1. Chapter 11: Sustaining Aquatic Biodiversity
The coastal zone may be the single most important portion of our planet. The loss of biodiversity may have repercussions far beyond our worst fears. – G. Carelton Ray

2. Case Study: Invaders Have Ravaged Lake Victoria
Loss of biodiversity and cichlids
Nile perch: deliberately introduced
Frequent algal blooms
Nutrient runoff
Spills of untreated sewage
Less algae-eating cichlids
Water hyacinths: supported by nutrient runoff

3. Natural Capital Degradation: The Nile Perch In Lake Victoria
Figure 11.4: Natural capital degradation.
The Nile perch (right) is a fine food fish that can weigh more than 91 kilograms (200 pounds). However, this deliberately introduced fish has played a key role in a major loss of biodiversity in East Africa’s Lake Victoria (left).
Fig. 11-4a, p. 254

4. Water Hyacinths in Lake Victoria
Figure 11.5: Invasive water hyacinths, supported by nutrient runoff, blocked a ferry terminal on the Kenyan shores of Lake Victoria in By blocking sunlight and consuming oxygen, this invasion has reduced biodiversity in the lake. Scientists reduced the problem at strategic locations by removing the hyacinth and by introducing two weevils (a type of beetle) that feed on the invasive plant.
Fig. 11-5, p. 255

5. 11-1 What Are the Major Threats to Aquatic Biodiversity?
Concept Aquatic species are threatened by habitat loss, invasive species, pollution, climate change, and overexploitation, all made worse by the growth of the human population.

6. 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

7. Natural Capital: Marine Ecosystems
Figure 8.5: Marine systems provide a number of important ecological and economic services (Concept 8-2). Questions: Which two ecological services and which two economic services do you think are the most important? Why?
Fig. 8-5, p. 172

8. Natural Capital: Freshwater Systems
Figure 8.15: Freshwater systems provide many important ecological and economic services (Concept 8-4). Questions: Which two ecological services and which two economic services do you think are the most important? Why?
Fig. 8-15, p. 181

9. Human Activities Are Destroying and Degrading Aquatic Habitats
The greatest threats to the biodiversity of the marine and freshwater ecosystems: HIPPCO
Marine
Coral reefs
Mangrove forests
Seagrass beds
Sea-level rise from global warming will harm coral reefs and low-lying islands with mangrove forests
Ocean floor: effect of trawlers
Freshwater
Dams
Excessive water withdrawal

10. Natural Capital Degradation: Area of Ocean Bottom Before and After a Trawler
Figure 11.2: Natural capital degradation.
These photos show an area of ocean bottom before (left) and after (right) a trawler net scraped it like a gigantic bulldozer. These ocean-floor communities could take decades or centuries to recover. According to marine scientist Elliot Norse, “Bottom trawling is probably the largest human-caused disturbance to the biosphere.” Trawler fishers disagree and claim that ocean bottom life recovers after trawling. Question: What land activities are comparable to this?
Fig. 11-2, p. 252

11. Invasive Species Are Degrading Aquatic Biodiversity
Threaten native species
Disrupt and degrade whole ecosystems
Examples
Asian swamp eel: waterways of south Florida
Purple loosestrife: wetlands in parts of Europe
Water hyacinth (Lake Victoria)

12. Science Focus: How Carp Have Muddied Some Waters
Lake Wingra, Wisconsin (U.S.): eutrophic
Contains invasive species
Purple loosestrife and the common carp
 eat algae which stabilize sediment
 fish movements & wind cause turbidity
Dr. Richard Lathrop
Removed carp from an area of the lake
This area appeared to recover
 native plants receive more sunlight

13. Lake Wingra in Madison, Wisconsin
Figure 11.A: Lake Wingra in Madison, Wisconsin (USA) has become clouded with sediment partly because of the introduction of invasive species such as the common carp. Removal of carp in the experimental area shown here resulted in a dramatic improvement in the clarity of the water and subsequent regrowth of native plant species in shallow water.
Fig. 11-A, p. 255

