Overexploitation
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Transcript of Overexploitation
Overexploitation
Tokyo Tuna Market
Commercial exploitation
Morel Mushrooms for Sale
Coral harvested for jewelry
Rhinoceros exploitation
Rhino hornProducts – Dagger marketin Yemen
Rhino Horn in Traditional Medicine
Wild Blueberries
Wild Salmon
Egret plumes and feathered hat
Tragedy of the Commons
Japanese Whaling Ships
Subsistence exploitation
Subsistence Hunting
Recreational exploitation
Hunting as Recreation
Shell Collection
Gordon Alcorn
Photographic safari
Cheetah on Land Rover
Incidental exploitation
Kemp’s Ridley Sea Turtle
Trawling
Shrimp net with TED – turtle exclusion device
Indirect exploitation
Domestic cats preying on small birds
Pet market
Tropical Fish for Aquarium Trade
Cactus Market
Saguaro Cactus
Consequences of Overexploitation
1. Population Effects- Reduction in population size- Age structure- Sex ratio- Genetic structure
2. Ecosystem Effects
Age Structure: A – fish in typical populationB – fish taken by fishing
Sex Ratios – The Fisher
Fisher Distribution
Genetic Structure – Coho Salmon
Genetic Structure – Coho Salmon
Ecosystem Structure – Loss of Large Trees
Planting Sequoias
Giant Redwood
Redwood Forest in the Air
Ecosystem Structure – Loss of Snags
Loss of Keystone Species - Sea Otter with Sea Urchin
Loss of Keystone Species - Glyptodont
Exotic Species
Mrs. Black Horse, Cheyenne Nation, and dog travois
American Chestnut
Cracking From Chestnut Blight
Exotic Species• Conservation biologists typically call
introduced species “exotic species” - species which live outside their natural range
• Botanists typically refer to exotic plants as alien species
• Other terms you may see include biological invaders, introduced species, invasive species, non-indigenous species, non-native species (my preferred term)
How Do Exotic Species Get Dispersed?
1. Stowaways2. Subsistence and Commerce3. Recreation4. Whimsy or aesthetics5. Science6. Biological Control
Norway Rat as ship rat
Earthworms and pre-exotic distribution
Cars transport seeds via mud stuck to car
Ballast Water Discharge
Commerce and Subsistence
Commerce and Subsistence
Monterey Pine
Blue Gum Eucalyptus
Feral Pig - Florida