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Sustaining Aquatic Biodiversity Chapter 11 Core Case Study: A Biological Roller Coaster Ride in Lake Victoria Loss of biodiversity and cichlids Nile perch: deliberately introduced in 1950s and 1960s to stimulate exports of the fish Frequent algal blooms due to Nutrient runoff Spills of untreated sewage Less algae-eating cichlids Natural Capital Degradation: The Nile Perch Nile perch population is decreasing due to reduced food supply of smaller fishes (cichlids) and being overfished. What Are the Major Threats to Aquatic Biodiversity? Aquatic species are threatened by habitat loss, invasive species, pollution, climate change, and overexploitation, all made worse by the growth of the human population. (HIPPCO) We Have Much to Learn about Aquatic Biodiversity Greatest marine biodiversity occurs in Coral reefs Estuaries Deep-sea ocean floor Biodiversity is higher Near the coasts because of great variety of producers, habitats, and nursery areas than in the open sea In the bottom region than in the surface region of the ocean due to a greater variety of habitats Human Activities are Destroying and Degrading Aquatic Habitats Habitat loss and degradation – the “H” in HIPPCO – the greatest threat to the biodiversity of oceans Marine – only 4% of the world’s oceans are NOT affected by pollution Coastal – coral reefs, mangrove forests, and coastal wetlands Ocean floor – effect of trawlers which drag huge nets weighted with heavy chains and steel plates, reduce coral reefs to rubble Freshwater Habitats Dams Excessive water withdrawal Invasive Species are Degrading Biodiversity Invasive species - the “I” in HIPPCO 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 Treating with natural predators—a weevil species and a leaf-eating beetle—Will it work? Invasive Water Hyacinth Science Focus: How Carp Have Muddied Some Waters Lake Wingra, Wisconsin (U.S.): eutrophic, excessive nutrient inputs from run off with fertilizers from farms/lawns Contains invasive species Purple loosestrife and the common carp, which devour the algae Dr. Richard Lathrop Removed carp from an area of the lake This area appeared to recover Population Growth and Pollution Can Reduce Aquatic Biodiversity The two “P’s” in HIPPCO By 2020, 80% of the world’s population will live near coasts Population growth and pollution have drastic effects on ocean systems Nitrates and phosphates mainly from fertilizers enter water Leads to algal bloom and eventual eutrophication, fish die offs Toxic pollutants from industrial and urban areas kill some forms of aquatic life by poisoning them Hawaiian Monk Seal Plastic items from ships and litter on beaches kill seabirds, mammals, and sea turtles – POLLUTION Climate Change Is a Growing Threat The “C” in HIPPCO Global Warming: sea levels will rise and aquatic biodiversity is threatened – during the past 100 years, average sea levels have risen an average of 10-20 cm and scientists estimate they will rise another 18-59 cm, and perhaps as high as 1-1.6 m between 2050 and 2100 ◦ Destroy coral reefs ◦ Swamp some low-lying islands ◦ Drown many highly productive coastal wetlands including New Orleans, Louisiana Overfishing and Extinction Overfishing – the “O” in HIPPCO Marine and Freshwater Fish Threatened with extinction by human activities more than any other group of species. Commercial Extinction – due to overfishing which occurs when it is no longer profitable to continue fishing the affected species. Industrialized fishing fleets can deplete marine life at a much faster rate. Can deplete 80% of target fish species in 10-15 years. Collapse of the cod fishery off the coast of Newfoundland and its domino effect leading to collapse of other species. Bycatch – seals, dolphins (non-target species, 1/3 of annual fish catch) Biological Extinction – 34% of marine and 71% of fresh water species face extinction within your life time. 900,000 800,000 700,000 Fish landings (tons) 600,000 500,000 400,000 1992 300,000 200,000 100,000 0 1900 1920 1940 1960 Year 1980 2000 Fig. 11-6, p. 254 Science Focus: Protecting and Restoring Mangroves Protect and restore mangroves because they provide important ecological services. Reduce the impact of rising sea levels Protect against tropical storms and tsunamis Cheaper than building concrete sea walls Due to coastal development in Indonesia, about 70% of mangroves have been degraded or destroyed. Now efforts to protect those areas. Case Study: Industrial Fish Harvesting Methods are Vacuuming the Seas Trawler fishing – fish and shellfish Purse-seine fishing – surface dwelling species like tuna, mackerel Long-lining – open ocean fish species like tuna, swordfish, sharks Drift-net fishing – 1992 ban on the use of drift nets longer than 2.5 km in international waters How Can We Protect and Sustain Marine Biodiversity? 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. 