Sustaining Aquatic Biodiversity G. Tyler Miller’s Living in the Environment 13th Edition Chapter 24

Key Concepts Economic and ecological importance Effects of human activities Protecting and sustaining aquatic diversity Protecting and sustaining fisheries Protecting and restoring wetlands

Case Study: A Biological Roller Coaster Ride in Lake Victoria Lake Victoria has lost its endemic fish species to large introduced predatory fish.

A Biological Roller Coaster Ride in Lake Victoria Reasons for Lake Victoria’s loss of biodiversity: Introduction of Nile perch. Loss of native cichlid species Lake experienced algal blooms from nutrient runoff. Invasion of water hyacinth has blocked sunlight and deprived oxygen. Nile perch is in decline because it has eaten its own food supply.

AQUATIC BIODIVERSITY We know fairly little about the biodiversity of the world’s marine and freshwater systems. The world’s marine and freshwater systems provide important ecological and economic services.

The Importance of Aquatic Biodiversity The most biologically diverse habitats include: Coral reefs Estuaries Deep ocean floor Highest near the coast 25,000 known fish species

The Importance of Aquatic Biodiversity: Ecological and Economic Food Items 6% of total protein; 16% of animal protein Many Chemicals Cosmetics from seaweed Medicines and Drugs Antibiotics and anticancer drug, adhesives, bone reconstructive materials seaweed, sponges, mollusks, coral barnacles, and other fish

Human Impacts on Aquatic Biodiversity Species loss and endangerment Marine habitat loss and degradation Freshwater habitat loss and degradation Overfishing Nonnative species Pollution and global warming

Species Loss and Endangerment Overfishing Habitat destruction Pollution Freshwater species at greater risk Mussels, crayfish, amphibians, fish

Marine Habitat Loss and Degradation 53% of coastal wetlands in US have disappeared Agriculture Coastal development 58% of world’s coral reefs are threatened Pollution Warmer ocean temperatures Two-thirds of US estuaries are at risk from pollution 35% of world’s mangroves have disappeared

Freshwater Habitat Loss and Degradation The world has lost more than half of its inland wetlands Agricultural and urban development 60% of the world’s larger rivers are fragmented by dams, diversions, and canals Flood control levees and dikes Alter and destroy aquatic habitats Disconnect rivers from their floodplains Eliminate wetlands and backwaters (spawning areas)

Overfishing 75% of the world’s 200 commercially valuable marine fish species are overfished Overfishing leads to commercial extinction Depletions and extinction of species unintentionally caught as bycatch

Non-native Species Deliberate or accidental introduction into coastal waters, lakes and wetlands purple loosestrife Asian swamp eel zebra mussle Displace or cause extinction of native species 68% of fish extinctions

Pollution and Global Warming 44% comes from runoff from developed coastal areas Major pollution threats Oil Acid deposition Plant nutrients Toxic chemicals Coastal development Sediment and soil erosion Global warming could alter migration and feeding patterns increase ocean temperature raise sea levels

PROTECTING AND SUSTAINING MARINE BIODIVERSITY Six of the world’s seven major turtle species are threatened or endangered because o human activities. Figure 12-4

Protect endangered and threatened species Example: Sea turtle Turtle extrusion devices (TEDs) Loggerhead Olive ridley Leatherback Hawksbill Green turtle Kemp's Ridley Black turtle Australian flatback

Turtle Extrusion Device Shrimp trawler Turtle Extrusion Device Area enlarged right

Case Study: The Florida Manatee and Water Hyacinths Manatee can eat unwanted Water Hyacinths. Endangered due to: Habitat loss. Entanglement from fishing lines and nets. Hit by speed boats. Stress from cold. Low reproductive rate

Case Study: Commercial Whaling After many of the world’s whale species were over-harvested, commercial whaling was banned in 1960, but the ban may be overturned.

Commercial Whaling Despite ban, Japan, Norway, and Iceland kill about 1,300 whales of certain species for “scientific purposes”. Although meat is still sold commercially.

