1. Chapter 7, Living in the Environment, 14th edition, G. Tyler Miller
Aquatic Biodiversity
Chapter 7, Living in the Environment, 14th edition,
G. Tyler Miller

2. Water on this planet

3. 71% of earth’s surface covered by water
Text figure 7-2
Look for lakes, coral reefs and mangroves. See next slide for rivers
What’s saltwater? Where’s the freshwater?

4. Rivers, lakes, ponds, streams, inland wetlands are freshwater
-97.4% of world’s water is salty; 2.6% fresh water
-1.984% freshwater in ice caps & glaciers
-.014% available to us
-Good thing for the hydrologic cycle!

5. Life in the oceans…advantages & disadvantages
Physical support
From water buoyancy
Fairly constant
temperature
Nourishment from dissolved nutrients
Water availability
Easy dispersal of organisms, larvae,
and eggs
Less exposure to harmful UV radiation
Dilution and
dispersion of
pollutants
Life in the oceans…advantages & disadvantages
Life here can only tolerate a narrow range of
temperatures
Organisms are exposed
to dissolved pollutants
Fluctuating population size for many species
Dispersion separates many
aquatic offspring from parents
Figure 7-3

6. Who are the players in aquatic life zones?
Add in:
Ultraplankton
Phytoplankton
Zooplankton
Decomposers

7. Pictures you can look at later!

8. We need oceans! Food Climate moderation Animal and pet CO2 absorption
feed (fish meal)
Pharmaceuticals
Harbors and transportation routes
Coastal habitats for humans
Recreation
Employment
Offshore oil and
natural gas
Minerals
Building materials
Climate moderation
CO2 absorption
Nutrient cycling
Waste treatment and dilution
Reduced storm impact (mangrove, barrier islands, coastal wetlands)
Habitats and nursery areas
Genetic resources
and biodiversity
Scientific information
Figure 7-5

9. © 2004 Brooks/Cole – Thomson Learning
High tide
Depth in
meters
Sun
Low tide
Coastal Zone
Open Sea
Sea level 50
Euphotic Zone
Photosynthesis
Estuarine
Zone
100
Continental
shelf
200
500
Bathyal Zone
Twilight
1,000
1,500
2,000
Abyssal Zone
3,000
4,000
Darkness
5,000
10,000
© 2004 Brooks/Cole – Thomson Learning
Figure 7-6: Major life zones in the ocean

10. What’s an estuary?
Region where rivers (fresh water) & ocean (salt water) mix by action of tides and river flow. Bays, mouths of rivers, salt marshes & lagoons. The brackish waters feed marine life, birds & other wildlife.

12. Figure 7-8 An estuary…. salt marsh ecosystem
Who are the Producers? Consumers? Decomposers?
Also, think food chains, food webs, connections in ecosystem.

13. Figure 7-12
The Coral Reef
Who are the herbivores? Carnivores? Omnivores?
What if the producers were destroyed by UV radiation?

14. Threats to coral reefs! Figure 7-13 Ocean warming Soil erosion
Algae growth from fertilizer runoff
Mangrove destruction
Coral reef bleaching
Rising sea levels
Increased UV exposure from
ozone depletion
Using cyanide and dynamite
to harvest coral reef fish
Coral removal for building material, aquariums, and jewelry
Damage from anchors, ships,
and tourist divers
Threats to coral reefs!
Figure 7-13

15. Threats to marine ecosystems
Half of coastal wetlands lost to agriculture and urban development
Over one-third of mangrove forests lost since 1980 to agriculture, development, and aquaculture shrimp farms
About 10% of world’s beaches eroding because of coastal development and rising sea level
Ocean bottom habitats degraded by dredging and trawler fishing boats
Over 25% of coral reefs severely damaged and 11% have been destroyed
Threats to marine ecosystems
Text page 137

16. Freshwater….zones of life in a deep lake
Limnetic zone
Profundal zone
Benthic zone
Fig 7-16
Oligotrophic? Eutrophic?

17. Freshwater ecosystems
The Circle of Life
Climate moderation
Nutrient cycling
Waste treatment and dilution
Flood control
Groundwater
recharge
Habitats for aquatic & terrestrial species
Genetic resources
and biodiversity
Scientific information
Economic Importance
Food
Drinking water
Irrigation water
Hydroelectricity
Transportation
corridors
Recreation
Employment
Figure 7-15

18. Other freshwater ecosystem words to know!
“Precipitation that does not sink into the ground or evaporate is surface water. It becomes runoff when it flows into streams. The land area that delivers runoff, sediment and dissolved substances to a stream is called a watershed or drainage basin.” page 140, text

19. Watersheds are important to all life…
Drinking water... Recreation... Wildlife habitats... Economic benefits
Point & Nonpoint pollution sources…what are they?
Water picks up pollutants left by human activities…
Farmers, businesses & homeowners use fertilizers & pesticides. These run-off into water supplies.
Industrial pollutants are dumped or run-off into our waterways
Individuals like you and me…
Fail to pick up after our pets
Dump auto fluids, gasoline from lawn mowers, etc. down storm drains
Leave grass clippings and leaves on paved surfaces
Wash cars on the street or driveway

20. Click below to read about other problems!