Aquatic Biodiversity

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Aquatic Biodiversity
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Question for Today

• What are the different niches that organisms can
  occupy in an aquatic ecosystem?
• How are marine ecosystems organized?
• How are freshwater systems organized?
• What are the differences between an oligotrophic
  and eutrophic lake?
• How do humans affect marine and freshwater
  ecosystems?

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Aquatic life zones and niches

• Aquatic life zones are similar to terrestrial
  biomes.
• Instead of looking at temperature and
  precipitation, aquatic life zones classify by
  salinity.

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Aquatic life zones and niches

• Two major life zones
• Saltwater or marine
• Oceans
• Estuaries and coastal wetlands
• Shorelines, coral reefs and mangrove forests
• Freshwater
• Lakes, rivers, streams and inland wetlands

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Aquatic Life Zones and Niches

• Aquatic systems contain floating, drifting,
  swimming, bottom-dwelling, and decomposer
  organisms.
• Plankton important group of weakly swimming,
  free-floating biota.
• Phytoplankton (plant), Zooplankton (animal),
  Ultraplankton (photosynthetic bacteria)
• Nekton fish, turtles, whales.
• Benthos bottom dwellers (barnacles, oysters).
• Decomposers breakdown organic compounds (mostly
  bacteria).

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Phytoplankton

• Description small drifting plants
• Niche they are producers that support most
  aquatic food chains
• Example cyanobacteria many types of algae

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Zooplankton

• Description herbivores that feed on
  phytoplankton or other zooplankton
• Niche food stock for larger consumers
• Example krill small crustaceans

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Nekton

• Description larger, strong-swimming consumers
• Niche top consumers in the aquatic ecosystem
• Example fish, turtles, and whales

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Benthos

• Description bottom-dwelling creatures
• Niche primary consumers, decomposers
• Example barnacles, oysters, and lobsters

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Marine Life zones

• Most Marine Life Zones are organized by
  depth/light penetration, and distance from the
  shore
• Three zones based off distance from the shore
• Intertidal zone, Coastal Zone and the Open Sea
• Three Zones based off depth/light penetration
• Euphotic Zone
• Bathyal Zone
• Abyssal Zone

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Freshwater Ecosystems

• Freshwater Ecosystems are organized in a similar
  way to Marine Ecosystem
• Two types of Freshwater Ecosystems
• Lentic (Standing)
• Lakes, Ponds, inland wetlands
• Lotic (Flowing)
• Rivers, Streams

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Lakes

• Lakes are large natural bodies of standing
  freshwater formed when precipitation, runoff, or
  groundwater seepage fills a depressions in
  earths surface.
• Can be caused by glaciation, crustal
  displacement, and volcanic activity
• Lakes are stratified due to Light Penetration and
  Temperature.
• Littoral
• Limnetic
• Profundal
• Benthic

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Oligotrophic vs. Eutrophic

• Ecologist can also classify lakes according to
  nutrient content and primary productivity.
• Two Types
• Oligotrophic Lakes
• Low Nutrient, Low Productivity
• Crystal-clear water
• Small population of phytoplankton and fish.
• Eutrophic Lakes
• High Nutrient, High Productivity
• High Turbidity, murky-brown or green water

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How do Humans affect marine biomes?

• Major threats to marine systems
• Coastal development
• Overfishing
• Runoff of nonpoint source pollution
• Point source pollution
• Habitat destruction
• Introduction of invasive species
• Climate change from human activities
• Pollution of coastal wetlands and estuaries

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How do Humans effect freshwater ecosystem?

• Impact of dams and canals on rivers
• Impact of flood control levees and dikes along
  rivers
• Impact of pollutants from cities and farms on
  rivers
• Impact of drained wetlands