Aquatic Ecosystems

1
Aquatic Ecosystems

• Chapter 7

2
Aquatic Environments Types and Characteristics

• Aquatic life zones
• Saltwater
• Freshwater

3
The Aquatic World
Fig. 5-23a, p. 96
4
Organisms in Aquatic Life Zones

• Phytoplankton
• Zooplankton
• Nekton- Strong swimming (fish, sharks, etc.)
• Benthos - Bottom-dwelling (crabs, shellfish,
  worms)
• Decomposers

Free floating
5
Factors that Limit Life with Water Depth

• Temperature
• Sunlight (photosynthesis, euphotic zone)
• Dissolved oxygen content
• Availability of nutrients (like phosphorus and
  nitrates- net primary productivity)

6
Saltwater Life Zones

• Open ocean
• Coastal zone
• Estuaries
• Coastal wetlands
• Mangrove swamps
• Intertidal zones (rocky shores and barrier
  beaches)
• Coral reefs

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Major Life Zones in the Ocean
High tide
Open Sea
Sun
Low tide
Coastal Zone
Sea level
Euphotic Zone
Photosynthesis
Estuarine Zone
Continental shelf
Bathyal Zone
Twilight
Abyssal Zone

• Biological Zones in Open Sea
• Euphotic zone
• Bathyal zone
• Abyssal zone

Darkness
Fig. 5-26, p. 98
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Marine Ecosystems
Natural Capital
Marine Ecosystems
EcologicalServices
EconomicServices
Climate moderation CO2 absorption Nutrient
cycling Waste treatment and dilution Reduced
storm impact (mangrove, barrier islands, coastal
wetlands) Habitats and nursery areas for marine
and terrestrial species Genetic resources and
biodiversity Scientific information
Food Animal and pet feed (fish
meal) Pharmaceuticals Harbors and
transportation routes Coastal habitats for
humans Recreation Employment Offshore oil and
natural gas Minerals Building materials
Fig. 5-25, p. 97
9
Estuaries

• Where freshwater and saltwater meet.
• Highly variable environment
• (salinity, temperature, light penetration
  rapidly changes).
• Many fishes and shellfish spend larval stages
  here.

10
Sediment Plume in an Estuary
Madagascars Betsiboka River flowing into
Mozambique Channel
Fig. 5-27, p. 98
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Estuaries

• Two general types

1) Salt marshes
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Salt Marsh in Lake Titicaca, Peru
Fig. 5-28b, p. 99
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Salt Marsh Ecosystem
Herring gulls
Peregrine falcon
Producer to primary consumer
Snowy egret
Cordgrass
Short-billed dowitcher
Primary to secondary consumer
Marsh periwinkle
Secondary to higher-level consumer
Phytoplankton
Smelt
All producers and consumers to decomposers
Zooplankton and small crustaceans
Soft-shelled clam
Clamworm
Bacteria
Fig. 5-28a, p. 99
14
Marine Ecosystems

• Intertidal Zone

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Beach Organisms
Hermit crab
Shore crab
Sea star
Rocky Shore Beach
High tide
Periwinkle
Sea urchin
Anemone
Mussel
Low tide
Sculpin
Barnacles
Kelp
Sea lettuce
Monterey flatworm
Nudibranch
Fig. 5-29a, p. 101
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Beach Organisms
Barrier beach
Beach flea
Peanut worm
Tiger beetle
Blue crab
Clam
Dwarf olive
High tide
Sandpiper
Ghost shrimp
Silversides
Low tide
Mole shrimp
White sand macoma
Sand dollar
Moon snail
Fig. 5-29b, p. 101
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Barrier island Miami Beach
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Primary and Secondary Beach Dunes
Ocean
Beach Intensive recreation, no building
Primary Dune No direct passage or building
Trough Limited recreation and walkways
Secondary Dune No direct passage or building
Bay or Lagoon Intensive recreation
Back Dune Most suitable for development
Bay shore No filling
Grasses or shrubs
Taller shrubs
Taller shrubs and trees
Fig. 5-30, p. 102
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Coral Reef Ecosystem
Gray reef shark
Green sea turtle
Sea nettle
Producer to primary consumer
Fairy basslet
Blue tangs
Primary to secondary consumer
Parrot fish
Sergeant major
Brittle star
Banded coral shrimp
Hard corals
Algae
Secondary to higher-level consumer
Phytoplankton
Coney
Symbiotic algae
Zooplankton
Blackcap basslet
All producers and consumers to decomposers
Sponges
Moray eel
Bacteria
Fig. 5-31, p. 102
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Global Distribution of Coral Reefs
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Major Threats to Coral Reefs
Natural Capital Degradation
Coral Reefs
Ocean warming Soil erosion Algae growth from
fertilizer runoff Mangrove destruction Coral
reef bleaching Rising sea levels Increased UV
exposure from ozone depletion Using cyanide and
dynamite to harvest coral reef fish Coral
removal for building material, aquariums, and
jewelry Damage from anchors, ships, and tourist
divers
Fig. 5-32, p. 103
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Human Impacts on Marine Ecosystems
Natural Capital Degradation
Marine Ecosystems
Half of coastal wetlands lost to agriculture and
urban development Over one-third of mangrove
forests lost since 1980 to agriculture,
development, and aquaculture shrimp farms About
10 of worlds beaches eroding because of coastal
development and rising sea level Ocean bottom
habitats degraded by dredging and trawler fishing
boats Over 25 of coral reefs severely damaged
and 11 have been destroyed
Fig. 5-33, p. 103
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Aquatic Ecosystems

