Apes chapter 11 aquatic biodiversity
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Key Concepts
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Economic and ecological importance
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Effects of human activities
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Protecting and sustaining aquatic diversity
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Protecting and sustaining fisheries
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Protecting and restoring wetlands
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11-1 What Are the Major Threats to Aquatic Biodiversity?
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Concept 11-1 Aquatic species are threatened by habitat loss, invasive species, pollution, climate
change, and overexploitation, all made worse by the growth of the human population.
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We Have Much to Learn about
Aquatic Biodiversity
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Greatest marine biodiversity
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Coral reefs
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Estuaries
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Deep-ocean floor
Biodiversity is higher
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Near the coast than in the open sea
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In the bottom region of the ocean than the surface region
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Human Activities Are Destroying and Degrading Aquatic Habitats
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Habitat loss and degradation
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Marine
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Coastal
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Ocean floor: effect of trawlers
Freshwater
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Dams
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Excessive water withdrawal
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Invasive Species Are Degrading
Aquatic Biodiversity
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Invasive species
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Threaten native species
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Disrupt and degrade whole ecosystems
Three examples
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Water hyacinth: Lake Victoria (East Africa)
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Asian swamp eel: waterways of south Florida
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Purple loosestrife: indigenous to Europe
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Treating with natural predators—a weevil species and a leaf-eating beetle—Will
it work?
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Invasive Water Hyacinths
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Climate Change Is a Growing Threat
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Global warming: sea levels will rise and aquatic biodiversity is threatened
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Coral reefs
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Swamp some low-lying islands
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Drown many highly productive coastal wetlands
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New Orleans, Louisiana, and New York City
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Tampa?
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Aquatic Biodiversity
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Oceans cover 71% of the earth surface
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63% of the fish are marine, 50% coastal, 12% deep sea, 1% open ocean, 37% fresh water
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2003 Pew Oceans Commission recommendations:
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Pass National Oceans Act
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Double federal budget for ocean research
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Base fisheries management on preserving ecosystem not on catch limits
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Set up a network of marine preserves
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Paterns of Aquatic Biodiversity
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Coral reefs: Greatest marine diversity, followed by estuaries, deep-ocean floor
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Biodiversity is higher near coast than open ocean
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Biodiversity higher on bottom (benthic) than the surface (pelagic)
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Lowest diversity is in the middle depths of the open ocean
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The Importance of Aquatic Biodiversity
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Globally a 6% of total protein and 1/5 of our animal protein comes from marine organisms
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Algae used in cosmetics and pharmaceuticals
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Algae, sea anemones, sponges, porcupine fish, puffer fish shark livers, mollusks used for
antibiotics and anticancer drugs
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Algae and octopus is used for treating hypertension and coral for bone reconstruction
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Human Impacts on Aquatic Biodiversity
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Marine habitat loss and degradation
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½ of wetlands are lost
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¼ of coral reefs are severely destroyed; projected that by 2050 another 70% will be destroyed
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Over a 1/3 on mangrove forest swamps are gone
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Many bottom habitats are being destroyed by dredging and trawling
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Human Impacts on Aquatic Biodiversity
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Overfishing
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¾ of commercial valuable fish are overfished
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Industrial fishing can deplete a target fish population 80% in 10-15 years
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Going after big fish has caused a directional selection to smaller fish
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Up to 90% of fish catch is bycatch
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Commercial extinction
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Natural Capital Degradation: Collapse of the Cod Fishery Off the Canadian Coast
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Catching and Raising More Fish
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Fisheries: 55% from the ocean, 45% from aquaculture
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Fishing methods: Trawling, purse-seine, driftnet, longline
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Overfishing: Not enough breeding stock to maintain population numbers
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Commercial extinction: Population numbers drop so low that it is no longer profitable to
harvest
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Human Impacts on Aquatic biodiversity
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Freshwater habitat loss and degradation
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Nonnative species
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Deliberate of accidental (ballast water)
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Overpopulate with no natural predators
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Asian swamp eel (Florida)
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Purple loosestrife
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Zebra mussel
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Protecting and Sustaining Marine Biodiversity
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Protect endangered and threatened species
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International agreements
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Integrated coastal management
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Reconciliation ecology
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Sustainable management of marine fisheries
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1989 Turtle exclusion devices (TEDs)
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2004 changes in longline fishing to reduce turtle kills by 65-90%
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Protecting and Sustaining Marine Biodiversity
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International:
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1975 Convention on International Trade in Endangered Species (CITES)
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1979 Global Treaty on Migratory Species
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1995 International Convention on Biological Diversity
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U.S.
