honors biology 2011-2012 honors biology 2011-2012

Download Honors Biology 2011-2012 Honors Biology 2011-2012

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  • Honors Biology 2011-2012 Honors Biology 2011-2012
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  • Impacts on Biodiversity: Over fishing and Over hunting Invasive species
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  • Over fishing and Over Hunting One threat to biodiversity occurs when humans cause ecosystems to collapse by using too many natural resources or taking away a Key Stone Species.
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  • Over fishing and Over Hunting Key Stone Species: An organism that is necessary for keeping an ecosystem in balance. Example: Sea Otter
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  • Sea Otter Facts Only marine mammal without blubber How do they stay warm in the cold ocean? Otters have the densest fur of any mammal. Fur is so thick that their skin never gets wet when they swim: 400,000 hairs per square centimeter.
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  • Sea Otter Facts During the fur trade Humans hunted otters almost to extinction for their thick warm pelts. By 1911 the sea otter population had dropped to roughly 1, 000 individuals! How will this effect the ecosystem?
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  • Sea Otters Niche: Eats sea urchins. Uses rocks and shells to break opened sea urchins Predators: Sharks and Humans (now Orcas) Uses seaweed to anchor themselves while they eat and sleep.
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  • How sea otters keep their ecosystem in balance: Otters keep the sea urchin population down. Sea urchins eat away at the base of sea weed. Fish and other sea life rely on the sea weed forests for food and shelter.
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  • Over Hunting Key Stone Species How do you think the decreasing otter population effects the ocean ecosystem? Otter Population is Down Sea Urchin Population = _____________ Sea Weed Population = ______________ Fish Population = _________________ Seal Population = _________________ Orca Population = _________________ Increases Decreases
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  • Results? What are the long term implications on the food web in this situation?
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  • Over Hunting Key Stone Species Result: Urchin Barrens
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  • Over fishing and over hunting By over fishing and over hunting humans have the power to irreversibly change an ecosystem. Sea Otters and OrcasSea Otters and CO2 Sea Otters and OrcasSea Otters and CO2
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  • Invasive Species Species that are brought to an ecosystem by humans and harm the ecosystem because they do not have any natural predators in their new environment.
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  • 50,000 exotic species live in the US $138 billion per year spent to help undo the damage they cause Invasive species also threaten nearly half of the species currently protected under the Endangered Species Act.
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  • Invasive Species (Animal Planet videos) (Animal Planet videos) Example: Burmese Python in Florida (Article)(Article)