1. Water Use

2. Fishing Techniques
Bottom Trawling
Drift Nets
Long Lines
Purse Seine

3. Overfishing Statistics Oceans viewed as unlimited resources
52% of fish stock fully exploited
16% overexploited
8% depleted
Oceans viewed as unlimited resources
Ocean productivity is low
Light restricted to surface

4. Overfishing Supply 1% of food, represents 10% of protein
1/3 of catch used for other purposes than food
Fish oil, fish meal, animal feed
1/3 of global catch is bycatch
Discarded catch – sea turtles, marine mammals, shellfish

5. Maximum Sustainable Yield
Highest rate of use that can be matched by replacement
Maximum that can be caught without causing population to crash
Generally occurs at ½ carrying capacity

6. Maximum Sustainable Yield
How does it work?
How to determine it?

7. Managing Fisheries
Regulate locations of fish farms and monitor pollution
Encourage production of herbivorous fish
Label products to indicated raised or caught by sustainable methods
Set catch limits below MSY
Prevent importation if not caught using sustainable methods
Increase marine sanctuaries and no-fishing areas
Monitor and destroy invasive species
Ban throwing back bycatch

8. Restoring Habitats for Freshwater Fish

9. Aquaculture Commercial growing of aquatic organisms for food
Stocking, feeding, protecting, harvesting

10. Aquaculture Growing about 6% annually
Provides 5% of total food production
Most common products – seaweeds, mussels, oysters, shrimp, certain fish (salmon, trout, catfish)

11. Aquaculture
Problems

12. International Whaling
Heavily depleted until 1980s
1974 International Whaling Commission (IWC)
1986 IWC enacted moratorium on all whaling

13. Coral Reef

14. Coral Reefs Most diverse and biologically productive ecosystems
Corals (animal) have a mutualistic relationship with photosynthetic algae (zooxanthellae)
Generate $375 billion in tourism and fishing revenue

15. Coral Reefs
Bleaching
Exploitation

16. Mangroves Often located inland of coral reefs
Trees have ability to root and grow in shallow marine sediments

17. Mangroves
Services

18. Mangroves Damage Coastal development Logging Shrimp aquaculture
Mangrove is cleared
Land bulldozed to make shallow ponds
Black tiger prawns grown in ponds ($multibillion industry)
Pond becomes polluted  shrimp no longer grow  new ponds created, old ponds are flushed and pollution damages adjacent coastal environments