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 that can absorb an almost infinite amount of waste. Most of the ocean lies outside the legal jurisdiction of any country. Treaties - CITES, Marine Mammal Protection Act, Endangered Species Act, Whale Conservation and Protection Act, International Convention on Biological Diversity. Protecting Whales: A Success Story… So Far Cetaceans: two groups – toothed whales and baleen whales Overharvesting has driven some valuable species to almost extinction. 1946: International Whaling Commission (IWC) – set annual quotas 1970: U.S. Stopped all commercial whaling Banned all imports of whale products 1986: IWC imposed a moratorium on commercial whaling – this worked Japan ,Norway, Iceland, Russia do not support the IWC ban. Norwegian Whalers Harpooning a Sperm Whale Economic Incentives Can Be Used to Sustain Aquatic Biodiversity Tourism – example: sea turtles, worth more to local communities alive than dead (WWF); brings in almost three times more money than does the sale of turtle products such as meat, leather, and eggs. Economic Rewards Reconciliation Ecology – science of inventing, establishing, and maintaining habitats to conserve species diversity in places where people live, work, and play. Example: artificial coral reef created in Israel. Case Study: Holding Out Hope for Marine Turtles (6 of the 7 species are endangered) Carl Safina, Voyage of the Turtle ◦ Studies of the leatherback turtle Threats to the leatherbacks ◦ Trawlers destroy coral reefs which is their feeding grounds ◦ Entangled in fishing nets and lines ◦ Pollution—discarded plastic bags ◦ Climate change—rising sea levels will flood nesting and feeding areas Communities protecting the turtles Turtle Excluder Devices required on trawlers (shrimp boats) by the U.S. government An Endangered Leatherback Turtle is Entangled in a Fishing Net Marine Sanctuaries Protect Ecosystems and Species Offshore Fishing Zone – extends to 370 kilometers from its shores Exclusive Economic Zones – foreign fishing vessels can take certain quotas of fish within these zones with a government’s permission. High Seas – ocean area’s beyond the legal jurisdiction of any country. Laws and treaties pertaining to the high seas are difficult to monitor and enforce. Law of the Sea Treaty – world’s coastal nations have jurisdiction over 36% of the ocean surface and 90% of the world’s fish stocks. Marine Protected Areas (MPAs) – 4000 world wide, 200 in US waters. Most MPAs allow ecologically harmful activities like trawling, dredging, and resource extraction. Establishing a Global Network of Marine Reserves: An Ecosystem Approach to Sustainability Primary Objective – protect and sustain whole marine ecosystems for current and future generations instead of focusing primarily on protecting individual species. Marine Reserves closed to extractive activities such as Commercial fishing Dredging reserves Mining and waste disposal Core zone – No human activity allowed Less harmful activities allowed – recreational boating and shipping Fully protected marine reserves work and work fast Fish populations double Fish size grows by almost one-third Reproduction triples Species diversity increase by almost one-fourth But, less than 1% of the world’s ocean area is closed to fishing in marine reserves. Protecting Marine Biodiversity: Individuals and Communities Together Integrated Coastal Management Community-based effort to develop and use coastal resources more sustainably Community-based group to prevent further degradation of the ocean More that 100 such groups Seek reasonable short term trade offs that can lead to long term ecological and economic benefits An atoll of Australia’s Great Barrier Reef How Should We Manage and Sustain Marine Fisheries? Sustaining marine fisheries will require improved monitoring of fish populations, cooperative fisheries management among communities and nations, reduction of fishing subsidies, and careful consumer choices in seafood markets. Estimating and Monitoring Fishery Populations Is the First Step Maximum Sustained Yield (MSY)—mathematical model where the maximum number of fish that can be harvested annually without causing a population drop is calculated. Traditional approach. Optimum Sustained Yield (OSY)—takes into account interactions with other species and allows more room for error. Multispecies Management—of a number of interaction species, which accounts for competition and predator-prey interactions. Large Marine Systems—using large complex computer models. Precautionary Principle—use this method because of the uncertainty of all the above methods. Some Communities Cooperate to Regulate Fish Harvests Community Management of the Fisheries – allotment and enforcement systems. Norway’s Lofoten fishery (cod) is self-regulated with no participation by the Norwegian government. Co-management of the Fisheries with the Government – sets quotas for various species and divide the quotas among communities. Government Subsidies Can Encourage Overfishing: $30-34 Billion Around the World 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) – assigned to each fisherman – can be bought, sold, or leased like private property. Use to control access to fisheries New Zealand – 1986 and Iceland - 1990 Difficult to enforce U.S. - 