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SNS COLLEGE OF ENGINEERING
Global Biodiversity
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What is Biodiversity? We’ll get to that, but first. . . .
Let’s take a step back in time.
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Whatever Happened to HIM??
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. . . or Them ???
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Almost all dinosaurs became extinct. But why?
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Does anyone really know?—It was 65 million years ago!!!!!
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Could it have been “natural” extinction?
Natural extinction happens when a species fails to adapt to the environment (or changes in the environment) as efficiently as other species and eventually dies off. May have played a role, but scientists think there was a more dramatic contributing cause . . .
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Thought to Be Global Climate Change of Unknown Cause (External or Internal; Sudden or Gradual)
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Mass Extinction When more than 50% (half) of all known, living species become extinct in a short period of time (less than 2 million years)
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Is this just irrelevant ancient history?
NO! ! ! ! ! ! ! !
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Why it’s relevant: The mass extinction involving the dinosaurs was only one in a series of known mass extinctions. There have been others. Some scientists think we are on the verge of yet another in our lifetimes.
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Tiger
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Elephant
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Manatee The large mammals spend a lot of time close to the top of the water, which brings them into contact with recreational boaters frequently.
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DDT was banned in the United States in 1972
DDT was banned in the United States in Many other countries are looking to phase out the chemical. Laws were passed to protect them from illegal hunting. Special protected areas, called refuges were created all over the United States for eagles to live and breed. Bald Eagle
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Northern Wild Monkshood
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Hungerford’s Crawling Water Beetle
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Karner Blue Butterfly
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What do these species have in common with dinosaurs?
They, too could become EXTINCT!
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Species Group of organisms capable of interbreeding (reproducing) with each other but not with other groups.
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Species at Risk— 2 types “Endangered Species”: Species that are at risk of becoming extinct in the near future throughout much or all of their habitat range. “Threatened Species”: Species that are at risk but not yet in as much danger as endangered species. They are likely to become endangered in the near future.
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Notes About Endangered and Threatened Species
NOT JUST ANIMAL SPECIES! Includes plant and insect species as well. Worldwide, there are at least 1832 endangered or threatened species. And that’s just the official list! Over 1,000 are found in the United States. About half the counties in the U.S. contain endangered or threatened species.
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What’s the connection between endangered species and “biodiversity?”
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Biodiversity is… Variety among all levels of life on Earth. The two main levels for thinking about biodiversity are the species level and the ecosystems level. We’ll discuss the current threats to biodiversity by first looking at species, then we’ll discuss ecosystems. The same threats affect both levels of biodiversity. A third component is genetic material, but this may be difficult to explain.
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(Among other things) WE DO!!
What threatens biodiversity today? (Among other things) WE DO!! Human civilization and economic activity put pressure on aspects of biodiversity. The present rate of extinction is believed to be much higher than can be explained totally by natural causes. We must be careful to balance our needs with those of other species.
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Three major human-related threats to biodiversity
Trade (and illegal poaching) Development/ Loss of Habitat Pollution
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Threat One: Trade What is trade? Trade is traffic in goods, such as by gift, barter (swapping), or sale. People all over the world engage in trade, on the local, national, or global level. Sometimes when species are taken from the wild or from other settings to be traded, we refer to this as harvesting the species.
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How do harvesting and trade affect species?
Some species are hunted for their meat, their fur, or other parts of their body (such as elephants for their ivory). Some are sought as pets. Some of this trade is legal, but some is illegal (poaching). If too many species are hunted or harvested too quickly, the species population may shrink. Not enough young are born to become adults and make up for those being harvested. Other animals can be indirectly harmed in the process of other animals being hunted or harvested (such as dolphins caught in tuna nets).
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What is Poaching? The illegal practice of trespassing on private or protected property (such as national parks or wildlife preserves) to hunt, fish, or steal game. Also includes illegally removing game, fish, plants, or parts of animals to trade illegally. Illegal hunting is a major problem for certain wildlife populations around the world. In some areas poaching is devastating wildlife and its ecosystems.
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In the 1970s, the global demand for ivory threatened to make the elephant extinct. Poachers, with access to automatic weapons derived from civil wars and international arms sales, were killing herds of elephants faster than ever before. From 1970 to 1985, the total elephant population of Africa decreased by half. At a 1989, CITES (Convention on International Trade in Endangered Species of Wildlife Fauna and Flora) meeting, 115 countries decided to ban the international trade of ivory in the hopes of restoring elephant populations to healthy levels. The years 1996 and 1997 witnessed an effort of southern African countries to lift, at least partially, this ban. Elephant populations in Africa as a whole are increasing, in part, thanks to the CITES ban and listing of elephants on the most endangered species list. Elephant poaching is a problem in many countries. They are hunted mainly for their ivory tusks.
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Caption (from internet): Seizure of a tiger skin and tiger bones at Ramnagar near Corbett National Park (U.P.) (India). The two offenders are sitting on the ground. They are surrounded by members of the U.P. Forest Departrment, who carried out the operation assisted by WPSI. The two offenders are sitting on the ground. People standing belong to the U.P. Forest Department In some countries, such as India, tigers are poached for their skins, bones, and claws. These poachers were caught by Indian authorities.
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Why poach? As species become more and more endangered, each remaining specimen becomes more and more valuable. Some people are willing to pay a lot of money to get rare goods associated with these species. This creates an incentive for people to hunt, or “take” the species, even though they are protected by law. The poachers want to make money from this, which usually is more than they could make at other jobs.
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Regulating Poaching Many individual countries have enacted specific laws outlawing poaching of various species and their products. Some international laws have also been put in place to outlaw trade in endangered species. But the behavior is difficult to control. Sale of poached goods provides income for the poachers, who do not want to stop.
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Some plants are illegally traded too!
Agarwood, the fragrant wood produced by a species of the Asian Aquilaria tree family, may be over-exploited to commercial extinction due to over harvesting and illegal trade. Ocean plants are also sometimes illegally traded, which harms other species in their ecosystems
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Threat Two: Development
“Development” refers to processes that transform a place to make it suitable for commercial or residential purposes
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Development can threaten biodiversity by:
Destroying animal’s habitats Destroying some animals’ food sources (such as plants) Bringing pollution to previously clean areas
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Case Study in Development: The Everglades
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Where and what are the Everglades?
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The Everglades is home to a variety of plant and animal species, such as. . .
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Mangrove trees
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Blue Herons
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Florida Panthers
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Florida Alligators
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How are the species of the Everglades threatened by development?
900 people move to Florida each day 39 million people vacation in Florida annually 12 million people spend the winter in Florida And all those people need…
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Places to live,….
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Thank You
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