IPCC Report, Climate and Corals, The Lone Shark, Rat Scans, The Chickens Fight Back, Question of the Week: Bird Bones

 

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IPCC Report

This week, the report of the Intergovernmental Panel on Climate Change, Working Group II, was issued. Unlike Working Group I, which focused on the mechanisms of climate change, this report looks at how climate change is affecting our planet right now. Ice is disappearing earlier in the spring, trees are budding earlier, and extreme weather events are causing more outbreaks of disease, than 20 years ago. This report summarizes the latest in effects of climate change, as well as offering suggestions for ways to adapt to the changes. Linda Mortsch is a Senior Researcher with the Adaptation and Impacts Research Division of Environment Canada, and was the lead author for the North American chapter of the report.

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Climate and Corals

coral-bleached.jpg Bleached coral - Courtesy, NASA

In 2005, coral reefs across the Caribbean were damaged by a massive bleaching event. This occurs when water becomes too warm for coral, and they expel their colourful algae. Dr. Simon Donner, a Canadian climate scientist at the Woodrow Wilson School of Public and International Affairs at Princeton University, is trying to understand how greenhouse gases might be implicated in such events. He's found that weather leading to coral-destroying bleaching is ten times more likely with current greenhouse gas levels, and such events will become far more frequent in future climate scenarios.

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The Lone Shark

cowray.jpg Cow-nosed rays - Copyright, Joe Brown NOAA

Four years ago, we reported on a dramatic decline in the shark populations of the Atlantic Ocean. At the time, no one knew what this would mean for the ecology of the ocean as a whole. Now, a group of researchers, including Julia Baum, a Ph.D. candidate at Dalhousie University, has shown how taking out the sharks can destroy commercial fisheries. The story is the case of the bay scallop, a native of the US eastern seaboard. The bay scallop is one of the main food sources of the cow-nosed ray, which is, in turn, prey for large sharks. Without the larger sharks keeping the ray populations under control, these rays have started eating up almost all the scallops they can find. As a result, the commercial bay scallop fishery has collapsed.

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Rat Scans

pupsandmom.jpg Rat mother with pups - Courtesy, Dr. Gore

Studies in rats have shown that a fungicide commonly used in the grape industry causes changes to the germline of male offspring, if a female rat is exposed while she's pregnant. The changes mean the rats are born healthy, but in middle age, they all develop infertility and various cancers. And so do any male offspring they might have sired before they became ill, and their offspring after that, and so forth, even though the initial chemical exposure was several generations back.

But new research by Dr. Andrea Gore, a professor of endocrinology at the University of Texas, shows that female rats looking to mate can somehow tell the rats with this predisposition apart from healthy rats, even though there are no physical signs of any disease yet. She speculates that there might be some pheromonal cue that acts as a biomarker and that allows the females to pick the rat with the better germline.

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The Chickens Fight Back

chickenfight.jpg The Chickens Fight Back, by David Waltner-Toews

Disease has always been a part of human life. But in the last few years, it seems like the number of new and emerging diseases has gone up. SARS and Ebola virus both emerged from wild animal populations to infect humans. Throughout the winter, we're flooded with stories about the coming, "avian flu pandemic." But according to Dr. David Waltner-Toews, it's really our own fault. As we've encroached on previously untouched territories and cut out wild animal habitats, we've forced ourselves into increased contact with the other animals with which we share the planet. And now, the chickens are fighting back, at least metaphorically, by introducing new diseases into the human population. Dr. Waltner-Toews takes us on a journey through the world of animal transmission of infection in his new book, The Chickens Fight Back: Pandemic Panics and Deadly Diseases that Jump from Animals to Humans. Dr. Waltner-Toews is a veterinary epidemiologist at the University of Guelph, and the founding president of Veterinarians without Borders-Canada.

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Question of the Week: Bird Bones

This week's question comes from Andrew Breen, from Fort McMurray, Alberta, who asks: If birds have hollow bones, where do they produce marrow? And if they don't produce marrow, how does their immune system work?

For the answer, we go to Dr. Russell Dawson, who's a Canada Research Chair in avian ecology, and an associate professor at the University of Northern British Columbia, in Prince George.

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