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Their findings shed light on how human disturbance of the naturalworld may lead to widespread, yet largely invisible, disruptions ofecological interaction chains. This, in turn, highlights the needto build non-traditional alliances -- among marine biologists andforesters, for example -- to address whole ecosystems acrosspolitical boundaries. This past fall, McCauley, a graduate student, and DeSalles, anundergraduate, were in remote Palmyra Atoll in the Pacific trackingmanta rays' movements for a predator-prey interaction study.Swimming with the rays and charting their movements with acoustictags, McCauley and DeSalles noticed the graceful creatures keptreturning to certain islands' coastlines. Meanwhile, graduatestudent Hillary Young was studying palm tree proliferation'seffects on bird communities and native habitats. Palmyra is a unique spot on Earth where scientists can comparelargely intact ecosystems within shouting distance of recentlydisturbed habitats. A riot of life -- huge grey reef sharks, rays,snapper and barracuda -- plies the clear waters while seabirdsflock from thousands of miles away to roost in the verdant forestsof this tropical idyll. Over meals and sunset chats at the small research station,McCauley, DeSalles, Young and other scientists discussed their workand traded theories about their observations. "As thefrequencies of these different conversations mixed together, thepicture of what was actually happening out there took form in frontof us," McCauley said. Through analysis of nitrogen isotopes, animal tracking and fieldsurveys, the researchers showed that replacing native trees withnon-native palms led to about five times fewer roosting seabirds(they seemed to dislike palms' simple and easily wind-swayedcanopies), which led to fewer bird droppings to fertilize the soilbelow, fewer nutrients washing into surrounding waters, smaller andfewer plankton in the water and fewer hungry manta rays cruisingthe coastline. "This is an incredible cascade," said researcher RodolfoDirzo, a professor of environmental science and senior fellow withthe Stanford Woods Institute for the Environment. "As anecologist, I am worried about the extinction of ecologicalprocesses. This dramatically illustrates the significance of suchextinctions." Equally important is what the study suggests about these cascadesgoing largely unseen. "Such connections do not leave any tracebehind," said researcher Fiorenza Micheli, an associateprofessor of biology affiliated with the Stanford Woods Institute."Their loss largely goes unnoticed, limiting our understandingof and ability to protect natural ecosystems." McCauley put itanother way: "What we are doing in some ecosystems is akin topopping the hood on a car and disconnecting a few wires andrerouting a few hoses. All the parts are still there -- the enginelooks largely the same -- but it's anyone's guess as to how or ifthe car will run." By way of comparison, researcher Robert Dunbar, a professor ofearth sciences and Stanford Woods Institute senior fellow, recalledthe historical chain effects of increasing demands on water fromCentral California's rivers. When salmon runs in these riversslowed from millions of fish each year to a trickle, natural andagricultural land systems lost an important source ofmarine-derived fertilizer. These lost subsidies from the sea arenow replaced by millions of dollars' worth of artificial fertilizerapplications. "Humans can really snip one of these chains inhalf," Dunbar said. The e-commerce company in China offers quality products such as China Ipad Spare Parts , China MMC Flash Memory Card, and more. For more , please visit PS2 Replacement Parts today!
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