11-4 How Should We Protect and Sustain Wetlands?

By Joel Juver and Michael Cimino – Period 3

Concept 11-4

• To maintain the ecological and economic services of wetlands, we must maximize preservation of remaining wetlands and restoration of degraded and destroyed wetlands.

Coastal and Inland Wetlands Are Disappearing around the World

• They are important reservoirs of aquatic biodiversity that provide vital ecological and economic services. • The U.S has lost more than half of its coastal and

inland wetlands since 1900. • People have drained, filled in, or covered over swamps,

marshes, and other wetlands for centuries to create land suitable for growing crops, expanding cities, and building roads.

Wetlands Serve as Natural Filters

• The wetlands surrounding Lake Victoria, over time, have captured human and animal wastes.

• They kept the Lake and water clean enough to be used as drinking water for millions of Africans.

• Extensive draining and building on Lake Victoria's coastal wetlands led to serious water contamination that was killing fish and polluting the drinking water.

Rising Sea Levels

• Coastal wetlands in many parts of the world will probably be under water during our lifetime due to rising sea levels.• Could degrade aquatic biodiversity • May diminish other ecologoical and economic services

provided by these wetlands.

Preserving and Restoring Wetlands

• Laws have been passed to protect existing wetlands.• Zoning laws- used to steer development away from

wetlands.• Mitigation banking- allows destruction of existing

wetlands as long as an equal area of the same type of wetland is created or restored.• 2001 study showed that at least half of the attempts

to create new wetlands failed. The ones that were created did not provide the ecological functions of natural wetlands. Ecologists argue that mitigation banking should be used as a last resort.

• Case Study: page 267- Can We Restore the Everglades?

11-5 How Can We Protect and Sustain Freshwater Lakes, Rivers, and Fisheries?

Concept 11-5

• Freshwater ecosystems are strongly affected by human activities on adjacent lands, and protecting these ecosystems must include protection of their watersheds.

Freshwater Ecosystems under Major Threats

• Human activities severely threaten the ecological and economic services provided by freshwater ecosystems • HIPPCO can be used to summarize these threats

• Invasions by alien species in the Great Lakes (Zebra Mussels)• 40% of the world’s rivers have been dammed or otherwise

engineered• Vast proportions of wetlands have been destroyed

• Restoring and sustaining the biodiversity/ecological services by freshwater lakes and rivers is a complex and challenging task. (Case Study Page 269)

We Can Protect Freshwater Ecosystems by Protecting Watersheds

• Watershed- an area or ridge of land that separates waters flowing to different rivers, basins, or seas.

• Sustaining these ecosystems begins with our realizing that what we do on land and in water has some effect on these freshwater systems. • Land and water are always connected in some way. (Lakes and

streams receive many of their nutrients from the ecosystems of bordering land.)• Falling leaves • Pollutants generated by people• Animal feces

• To protect a lake or stream from excessive inputs of nutrients/pollutants, we must protect its watershed.

Protection of Marine Systems

• Freshwater ecosystems can be protected through…• Laws• Economic incentives• Restoration efforts

• Some scientists and politicians have argued for protecting all remaining free flowing rivers. • Why?

• Restoring and sustaining the ecological and economic services of rivers will most likely require taking down some dams and restoring river flows.

National Wild and Scenic Rivers Act

• Passed in 1968 by Congress• Established the protection of rivers with outstanding

scenic, recreational, geological, wildlife, historical, or cultural values.• Classified wild rivers as those that are relatively

inaccessible (except by trail) and scenic rivers as rivers of great scenic value that are free of dams, mostly undeveloped, and accessible in only a few places by roads.

Sustainable Management

• Sustainable management of freshwater fishes involves..• Supporting populations of commercial and sport fish species• Preventing such species from being overfished • Reducing or eliminating populations of harmful invasive species.

*Regulate the time and length of fishing seasons and the number and size of fish that can be taken (traditional way).*Building reservoirs and farm ponds and stocking them with fish, fertilizing nutrient poor lakes and ponds, and protecting and creating fish spawning sites.

11-6 What Should Be Our Priorities for Sustaining Biodiversity and Ecosystem Services

Concept 11-6

• Sustaining the world’s biodiversity and ecosystem services will require mapping terrestrial and aquatic biodiversity, maximizing protection of undeveloped terrestrial and aquatic areas, and carrying out ecological restoration projects worldwide.

We NEED to Establish Priorities for Protecting Biodiversity and Ecosystem

Services • Edward O. Wilson proposed the following priorities

for protecting most of the worlds remaining ecosystems and species:• Complete the mapping of the world’s terrestrial and

aquatic biodiversity so we know what we have and therefore can make conservation efforts more precise and cost-effective.• Keep intact the world’s remaining old-growth forests and

cease all logging of such forests.• Identify and preserve the world’s terrestrial and aquatic

biodiversity hotspots and areas where deteriorating ecosystem services threaten people and many other forms of life

Priorities Continued…

• Protect and restore the world’s lakes and river systems, which are the most threatened ecosystems of all.

• Carry out ecological restoration projects worldwide to heal some of the damage we have done and to increase the share of the earth’s land and water allotted to the rest of nature.

• Find ways to make conservation financially rewarding for people who live in or near terrestrial and aquatic reserves so they can become partners in the protection and sustainable use of the reserves. • Such conservation strategy would cost about $30 billion per year

according to Edward O. Wilson.