320 likes | 451 Views
Sustaining Aquatic Biodiversity. Unit Four Chapter 13 APES Mrs. Dow. A Biological Rollercoaster Ride in Lake Victoria. SUDAN. ETHIOPIA. AFRICA. KENYA. LAKE VICTORIA. BURUNDI. ZAIRE. TANZANIA. East Africa World’s 2 nd largest freshwater lake
E N D
Sustaining Aquatic Biodiversity Unit Four Chapter 13 APES Mrs. Dow
A Biological Rollercoaster Ride in Lake Victoria SUDAN ETHIOPIA AFRICA KENYA LAKE VICTORIA BURUNDI ZAIRE TANZANIA
East Africa • World’s 2nd largest freshwater lake • Until the late 1980 it had more than 500 endemic species of fish • 80% cichlids- small algae eating fish • Since 1980 some 200 cichlid species have become extinct • Nile perch was deliberately introduced during the 50’s & 60’s to stimulate fishing industry • Frequent alga blooms • Water hyacinth invaded and rapidly took over • Nile perch is now being overfished
Aquatic Biodiversity 13.1 • Oceans cover 71% of Earth surface • Only explored 5% of the earth’s global oceans U.S. coastal waters in trouble • Pass National Ocean Policy Act • Protects, sustains, restores the living oceans • Double federal budget for ocean research • Fisheries management • Marine reserves for breeding
Marine Biodiversity Cobia Hogfish Kelp Pacific sailfish Carrageen Moray Yellow jack Red snapper Red algae Batfish Bladder kelp Striped drum Angelfish Chinook salmon Sea lettuce Orange roughy Devilfish Porcupine fish Great barracuda Laminaria Sockeye salmon Grouper Chilean sea bass Dulse
Freshwater Biodiversity Brook trout White waterlily Bluegill White bass Bulrush Muskellunge Rainbow trout Rainbow darter Water lettuce Bowfish Water hyacinth Bladderwort Largemouth black bass Black crappie White sturgeon Yellow perch Velvet cichlid American smelt Walleyed pike Eelgrass Longnose gar Duckweed Common piranha Carp Egyptian white lotus Channel catfish African lungfish
Marine (ocean) biodiversity • Coral reefs & deep-sea (greatest) • Greater near coasts (habitats, producers) • Lowest diversity in middle (no habitat) • Source of protein • Seaweed (cosmetics, pharmaceuticals) • Antibiotics/anticancer
Human impacts 13.2 • Greatest threat (loss & degradation of habitat) • ½ worlds coasts lost in last century • Coral reefs severely damaged • >33% mangrove swamps gone • Dredging destroying habitats • ¾ marine species over fished
Overfishing • Leads to commercial extinction • Industrialized • 90% loss of large, open sea fish • Faster-growing varieties @ top of trophic level taken • 1/3 fish caught are bycatch
Purple loosestrife Present Not present No data
Freshwater animals are disappearing 5x faster than land animals • Seahorse used in Chinese medicine • Nonnative threat • Displace native; arrive in ship ballast • Asian eel- invaded waterways of South FL • Purple loosestrife imported as a ornamnetal plant
Protecting Marine Environments 13.3 • Difficult • Coastal development; inputs of sediment, waste • Hard to visualize damage • False sense that large size of ocean prevents damage • Deemed “tragedy of commons”
Bowhead whale Bowhead whale Bowhead whale Humpback whale Northern right whale Bowhead whale Saimaa seal Fin whale Northern right whale Hawksbill turtle Mediterranean monk seal Japanese sea lion Kemp's ridley turtle Humpback whale Hawksbill turtle Fin whale Hawksbill turtle Olive ridley turtle Olive ridley turtle Leatherback turtle Olive ridley turtle Hawaiian monk seal Green turtle Green turtle Leatherback turtle Leatherback turtle Leatherback turtle Humpback whale Green turtle Hawksbill turtle Green turtle Humpback whale Hawksbill turtle Hawksbill turtle Humpback whale Leatherback turtle Fin whale Fin whale Whale Turtle Seal Sea lion
Species of Sea Turtles Olive ridley 76 centimeters Australian flatback 99 centimeters Loggerhead 119 centimeters Hawksbill 89 centimeters Black turtle 99 centimeters Green turtle 124 centimeters Leatherback 188 centimeters Kemp's ridley 76 centimeters