14. Population Growth and Pollution Can Reduce Aquatic Biodiversity
Nitrates and phosphates, mainly from fertilizers, enter water
Leads to eutrophication
Toxic pollutants from industrial and urban areas
Plastics

15. Hawaiian Monk Seal
Figure 11.6: This Hawaiian monk seal was slowly starving to death before a discarded piece of plastic was removed from its snout. Each year, plastic items dumped from ships and garbage barges, and left as litter on beaches threaten the lives of millions of marine mammals, turtles, and seabirds that ingest, become entangled in, or are poisoned by such debris.
Fig. 11-6, p. 256

16. Climate Change Is a Growing Threat
Global warming: sea levels will rise and aquatic biodiversity is threatened
Coral reefs
Swamp some low-lying islands
Drown many highly productive coastal wetlands
New Orleans, Louisiana, and New York City

17. Overfishing and Extinction: Gone Fishing, Fish Gone (1)
Fishery: concentration of a particular wild aquatic species suitable for commercial harvesting in a specific area
Fishprint: area of ocean needed to sustain the fish consumption of a person, country, or the world
All nation together are overfishing the world´s global oceans by an unsustainable 157%
Marine and freshwater fish
Threatened with extinction by human activities more than any other group of species

19. Overfishing and Extinction: Gone Fishing, Fish Gone (2)
Commercial extinction: no longer economically feasible to harvest a species.
Recovery times for severely depleted populations are increasing (industrialized fishing fleets): can take 2 decades or more.
Collapse of the Canada Atlantic cod fishery and its domino effect (sharks-rays and skates-bay scallops)
Fewer larger fish
Bycatch (non target species): Almost one-third of the world´s annual fish catch by weight.
More problems with invasive species

20. Overfishing and Extinction: Gone Fishing, Fish Gone (3)
Fish species are also threatened with biological extinction, mostly from overfishing, water pollution, wetlands destruction, and excessive removal of water from rivers and lakes.
34% of the world´s known marine fish species and 71% of the world´s freshwater fish species face extinction within your life time.

21. Natural Capital Degradation: Collapse of the Cod Fishery Off the Canadian Coast
Figure 11.7: Natural capital degradation.
This graph illustrates the collapse of Canada’s 500-year-old Atlantic cod fishery off the coast of Newfoundland in the northwest Atlantic. 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 decline throughout the 1970s, followed by a slight recovery in the 1980s, and then total collapse by 1992, when the fishery was shut down. Despite a total ban on fishing, the cod population has not recovered. The fishery was reopened on a limited basis in 1998 but then closed indefinitely in 2003 and today shows no signs of recovery. (Data from Millennium Ecosystem Assessment)
Fig. 11-7, p. 257

22. Case Study: Industrial Fish Harvesting Methods
Trawler fishing
Purse-seine fishing
Longlining
Drift-net fishing
Bycatch problem
Figure 11.8: This diagram illustrates several major commercial fishing methods used to harvest various marine species (along with methods used to raise fish through aquaculture). These fishing methods have become so effective that many fish species have become commercially extinct.

23. 11-2 How Can We Protect and Sustain Marine Biodiversity?
Concept 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.

24. Legal Protection of Some Endangered and Threatened Marine Species (1)
Why is it hard to protect marine biodiversity?
Human ecological footprint and fishprint are expanding
Much of the damage in the ocean is not visible
The oceans are incorrectly viewed as an inexhaustible resource that can absorb waste and pollution
Most of the ocean lies outside the legal jurisdiction of any country. Thus, it is an open-access resource, subject to overexploitation.

