2. Sustaining Aquatic Biodiversity
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 24

3. Key Concepts Economic and ecological importance
Effects of human activities
Protecting and sustaining aquatic diversity
Protecting and sustaining fisheries
Protecting and restoring wetlands

4. Case Study: A Biological Roller Coaster Ride in Lake Victoria
Lake Victoria has lost its endemic fish species to large introduced predatory fish.

5. A Biological Roller Coaster Ride in Lake Victoria
Reasons for Lake Victoria’s loss of biodiversity:
Introduction of Nile perch.
Loss of native cichlid species
Lake experienced algal blooms from nutrient runoff.
Invasion of water hyacinth has blocked sunlight and deprived oxygen.
Nile perch is in decline because it has eaten its own food supply.

6. AQUATIC BIODIVERSITY
We know fairly little about the biodiversity of the world’s marine and freshwater systems.
The world’s marine and freshwater systems provide important ecological and economic services.

7. The Importance of Aquatic Biodiversity
The most biologically diverse habitats include:
Coral reefs
Estuaries
Deep ocean floor
Highest near the coast
25,000 known fish species

8. The Importance of Aquatic Biodiversity: Ecological and Economic
Food Items
6% of total protein; 16% of animal protein
Many Chemicals
Cosmetics
from seaweed
Medicines and Drugs
Antibiotics and anticancer drug, adhesives, bone reconstructive materials
seaweed, sponges, mollusks, coral barnacles, and other fish

9. Human Impacts on Aquatic Biodiversity
Species loss and endangerment
Marine habitat loss and degradation
Freshwater habitat loss and degradation
Overfishing
Nonnative species
Pollution and global warming

10. Species Loss and Endangerment
Overfishing
Habitat destruction
Pollution
Freshwater species at greater risk
Mussels, crayfish, amphibians, fish

11. Marine Habitat Loss and Degradation
53% of coastal wetlands in US have disappeared
Agriculture
Coastal development
58% of world’s coral reefs are threatened
Pollution
Warmer ocean temperatures
Two-thirds of US estuaries are at risk from pollution
35% of world’s mangroves have disappeared

12. Freshwater Habitat Loss and Degradation
The world has lost more than half of its inland wetlands
Agricultural and urban development
60% of the world’s larger rivers are fragmented by dams, diversions, and canals
Flood control levees and dikes
Alter and destroy aquatic habitats
Disconnect rivers from their floodplains
Eliminate wetlands and backwaters (spawning areas)

13. Overfishing
75% of the world’s 200 commercially valuable marine fish species are overfished
Overfishing leads to commercial extinction
Depletions and extinction of species unintentionally caught as bycatch

14. Non-native Species
Deliberate or accidental introduction into coastal waters, lakes and wetlands
purple loosestrife
Asian swamp eel
zebra mussle
Displace or cause extinction of native species
68% of fish extinctions

15. Pollution and Global Warming
44% comes from runoff from developed coastal areas
Major pollution threats
Oil
Acid deposition
Plant nutrients
Toxic chemicals
Coastal development
Sediment and soil erosion
Global warming could
alter migration and feeding patterns
increase ocean temperature
raise sea levels

16. PROTECTING AND SUSTAINING MARINE BIODIVERSITY
Six of the world’s seven major turtle species are threatened or endangered because o human activities.
Figure 12-4

17. Protect endangered and threatened species
Example: Sea turtle
Turtle extrusion devices (TEDs)
Loggerhead
Olive ridley
Leatherback
Hawksbill
Green turtle
Kemp's Ridley
Black turtle
Australian
flatback

18. Turtle Extrusion Device
Shrimp trawler
Turtle Extrusion Device
Area enlarged right

19. Case Study: The Florida Manatee and Water Hyacinths
Manatee can eat unwanted Water Hyacinths.
Endangered due to:
Habitat loss.
Entanglement from fishing lines and nets.
Hit by speed boats.
Stress from cold.
Low reproductive rate

20. Case Study: Commercial Whaling
After many of the world’s whale species were over-harvested, commercial whaling was banned in 1960, but the ban may be overturned.

21. Commercial Whaling
Despite ban, Japan, Norway, and Iceland kill about 1,300 whales of certain species for “scientific purposes”.
Although meat is still sold commercially.

