1. Sustaining Aquatic Biodiversity
Chapter 11

2. A Biological Roller Coaster Ride in Lake Victoria
Loss of biodiversity and cichlids
Nile perch: deliberately introduced
Frequent algal blooms
Nutrient runoff
Spills of untreated sewage
Less algae-eating cichlids
A Biological Roller Coaster Ride in Lake Victoria

3. Natural Capital Degradation: The Nile Perch

4. What Are the Major Threats to Aquatic Biodiversity?
Aquatic species are threatened by habitat loss, invasive species, pollution, climate change, and overexploitation, all made worse by the growth of the human population.

5. We Have Much to Learn about Aquatic Biodiversity
Greatest marine biodiversity
Coral reefs
Estuaries
Deep-ocean floor
Biodiversity is higher
Near the coast than in the open sea
In the bottom region of the ocean than the surface region, greater variety of habitats

6. Human Activities Are Destroying Habitats
Habitat loss and degradation - HIPPCO
Marine – only 4% of the world’s oceans are not affected by pollution
Coastal
Ocean floor: effect of trawlers, which drag huge nets weighted with heavy chains and steel plates, reduce coral reefs to rubble
Freshwater
Dams
Excessive water withdrawal

7. Invasive Species Are Degrading Biodiversity
Threaten native species
Disrupt and degrade whole ecosystems
Water hyacinth: Lake Victoria (East Africa)
Asian swamp eel: waterways of south Florida
Purple loosestrife: indigenous to Europe
Treating with natural predators—a weevil species and a leaf-eating beetle—
Invasive water hyacinth

8. How Carp Have Muddied Some Waters
Lake Wingra, Wisconsin (U.S.): eutrophic, excessive nutrient inputs from run off with fertilizers from farms/lawns
Contains invasive species
Purple loosestrife and the common carp, which devour the algae
Dr. Richard Lathrop
Removed carp from an area of the lake
This area appeared to recover

9. Population Growth and Pollution Can Reduce Aquatic Biodiversity
Nitrates and phosphates mainly from fertilizers enter water
Leads to algal bloom and eventual eutrophication, fish die offs
Toxic pollutants from industrial and urban areas, plastic items
Hawaiian Monk Seal

10. Climate Change Is a Growing Threat
Global warming: sea levels will rise and aquatic biodiversity is threatened – in the past 100 years , average cm and scientists estimate another cm, perhaps as high as m
Coral reefs
Swamp some low-lying islands
Drown many highly productive coastal wetlands
New Orleans, Louisiana, and New York City

11. Overfishing and Extinction
Marine and freshwater fish
Threatened with extinction by human activities more than any other group of species
Commercial extinction – industrialized fishing fleets can deplete marine life at a much faster rate. Can cause 80% in years
Collapse of the cod fishery of the coast of Newfoundland and its domino effect leading to collapse of other species
Bycatch – seals, dolphins. 34% of marine, 71% of fresh water species face extinction within your life time.

12. 900,000
800,000
700,000
600,000
500,000
Fish landings (tons)
400,000
1992
300,000
Figure 11.6
Natural capital degradation: this graph illustrates the collapse of the cod fishery in the northwest Atlantic off the Canadian coast. Beginning in the late 1950s, fishers used bottom trawlers to capture more of the stock, reflected in the sharp rise in this graph. This resulted in extreme overexploitation of the fishery, which began a steady fall throughout the 1970s, followed by a slight recovery in the 1980s and total collapse by 1992 when the site was closed to fishing. Canadian attempts to regulate fishing through a quota system had failed to stop the sharp decline. The fishery was reopened on a limited basis in 1998 but then closed indefinitely in (Data from Millennium Ecosystem Assessment)
200,000
100,000
1900
1920
1940
1960
1980
2000
Year
Fig. 11-6, p. 254

13. Protecting and Restoring Mangroves
Protect and restore mangroves
Reduce the impact of rising sea levels
Protect against tropical storms and tsunamis
Cheaper than building concrete sea walls
Mangrove forests in Indonesia

14. Industrial Fish Harvesting Methods are vacuuming the seas
Trawler fishing- shrimp, scallops
Purse-seine fishing
tuna, mackarel
Longlining – tuna, swordfish, sharks
Drift-net fishing – ban on the use of drift nets longer than 2.5 km

15. Protect and Sustain Marine Biodiversity..
We can help to sustain marine biodiversity by using laws and economic incentives to protect species, setting aside marine reserves to protect ecosystems, and using community-based integrated coastal management.

