1. Aquatic Ecology
Chapter 6

2. 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

3. 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

4. Categories of organisms
Floating algae – phytoplankton
Swimming microscopic and macroscopic organisms – zooplankton
Fish – nekton
Tube worms, crabs - benthos

5. 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)

6. 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

7. Fig. 7.7, p. 157

8. 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

9. 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

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

11. 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

12. Limnetic zone Dense fish population
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

13. nutrition and plankton
Sunlight
Little shore
vegetation
Narrow
littoral
zone
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

14. 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

15. Dissolved O2 concentration
22˚ 4˚
20˚
Epilimnion 4˚
18˚ 4˚ 8˚ 4˚ 6˚ 4˚
Hypolimnion 5˚
4˚C
4˚C
Thermocline
Summer
Fall overturn 0˚ 4˚ 2˚ 4˚ 4˚ 4˚ 4˚ 4˚ 4˚ 4˚
4˚C
4˚C
Winter
Spring overturn
Dissolved O2 concentration
High
Medium
Low
Fig. 7.16, p. 167

16. It’s 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

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

18. Say hello to my little friends