Aquatic Ecosystems Aquatic ecosystems are classified as Freshwater

Aquatic Ecosystems � Aquatic ecosystems are classified as ◦ Freshwater (inland), or ◦ Saltwater � Wetlands areas that are web for at least part of the year ◦ Marshes ◦ Swamps ◦ Bogs 2

Freshwater and Saltwater Ecosystems Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. stream Carp, Cyprinus carpio river lake Blue crab, Callinectes sapidus delta salt marsh Stonefly larva, Plecoptera sp. Rainbow trout, Salmo gairdneri (Stonefly): © Kim Taylor/Bruce Coleman, Inc. ; (Trout): © William H. Mullins/Photo Researchers, Inc. ; (Carp): © Robert Maier/Animals/Earth Scenes; (Crab): © Gerlach Nature Photography/Animals/Earth Scenes 3

Aquatic Ecosystems � Lakes ◦ Bodies of water classified by nutrient status �Oligotrophic - Nutrient-poor �Eutrophic - Nutrient-rich ◦ Lake Stratification �In temperate zones, deep lakes are stratified in the summer and winter and have distinct vertical zones 4

Types of Lakes Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. a. Oligotrophic lake b. Eutrophic lake a: © Roger Evans/Photo Researchers, Inc. ; b: © Michael Gadomski/Animals/Earth Scenes 5

Lake Stratification in a Temperate Region Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. wind epilimnion 24°– 25°C thermocline 13°– 18 ° hypolimnion 5°– 8° Summer Stratification wind Spring Overturn Fall Overturn ice wind 2°– 3°C most of lake 4°C Winter Stratification 6

Aquatic Life Zones � Plankton ◦ Important community in fresh water and salt water ecosystems �Phytoplankton - Photosynthetic algae �Zooplankton - Animals � Life ◦ ◦ Zones Littoral zone - Closest to shore Limnetic zone - Sunlit areas Profundal zone - Below light penetration Benthic zone - Soil-Water interface 7

Zones of a Lake Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Littoral Zone surface organisms Water strider , Gerris sp. clinging organisms fishes Benthic Zone phytoplankton zooplankton insect larvae Limnetic Zone Northern pike, Esox lucius bottom-dwelling organisms Profundal Zone (Pike): © Robert Maier/Animals/Earth Scenes; (Water strider): © G. I. Bernard/Animals/Earth Scenes 8

Coastal Ecosystems � Estuaries ◦ Partially enclosed bodies of water where fresh water and seawater meet and mix ◦ Organisms must be able to adapt to changing salinity ◦ Nearly two thirds of all marine fishes and shellfish require development in estuaries 9

Coastal Ecosystems Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. a. Mudflat b. Mangrove swamp c. Rocky shore a: © John Eastcott/Yva Momatiuk/Animals/Earth Scenes; b: © Theo Allofs/Visuals Unlimited; c: © Brandon Cole/Visuals Unlimited. 10

Seashores � Littoral marks zone lies between high and low water ◦ Rocky Shores �Many attached organisms �Littoral zone of rocky beach divided into subzones ◦ Sandy beach �No attachment sites available �Nearly all permanent residents dwell underground 11

Oceans � Euphotic Zone ◦ Contain a greater concentration of organisms than the rest of the sea � Coral Reefs ◦ Located just below the surface in shallow, warm, tropical waters ◦ Densely populated with life 12

Ocean Ecosystems Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. low tide high tide intertidal zone euphotic zone deep-sea waters continental shelf continental slope abyssal plain 13

Oceans �Pelagic Zone ◦ Epipelagic Zone �Lacks inorganic nutrients �Does not have high concentration of phytoplankton ◦ Mesopelagic Zone �High concentration of organisms due to sunlight penetration and supply of inorganic nutrients �Coral Reefs ◦ Bathypelagic Zone �Complete darkness except for bioluminescent light �Carnivores and scavengers 14

Ocean Inhabitants Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. baleen whale dolphin shark barracuda sea turtle Epipelagic Zone ocean bonito prawn mackerel Mesopelagic Zone tuna lantern fish giant squid midshipman sperm whale viperfish anglerfish Bathypelagic Zone hagfish gulper deep-sea shrimp 15

Oceans � Abyssmal Plain ◦ High pressure and extreme cold ◦ Organisms are dependent on debris sinking down from above ◦ Interrupted by oceanic ridges ◦ Hydrothermal vents 16

Ocean Currents � Major ocean currents move heat from the equator to cooler parts of the biosphere ◦ Gulf Stream warms the east coast of North America and parts of western Europe ◦ Another current in the Southern Hemisphere warms the eastern coast of South America ◦ The Humboldt Current in the Southern Hemisphere carries cold water northward along the western coast of South America �El Nino Southern Oscillation--Cold upwelling off west coast of South America subsides 17

Ocean Currents Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Asia Japan ent Curr North America Europe am tre lf S Gu Africa equatorial countercurrent South America Australia west w ind dr ift west wind drift east wind drift warm currents Antarctica cold currents 18

Review �Climate and the Biosphere ◦ Solar Radiation ◦ Global Wind Circulation �Terrestrial Ecosystems ◦ ◦ ◦ Tundra Forests Shrublands Grasslands Deserts l Aquatic Ecosystems l l l Lakes Life Zones Estuaries Seashores Oceans 19

Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Openers (Earth): Courtesy NASA; (Lake): © Stephen J. Krasemann/Photo Researchers, Inc. ; (Birch): © Dwight Kuhn; (Sunflowers): © Jim Brandenburg/Minden Pictures; (Acacia tree): © Konrad Wothe/Minden Pictures; (Rain forest): © age fotostock/Super. Stock; (Lynx): © Imagebroker/Alamy; (Salamander): © David M. Dennis/Animals/Earth Scenes; (Buffalo): © Eastcott Momatiuk/Getty Images; (Lion): © age fotostock/Super. Stock; (Toucan): © age fotostock/Super. Stock 20