Presentation on theme: "Chapter 11: Sustaining Aquatic Biodiversity"— Presentation transcript:
1 Chapter 11: Sustaining Aquatic Biodiversity The coastal zone may be the single most important portion of our planet. The loss of biodiversity may have repercussions far beyond our worst fears. – G. Carelton Ray
2 Case Study: Protecting Whales: A Success Story… So Far (1) Cetaceans: Toothed whales and baleen whales8 of 11 major species hunted to commercial extinction by 19751946: International Whaling Commission (IWC)Quotas based on insufficient dataQuotas often ignoredFigure 11.1: Cetaceans are classified as either toothed whales or baleen whales.
3 Case Study: Protecting Whales: A Success Story… So Far (2) 1970: U.S.Stopped all commercial whalingBanned all imports of whale products1986: IWC moratorium on commercial whaling42,480 whales killed in 19701500 killed in 2009Norway, Japan, and Iceland ignore moratorium
4 11-1 What Are the Major Threats to Aquatic Biodiversity? Concept Aquatic species are threatened by habitat loss, invasive species, pollution, climate change, and overexploitation, all made worse by the growth of the human population.
5 We Have Much to Learn about Aquatic Biodiversity Greatest marine biodiversityCoral reefsEstuariesDeep-ocean floorBiodiversity is higherNear the coast than in the open seaIn the bottom region of the ocean than the surface region
6 Natural Capital: Marine Ecosystems Figure 8.5: Marine systems provide a number of important ecological and economic services (Concept 8-2). Questions: Which two ecological services and which two economic services do you think are the most important? Why?Fig. 8-5, p. 172
7 Natural Capital: Freshwater Systems Figure 8.15: Freshwater systems provide many important ecological and economic services (Concept 8-4). Questions: Which two ecological services and which two economic services do you think are the most important? Why?Fig. 8-15, p. 181
8 Human Activities Are Destroying and Degrading Aquatic Habitats MarineCoral reefsMangrove forestsSeagrass bedsSea-level rise from global warming will harm coral reefs and low-lying islands with mangrove forestsOcean floor: effect of trawlersFreshwaterDamsExcessive water withdrawal
9 Natural Capital Degradation: Area of Ocean Bottom Before and After a Trawler Figure 11.2: Natural capital degradation.These photos show an area of ocean bottom before (left) and after (right) a trawler net scraped it like a gigantic bulldozer. These ocean-floor communities could take decades or centuries to recover. According to marine scientist Elliot Norse, “Bottom trawling is probably the largest human-caused disturbance to the biosphere.” Trawler fishers disagree and claim that ocean bottom life recovers after trawling. Question: What land activities are comparable to this?Fig. 11-2, p. 252
10 Invasive Species Are Degrading Aquatic Biodiversity Threaten native speciesDisrupt and degrade whole ecosystemsTwo examplesAsian swamp eel: waterways of south FloridaLionfish in the Atlantic
11 Invasive LionfishFigure 11.3: One scientist has described this common lionfish as “an almost perfectly designed invasive species.” It reaches sexual maturity rapidly, has large numbers of offspring, and is protected by venomous spines. In the eastern coastal waters of North America, it has few if any predators, except perhaps for people. It is hoped that commercial fishers can find ways to capture lionfish economically and that consumers will choose them from seafood menus.Fig. 11-3, p. 254
12 Science Focus: How Carp Have Muddied Some Waters Lake Wingra, Wisconsin (U.S.): eutrophicContains invasive speciesPurple loosestrife and the common carp eat algae which stabilize sediment fish movements & wind cause turbidityDr. Richard LathropRemoved carp from an area of the lakeThis area appeared to recover native plants receive more sunlight
13 Lake Wingra in Madison, Wisconsin Figure 11.A: Lake Wingra in Madison, Wisconsin (USA) has become clouded with sediment partly because of the introduction of invasive species such as the common carp. Removal of carp in the experimental area shown here resulted in a dramatic improvement in the clarity of the water and subsequent regrowth of native plant species in shallow water.Fig. 11-A, p. 255
