Researchers from the University of Oxford,\u00a0Louisiana State University, University of Rhode Island, University of California Santa Cruz, and the University of Saskatchewan\u00a0have studied penguin populations\u00a0with the goal of understanding how human interference in Antarctic ecosystems during the past century led to booms and busts in the availability of a key food source for penguins: Antarctic krill.<\/p>\n
\u2018Antarctic krill is a shrimp-like crustacean that is a key food source for penguins, seals, and whales. When seal and whale populations dwindled due to historic over-harvesting, it is thought to have led to a surplus of krill during the early to mid-1900s. In more recent times, the combined effects of commercial krill fishing, anthropogenic climate change, and the recovery of seal and whale populations are thought to have drastically decreased the abundance of krill,\u2019\u00a0says Michael\u00a0Polito,\u00a0co-lead author and\u00a0assistant professor in Louisiana State University\u2019s\u00a0Department of Oceanography & Coastal Sciences.<\/p>\n
In this study, the team\u00a0focused on\u00a0the diets of chinstrap and gentoo penguins by analyzing the nitrogen stable isotope values of amino acids, which\u00a0acts as a chemical signal of what the penguin has eaten,\u00a0in penguin feathers collected during explorations of the Antarctic Peninsula during the past century.\u00a0The\u00a0findings\u00a0were published today\u00a0in the\u00a0Proceedings of the National Academy of Sciences.<\/em><\/p>\n \u2018Given that gentoo penguins are commonly thought of as climate change winners and chinstrap penguins as climate change losers we wanted to investigate how differences in their diets may have allow one species to cope with a changing food supply while the other could not,\u2019\u00a0said Tom Hart, co-author and\u00a0penguinologist\u00a0at the\u00a0Department of Zoology,\u00a0University of Oxford.\u00a0\u2018We wanted to understand why\u00a0chinstrap penguins have had severe population declines, while\u00a0gentoo penguin populations have increased in the Antarctic Peninsula over the past half century.\u2019<\/p>\n The team found that both penguin species primarily fed on krill during the krill surplus in the early to mid-1900s that was caused by seal and whale harvesting. In contrast, during the latter half of the past century, gentoo penguins increasingly showed an adaptive shift from strictly eating krill to including fish and squid in their diets, unlike the chinstrap penguins that continued to feed exclusively on krill.<\/p>\n \u2018Our results indicate that historic\u00a0marine mammal\u00a0harvesting and recent climate change have altered the Antarctic marine food web over the past century. Moreover, the differing diet and population responses we observed in penguins indicate that species such as chinstrap penguins, with specialized diets and a strong reliance on krill, will likely continue to do poorly as climate change and other human impacts intensify,\u2019\u00a0says\u00a0Kelton McMahon, co-lead author and assistant professor at the University of Rhode Island.<\/p>\n The authors predict that the Antarctic Peninsula region will remain a hotspot for climate change and human impacts during the next century, and they believe their research will be beneficial in predicting which species are likely to fare poorly and which will withstand\u2014or even benefit from\u2014future changes.<\/p>\n According to McMahon,\u00a0\u2018By understanding how past ecosystems respond to environmental change, we can better predict future responses to better manage human-environment interactions in Antarctica.\u2019<\/p>\n \n","protected":false},"excerpt":{"rendered":" Researchers from the University of Oxford,\u00a0Louisiana State University, University of Rhode Island, University of California Santa Cruz, and the University of Saskatchewan\u00a0have studied penguin populations\u00a0with the goal of understanding how human interference in Antarctic ecosystems during the past century led to booms and busts in the availability of a key food source for penguins: Antarctic […]<\/p>\n","protected":false},"author":410,"featured_media":47641,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6038,6029,984],"tags":[6325,7466,7597],"yoast_head":"\n