Climate change and human activities threatens picky penguins

December 02, 2019

Eating a krill-only diet has made one variety of Antarctic penguin especially susceptible to the impacts of climate change, according to new research involving the University of Saskatchewan (USask) which sheds new light on why some penguins are winners and others losers in their rapidly changing ecosystem.

Human activities in Antarctica since the 1930s led to massive shifts in the population of krill--a shrimp-like crustacean that is a key food source for penguins, seals, and whales. The result has been that one species--gentoo penguins--thrive, while the population of chinstrap penguins dwindles, according to research published today in Proceedings of the National Academy of Sciences.

"Human activities, like hunting and global warming, are not only affecting species we routinely harvest - like krill. Gentoo penguins adapted by eating what was most available. Chinstrap penguins, picky eaters who continued to eat krill, didn't do as well, " said USask's William Patterson, part of the research team co-led by Louisiana State University's Michael Polito and Kelton McMahon from University of Rhode Island, and also involving researchers at University of Oxford and University of California, Santa Cruz.

The authors predict that the Antarctic Peninsula Region will remain a hotspot for climate change and human impacts during the next century, and believe their research will be beneficial in predicting which species are likely to fare poorly and which will withstand--or even benefit from--future changes.

"By understanding how past ecosystems respond to environmental change, we can improve our predictions of future responses and better manage human-environment interactions in Antarctica," said McMahon.

The research team analyzed 100 years-worth of penguin feathers to determine what the penguins had eaten by measuring stable nitrogen isotope values of amino acids. For chinstrap penguins, the answer was almost exclusively krill.

"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," said Polito. The result: a population explosion for both species of penguin.

"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."

Gentoo penguins adapted by eating relatively more fish and squid, while chinstrap penguins continued to feed exclusively on krill.

"Since the 1930s, human activities have reduced the population of chinstrap penguins by 30 to 50 per cent. That's accompanied by increases in the gentoo population of up to 600 per cent in some locations," said Patterson. "This has implications for future populations, where the specialists are more likely to be endangered by human activities and variability in the natural environment."
-end-
The National Science Foundation Office of Polar Programs in the United States and the Antarctic Science Bursary provided funding for the research.

Read the full paper, "Divergent Trophic Responses of Sympatric Penguin Species to Historic Anthropogenic Exploitation and Recent Climate Change" in Proceedings of the National Academy of Sciences' website, https://www.pnas.org/cgi/doi/10.1073/pnas.1913093116

University of Saskatchewan

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.