14 Case Study: Invaders Have Ravaged Lake Victoria Loss of biodiversity and cichlidsNile perch: deliberately introducedFrequent algal bloomsNutrient runoffSpills of untreated sewageLess algae-eating cichlidsWater hyacinths: supported by nutrient runoff
15 Natural Capital Degradation: The Nile Perch In Lake Victoria Figure 11.4: Natural capital degradation.The Nile perch (right) is a fine food fish that can weigh more than 91 kilograms (200 pounds). However, this deliberately introduced fish has played a key role in a major loss of biodiversity in East Africa’s Lake Victoria (left).Fig. 11-4a, p. 254
16 Water Hyacinths in Lake Victoria Figure 11.5: Invasive water hyacinths, supported by nutrient runoff, blocked a ferry terminal on the Kenyan shores of Lake Victoria in By blocking sunlight and consuming oxygen, this invasion has reduced biodiversity in the lake. Scientists reduced the problem at strategic locations by removing the hyacinth and by introducing two weevils (a type of beetle) that feed on the invasive plant.Fig. 11-5, p. 255
17 Population Growth and Pollution Can Reduce Aquatic Biodiversity More noise and crowding from humansNitrates and phosphates, mainly from fertilizers, enter waterLeads to eutrophicationToxic pollutants from industrial and urban areasPlastics
18 Hawaiian Monk SealFigure 11.6: This Hawaiian monk seal was slowly starving to death before a discarded piece of plastic was removed from its snout. Each year, plastic items dumped from ships and garbage barges, and left as litter on beaches threaten the lives of millions of marine mammals, turtles, and seabirds that ingest, become entangled in, or are poisoned by such debris.Fig. 11-6, p. 256
19 Climate Change Is a Growing Threat Global warming: sea levels will rise and aquatic biodiversity is threatenedCoral reefsSwamp some low-lying islandsDrown many highly productive coastal wetlandsNew Orleans, Louisiana, and New York City
20 Overfishing and Extinction: Gone Fishing, Fish Gone (1) Fishery: concentration of a particular wild aquatic species suitable for commercial harvesting in a specific areaFishprint: area of ocean needed to sustain the fish consumption of a person, country, or the worldMarine and freshwater fishThreatened with extinction by human activities more than any other group of species
22 Overfishing and Extinction: Gone Fishing, Fish Gone (2) Commercial extinction: no longer economically feasible to harvest a speciesCollapse of the Atlantic cod fishery and its domino effectFewer larger fishMore problems with invasive species
23 Natural Capital Degradation: Collapse of the Cod Fishery Off the Canadian Coast Figure 11.7: Natural capital degradation.This graph illustrates the collapse of Canada’s 500-year-old Atlantic cod fishery off the coast of Newfoundland in the northwest Atlantic. Beginning in the late 1950s, fishers used bottom trawlers to capture more of the stock, reflected in the sharp rise in this graph. This resulted in extreme overexploitation of the fishery, which began a steady decline throughout the 1970s, followed by a slight recovery in the 1980s, and then total collapse by 1992, when the fishery was shut down. Despite a total ban on fishing, the cod population has not recovered. The fishery was reopened on a limited basis in 1998 but then closed indefinitely in 2003 and today shows no signs of recovery. (Data from Millennium Ecosystem Assessment)Fig. 11-7, p. 257
24 Science Focus: Clashing Scientific Views Can Lead to Cooperation and Progress Ray Hilborn disagreed Boris Worm with about the long-term prognosis for the world’s fisheriesThe two agreed to work togetherDeveloped new research methods and standardsExamined maximum sustained yieldReported findings and prognosis in 2009
25 Case Study: Industrial Fish Harvesting Methods Trawler fishingPurse-seine fishingLongliningDrift-net fishingBycatch problemFigure 11.8: This diagram illustrates several major commercial fishing methods used to harvest various marine species (along with methods used to raise fish through aquaculture). These fishing methods have become so effective that many fish species have become commercially extinct.
26 11-2 How Can We Protect and Sustain Marine Biodiversity? Concept 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.
