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 Frequent algal blooms Nutrient runoff Spills of untreated sewage Less algae-eating cichlids

Lake Victoria Is a Large Lake in East Africa

Natural Capital Degradation: The Nile Perch

11-1 What Are the Major Threats to Aquatic Biodiversity? 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.

We Have Much to Learn about Aquatic Biodiversity Greatest marine biodiversity Coral reefs Estuaries Deep-ocean floor Biodiversity is higher Near the coast than in the open sea In the bottom region of the ocean than the surface region

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 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 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

Lake Wingra in Madison, Wisconsin (U.S.)

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

Hawaiian Monk Seal

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

Science Focus: Protecting and Restoring Mangroves Protect and restore mangroves Reduce the impact of rising sea levels Protect against tropical storms and tsunamis Cheaper than building concrete sea walls Mangrove forests in Indonesia

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 Bycatch

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

900,000 800,000 700,000 600,000 500,000 Fish landings (tons) 400,000 1992 300,000 Figure 11.6 Natural capital degradation: this graph illustrates the collapse of the cod fishery in the northwest Atlantic off the Canadian coast. 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 fall throughout the 1970s, followed by a slight recovery in the 1980s and total collapse by 1992 when the site was closed to fishing. Canadian attempts to regulate fishing through a quota system had failed to stop the sharp decline. The fishery was reopened on a limited basis in 1998 but then closed indefinitely in 2003. (Data from Millennium Ecosystem Assessment) 200,000 100,000 1900 1920 1940 1960 1980 2000 Year Fig. 11-6, p. 254

Case Study: Industrial Fish Harvesting Methods Trawler fishing Purse-seine fishing Longlining Drift-net fishing

Major Commercial Fishing Methods Used to Harvest Various Marine Species

Deep sea aquaculture cage Fish caught by gills Fish farming in cage Trawler fishing Spotter airplane Sonar Purse-seine fishing Drift-net fishing Long line fishing Figure 11.7 Major commercial fishing methods used to harvest various marine species. These methods have become so effective that many fish species have become commercially extinct. Float Buoy lines with hooks Deep sea aquaculture cage Fish caught by gills Fig. 11-7, p. 256

Deep sea aquaculture cage Fish farming in cage Trawler fishing Sonar Spotter airplane Purse-seine fishing Drift-net fishing Float Buoy Fish caught by gills Long line fishing lines with hooks Figure 11.7 Major commercial fishing methods used to harvest various marine species. These methods have become so effective that many fish species have become commercially extinct. Deep sea aquaculture cage Stepped Art Fig. 11-7, p. 256

11-2 How Can We Protect and Sustain Marine Biodiversity? Concept 11-2 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 Most of the ocean lies outside the legal jurisdiction of any country

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

Examples of Cetaceans

Figure 11.8 Examples of cetaceans, which can be classified as either toothed whales or baleen whales. Fig. 11-8a, p. 258

Toothed whales Sperm whale with squid Killer whale Narwhal Figure 11.8 Examples of cetaceans, which can be classified as either toothed whales or baleen whales. Bottlenose dolphin 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Meters Fig. 11-8a, p. 258

Figure 11.8 Examples of cetaceans, which can be classified as either toothed whales or baleen whales. Fig. 11-8b, p. 258

Baleen whales Blue whale Fin whale Bowhead whale Right whale Sei whale Figure 11.8 Examples of cetaceans, which can be classified as either toothed whales or baleen whales. Humpback whale Gray whale Minke whale 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Meters Fig. 11-8b, p. 258

Baleen whales Blue whale Fin whale Bowhead whale Right whale Sei whale Toothed whales Sperm whale with squid Killer whale Narwhal Bottlenose dolphin 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Meters Baleen whales Blue whale Fin whale Bowhead whale Right whale Sei whale Humpback whale Gray whale Minke whale 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Meters Figure 11.8 Examples of cetaceans, which can be classified as either toothed whales or baleen whales. Stepped Art Fig. 11-8a, p. 258

Norwegian Whalers Harpooning a Sperm Whale

Economic Incentives Can Be Used to Sustain Aquatic Biodiversity Tourism Economic rewards Reconciliation ecology

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

An Endangered Leatherback Turtle is Entangled in a Fishing Net

Individuals Matter: Creating an Artificial Coral Reef in Israel Reuven Yosef, Red Sea Star Restaurant Coral reef restoration Reconciliation ecology Treatment of broken coral with antibiotics

Marine Sanctuaries Protect Ecosystems and Species Offshore fishing Exclusive economic zones High seas Law of the Sea Treaty Marine Protected Areas (MPAs)

Establishing a Global Network of Marine Reserves: An Ecosystem Approach (1) 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

Establishing a Global Network of Marine Reserves: An Ecosystem Approach (2) Fully protected marine reserves work fast Fish populations double Fish size grows Reproduction triples Species diversity increase by almost one-fourth

Protecting Marine Biodiversity: Individuals and Communities Together Integrated Coastal Management Community-based group to prevent further degradation of the ocean

An Atoll of Australia’s Great Barrier Reef

Video: Humpback whales

Video: Loggerhead turtles

11-3 How Should We Manage and Sustain Marine Fisheries? Concept 11-3 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): traditional approach Optimum sustained yield (OSY) Multispecies management Large marine systems: using large complex computer models Precautionary principle

Some Communities Cooperate to Regulate Fish Harvests Community management of the fisheries Comanagement of the fisheries with the government

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

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

Solutions: Managing Fisheries

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 Economic Approaches Ban throwing edible and marketable fish back into the sea Sharply reduce or eliminate fishing subsidies Aquaculture Charge fees for harvesting fish and shellfish from publicly owned offshore waters Restrict coastal locations for fish farms Protect Areas Control pollution more strictly Depend more on herbivorous fish species Certify sustainable fisheries Figure 11.12 Ways to manage fisheries more sustainably and protect marine biodiversity and ecosystem services. Question: Which four of these solutions do you think are the most important? Why? Establish no-fishing areas Nonnative Invasions Establish more marine protected areas Kill organisms in ship ballast water Rely more on integrated coastal management Filter organisms from ship ballast water Consumer Information Label sustainably harvested fish Dump ballast water far at sea and replace with deep- sea water Publicize overfished and threatened species Fig. 11-12, p. 265

11-4 How Should We Protect and Sustain Wetlands? 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 Highly productive wetlands Provide natural flood and erosion control Maintain high water quality; natural filters Effect of rising sea levels

We Can Preserve and Restore Wetlands Laws for protection Mitigation banking Ecologists argue this as a last resort

Natural Capital Restoration: Wetland Restoration in Canada

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

Case Study: Can We Restore the Florida Everglades? (1) “River of Grass”: south Florida, U.S. Since 1948: damaged Drained Diverted Paved over Nutrient pollution from agriculture Invasive plant species 1947: Everglades National Park unsuccessful protection project

Case Study: Can We Restore the Florida Everglades? (2) 1970s: political haggling 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 Goal?

Case Study: Can We Restore the Florida Everglades? (3) 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?

The World’s Largest Restoration Project

11-5 How Can 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 Are under Major Threats Think: HIPPCO

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 Pros and cons Snake River: Washington state, U.S. Hydroelectric dams

Natural Capital: Ecological Services of Rivers

We Can Protect Freshwater Ecosystems by Protecting Watersheds Freshwater ecosystems protected through Laws Economic incentives Restoration efforts Wild rivers and scenic rivers Sustainable management of freshwater fishes

Video: Salmon swimming upstream

11-6 What Are the Priorities for Sustained Biodiversity, 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 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