14 May 2013:
Shifting Petrel Diets Suggest
Effect of Humans on Ocean Food Web
An analysis of the bones of ancient and modern Hawaiian petrels has revealed that modern petrels, which forage in the open ocean, are eating prey lower on the food chain
than in centuries past, a
dramatic shift that coincides with the rise of industrial fishing. In tests conducted on petrel bones collected over three decades in the Hawaiian islands, a team of scientists found that the bones from 4,000 to 100 years ago contained higher ratios of nitrogen-15 and nitrogen-14 isotopes than the more recent bones, suggesting that the earlier birds ate bigger prey before changes in the food web composition of the Northeast Pacific. According to the scientists, the nitrogen ratio started to decline in the decades after the early 1950s, when industrial fishing started to extend beyond the continental shelves. “Our bone record is alarming because it suggests that open-ocean food webs are changing on a large scale due to human influence,” said Peggy Ostrom, a zoologist at Michigan State University and co-author of the study, published in the Proceedings of the National Academy of Sciences
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
Yale Environment 360
articles are now available in Spanish and Portuguese on Universia
, the online educational network. Visit the site.
Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology
Antarctica and the Arctic
Central & South America
A three-part series Tainted Harvest
looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup. Read the series.
is now available for mobile devices at e360.yale.edu/mobile
The Warriors of Qiugang
, a Yale Environment 360
video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.
Top Image: aerial view of Iceland
. © Google & TerraMetrics.
, winner of the Yale Environment 360 Video Contest, documents the work of African researchers monitoring wildlife in Uganda's remote Bwindi Impenetrable National Park. Watch the video.