27 Legal Protection of Some Endangered and Threatened Marine Species (1) Why is it hard to protect marine biodiversity?Human ecological footprint and fishprint are expandingMuch of the damage in the ocean is not visibleThe oceans are incorrectly viewed as an inexhaustible resourceMost of the ocean lies outside the legal jurisdiction of any country
28 Legal Protection of Some Endangered and Threatened Marine Species (2) 1975 Convention on International Trade in Endangered Species1979 Global Treaty on Migratory SpeciesU.S. Marine Mammal Protection Act of 1972U.S. Endangered Species Act of 1973U.S. Whale Conservation and Protection Act of 19761995 International Convention on Biological Diversity
29 Economic Incentives Can Be Used to Sustain Aquatic Biodiversity TourismSea turtlesWhalesEconomic rewards
30 Case Study: Holding Out Hope for Marine Turtles Threats to the leatherback turtleTrawlers and drowning in fishing netsHuntingEggs used as foodPollutionClimate changeFishing boats using turtle excluder devicesCommunities protecting the turtles
31 Sea Turtle SpeciesFigure 11.9: Several major species of sea turtles have roamed the sea for 150 million years. The hawksbill, Kemp’s ridley, and leatherback turtles are critically endangered. Flatbacks live along the coasts of northern Australia and Papua, New Guinea, and are not classified as endangered because they nest in very remote places, but the Australian government classifies them as vulnerable. The loggerhead, green, and olive ridley are classified as endangered. See the photo of an endangered green sea turtle on the title page.Fig. 11-9, p. 262
32 An Endangered Leatherback Turtle is Entangled in a Fishing Net Figure 11.10: This endangered leatherback sea turtle was entangled in a fishing net and could have starved to death had it not been rescued.Fig , p. 262
33 Marine Sanctuaries Protect Ecosystems and Species Offshore fishingExclusive economic zones for countries200 nautical milesHigh seas governed by treaties that are hard to enforceLaw of the Sea TreatyMarine Protected Areas (MPAs)
34 Establishing a Global Network of Marine Reserves: An Ecosystem Approach (1) Closed toCommercial fishingDredgingMining and waste disposalCore zoneNo human activity allowedLess harmful activities allowedE.g., recreational boating and shipping
35 Establishing a Global Network of Marine Reserves: An Ecosystem Approach (2) Fully protected marine reserves work fastFish populations doubleFish size growsReproduction triplesSpecies diversity increase by almost one-fourthCover less than 1% of world’s oceansMarine scientists want 30-50%
36 Protecting Marine Biodiversity: Individuals and Communities Together Oceans 30% more acidic from increased carbon dioxide in atmosphere and increased temperature
37 11-3 How Should We Manage and Sustain Marine Fisheries? Concept Sustaining marine fisheries will require improved monitoring of fish and shellfish populations, cooperative fisheries management among communities and nations, reduction of fishing subsidies, and careful consumer choices in seafood markets.
38 Estimating and Monitoring Fishery Populations Is the First Step Maximum sustained yield (MSY): traditional approachOptimum sustained yield (OSY)Multispecies managementLarge marine systems: using large complex computer modelsPrecautionary principle
39 Some Communities Cooperate to Regulate Fish Harvests Community management of the fisheriesCo-management of the fisheries with the governmentGovernment sets quotas for species and divides the quotas among communitiesLimits fishing seasonsRegulates fishing gear
40 Government Subsidies Can Encourage Overfishing Governments spend billion dollars per hear subsidizing fishingOften leads to overfishingDiscourages long-term sustainability of fish populations
41 Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity Need labels to inform consumers how and where fish was caught1999: Marine Stewardship Council (MSC)Certifies sustainably produced seafoodProper use of sustainable aquaculturePlant eating fish best -- Tilapia
42 Solutions: Managing Fisheries Figure 11.11: There are a number of ways to manage fisheries more sustainably and protect marine biodiversity. Questions: Which four of these solutions do you think are the most important? Why?Fig , p. 267
43 11-4 How Should We Protect and Sustain Wetlands? Concept To maintain the ecological and economic services of wetlands, we must maximize preservation of remaining wetlands and restoration of degraded and destroyed wetlands.
