Natural Capital Degradation: The Nile Perch

Core Case Study: 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

Sustaining Aquatic Biodiversity

Chapter 11

We Have Much to Learn about Aquatic Biodiversity

• Greatest marine biodiversity– Coral reefs– Estuaries – Continental shelf

• Biodiversity is higher– Near the coast than in the open sea – In the bottom region of the ocean than the surface region

Why?

Don’t Forget!

Natural Capital

HIPPCO

Human Activities Are Destroying and Degrading Aquatic Habitats

• Habitat loss and degradation– Marine • Coastal• Ocean floor: effect of trawlers

– Freshwater• Dams• Excessive water withdrawal

Natural Capital Degradation: Area of Ocean Bottom Before and After a Trawler

Invasive Species Are Degrading Aquatic Biodiversity

• Invasive species – Threaten native species– Disrupt and degrade whole ecosystems

• Three examples– Water hyacinth: Lake Victoria (East Africa)– Asian swamp eel: waterways of south Florida – Purple loosestrife: indigenous to Europe

Invasive Water Hyacinths

Science Focus: How Carp Have Muddied Some Waters

• Lake Wingra, Wisconsin (U.S.): eutrophic– Contains invasive species• Purple loosestrife and the common carp

• Dr. Richard Lathrop– Removed carp from an area of the lake• This area appeared to recover

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

biomagnification

Hawaiian Monk Seal

Plastics

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

Warming seas . . . Rising seas . . . Acidic seas

Overfishing and Extinction: Gone Fishing, Fish Gone

• Marine and freshwater fish – Threatened with extinction by human activities

more than any other group of species• Commercial extinction• Collapse of the cod fishery and its domino

effect

Natural Capital Degradation: Collapse of the Cod Fishery Off the Canadian Coast

Watery Wasteland

http://s.ngeo.com/wpf/media-live/photos/000/001/cache/dead-fish-tossed_131_600x450.jpg

•Bycatch

Case Study: Industrial Fish Harvesting Methods

• Trawler fishing

• Purse-seine fishing

• Longlining

• Drift-net fishing

Fishprint

Sea Around Us Project

Legal Protection of Some Endangered and Threatened Marine Species

• 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– Most of the ocean lies outside the legal jurisdiction of any

country

• Regulatory Approach – CITES, US Marine Mammal Protection Act, US ESA, 1995 International Convention on Biodiverstiy (CBD)

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Solutions

Case Study: Protecting Whales: A Success Story… So Far

• Cetaceans: Toothed whales and baleen whales• 1946: International Whaling Commission (IWC)• 1970: U.S. – Stopped all commercial whaling– Banned all imports of whale products

• 1986: moratorium on commercial whaling– Pros– Cons

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Fig. 11-8b, p. 258

Norwegian Whalers Harpooning a Sperm Whale

Economic Incentives Can Be Used to Sustain Aquatic Biodiversity

• Tourism

• Economic rewards– Reconciliation ecology- See Red Sea Star Restaurant

Ex: Reuven Yosef, Red Sea Star RestaurantCoral reef restoration

Case Study: Holding Out Hope for Marine Turtles

• Carl Safina, Voyage of the Turtle– Studies of the leatherback turtle

• Threats to the leatherbacks– Trawlers– Pollution– Climate change

• Communities protecting the turtles

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Marine Sanctuaries Protect Ecosystems and Species

• Offshore fishing– Exclusive economic zones – High seas

• Law of the Sea TreatyLOST

• Marine Protected Areas (MPAs)

Establishing a Global Network of Marine Reserves: An Ecosystem Approach

• 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

• Fully protected marine reserves work fast– Fish populations double– Fish size grows– Reproduction triples– Species diversity increase by almost one-fourth

Other Side

Protecting Marine Biodiversity: Individuals and Communities Together

• Integrated Coastal Management – Community-based group to prevent further degradation of

the oceanfishers, business owners,developers, scientists, citizens, politicians

Estimating and Monitoring Fishery Populations Is the First Step

• Maximum sustained yield (MSY): traditional approach

• Optimum sustained yield (OSY)

• Precautionary principle

Some Communities Cooperate to Regulate Fish Harvests

• Community management of the fisheries

• Lofoten Fishery - Norway

• Comanagement of the fisheries with the government

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Government Subsidies Can Encourage Overfishing

• 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

Some Countries Use the Marketplace to Control Overfishing

• Individual transfer rights (ITRs) – Control access to fisheries • New Zealand and Iceland• Difficult to enforce

• Problems with the ITR approach

(% of TAC)

Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity

• 1997: Marine Stewardship Council (MSC), London– Supports sustainable fishing– Certifies sustainably produced seafood

• Manage global fisheries more sustainably– Individuals– Organizations– Governments

Marine Stewardship Council

Solutions: Managing Fisheries

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

BOLSA CHICA

Bolsa Chica Land Trust

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We Can Preserve and Restore Wetlands

• Laws for protection

• Mitigation banking– Ecologists argue this as a last resortSkip

We Need to Set 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