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Aquatic Biodiversity

  • Abiotic Factors
    • Life in water depends on:
    • Temperature
    • Sunlight penetration
      • For photosynthesis
      • Affected by depth and turbidity of water
    • Amount of dissolved oxygen
    • Salinity
    • pH
    • Nutrient availability
      • Shallow waters have lots of nutrients
  • Organisms and Aquatic Life Zones
    • Plankton: free floating, weakly swimmers
    • Phytoplankton
      • Autotroph
    • Zooplankton
      • Heterotroph
    • Ultraplankton
      • Autotrophic bacteria
    • Nekton: free-swimming
    • Benthos: bottom dwellers
    • Decomposers
  • Oceans
    • High biodiversity
    • 2 zones
    • Coastal
      • Warm and nutrient rich area
      • 90% of all marine species
    • Open sea
      • Cooler
      • Fewer species
    • Ocean bottom
  • Types of Estuaries
    • Mangrove Forests
    • Swamps and mangrove forests are dominated by trees, while salt marshes are dominated by grasses
    • Coastal Zone
    • Enclosed body of water formed where seawater mixes with freshwater from rivers and streams
    • Called “marine nurseries”
      • Habitats for many juvenile fish species
    • Salt tolerant trees that reduce erosion
  • Estuaries
    • Extremely fertile because the river brings lots of sediments
    • Stressful conditions and abundant nutrients result in low species diversity, but great abundance of the species present
  • Intertidal Zone
    • The area between high tides and low tides
    • Organisms have some adaptation to withstand wave activity
    • Rocky shores
    • Areas pounded by waves
    • Varieties of algae, snails, crabs, etc.
    • Sandy shores
    • No plants or algae
    • Insects, shorebirds, crabs, and worms
  • Barrier Islands
    • Long, narrow, offshore deposits of sand or sediments that parallel to the coastline
    • Aid in protecting mainland, estuaries, and coastal wetlands
    • Found along eastern coasts and Gulf of Mexico
    • Lots of development
  • Coral Reefs
    • Structure that is formed by coral polyps
    • Typically found in warm coastal waters of the tropics and subtropics
    • Coral polyps form a hard, stony, exoskeleton made of limestone
  • Coral Reefs Climate
    • Usually found near land in shallow, warm, salty water
  • Importance of Coral Reefs
    • High biodiversity
    • Considered the most diverse and productive
    • Grow very slowly
    • Complex relationships that exist between many organisms
  • Damage to Coral Reefs
    • Very sensitive to environment changes
    • Natural disturbances
    • Hurricanes or typhoons, and predation by a large starfish
    • Anthropogenic disturbances
    • Sediment runoff
    • Pollution
    • Reef fishing
    • Coral bleaching
    • 300+ reefs are protected as reserves or parks
  • Freshwater Life Zone
    • Cover less than 1% of Earth’s surface
    • Low salt concentration
    • Less than 1%
    • Types
    • Flowing
      • Streams
      • Rivers
    • Standing
      • Ponds
      • Lakes
      • Inland wetlands
  • Lake and Pond Zones
    • Divided into four zones determined by depth and distance from the shoreline
    • Littoral zone
      • Top layer
      • Shallow
      • Near shore
      • High biodiversity
      • Aquatic plants
      • Grazing snails
      • Clams
      • Insects
      • Crustaceans
      • Fish
      • Amphibians
    • Limnetic zone
      • Sunlit water
      • Surface layer
      • Main photosynthetic layer
      • Plankton
      • Fish
    • Profundal zone
      • Cools and dark layer
      • Low oxygen
    • Benthic zone
      • Bottom layer
      • Decomposers and detritivores
  • Lake Classification
    • Oligotrophic
    • Newly formed
    • Poorly nourished
    • Little sediment
    • Deep water
    • Clear water color
    • Low net primary production
    • Eutrophic
    • Excess supply of nutrients
      • Phosphates and nitrates
    • Shallow water
    • Murky water color
    • High net production
  • Characteristics of Rivers and Streams
    • Bodies of flowing water moving in one direction
    • Found everywhere
    • Get their start at headwater, which may be springs, snowmelt or even lakes
    • Travel all the way to their mouths
    • Usually another water channel or the ocean
  • Freshwater Inland Wetlands
    • Lands that are covered with fresh water year round or seasonally and located away from coastal areas
    • High biodiversity
    • Vary in size
    • Important in filtering pollutants, absorbing excess water from storms, and providing habitats
  • Impacts of Human Activities on Freshwater Systems
    • Dams, cities, farmlands, and filled-in wetlands alter and degrade freshwater habitats
    • Dams, diversions, and canals have fragmented about 40% of the world’s 237 large rivers
    • Flood control levees and dikes alter and destroy aquatic habitats
    • Cities and farmlands add pollutants and excess plant nutrients to streams and rivers
    • Many inland wetlands have been drained or filled for agriculture or urban development