Saturday, July 18, 2015

Loss of Seabirds Highlights Double Danger for Species

Scientists say increasing human impacts on habitat are combining with climate change to put serious survival stresses on species and ecosystems.

The population size of seabirds such as albatross is one measure of ocean health. (Image Credit: David Cook via Flickr) Click to Enlarge.
A grim decline of seabird populations, native trout being driven out because of the warming of Canadian lakes, and the destruction of an entire ecosystem in the US are all highlighted in new research.

The combined evidence shows that climate change offers a part-explanation for all three observations - but human pressure and human destruction of habitat are mostly to blame.

The world’s seabirds – such as terns, albatrosses, cormorants, gulls and petrels – are quietly flying away to nowhere.

In the lakes of Ontario, the warm water-loving bass is beginning to drive out the native trout.

And in the Great Basin of the United States, a whole ecosystem has become impoverished as the flow of energy through the vegetation and its animal populations has dwindled.

Biologists’ warning
Marine biologists have for decades been warning about the state of the world’s oceans, and seabird populations are one measure of ocean health.

Michelle Paleczny, a researcher at the University of British Columbia Fisheries Centre in Vancouver, and colleagues report in the Public Library of Science journal PLOS One that they compiled a global database of seabird population records and then examined the population trends in colonies monitored between 1950 and 2010.

This monitored population added up to about 19% of the global count of seabirds and showed a grim decline.  Overall, seabird counts had fallen by more than 69% - which adds up to 230 million birds - in the past six decades, and those seabirds that ranged the widest seemed to fare the worst.

In some cases, global warming as a consequence of the build-up of carbon dioxide levels in the atmosphere because of fossil fuel burning has altered the water chemistry and local climate and food supplies for seabird colonies.

Read moee at Loss of Seabirds Highlights Double Danger for Species

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