44 Coastal and Inland Wetlands Are Disappearing around the World Highly productive wetlandsProvide natural flood and erosion controlMaintain high water quality; natural filtersEffect of rising sea levels
45 We Can Preserve and Restore Wetlands Laws for protectionZoning laws steer development away from wetlandsIn U.S., need federal permit to fill wetlands greater than 3 acresMitigation bankingCan destroy wetland if create one of equal areaEcologists argue this as a last resort
46 Human-Created Wetland in Florida Figure 11.12: This human-created wetland is located near Orlando, Florida (USA).Fig , p. 268
47 Case Study: Can We Restore the Florida Everglades? (1) “River of Grass”: south Florida, U.S.Damage in the 20th centuryDrainedDivertedPaved overNutrient pollution from agricultureInvasive plant species1947: Everglades National Park unsuccessful protection project
48 Case Study: Can We Restore the Florida Everglades? (2) 1990: Comprehensive Everglades Restoration Plan (CERP)Restore curving flow of ½ of Kissimmee RiverRemove canals and levees in strategic locationsFlood farmland to create artificial marshesCreate 18 reservoirs to create water supply for lower Everglades and humansRecapture Everglades water flowing to sea and return it to EvergladesAlready weakened by Florida legislature
49 The World’s Largest Restoration Project Figure 11.13: The world’s largest ecological restoration project is an attempt to undo and redo an engineering project that has been destroying Florida’s Everglades (USA, see photo) and threatening water supplies for south Florida’s rapidly growing population.Fig , p. 269
50 11-5 How Should We Protect and Sustain Freshwater Lakes, Rivers, and Fisheries? Concept Freshwater ecosystems are strongly affected by human activities on adjacent lands, and protecting these ecosystems must include protection of their watersheds.
51 Freshwater Ecosystems Are under Major Threats Think: HIPPCO40% of world’s rivers are dammedMany freshwater wetlands destroyedInvasive speciesThreatened speciesOverfishingHuman population pressures
52 Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species? Collectively, world’s largest body of freshwaterInvaded by at least 162 nonnative speciesSea lampreyZebra musselQuagga musselAsian carp
53 Zebra Mussels Attached to a Water Current Meter in Lake Michigan Figure 11.14: These zebra mussels are attached to a water current meter in Lake Michigan. This invader entered the Great Lakes through ballast water dumped from a European ship. It has become a major nuisance and a threat to commerce as well as to biodiversity in the Great Lakes.Fig , p. 271
54 Asian Carp from Lake Michigan Figure 11.15: According to U.S. Environmental Protection Agency, two species of Asian carp were close to invading Lake Michigan in If they become established in Lake Michigan, they are likely to spread rapidly and disrupt the food web that supports the lakes’ native fish populations. Eventually, they could become the dominant fish species in the interconnected Great Lakes.Fig , p. 271
55 Managing River Basins Is Complex and Controversial Columbia River: U.S. and CanadaSnake River: Washington state, U.S.DamsProvide hydroelectric powerProvide irrigation waterHurt salmon
56 Natural Capital: Ecological Services of Rivers Figure 11.16: Rivers provide some important ecological services. Currently, the services are given little or no monetary value when the costs and benefits of dam and reservoir projects are assessed. According to environmental economists, attaching even crudely estimated monetary values to these ecosystem services would help to sustain them. Questions: Which two of these services do you believe are the most important? Why?Fig , p. 272
57 We Can Protect Freshwater Ecosystems by Protecting Watersheds Freshwater ecosystems protected throughLawsEconomic incentivesRestoration effortsWild rivers and scenic rivers1968 National Wild and Scenic Rivers Act
58 11-6 What Are the Priorities for Sustained Biodiversity, Ecosystem Services? Concept Sustaining the world’s aquatic biodiversity requires mapping it, protecting aquatic hotspots, creating large, fully protected marine reserves, protecting freshwater ecosystems, and carrying out ecological restoration of degraded coastal and inland wetlands.
59 Using an Ecosystem Approach to Sustaining Aquatic Biodiversity Edward O. WilsonComplete the mapping of the world’s aquatic biodiversityIdentify and preserve aquatic diversity hotspotsCreate large and fully protected marine reservesProtect and restore the world’s lakes and riversEcological restoration projects worldwideMake conservation financially rewarding
60 Three Big IdeasThe world’s aquatic systems provide important ecological and economic services, and scientific investigation of these poorly understood ecosystems could lead to immense ecological and economic benefits.Aquatic ecosystems and fisheries are being severely degraded by human activities that lead to aquatic habitat disruption and loss of biodiversity.
61 Three Big IdeasWe can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.