• Human Impacts on the Ocean

25
Aquatic Ecosystems

• Human Impacts on the Ocean

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Freshwater Life Zones

• Standing (lentic) water - lakes and ponds
• Flowing (lotic) water - streams and rivers

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Major Services of Freshwater Systems
Natural Capital
Freshwater Systems
EcologicalServices
EconomicServices
Food Drinking water Irrigation
water Hydroelectricity Transportation corridors
Recreation Employment
Climate moderation Nutrient cycling Waste
treatment and dilution Flood control Groundwater
recharge Habitats for aquatic and terrestrial
species Genetic resources and biodiversity Scien
tific information
Where does our freshwater come from???
Fig. 5-34, p. 104
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Zones in a Temperate Lake
Sunlight
Painted turtle
Green frog
Blue-winged teal
Muskrat
Pond snail
Littoral zone
Limnetic zone
Diving beetle
Plankton
Profundal zone
Benthic zone
Northern pike
Yellow perch
Bloodworms
Fig. 5-35, p. 105
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Freshwater Ecosystems

• Lakes and Ponds

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Freshwater Ecosystems

• Lakes and Ponds

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Freshwater Ecosystems

• Thermal stratification in temperate lakes

32
Freshwater Ecosystems

• Turnover in temperate lakes

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Nutrient effects on lakes and streams

• Oligotrophic- nutrient poor, therefore low net
  primary productivity clear blue-green water
• Eutrophic- nutrient rich with nitrates and
  phosphates lead to increase algae and excessive
  growth of producers murky brown or green water
  with poor visibility.

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Humans accelerate eutrophication of lakes and
streams

• Animation of river eutrophication

35
Freshwater Streams and Rivers

• Surface water- precipitation that does not sink
  into the ground.
• Runoff
• Watershed or drainage basin- area of land where
  rivers and streams come together (river basin-
  all the water drains into a large river)
• Aquifers- porous, water-saturated layers of
  sand, gravel or bedrock that are filled from
  surface water percolating down through the
  sediments.
• Water table- upper surface of the zone of
  saturation , where all pores between sediment
  particles are filled with water.

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• Flowing water zones- (Planet Earth)
• Source Tend to be narrow, swift, clear, cold,
  nutrient poor, and highly oxygenated not very
  productive
• Transition warmer, wider, deeper streams,
  support more producers than source zone
• Floodplain Tend to be wide, deeper river meet
  valleys. slow, cloudy, warm, nutrient rich, and
  less oxygenated large levels of algae, aquatic
  plant

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Stream Zones
Rain and snow
Lake
Glacier
Rapids
Waterfall
Tributary
Flood plain
Oxbow lake
Salt marsh
Ocean
Delta
Deposited sediment
Source Zone
Transition Zone
Water
Sediment
Floodplain Zone
Fig. 5-36, p. 106
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Freshwater Inland Wetlands

• Importance of inland wetlands
• Natural sponges/ remove pollutants
• Diverse habitats
• Types of wetlands
• Marshes (dominated by grasses/reeds)
• Swamps (dominated by trees/shrubs)
• Prairie potholes (depressions carved out by
  glaciers)
• Floodplains
• Arctic tundra (in summer)
• Seasonal wetlands

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Freshwater Ecosystems

• Freshwater Swamps

• Marsh

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Freshwater Ecosystems

• Prairie potholes

• Floodplain- Mississippi River

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Freshwater Ecosystems

• Artic tundra- Alaska in summer

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Human Impacts on Freshwater Systems

• Dams, diversions and canals - Animation
• Flood control levees and dikes
• Pollutants from cities and farmlands
• Wetland destruction

43
Interaction of Life Zones

• Case-in-Point The Everglades

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What are the Everglades?

• Used to cover over 11,000 square miles flowing
  from Kissimmee River to Lake Okeechobee, and then
  south through the Everglades to Florida Bay (KOE
  watershed)
• Spans up to 60 miles in width, but can be only 6
  inches in depth in some areas
• Considered a hot spot of biodiversity
• Only area in the world where Alligators and
  Crocodiles exist side by side
• Nicknamed River of Grass (Marjorie Stoneman
  Douglas)

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History of the Everglades

• 1905- FL governor Napoleon Bonaparte Broward
  began the push to drain the Everglades
• Miami and Ft. Lauderdale were created when tracts
  of land were drained into farmland
• 1948- Central and South Florida Project (US
  congress)-- created man-made canals and levees
  moving over 1 billion gallons of water daily into
  the ocean
• The Everglades is now one half of the size it
  used to be due to this change

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What is being done?

• CERP (Comprehensive Everglades Restoration Plan)
• 30 year, 10.9 billion
• 50-50 partnership with FL and US govts
• Improve water quality and water flow
• Flow maps

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The major CERP Plan components

• Surface Water Storage Reservoirs
• Water Preserve Areas
• Management of Lake Okeechobee as an Ecological
  Resource
• Improved Water Deliveries to the Estuaries
• Underground Water Storage
• Treatment Wetlands
• Improved Water Deliveries to the Everglades
• Removal of Barriers to Sheetflow
• Storage of Water in Existing Quarries
• Reuse of Wastewater
• Improved Water Conservation
• Additional Feasibility Studies