Aquatic Biodiversity

1
Chapter 6

• Aquatic Biodiversity

2
Saltwater Life Zones

• Coastal zone and Open Sea

• Estuaries-Salt and fresh water

• Coastal wetlands- Covered in water

• Mangroves-Salt tolerant trees

• Intertidal zones-Between tides.
• Coral Reefs

• Barrier islands-Low offshore islands

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Ocean Zones
Dissolved Oxygen
Fig. 6-5
4
Fig. 6-1a, p. 126
5
Core Case StudyWhy Should We Care About Coral
Reefs?

• Coral reefs form in clear, warm coastal waters of
  the tropics and subtropics.
• Formed by massive colonies of polyps.

Figure 6-1
6
Core Case StudyWhy Should We Care About Coral
Reefs?

• Help moderate atmospheric temperature by removing
  CO2 from the atmosphere.
• Act as natural barriers that help protect 14 of
  the worlds coastlines from erosion by battering
  waves and storms.
• Provide habitats for a variety of marine
  organisms.

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Fig. 6-7b, p. 131
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Estuaries and Coastal Wetlands Centers of
Productivity

• Estuaries and coastal marshes provide ecological
  and economic services.
• Filter toxic pollutants, excess plant nutrients,
  sediments, and other pollutants.
• Reduce storm damage by absorbing waves and
  storing excess water produced by storms and
  tsunamis.
• Provide food, habitats and nursery sites for many
  aquatic species.

9
y
Herring gulls
Peregrine falcon
Snowy Egret
Cordgrass
Short-billed Dowitcher
Marsh Periwinkle
Phytoplankton
Smelt
Zooplankton and small crustaceans
Soft-shelled clam
Clamworm
Bacteria
Producer to primary consumer
All consumers and producers to decomposers
Secondary to higher-level consumer
Primary to secondary consumer
Fig. 6-7a, p. 131
10
Freshwater Inland Wetlands Vital Sponges

• Inland wetlands act like natural sponges that
  absorb and store excess water from storms and
  provide a variety of wildlife habitats.

Figure 6-18
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Case StudyDams, Wetlands, Hurricanes, and New
Orleans

• Dams and levees have been built to control water
  flows in New Orleans.
• Reduction in natural flow has destroyed natural
  wetlands.
• Causes city to lie below sea-level (up to 3
  meters).
• Global sea levels have risen almost 0.3 meters
  since 1900.

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Mangrove Forests
Figure 6-8
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What Kinds of Organisms Live in Aquatic Life
Zones?

• 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)
• Necton fish, turtles, whales.
• Benthos bottom dwellers (barnacles, oysters).
• Decomposers breakdown organic compounds (mostly
  bacteria).

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Rocky and Sandy Shores Living with the Tides

• Organisms in intertidal zone develop specialized
  niches to deal with daily changes in
• Temperature
• Salinity
• Wave action

Figure 6-9
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Barrier Islands

• Low, narrow, sandy islands that form offshore
  from a coastline.
• Primary and secondary dunes on gently sloping
  sandy barrier beaches protect land from erosion
  by the sea.

Figure 6-10
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Human influences

• 40 of worlds population 62 miles of coast
• 53 of lower 48 wetlands lost
• 91 wetlands in Calif. Lost
• 35 of worlds mangroves
• 27worlds coral reefs damaged 11 destroyed By
  2050 70 could be gone.

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Freshwater Life Zones
Fig. 6-15
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Types of Lakes Oligotrophic
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Types of Lakes Eutrophic
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Effects of Plant Nutrients on LakesToo Much of
a Good Thing

• Plant nutrients from a lakes environment affect
  the types and numbers of organisms it can support.

Figure 6-16
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River Systems

• Runoff

• Drainage basin

• Watershed

• Floodplain

Rain and snow
Source Zone
Fig. 6-17
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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 worlds 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 (sub)urban development.

23
Rachel Carson

• All at last returns to the sea-to Oceanus, the
  ocean river, like the ever-flowing stream of
  time, the beginning and the end.
• End chapter 6