25. Legal Protection of Some Endangered and Threatened Marine Species (2)
1975 Convention on International Trade in Endangered Species
1979 Global Treaty on Migratory Species
U.S. Marine Mammal Protection Act of 1972
U.S. Endangered Species Act of 1973
U.S. Whale Conservation and Protection Act of 1976
1995 International Convention on Biological Diversity

26. Case Study: Protecting Whales: A Success Story… So Far (1)
Cetaceans: Toothed whales and baleen whales
8 of 11 major species hunted to commercial extinction by 1975
1946: International Whaling Commission (IWC)
Quotas based on insufficient data
Quotas often ignored
Figure 11.1: Cetaceans are classified as either toothed whales or baleen whales.

27. Case Study: Protecting Whales: A Success Story… So Far (2)
1970: U.S.
Stopped all commercial whaling
Banned all imports of whale products
1986: IWC moratorium on commercial whaling
42,480 whales killed in 1970
1500 killed in 2009
Norway, Japan, and Iceland ignore moratorium

28. Economic Incentives Can Be Used to Sustain Aquatic Biodiversity
Tourism
Sea turtles
Whales
Economic rewards
Animals worth more to local communities alive than dead.
Education can inspire protection

29. Case Study: Holding Out Hope for Marine Turtles
Threats to the leatherback turtle
Trawlers and drowning in fishing nets
Hunting
Eggs used as food
Pollution
Climate change
Fishing boats using turtle excluder devices
Communities protecting the turtles

30. Sea Turtle Species
Figure 11.9: Several major species of sea turtles have roamed the sea for 150 million years. The hawksbill, Kemp’s ridley, and leatherback turtles are critically endangered. Flatbacks live along the coasts of northern Australia and Papua, New Guinea, and are not classified as endangered because they nest in very remote places, but the Australian government classifies them as vulnerable. The loggerhead, green, and olive ridley are classified as endangered. See the photo of an endangered green sea turtle on the title page.
Fig. 11-9, p. 262

31. An Endangered Leatherback Turtle is Entangled in a Fishing Net
Figure 11.10: This endangered leatherback sea turtle was entangled in a fishing net and could have starved to death had it not been rescued.
Fig , p. 262

32. Marine Sanctuaries Protect Ecosystems and Species
Offshore fishing
Exclusive economic zones for countries
200 nautical miles (370 km)
High seas (ocean areas beyond the legal jurisdiction of any country) governed by treaties that are hard to enforce
Law of the Sea Treaty
Marine Protected Areas (MPAs) : areas of ocean partially protected from human activities. But most are only partially protected from human activities.

33. Establishing a Global Network of Marine Reserves: An Ecosystem Approach (1)
The primary objective is to protect and sustain whole marine ecosystems instead of focusing on protecting individual species.
Marine reserves
Closed to
Commercial fishing
Dredging
Mining and waste disposal
Core zone
No human activity allowed
Less harmful activities allowed
E.g., recreational boating and shipping

34. Establishing a Global Network of Marine Reserves: An Ecosystem Approach (2)
Fully protected marine reserves work fast (2-4 years after restriction)
Fish populations double
Fish size grows
Reproduction triples
Species diversity increase by almost one-fourth
Benefit nearby fisheries.
Cover less than 1% of world’s oceans
Marine scientists want 30-50%

35. Establishing a Global Network of Marine Reserves: An Ecosystem Approach (3)
Scientists urge connecting the global network of marine reserves, especially those in coastal waters, with protected corridors.
This would also help species to move to different habitats in the process of adapting to the effects of ocean warming, acidification, and many forms of ocean pollution.
Cost: $12-14 billion a year= amount currently spent by governments on subsidies for the fishing industry.

36. Protecting Marine Biodiversity: Individuals and Communities Together (1)
Oceans 30% more acidic from increased carbon dioxide in atmosphere
Major impact on coral reefs and other marine organisms that build shells and skeletal structures out of calcium carbonate, which can dissolve ate certain acidity levels.

37. Protecting Marine Biodiversity: Individuals and Communities Together (2)
Communities must monitor and regulate fishing and coastal land development and prevent pollution from land-based activities.
People should buy only sustainably harvested seafood.
Coastal residents must think about chemicals for their lawns.