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1972 U.S. Marine Mammal Protection Act
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1976 U.S. Whale Conservation and Protection Act
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Commercial Whaling
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Estimated 1.5 million whales were killed between 1925-1975
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8 of the 11 major species reached commercial extinction
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Giant blue whale and others are close to biological extinction
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1946 International Convention for the Regulation of Whaling established International Whaling
Commission
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Commercial Whaling
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1970 U.S. bans whaling and import of whale products
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1986 IWC imposes moratorium on whaling
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Commercial whale kills drop from 42,480 in 1970 to about 1200 in 2004
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Japan, Norway, Iceland, Russia and some small tropical island countries still whale
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Marine Sanctuaries Protect Ecosystems and Species
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Offshore fishing
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Exclusive economic zones
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High seas
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Law of the Sea Treaty
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Marine Protected Areas (MPAs)
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Establishing a Global Network of Marine Reserves: An Ecosystem Approach
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Marine reserves
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Closed to
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Commercial fishing
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Dredging
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Mining and waste disposal
Core zone
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No human activity allowed
Less harmful activities allowed
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E.g., recreational boating and shipping
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Establishing a Global Network of Marine Reserves: An Ecosystem Approach
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Fully protected marine reserves work fast
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Fish populations double
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Fish size grows
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Reproduction triples
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Species diversity increase by almost one-fourth
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Estimating and Monitoring Fishery Populations Is the First Step
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Maximum sustained yield (MSY): traditional approach
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Optimum sustained yield (OSY)
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Multispecies management
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Large marine systems: using large complex computer models
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Precautionary principle
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Government Subsidies Can Encourage Overfishing
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2007: World Trade Organization, U.S.
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Proposed a ban on fishing subsidies
Reduce illegal fishing on the high seas and in coastal waters
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Close ports and markets to such fishers
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Check authenticity of ship flags
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Prosecution of offenders
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Some Countries Use the Marketplace to Control Overfishing
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Individual transfer rights (ITRs)
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Control access to fisheries
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New Zealand and Iceland
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Difficult to enforce
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Problems with the ITR approach?
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Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity
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1997: Marine Stewardship Council (MSC), London
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Supports sustainable fishing
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Certifies sustainably produced seafood
Manage global fisheries more sustainably
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Individuals
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Organizations
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Governments
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Aquaculture
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Aquiculture: The raising of fish and shellfish instead of hunting or gathering
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Fish farming: Cultivating fish in a controlled environment & harvesting them when size is right
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Ranching: Raising fish for part of their life, then releasing to harvest when they return to
spawn (salmon)
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11-4 How Should We Protect and
Sustain Wetlands?
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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.
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Coastal and Inland Wetlands Are Disappearing around the World
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Highly productive wetlands
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Provide natural flood and erosion control
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Maintain high water quality; natural filters
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Effect of rising sea levels
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We Can Preserve and Restore Wetlands
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Laws for protection
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Mitigation banking
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Ecologists argue this as a last resort
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Individuals Matter: Restoring a Wetland
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Jim Callender: 1982
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Scientific knowledge + hard work =
a restored wetland in California, U.S.
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Marsh used again by migratory fowl
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Protecting, Sustaining, and Restoring Wetlands
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Regulations
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Wetlands protection (only 8%)
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Mitigation banking (scam)
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Wetlands restoration
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Control of invasive species
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Case Study: Can We Restore the Florida Everglades?
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“River of Grass”: south Florida, U.S.
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Since 1948: damaged
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Drained
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Diverted
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Paved over
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Nutrient pollution from agriculture
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Invasive plant species
1947: Everglades National Park unsuccessful protection project
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Case Study: Can We Restore the Florida Everglades?
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1970s: political haggling
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1990: Comprehensive Everglades Restoration Plan (CERP)
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Restore the curving flow of most of the Kissimmee River
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Remove canals and levees in strategic locations
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Flood 240 sq. km farmland to create artificial marshes
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Goal?
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Case Study: Can We Restore the Florida Everglades?
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Comprehensive Everglades Restoration Plan (CERP) cont…
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Create reservoirs and underground water storage areas
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Build new canals, reservoirs and efficient pumping systems
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Why isn’t this plan working?
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11-5 How Can Protect and Sustain Freshwater Lakes, Rivers, and Fisheries?
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Concept 11-5 Freshwater ecosystems are strongly affected by human activities on adjacent
lands, and protecting these ecosystems must include protection of their watersheds.
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Freshwater Ecosystems Are under
Major Threats
Think: HIPPCO
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Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species?
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Collectively, world’s largest body of freshwater
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Invaded by at least 162 nonnative species
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Sea lamprey
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Zebra mussel
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Good and bad
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Quagga mussel
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Asian carp
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Managing River Basins Is Complex
and Controversial
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Columbia River: U.S. and Canada
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Dam system
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Pros and cons
Snake River: Washington state, U.S.
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Hydroelectric dams
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Pros and cons
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Protecting, Sustaining, and Restoring Rivers
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Pollution
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Disruption of water flow
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Loss of biodiversity
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Invasive species
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Rebuilding Salmon Populations
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Build upstream hatcheries
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Repopulating streams
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Build fish ladders
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Transport salmon around dams
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Reduce silt runoff
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Restrict dam construction
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We Can Protect Freshwater Ecosystems by Protecting Watersheds
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Freshwater ecosystems protected through
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Laws
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Economic incentives
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Restoration efforts
Wild rivers and scenic rivers
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Sustainable management of freshwater fishes
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11-6 What Are the Priorities for Sustained Biodiversity, Ecosystem Services?
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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.
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We Need to Set Priorities for Protecting Biodiversity, Ecosystem Services
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2002: Edward O. Wilson
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Complete the mapping of the world’s terrestrial and aquatic biodiversity
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Keep old-growth forests intact; cease their logging
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Identify and preserve hotspots and deteriorating ecosystem services that threaten life
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Ecological restoration projects
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Make conservation financially rewarding