Bio171-F10-Lec 12 - Biology 171 Wednesday October 6, 2010...

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Lecture 12: Behavioral Ecology 1 Announcements This Week’s Discussion: Indirect effects Bioaccumulation (concluded) Endocrine Disrupters & Human Sex Ratios Avian Botulism Imprinting Optimal Foraging Text Reading: Lecture 12: 4 th : Chapter 51 (1019-1031) 3 rd : Chapter 51 (1149-1167) Lecture 13: 4 th : Chapter 51 (1031-1035) 3 rd : Chapter 51 (1167-1170) Biology 171 Wednesday October 6, 2010
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Biological magnification of PCBs in a Great Lakes food web. PolyChlorinated Biphenyls , a mixture of up to 209 chlorinated chemicals. PCBs have been used as coolants and lubricants in transformers, capacitors, and other electrical equipment because they don't burn easily and are good insulators. The manufacture of PCBs was stopped in the US in 1977 because of evidence they build up in the environment and can cause harmful health effects. Human and animal studies on exposure to PCBs found the following: Developmental problems and reduced mental abilities in infants and children born to women who were exposed to PCBs Problems with the nervous, immune, circulatory and hormonal systems Liver damage, brain disorders, and skin problems Increased risk of cancer. 27
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Toxaphene Biomagnification - Arctic Canada Seawater 1 .03 ppb (parts per billion) Zooplankton 23.6 ppb Arctic cod muscle 46 ppb Ringed seal blubber 2130 ppb Beluga blubber 21380 ppb Narwhal blubber 22440 ppb Toxaphene Accumulation in Arctic Foodchains 28
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In the Canadian Arctic, toxaphene was found in indigenous people as a result of their position at the highest trophic level in the Arctic food chain, and the high lipid content of their diet. A study of women living in the Arctic and eating a traditional diet primarily of fish and blubber from marine mammals showed that they consumed twenty times the tolerable daily intake of toxaphene . (WFPHA, 2000). And eventually in Arctic Humans………. Breast-fed babies are especially vulnerable - the next trophic level 29
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Endocrine Disruptors Some chemicals mimic a natural hormone, fooling the body into over-responding to the stimulus or responding at inappropriate times. Other endocrine disrupting chemicals block the effects of a hormone from certain receptors. Still others directly stimulate or inhibit the endocrine system and cause overproduction or underproduction of hormone. 30
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Bio171-F10-Lec 12 - Biology 171 Wednesday October 6, 2010...

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