38. Integrated Coastal Management
Integrated coastal management (a community-based effort to develop and use coastal resources more sustainably).
The aim of such programs is for fishers, business owners, developers, scientists, citizens, and politicians to identify shared problems and goals in their use of marine resources to preserve biodiversity and environmental quality while also meeting various economic and social goals.

39. 11-3 How Should We Manage and Sustain Marine Fisheries?
Concept Sustaining marine fisheries will require improved monitoring of fish and shellfish populations, cooperative fisheries management among communities and nations, reduction of fishing subsidies, and careful consumer choices in seafood markets.

40. Estimating and Monitoring Fishery Populations Is the First Step
Maximum sustained yield (MSY): traditional approach. Difficulty in estimating the populations and growth rates of fish stocks, and can affect other species.
Optimum sustained yield (OSY). Takes into account interactions among species.
Multispecies management: takes into account their competitive and predator-prey interactions.
Large marine systems: using large complex computer models
Precautionary principle

41. Some Communities Cooperate to Regulate Fish Harvests
Community management of the fisheries. Ex. Norway´s Lofoten fishery (world´s largest cod fishery). Cooperation can work.
Co-management of the fisheries with the government
Government sets quotas for species and divides the quotas among communities
Limits fishing seasons
Regulates fishing gear

42. Government Subsidies Can Encourage Overfishing
Governments spend billion dollars per year subsidizing fishing
Often leads to overfishing
Discourages long-term sustainability of fish populations

43. Some countries use the marketplace to control overfishing
Individual transfer rights (ITRs) to control access to fisheries.
Government gives each fishing vessel owner a specific percentage of the total allowable catch (TAC) for a fishery in a given year. Owners can sell, byt or lease their fishing rights.
Critics identified 3 problems:
The public is responsable for the costs of enforcing and managing the system even for private comercial fishers.
The ITR system can squeeze out small fishing companies that do not have enough capital to buy ITR and can promote illegal fishing by them.
TAC’s are often set too high to prevent overfishing.

44. Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity
Need labels to inform consumers how and where fish was caught
1999: Marine Stewardship Council (MSC)
Certifies sustainably produced seafood
Walmart in 2006 pledged to sell only MSC-certified wild-caught fresh and frozen fish in North America within 3-5 years.

45. Solutions: Managing Fisheries
Figure 11.11: There are a number of ways to manage fisheries more sustainably and protect marine biodiversity. Questions: Which four of these solutions do you think are the most important? Why?
Fig , p. 267

46. 11-4 How Should We Protect and Sustain Wetlands?
Concept To maintain the ecological and economic services of wetlands, we must maximize preservation of remaining wetlands and restoration of degraded and destroyed wetlands.

47. 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

48. Coastal and Inland Wetlands Are Disappearing around the World
Wetlands have been destroyed to:
Create rice fields.
Expand cities.
Build roads.
Extract minerals, oil and gas natural
Reduce diseases such as malaria.

49. We Can Preserve and Restore Wetlands
Laws for protection
Zoning laws steer development away from wetlands
In U.S., need federal permit to fill wetlands greater than 3 acres
Mitigation banking
Can destroy wetland if create one of equal area
Ecologists argue this as a last resort

50. Human-Created Wetland in Florida
Figure 11.12: This human-created wetland is located near Orlando, Florida (USA).
Fig , p. 268

51. Case Study: Can We Restore the Florida Everglades? (1)
“River of Grass”: south Florida, U.S.
Damage in the 20th century
Drained
Diverted
Paved over
Nutrient pollution from agriculture
Invasive plant species
1947: Everglades National Park unsuccessful protection project

