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Chapter 7: Aquatic Ecology

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Determine by salinity 1. Saltwater (marine): Estuaries, coastlines, coral reefs, coastal marshes, mangrove swamps, ocean over the continental shelf, deep ocean 2.Freshwater: Lakes, ponds, streams, rivers, inland wetlands Two Major Aquatic Life Zones

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Plankton: weak swimming, free-floating 1.Phytoplankton: photosynthetic, algae, producers 2.Nanoplankton: recently discovered 3.Zooplankton: nonphotosynthetic primary consumers (herbivores); feed on phytoplankton or secondary consumers that feed on other zooplankton Aquatic Life Zone Organisms

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Nekton: strong swimming consumers (fish, turtles, whales)

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Benthos: bottom dwelling creatures (barnacles, oysters, worms, lobsters) Decomposers: (bacteria) break down organic compounds into simple nutrients Aquatic Life Zone Organisms

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buoyancy-provides physical support limited fluctuation in temperature-reduces risk of freezing or overheating nutrients- soluble and readily available Unique Properties of Water

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Affect life at different depths (surface, middle, and bottom layers) temperature access to sunlight dissolved oxygen content availability of nutrients Factors that Affect Aquatic Life

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A. Oceans 1. 71% of earth's surface 2. currents distribute solar heat and waste regulate the earth's climate two major life zones: a. coastal zone 10% of ocean area; 90% of all marine species b. open sea 90% of ocean area Saltwater Life Zones

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B. Estuaries and Tidal Ecosystems Estuary partially enclosed area of coastal water seawater mixes with freshwater

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Saltwater Life Zones C. Coastal Wetlands 1. Areas of coastal land covered all or part of the year by salt water. buffer against damage and erosion during storms

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Saltwater Life Zones D. Mangrove Swamp dominated by salt- tolerant trees or shrubs (mangroves) protect coastline from erosion and reduce damage from typhoons and hurricanes

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Saltwater Life Zones E. Rocky and Sandy Shores 1.Intertidal Zone shoreline area between high and low tides a. stressful area for organisms; must cope with waves, being left high and dry

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2.Barrier Beaches/Sandy Shores first line of defense against the ravages of the sea 3.Barrier Islands long, thin, low offshore islands of sediment running parallel to the shore protect the mainland by dispersing the energy of storms Saltwater Life Zones

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F. Coral Reefs form in clear, warm and shallow coastal waters of the tropics and subtropics; most biologically diverse life zones (equivalent of tropical rainforest) Saltwater Life Zones

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7. Human Impacts on Coastal Zones two-thirds of world's population lives within 100 miles of a coast 10% of coral reefs are dead; 30% in critical condition; 30% are threatened; 30% are stable. Beach Erosion Human Impacts on Coastal Zones

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8. Open Sea Divided into three zones based on sunlight penetration: Euphotic where photosynthesis occurs; low nutrient levels; high DO levels Bathyal dimly lit; no photosynthesis Abyssal dark; very cold; v. little DO; high nutrient level on ocean floor Open Sea

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A.About 1% of Earths surface water; 41% of worlds known fish species B.Lentic= standing bodies of water; lakes ponds, and inland wetlands C.Lotic= flowing bodies of water; streams and rivers Freshwater Life Zones

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A.Lakes = depression caused by glaciation, crustal displacement and volcanic activity 1.Zones= defined by depth and distance from shore a.Littoral zone = shallow area near the shore b.Limnetic zone = the open sunlit water surface layer away from the shore c.Profundal zone = deep open water; too dark for photosynthesis d.Benthic zone = bottom of the lake Aquatic Life Zones in Freshwater Lakes

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B.How Plant Nutrients Affect Lakes 1.Lakes are classified according to their nutrients a.Oligotrophic Lake = poorly nourished, newly formed lakes Aquatic Life Zones in Freshwater Lakes

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B.How Plant Nutrients Affect Lakes 1.Lakes are classified according to their nutrients a.Oligotrophic Lake = poorly nourished, newly formed lakes b.Eutrophic Lake = well nourished, older lakes Aquatic Life Zones in Freshwater Lakes

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B.How Plant Nutrients Affect Lakes 1.Lakes are classified according to their nutrients a.Oligotrophic Lake = poorly nourished, newly formed lakes b.Eutrophic Lake = well nourished, older lakes c.Mesotrophic Lake = most lakes fall somewhere between the two extremes of oligotrophic and eutrophic Aquatic Life Zones in Freshwater Lakes

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C.Seasonal Changes in Temperate Lakes 1.Thermal stratification of deep lakes in northern climates. Resists mixing because (in summer) warmer less dense water is on top. 2.Epiliminon = upper layer of warm water with high levels of Dissolved Oxygen 3.Hypoliminon = lower layer of colder, denser water with low level of Dissolved Oxygen 4.Thermocline = middle layer where water temperature changes rapidly with increased depth Aquatic Life Zones in Freshwater Lakes

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A.Watershed/drainage basin = the land area which delivers water to larger streams Freshwater Streams and Rivers

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Freshwater Inland Wetlands A.Lands covered with freshwater all or part of the time B.Includes marshes, prairie potholes, swamps, mud flats, floodplains, bogs, wet meadows, wet arctic tundra

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Covered only part of the year Seasonal Wetlands

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A.They are drained, dredged, filled in or covered over as a result of agriculture, mining, forestry, oil and gas extraction, highways, urban development B.Only 8% of remaining inland wetlands are under federal protection C.Mitigation Banking wetlands can be destroyed if equal areas of the same type of wetland are not created or restored. Mitigation banking protects wetlands by creating or restoring a wetland to offset negative human impact in another area. Human Impacts on Wetlands

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Aquatic Life Zones in Freshwater Lakes

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Thermal Stratification

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C.Seasonal Changes in Temperate Lakes 1.Thermal stratification of deep lakes in northern climates. Resists mixing because (in summer) warmer less dense water is on top. 2.Epiliminon = upper layer of warm water with high levels of Dissolved Oxygen 3.Hypoliminon = lower layer of colder, denser water with low level of Dissolved Oxygen 4.Thermocline = middle layer where water temperature changes rapidly with increased depth Aquatic Life Zones in Freshwater Lakes

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Lake Overturn