1. Preserving Aquatic Biodiversity
Chapter 12

2. Lake Victoria The second largest freshwater lake in the world
How have humans changed it?
Introduced Nile perch – killed other fish
Added nutrients – eutrophication
Introduce water hyacinth – blocks light

3. Aquatic biodiversity
Greatest marine diversity in coral reefs and deep-sea floor
Higher near coasts than open ocean
Higher in benthic layer than near the surface
Higher near tropics

4. How do humans benefit Food Seaweed (cosmetics) Chemicals Antibiotics
Anticancer
Hypertension
Bone replacement

5. Destroying freshwater habitats
Draining wetlands – lost over 50 % of wetlands
Introduction of non-native species
Dams, diversions, canals, flood control levees
Ruin existing habitat or changing flow rate, sediment deposits, spawning beds, migration patterns, plant life, nutrient cycles

6. Major loss of aquatic biodiversity by humans
Overfishing
Habitat destruction
Coastal development
Rising sea level
Trawler boats
Pollution
Introduction of alien species

7. Nonnative examples
Asian swamp eel – Florida, eats everything, can breath air, cross to new waterways
Purple loosestrife – wetlands, perennial plant in Eurasia, spreads rapidly, no native predators, displaces native plants, reduces biodiversity
Zebra mussels – Great Lakes, from ship ballasts, no natural predators, displaced other mussels, interrupted food chain, clogged pipes, grows in large masses on everything

8. Major pollution threats
Oil – especially from runoff
Acid deposition
Plant nutrients and oxygen demanding wastes
Toxic chemicals
Sedimentation from development

9. Protection of Marine Species
CITES
1979 Global Treaty on Migratory Species
U.S. Marine Mammal Protection Act of 1972
Endangered Species Act 1973
Whale conservation and protection act 1976
Changing fishing nets and fishing practice

10. Whaling
International Convention for the Regulation of Whaling formed the IWC to set quotas (often ignored)
IWC set moratorium on commercial whaling since 1986 (Inuits still allowed to hunt whale) many populations recovered
US banned whaling and importing goods
Japan and Norway still are large whaling countries

11. Restoring Wetlands
US requires a federal permit to drain/alter a wetland over 3 acres
Mitigation banking – allows development of wetlands if an equal area elsewhere is created or restored
Use proper planning to keep development/Ag away
Prevent introduction of alien species

12. Florida’s Mistake
Army Corps of Engineers diverted much of the Everglade’s natural flow with levees and canals
Wetlands dried and were converted to farmland
Runoff from fields introduced excess nutrients
Disrupted entire ecosystem
Now largest ecological restoration project (at least $7.8 billion)

13. Columbia River Basin
Located in Pacific Northwest – 1,200 miles of river
Largest hydroelectric power system
Provides jobs, electricity, flood control, stimulate industry/agriculture
Hurts habitats especially migratory fish (salmon)
Northwest Power Act 1980 – find way to generate power and rebuild wild salmon and other fish populations

14. Protecting Rivers
National Wild and Scenic Rivers Act 1968 – waterways kept free from development, no motors, no alterations
A river can be designated by congress based on outstanding scenic, recreational, geological, wildlife, historical, or cultural value

15. The Great Lakes Faces several threats
Alien species, like the zebra mussel, is the greatest, but also is encountering
Thermal pollution from power plants
Commercial fishing
Human sewage (mostly processed)
Acid rain (but there is more to the east)

16. Act Now
Approximately 50% of the world’s original coastal wetlands have been lost
Main reasons
Agriculture
Housing/building development

17. Commercial fishing techniques
While many systems are bad for the environment, these appear to be the worst
Trawling - nets destroy ocean floor habitat
Drift nets (more than 2 miles long) - kill many mammals, turtles and birds
Longlining - creates a lot of bycatch such as dolphin, shark, pilot whales, birds, and turtles

18. What can you do?
Use comsumer power to buy products that do not threaten aquatic species
Use environmentally friendly cleaners in the home
Prevent soil erosion
Vote against wetland development
Eat less fish and seafood (more organic veggies)