23. Key Concepts Economic and ecological importance
Effects of human activities
Protecting and sustaining aquatic diversity
Protecting and sustaining fisheries
Protecting and restoring wetlands

24. Protecting and Sustaining Marine Biodiversity
Identifying and protecting endangered and threatened species
Sea turtles
Turtle extrusion devices (TEDs)
National and International laws and treaties
CITES - Convention on International Trade and Endangered Species
Global Treaty on Migratory Species
US Marine Mammal Protection Act
US Endangered Species Act
US Whale Conservation and Protection Act
International Convention on Biological Diversity

25. Protecting and Sustaining Marine Biodiversity
Establish marine protected areas
Coastal nations have sovereignty over waters and seabeds up to 12 miles offshore
Jurisdiction over their Exclusive Economic Zone extends 200 miles offshore
Integrated coastal management
community based attempt to develop and use coastal resources sustainably

26. Protecting and Sustaining Marine Biodiversity
Regulating and preventing ocean pollution
Sustaining management of marine fisheries

27. Managing and Sustaining the World’s Marine Fisheries
Fishery regulation
Set, monitor, and enforce fishery catch limits below estimated MSY (maximum sustained yield)
Divide up fishing quotas
Require selective gear
Improve monitoring and enforcement
Economic approached
Reduce or eliminate subsidies
Impose fees for harvesting fish and shellfish from public managed offshore waters
Certify sustainable fisheries

28. Managing and Sustaining the World’s Marine Fisheries
Bycatch reduction
Wider mesh fish nets
Extrusion devices
Observers on boats
Multiple species licensing
Laws prohibiting throwing edible and marketable fish back to sea

29. Managing and Sustaining the World’s Marine Fisheries
Protected areas
Establish no-fishing marine areas
Protect marine habitats that are in good condition and disregard potentially hopeless cases
Strengthen commitment to marine biodiversity protection
Non-native invasions
Kill organisms in ship ballast water
Develop filters and traps
Require ships to dump ballast water beyond 200 mile limit

30. Managing and Sustaining the World’s Marine Fisheries
Consumer information
Use labeling to identify fish that have been harvested sustainably
Aquaculture
Restrict location of fish farms to reduce loss of mangrove forests
Enact and enforce stricter pollution regulations
Increase productions of herbivorous aquaculture fish species

31. Protecting, Sustaining, and Restoring Wetlands
Regulations
federal permit required
Mitigation banking
allows destruction of existing wetlands if an equal area of they same type of wetland is created or restored
Land use planning
steer agriculture and mining away from wetlands
Wetland restoration
often has limited success
Control of invasive species
purple loosestrife

32. Restoring the Florida Everglades
Natural flow of the Everglades has been diverted or disrupted.
Farmers planted vast agricultural land to sugarcane and vegetables.
Established Everglades National Park. Became the most endangered park.
Massive plumbing and land development projects cut off water flow

33. Restoring the Florida Everglades
1990 began the world’s largest ecological restoration project.
restore he curving flow of more than half of the Kissimmee River.
remove 400 km of canals and levees
create artificial marshes in previous farmland
add land adjacent to Everglades National Park
create network of artificial marshes
create 18 large reservoirs
capture much of the water flowing out to sea and return it to the Everglades

34. Protecting, Sustaining, and Restoring Wetlands

35. Protecting, Sustaining, and Restoring Lakes
Pollution
Zebra mussel
Cultural eutrophication
Water levels
Invasive species

36. Protecting, Sustaining, and Restoring Rivers
Pollution
Disruption of water flow
Loss of biodiversity
Invasive
species

37. Protecting, Sustaining, and Restoring Rivers
Disruption of water flow
119 dams,
19 hydroelectric dams
Salmon population dropped 94%
Salmon Restoration Project
upstream hatcheries
fish ladders
transport juveniles around dams
turning off turbines

38. PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERS
We can help sustain freshwater fisheries by building and protecting populations of desirable species, preventing over-fishing, and decreasing populations of less desirable species.
A federal law helps protect a tiny fraction of U.S. wild and scenic rivers from dams and other forms of development.
National Wild and Scenic Rivers Act (1968).