16. Legal Protection of Some Endangered and Threatened Marine Species
Why is it hard to protect marine biodiversity?
Human ecological footprint and fish print are expanding
Much of the damage in the ocean is not visible
The oceans are incorrectly viewed as an inexhaustible resource that can absorb an almost infinite amount of waste
Most of the ocean lies outside the legal jurisdiction of any country
Treaties - CITES, Marine Mammal Protection Act, Endangered Species Act, Whale Conservation and Protection Act, International Convention on Biological Diversity

17. Protecting Whales: Success Story… So Far
Cetaceans: Toothed whales and baleen whales
1946: International Whaling Commission (IWC) – set annual quotas
1970: U.S.
Stopped all commercial whaling
Banned all imports of whale products
1986: moratorium on commercial whaling
Japan ,Norway, Iceland, Russia do not support the IWC ban C

18. Norwegian Whalers Harpooning a Sperm Whale

19. Economic Incentives Can Be Used to Sustain Aquatic Biodiversity
Tourism – example : sea turtles, worth more to local communities alive than dead (WWF)
Economic rewards

20. Holding Out Hope for Marine Turtles(6 out of 7 endangered)
Carl Safina, Voyage of the Turtle
Studies of the leatherback turtle
Threats to the leatherbacks
Trawlers destroy coral reefs which is their feeding grounds
Entangled in fishing nets and lines
Pollution –discarded plastic bags
Climate change- rising sea levels will flood nesting and feeding areas
Communities protecting the turtles
Turtle Excluder Devices on shrimp boats

21. An Endangered Leatherback Turtle is Entangled in a Fishing Net

22. Marine Sanctuaries Protect Ecosystems and Species
Offshore fishing extends to 370 kilometers
Exclusive economic zones-can take certain quotas of fish
High seas-beyond legal jurisdiction of any country
Law of the Sea Treaty – world’s coastal nations have jurisdiction over 36% of the ocean surface and 90% of the world’s fish stocks
Marine Protected Areas (MPAs) – 4000 world wide, 200 in US waters

23. Ecosystem approach to sustainability
Marine
Commercial fishing
Dredging reserves
Mining and waste disposal
Core zone
No human activity allowed
Less harmful activities allowed
E.g., recreational boating and shipping
Fully protected marine reserves work fast
Fish populations double
Fish size grows
Reproduction triples
Species diversity increase by almost one-fourth

24. Protecting Marine Biodiversity: Individuals and Communities Together
Integrated Coastal Management
Community-based group to prevent further degradation of the ocean
More that 100 such groups
seek reasonable short term trade offs that can lead to long term ecological and economic benefits

25. How Should We Manage and Sustain Marine Fisheries?
Sustaining marine fisheries will require improved monitoring of fish populations, cooperative fisheries management among communities and nations, reduction of fishing subsidies, and careful consumer choices in seafood markets.

26. Estimating and Monitoring Fishery Populations Is the First Step
Maximum sustained yield (MSY): maximum number of fish that can be harvested annually without causing a population drop
Optimum sustained yield (OSY)-interactions among species
Multispecies management – of a number of interacting species
Large marine systems: using large complex computer models
Precautionary principle because of the uncertainty of all the above methods

27. Some Communities Cooperate to Regulate Fish Harvests
Community management of the fisheries – allotment and enforcement systems. Norway’s Lofoten fishery (cod)
Co management of the fisheries with the government – sets quotas for various species and divide the quotas among communities.

