1. Sustaining Aquatic
Biodiversity
Ch. 11, part 1

2. Biodiversity is highest at:
 Coral reefs, estuaries, and deep ocean
 Near coast since more producers there
 At bottom since more food and habitats

3. Threats to Aquatic Biodiversity
HIPPCO

4. H = habitat loss & degradation
 Mostly in coral reefs and mangroves
used by humans
Damage done
by trawling

5.  51% of
freshwater
species
threatened
with
extinction the most of
any group

6. I - invasive species
Water
hyacinth in
Lake
Victoria
 84% of coastal
waters invaded
 Causes 2/3 of
all fish
extinctions
 Cost USA ~$14
million/year
 Often arrive in
ballast water

9. P = population growth
 By 2020 - 80% of world’s people will live
in coastal cities
Rio de Janeiro
Lebanon

10. P = pollution
 Just 4% of world’s oceans unaffected
by pollution
 Most pollution comes from land
activities
 Pesticides/fertilizers
 Plastics
 Oil

11. C = climate change
 Causes sea levels to rise
 CO2 “sinks” coral reefs, swamps, wetlands
 Store CO2 – out of air
 Puts coastal cities underwater

12. O = overfishing
 Industrialized fishing
depletes populations
quickly
 Fishprint - area of
ocean needed to
sustain our fish
consumption
 Currently at 157%
 Commercial extinction no longer profitable to
fish since so few left

13. Bycatch

14. Fish farming in cage
Trawler fishing
Spotter airplane
Sonar
Purse-seine fishing
Drift-net fishing
Long line fishing
Float Buoy
lines with hooks
Deep sea
aquaculture cage
Fish caught by gills
Stepped Art
Fig. 11-7, p. 256

15. The numbers
 35% of marine species
 71% of freshwater species
 May go extinct in our lifetime
 The MOST AFFECTED GROUP of
all species by humans

16.  Dolphin and
whale slaughter
by Japan

17. Shark finning

18. What we can do to help
 Laws and treaties
 Difficult to enforce
 Most of ocean is not owned by anyone tragedy of the commons
 Economic Incentives - tourism
 Long term gain vs. short term profit

19. Some laws/treaties you should
know
CITES - 1975 - trade in endangered species
Global Treaty on Migratory Species - 1979
US Marine Mammal Protection Act - 1972
US Endangered Species Act - 1973
US Whale Conservation and Protection Act 1976
 International Convention on Biological
Diversity - 1995






20. Who owns the seas?
 A country owns from its coast to 200
miles out
 Beyond is the high seas - international
laws and treaties apply here - but who
enforces them?

21. Marine Sanctuaries & Marine
Protected Areas (MPAs)
 4000 worldwide; 200 in US
waters
 Offer only partial protection
 Most still allow dredging, trawler
fishing, drilling, etc
 CA is leading
 Most extensive network of MPAs
with most restrictions

22. The Ecosystem Approach
 Establish marine reserves all over, especially coastal
areas
 They work! - in 2-4 years see marked improvement
 Increase tourism
 Help fishing industry
 Only .1% of ocean is protected (so we have reserved
99.9% for us)
 Costs $12-14 billion/year to make reserves

23. What can you do?
 Purchase only sustainably harvested
seafood (WalMart)
 Support businesses that develop and
use resources sustainably
 Ecotourism
 NO Shell shops
thanks

24. Fisheries Management
 Step 1: figure out what we have out there!
 Step 2: switch from old model - Max. sustained
yield - to new model - optimum sustained yield
(take species interactions into account)
 Step 3: don’t forget the Precautionary Principle

25. What’s actually happening
1. Comanagement - local communities
regulate coastal fishing, government
regulates offshore
2. Government subsidies - gov’t (i.e.
taxes) support fisheries to keep them
in business; encourage expansion
(uh…)

26. 3. Individual transfer rights (ITRs)
 Gov’t gives each vessel of % of the total allowable catch for
the year; companies can trade with each other
 Problems:
 Fishing co. “owns” waters, but public still responsible for
cleaning up messes
 Harder for small operations to compete
 Too many ITRs given out - so still overfishing
 Successes
 1995, Alaskan halibut, fishing season went from 2 days to 260

27. End part 1