichens ....................... 196The Potential Role of Bryophytes as Biomonitors ...... 200Anthropogenic Impact on Lakes and Streams ........ 203Summary ............................. 20666.16.2Contaminants in Antarctic Seawater and Sediments .... 209Introduction ........................... 209Trace Elements in Antarctic Marine Waters .......... 211


Element Input from Atmospheric Dustin the Soiithern Ocean .....................Biogeochemistry of Cobalt. Copper. Nickel and Zinc ....The"Cadmium Anomaly"in the Southern Ocean ......Natural and Anthropogenic Sources of Lead .........A Neglected Element: Mercury .................Particles Fluxes and the Composition of Surface SedimentsEnvironmental Pollution in Marine Coastal Areas ......The Impact of Disused Whaling Stationsin Peri-Antarctic Islands ....................Accidental Oil Spills .......................The Impact of Coastal Scientific Stations ...........Effects of Local Environmental Pollutionon Benthic Communities ....................Summary .............................7 Persistent Contaminants in Antarctic Marine Food Chains .Introduction ...........................Trace Elements and POPs in Pelagic Plankton ........Bioaccumulation of Persistent Contaminantsin Euphausia superba (Krill) ..................Transfer of Contaminants in Pelagic Food Chains ......The (Hyper)Accumulation of Cd and Hg in Pelagic SeabirdsPOPs and Heavy Metals in Pelagic Marine Mammals ....Contaminants in Coastal Benthic Organisms .........Metal Accumulation and Homeostasis in Antarctic MolluscsAntarctic Fish and the Transfer of Contaminantsto Higher Vertebrates ......................Contaminants in Birds and Seals Breeding in Antarctica . .Penguins as Biomonitor Organisms ..............Contaminants in Seals and in a Top Predator Bird:the South Polar Skua ......................Summary .............................8 Climate Change. Anthropogenic Impact and EnvironmentalResearch in Antarctica: a Synthesis and Perspectives ....8.1 lntroduction ...........................8.2 Climate Change and Pathways of Persistent Contaminants .8.2.1 Future Trends in Trace Metal Deposition ...........


8.2.2 The Unpredictable Pathway and Temporal Trend of POPs . .8.3 The Development of Large-Scale Monitoring Networks . . .8.3.1 Regional Baseline Concentrationsof Persistent Contaminants . . . . . . . . . . . . . . . . . . .8.3.2 Circumpolar Biomonitoring of Coastal Marine Ecosystems .8.4 Global Environmental Challenges and the Reductionof Adverse Impacts in Antarctica . . . . . . . . . . . . . . .8.5 Science and the Protection of the Antarctic Environment . .8.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . .References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geographical Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Taxonomic Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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