28. Government Subsidies Can Encourage Overfishing-$30-34 billion around the world
2007: World Trade Organization, U.S.
Proposed a ban on fishing subsidies
Reduce illegal fishing on the high seas and in coastal waters
Close ports and markets to such fishers
Check authenticity of ship flags
Prosecution of offenders

29. Some Countries Use the Marketplace to Control Overfishing
Individual transfer rights (ITRs)
Control access to fisheries
New Zealand and Iceland
Difficult to enforce
US 1995 to protect the halibut fishery
Problems with the ITR approach
transfer ownership of fisheries in publically owned waters to private owners
squeeze out small fishing companies

30. Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity
1997: Marine Stewardship Council (MSC), London – 20 nations
Certifies that fish caught using sustainable practices
Manage global fisheries more sustainably
Individuals
Organizations
Governments

31. SOLUTIONS Managing Fisheries Fishery Regulations Bycatch
Set catch limits well below the maximum sustainable yield
Use wide-meshed nets to allow escape of smaller fish
Improve monitoring and enforcement of regulations
Use net escape devices for seabirds and sea turtles
Economic Approaches
Ban throwing edible and marketable fish back into the sea
Sharply reduce or eliminate fishing subsidies
Aquaculture
Charge fees for harvesting fish and shellfish from publicly owned offshore waters
Restrict coastal locations for fish farms
Protect Areas
Control pollution more strictly
Depend more on herbivorous fish species
Certify sustainable fisheries
Figure 11.12
Ways to manage fisheries more sustainably and protect marine biodiversity and ecosystem services. Question: Which four of these solutions do you think are the most important? Why?
Establish no-fishing areas
Nonnative Invasions
Establish more marine protected areas
Kill organisms in ship ballast water
Rely more on integrated coastal management
Filter organisms from ship ballast water
Consumer Information
Label sustainably harvested fish
Dump ballast water far at sea and replace with deep- sea water
Publicize overfished and threatened species
Fig , p. 265

32. How Should We Protect and Sustain Wetlands?
To maintain the ecological and economic services of wetlands, we must maximize preservation of remaining wetlands and restoration of degraded and destroyed wetlands.

33. Coastal and Inland Wetlands Are Disappearing around the World
Highly productive wetlands
Provide natural flood and erosion control
Maintain high water quality; natural filters
Effect of rising sea levels

34. Natural Capital Restoration: Wetland Restoration in Canada

35. Can We Restore the Florida Everglades?
“River of Grass”: south Florida, U.S.
Since 1948: damaged
Drained
Diverted
Paved over
Nutrient pollution from agriculture
Invasive plant species
1947: Everglades National Park unsuccessful protection project

36. Can We Restore the Florida Everglades?
1970s: political haggling
1990: Comprehensive Everglades Restoration Plan (CERP)
Restore the curving flow of most of the Kissimmee River
Remove canals and levees in strategic locations
Flood 240 sq. km farmland to create artificial marshes

37. Can We Restore the Florida Everglades?
Comprehensive Everglades Restoration Plan (CERP) cont…
Create reservoirs and underground water storage areas
Build new canals, reservoirs and efficient pumping systems
Why isn’t this plan working?

38. The World’s Largest Restoration Project

39. Protect and Sustain Freshwater Lakes, Rivers, and Fisheries
Freshwater ecosystems are strongly affected by human activities on adjacent lands, and protecting these ecosystems must include protection of their watersheds.

40. Freshwater Ecosystems Are under Major Threats
40% of the world’s rivers have been dammed or otherwise engineered
invasive species, pollution , climate change

41. Repeated Invasions by Alien Species in the Great Lakes
Collectively, world’s largest body of freshwater
Invaded by at least 162 nonnative species
Sea lamprey
Zebra mussel
Good and bad
Quagga mussel
Asian carp
Zebra Mussels Attached to a Water Current Meter in Lake Michigan, U.S.

42. Managing River Basins Is Complex and Controversial
Columbia River: U.S. and Canada
Dam system 119 dams , 19 of which are hydroelectric power plants
Pros –electricity ; con –salmon affected
Snake River: Washington state, U.S.
Hydroelectric dams removed
Pro – salmon saved ; con – economy affected

43. Natural Capital: Ecological Services of Rivers

44. Protect Freshwater Ecosystems by Protecting Watersheds
Freshwater ecosystems protected through
Laws
Economic incentives
Restoration efforts
National Wild and Scenic Rivers Act-reestablish protection of rivers
Sustainable management of freshwater fishes

45. Priorities for Protecting Biodiversity, Ecosystem Services
2002: Edward O. Wilson
Complete the mapping of the world’s terrestrial and aquatic biodiversity
Keep old-growth forests intact; cease their logging
Identify and preserve hotspots and deteriorating ecosystem services that threaten life
Ecological restoration projects
Make conservation financially rewarding