Aquatic Ecology

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Aquatic Ecology

• Chapter 6

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Coral Reefs

• What do coral reefs require?
• Answer dissolved oxygen, light and nutrients
• What threatens coral reefs? (3)
• Chemical pollution, global warming, extra UV from
  ozone hole, excess sediment from rivers (soil
  erosion), human contact

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Coral Reefs

• What percent of reefs is estimated to be
  destroyed by human intervention?
• 10 percent
• What about estuaries and wetlands?
• About 50(US) through filling, sewage, runoff
  pollution, and diversion

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Categories of organisms

• Floating algae phytoplankton
• Swimming microscopic and macroscopic organisms
  zooplankton
• Fish nekton
• Tube worms, crabs - benthos

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Reasons oxygen varies in water

• Number of consumers (respiration)
• Number of producers (photosynthesis)
• Temperature (cold holds more)
• Turgidity (rough water dissolves more)
• Number of decomposers (bacteria can take up a lot
  of oxygen)

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Salt water areas

• What zone is on the continental shelf?
• - the coastal zone
• What area exhibits variable temperature and
  salinity
• - Estuaries
• Where would you find a mangrove?
• - tropical coastal estuaries

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Fig. 7.7, p. 157
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Salt water areas

• What is the dim or twilight area of the open sea
  called?
• - bathyal zone
• What is the area with the highest photosynthetic
  rate in the sea called?
• - euphotic zone

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Fresh water areas

• Where does photosynthesis take place in lakes?
• - the limnetic zone, of course!
• Where do fish who like cool, dark water reside?
• - the profundal zone
• Where do the worms live?
• -the benthic zone

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Sunlight
Painted turtle
Green frog
Blue-winged teal
Muskrat
Pond snail
Littoral zone
Limnetic zone
Diving beetle
Plankton
Profundal zone
Benthic zone
Bloodworms
Northern pike
Yellow perch
Fig. 7.14, p. 165
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Nutrient levels in lakes

• A newly formed, nutrient poor lake is?
• - Oligotrophic
• A mature and nutrient rich lake is?
• - eutrophic
• A middle aged and moderately nutrient rich
  (normal) lake is?
• - mesotrophic

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Sunlight
Much shore vegetation
Much shore vegetation
Wide littoral zone
High concentration of nutrition and plankton
Limnetic zone
Dense fish population
Gently sloping shorelines
Salt, sand, clay bottom
Eutrophic Lake
Fig. 7.15b, p. 166
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Sunlight
Narrow littoral zone
Little shore vegetation
Low concentration of nutrition and plankton
Limnetic zone
Profundal zone
Steeply sloping shorelines
Sparce fish population
Sand, gravel, rock bottom
Oligotrophic Lake
Fig. 7.15a, p. 166
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Overturn

• When does overturn happen is a lake?
• When the weather changes from warm to cold, or
  cold to warm, so in spring and fall
• Which season produces the most profound
  thermoclines?
• summer

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22
4
20
4
Epilimnion
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4
8
4
6
4
Hypolimnion
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4C
4C
Thermocline
Summer
Fall overturn
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0
4
2
4
4
4
4
4
4
4C
4C
Winter
Spring overturn
Fig. 7.16, p. 167
Dissolved O2 concentration
High
Medium
Low
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Its okay to destroy when?

• If you ruin a wetland for agriculture (the number
  one reason), what says you have to build a new
  one somewhere else?
• Mitigation banking it is an agreement to
  restore or create new in another location
  whatever wetlands you ruin

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Rain and snow
Lake
Rapids
Glacier
Waterfall
Tributary
Flood plain
Oxbow lake
Salt marsh
Ocean
Delta
Deposited sediment
Source Zone
Transition Zone
Water
Flood-Plain Zone
Sediment
Fig. 7.17, p. 168
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