1995 introduced tradable quotas to regulate Alaska’s halibut fishery Problems with the ITR approach Transfers public ownership of fisheries in publically owned waters to private fishers Squeezes out small fishing companies Fishing quotas are often set too high Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity 1997: Marine Stewardship Council (MSC), London – operates in more than 20 nations Support sustainable fishing and certifies that fish are caught using sustainable practices. Manage global fisheries more sustainably. Individuals Organizations Governments SOLUTIONS Managing Fisheries Fishery Regulations Bycatch Set catch limits well below the maximum sustainable yield Use wide-meshed nets to allow escape of smaller fish Improve monitoring and enforcement of regulations Use net escape devices for seabirds and sea turtles Ban throwing edible and marketable fish back into the sea Economic Approaches Sharply reduce or eliminate fishing subsidies Charge fees for harvesting fish and shellfish from publicly owned offshore waters Protect Areas Certify sustainable fisheries Establish no-fishing areas Establish more marine protected areas Rely more on integrated coastal management Consumer Information Label sustainably harvested fish Publicize overfished and threatened species Aquaculture Restrict coastal locations for fish farms Control pollution more strictly Depend more on herbivorous fish species Nonnative Invasions Kill organisms in ship ballast water Filter organisms from ship ballast water Dump ballast water far at sea and replace with deep- sea water Fig. 11-12, p. 265 How Should We Protect and Sustain Wetlands? 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 U.S. has lost more than half of its coastal and inland wetlands since 1900. Ecological Value: Highly productive wetlands Provide natural flood and erosion control Maintain high water quality; natural filters Effected by rising sea levels due to global warming which will degrade aquatic biodiversity We Can Preserve and Restore Wetlands Laws for protection Mitigation Banking Allows destruction of existing wetlands as long as an equal area of the same type of wetland is created or restored. Ecologists argue this should be used only as a last resort. Individuals Matter: Restoring a Wetland Jim Callender: 1982 Scientific knowledge + hard work = a restored wetland in California, U.S. Marsh used again by migratory fowl Natural Capital Restoration: Wetland Restoration in Canada Case Study: Can We Restore the Florida Everglades? “River of Grass”: South Florida, U.S. Since 1948: damages Drained Diverted Paved over Nutrient pollution from agriculture Invasive plant species 1947: Everglades National Park unsuccessful protection project Can We Restore the Florida Everglades? 1970s: political haggling for 20 years 1990: Comprehensive Everglades Restoration Plan (CERP) Restore the curving flow of most of the Kissimmee River Remove canals and levees in strategic locations Flood 240 sq. km farmland to create artificial marshes Can We Restore the Florida Everglades? Comprehensive Everglades Restoration Plan (CERP) cont… Create reservoirs and underground water storage areas Build new canals, reservoirs and efficient pumping systems Why isn’t this plan working? Cannot undue 120 years of ecological damage done by agriculture and urban development Will take at least 50 years and too expensive The World’s Largest Restoration Project How Can We Protect and Sustain Freshwater Lakes, Rivers, and Fisheries? Freshwater ecosystems are strongly affected by human activities on adjacent lands, and protecting these ecosystems must include protection of their watersheds. Freshwater Ecosystems are Under Major Threats HIPPCO – major threats 40% of the world’s rivers have been dammed or otherwise engineered. Invasive species, pollution, climate change 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 Good and bad Quagga mussel Asian carp Zebra Mussels Attached to a Water Current Meter in Lake Michigan, U.S. Managing River Basins is Complex and Controversial Columbia River: U.S. and Canada Dam System: 119 dams, 19 of which are hydroelectric power plants. Pro–electricity; Con–salmon affected Snake River: Washington State, U.S. Hydroelectric dams removed Pro–salmon saved ; Con–economy affected Natural Capital: Ecological Services of Rivers We Can Protect Freshwater Ecosystems by Protecting Watersheds Freshwater ecosystems protected through Laws Economic Incentives Restoration Efforts National Wild and Scenic Rivers Act—passed in 1968 to protect rivers and river segments with outstanding scenic, recreational, geological, wildlife, historical, or cultural values. Sustainable management of freshwater fishes involves encouraging populations of commercial/sport species, prevents overfishing, and reduces or eliminates less desirable fish populations. What Should Be Our Priorities for Sustaining Biodiversity and Ecosystem Services? 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. What Should Be Our Priorities for Sustaining Biodiversity and 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.