52. Case Study: Can We Restore the Florida Everglades? (2)
1990: Comprehensive Everglades Restoration Plan (CERP)
Restore curving flow of ½ of Kissimmee River
Remove canals and levees in strategic locations
Flood farmland to create artificial marshes
Create 18 reservoirs to create water supply for lower Everglades and humans
Recapture Everglades water flowing to sea and return it to Everglades
Already weakened by Florida legislature

53. The World’s Largest Restoration Project
Figure 11.13: The world’s largest ecological restoration project is an attempt to undo and redo an engineering project that has been destroying Florida’s Everglades (USA, see photo) and threatening water supplies for south Florida’s rapidly growing population.
Fig , p. 269

54. 11-5 How Should We Protect and Sustain Freshwater Lakes, Rivers, and Fisheries?
Concept Freshwater ecosystems are strongly affected by human activities on adjacent lands, and protecting these ecosystems must include protection of their watersheds.

55. Freshwater Ecosystems Are under Major Threats
Think: HIPPCO
40% of world’s rivers are dammed
Many freshwater wetlands destroyed
Invasive species
Threatened species
Overfishing
Human population pressures

56. Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?
Collectively, world’s largest body of freshwater
Invaded by at least 162 nonnative species
Sea lamprey
Zebra mussel
Quagga mussel
Asian carp

57. Zebra Mussels Attached to a Water Current Meter in Lake Michigan
Figure 11.14: These zebra mussels are attached to a water current meter in Lake Michigan. This invader entered the Great Lakes through ballast water dumped from a European ship. It has become a major nuisance and a threat to commerce as well as to biodiversity in the Great Lakes.
Fig , p. 271

58. Asian Carp from Lake Michigan
Figure 11.15: According to U.S. Environmental Protection Agency, two species of Asian carp were close to invading Lake Michigan in If they become established in Lake Michigan, they are likely to spread rapidly and disrupt the food web that supports the lakes’ native fish populations. Eventually, they could become the dominant fish species in the interconnected Great Lakes.
Fig , p. 271

59. Managing River Basins Is Complex and Controversial
Columbia River: U.S. and Canada
Snake River: Washington state, U.S.
Dams
Provide hydroelectric power
Provide irrigation water
Hurt salmon

60. Natural Capital: Ecological Services of Rivers
Figure 11.16: Rivers provide some important ecological services. Currently, the services are given little or no monetary value when the costs and benefits of dam and reservoir projects are assessed. According to environmental economists, attaching even crudely estimated monetary values to these ecosystem services would help to sustain them. Questions: Which two of these services do you believe are the most important? Why?
Fig , p. 272

61. We Can Protect Freshwater Ecosystems by Protecting Watersheds
Freshwater ecosystems protected through
Laws
Economic incentives
Restoration efforts
Wild rivers and scenic rivers
1968 National Wild and Scenic Rivers Act to establish protection of rivers with outstanding scenic, recreational, geological, wildlife, historical, or cultural values.
Just 2% of U.S. rivers are kept and protects only 0.2% of the country´s total river length.

62. 11-6 What Are the Priorities for Sustained Biodiversity, Ecosystem Services?
Concept Sustaining the world’s biodiversity and economic services will require mapping terrestrial an aquatic biodiversity, maximizing protection of undeveloped terrestrial and aquatic areas, and carrying out ecological restoration projects worldwide.

63. We Need to Establish Priorities for Protecting Biodiversity and Ecosystem Services
Edward O. Wilson
Complete the mapping of the world’s aquatic biodiversity
Keep intact the world´s remaining old-growth forests.
Identify and preserve aquatic diversity hotspots
Create large and fully protected marine reserves
Protect and restore the world’s lakes and rivers
Ecological restoration projects worldwide
Make conservation financially rewarding

64. Three Big Ideas
The world’s aquatic systems provide important ecological and economic services, and scientific investigation of these poorly understood ecosystems could lead to immense ecological and economic benefits.
Aquatic ecosystems and fisheries are being severely degraded by human activities that lead to aquatic habitat disruption and loss of biodiversity.

65. Three Big Ideas
We can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.