This is what i have so far. I just want to make sure I'm on the right track.
Rough thesis: Polar bears are facing extinction because of exposure to pollutants, over hunting and climate change.
Polar bear are extremely vulnerable to certain pollutants. Persistent organic pollutants, such as pesticides and chemicals, are one of the most problematic. Persistent organic pollutants, or POP's, are a big problem to polar bears because POP's take years to biodegrade. This means that they will stay in the environment and affect polar bears for years to come. POPs also travel very fast from their source of origin. Even though these pollutants may have been used far away from the arctic, through long-range transport the pollutants reach the arctic quickly. (David Suzuki) They then reach the polar bears through the food chain because fish are the first to be affected by the pollutants, seals eat the fish and then polar bears eat the seals. By the time the pollutants reach the polar bears they are much more concentrated. (endangeredpolarbear.com/polar_bear_enemies.htm). POP's bond to fat molecules in the body of the polar bears and are stored in their organs (worldwildlife.org/species/finder/polarbear/threa ts.html). Studies have shown that POP's can cause baby polar bears to be born with both male and female reproductive organs, thus reducing their capability to reproduce (panda.org/about_wwf/where_we_work/europe/what_we _do/arctic/polar_bear/threats/toxic_pollution/index.cfm). This will cause less polar bears to be born, which will in turn decrease the number of populations of polar bears.
Over hunting is also becoming a large problem in polar bear regions. It is currently legal in Canada and Greenland for sport hunters to hunt polar bears. However in Russia, it is illegal to hunt polar bears and yet in 2002, over 250 polar bears were illegally hunted in Russia. Polar bears don't reproduce until they are much older which means that if hunters are hunting polar bears before the polar bears get a chance to reproduce, then even less polar bears will be born.
Rough thesis: Polar bears are facing extinction because of exposure to pollutants, over hunting and climate change.
Polar bear are extremely vulnerable to certain pollutants. Persistent organic pollutants, such as pesticides and chemicals, are one of the most problematic. Persistent organic pollutants, or POP's, are a big problem to polar bears because POP's take years to biodegrade. This means that they will stay in the environment and affect polar bears for years to come. POPs also travel very fast from their source of origin. Even though these pollutants may have been used far away from the arctic, through long-range transport the pollutants reach the arctic quickly. (David Suzuki) They then reach the polar bears through the food chain because fish are the first to be affected by the pollutants, seals eat the fish and then polar bears eat the seals. By the time the pollutants reach the polar bears they are much more concentrated. (endangeredpolarbear.com/polar_bear_enemies.htm). POP's bond to fat molecules in the body of the polar bears and are stored in their organs (worldwildlife.org/species/finder/polarbear/threa ts.html). Studies have shown that POP's can cause baby polar bears to be born with both male and female reproductive organs, thus reducing their capability to reproduce (panda.org/about_wwf/where_we_work/europe/what_we _do/arctic/polar_bear/threats/toxic_pollution/index.cfm). This will cause less polar bears to be born, which will in turn decrease the number of populations of polar bears.
Over hunting is also becoming a large problem in polar bear regions. It is currently legal in Canada and Greenland for sport hunters to hunt polar bears. However in Russia, it is illegal to hunt polar bears and yet in 2002, over 250 polar bears were illegally hunted in Russia. Polar bears don't reproduce until they are much older which means that if hunters are hunting polar bears before the polar bears get a chance to reproduce, then even less polar bears will be born.