To protect endangered marine species • Identify & protect endangered/threatened species • Prevent pollution • Educate public • CITES of 1975 • 1979 Global treaty on Migratory Species • U.S. Marine Mammal Protection Act of 1972 - U.S. Endangered Species Act of 1973 • U.S. Whale Conservation & Protection Act (1976) • International Convention on Biological Diversity (1995)
0 5 10 15 20 25 30m 0 10 20 30 40 50 60 70 80 90 100ft Atlantic white-sided dolphin Common dolphin Harbor porpoise Killer whale Bottlenose dolphin Beluga whale False killer whale Cuvier's beaked whale Pilot whale Narwhal Pygmy sperm whale Sperm whale Baird's beaked whale Squid Odontocetes (Toothed Whales)
Humpback whale Bowhead whale Minke whale Right whale Blue whale Fin whale Feeding on krill Sei whale Gray whale Mysticetes (Baleen Whales)
Whales • Commercial whaling banned in 1970 • Easy targets • 8 of 11 driven to commercial extinction • Alaska natives are exempt • Blue whale to edge of extinction • 10,000 left; low birth rate • International Whaling Commission (1946) • Sets quota for harvesting
Nations have 12 miles off coast to harvest • Exclusive Economic Zone (EEZ) • 200 miles from shore • 90 marine reserves in world
Integrated coastal management • Find cost-effective was to preserve biodiversity
U.S. banned all whaling (1970) • Japan, Norway, Iceland, Russia want ban repelled
Managing & sustaining 13.4 • Better way to project fish populations • Hard to measure • Based on unreliable catch figures • Quotas are hard to enforce • Mediterranean Sea has limited management
Suggestions • Central gvt sets quotas • Individual transfer quotas (ITQs) • Assigned to each fisherman • Limits bought, sold, leased
Critical for aquatic biodiversity Law permits fill or dredges Everglades National Park 90% wading birds gone Saltier & warmer (lack of water flow) Large algal blooms Wetlands 13.5
Kissimmee River ( ) ( ) miles 20 40 60 0 0 20 40 60 kilometers Channelized Unchannelized FLORIDA Lake Okeechobee West Palm Beach Fort Myers GULF OF MEXICO Naples Fort Lauderdale Agricultural area Treatment marsh Water conservation area Miami Canal Everglades National Park ATLANTIC OCEAN FLORIDA Key Largo Florida Bay Area of detail
Restoring the Florida Everglades • U.S. Army Corp of Engineers • Restoring flow of Kissimmee River • Removing canals south of Lake Okeechobee • Allow farmland to become marshes • Create reservoirs, canals, pumping stations
Restoring lakes & rivers 13.6 • Great Lakes • 162 nonnative species • Sea lampreys (reduce sport fish) • Zebra mussels (displaced native mussels; clogged pipes; fouled beaches)
Columbia River-North America’s 4th largest river • Altered by 119 dams; withdrawal of water for ag • Salmon need to return to spawning grounds • Salmon provide food; fertilizer for trees • Lack of trees makes water too warm • 9 species of Salmon are endangered or threatened • Northwest Power Act (1980) • Provide power & restore salmon
Human capture Fish change form Salmon processing plant Fish enter rivers and head for spawning areas To hatchery In the fall spawning salmon deposit eggs in gravel nests and die Modified Life Cycle Eggs are taken from adult females and fertilized with sperm “milked” from males Grow to maturity in Pacific Ocean in 1-2 years Fry hatch in the spring... Normal Life Cycle Eggs and young are cared for in the hatchery And grow in the stream for 1-2 years Grow to smolt and enter the ocean... Fingerlings are released into river Fingerlings migrate downstream
Sustainable management for freshwater • Regulate fishing; # & size taken • Improve habitats, breed genetically strong fish • Wild and Scenic Rivers Act (1968) • Protect rivers