Key Concepts Economic and ecological importance Effects of human activities Protecting and sustaining aquatic diversity Protecting and sustaining fisheries Protecting and restoring wetlands

Protecting and Sustaining Marine Biodiversity Identifying and protecting endangered and threatened species Sea turtles Turtle extrusion devices (TEDs) National and International laws and treaties CITES - Convention on International Trade and Endangered Species Global Treaty on Migratory Species US Marine Mammal Protection Act US Endangered Species Act US Whale Conservation and Protection Act International Convention on Biological Diversity

Protecting and Sustaining Marine Biodiversity Establish marine protected areas Coastal nations have sovereignty over waters and seabeds up to 12 miles offshore Jurisdiction over their Exclusive Economic Zone extends 200 miles offshore Integrated coastal management community based attempt to develop and use coastal resources sustainably

Protecting and Sustaining Marine Biodiversity Regulating and preventing ocean pollution Sustaining management of marine fisheries

Managing and Sustaining the World’s Marine Fisheries Fishery regulation Set, monitor, and enforce fishery catch limits below estimated MSY (maximum sustained yield) Divide up fishing quotas Require selective gear Improve monitoring and enforcement Economic approached Reduce or eliminate subsidies Impose fees for harvesting fish and shellfish from public managed offshore waters Certify sustainable fisheries

Managing and Sustaining the World’s Marine Fisheries Bycatch reduction Wider mesh fish nets Extrusion devices Observers on boats Multiple species licensing Laws prohibiting throwing edible and marketable fish back to sea

Managing and Sustaining the World’s Marine Fisheries Protected areas Establish no-fishing marine areas Protect marine habitats that are in good condition and disregard potentially hopeless cases Strengthen commitment to marine biodiversity protection Non-native invasions Kill organisms in ship ballast water Develop filters and traps Require ships to dump ballast water beyond 200 mile limit

Managing and Sustaining the World’s Marine Fisheries Consumer information Use labeling to identify fish that have been harvested sustainably Aquaculture Restrict location of fish farms to reduce loss of mangrove forests Enact and enforce stricter pollution regulations Increase productions of herbivorous aquaculture fish species

Protecting, Sustaining, and Restoring Wetlands Regulations federal permit required Mitigation banking allows destruction of existing wetlands if an equal area of they same type of wetland is created or restored Land use planning steer agriculture and mining away from wetlands Wetland restoration often has limited success Control of invasive species purple loosestrife

Restoring the Florida Everglades Natural flow of the Everglades has been diverted or disrupted. Farmers planted vast agricultural land to sugarcane and vegetables. Established Everglades National Park. Became the most endangered park. Massive plumbing and land development projects cut off water flow

Restoring the Florida Everglades 1990 began the world’s largest ecological restoration project. restore he curving flow of more than half of the Kissimmee River. remove 400 km of canals and levees create artificial marshes in previous farmland add land adjacent to Everglades National Park create network of artificial marshes create 18 large reservoirs capture much of the water flowing out to sea and return it to the Everglades

Protecting, Sustaining, and Restoring Wetlands

Protecting, Sustaining, and Restoring Lakes Pollution Zebra mussel Cultural eutrophication Water levels Invasive species

Protecting, Sustaining, and Restoring Rivers Pollution Disruption of water flow Loss of biodiversity Invasive species

Protecting, Sustaining, and Restoring Rivers Disruption of water flow 119 dams, 19 hydroelectric dams Salmon population dropped 94% Salmon Restoration Project upstream hatcheries fish ladders transport juveniles around dams turning off turbines

PROTECTING, SUSTAINING, AND RESTORING LAKES AND RIVERS We can help sustain freshwater fisheries by building and protecting populations of desirable species, preventing over-fishing, and decreasing populations of less desirable species. A federal law helps protect a tiny fraction of U.S. wild and scenic rivers from dams and other forms of development. National Wild and Scenic Rivers Act (1968).