June 21, 2012
Penguins Face Population Decline Due To Climate Change
Lee Rannals for redOrbit.com
Penguins in the colder regions of the world are being threatened by man, despite man not actually being present. Two studies have pointed to climate change being the reason for why penguins that frolic in Antarctica are dying off.
Scientists from the Woods Hole Oceanographic Institution in Massachusetts believe that there will be an 81 percent reduction in the number of emperor penguins by 2100, bringing the population totals from 3,000 to as low as 500.
These penguins also eat krill, and both breed and raise their chicks exclusively on ice. These researchers wrote in the journal Global Change Biology that if the ice continues to melt, population growth will suffer.
"People say the temperature may increase by two degrees, so what?'” biologist and study co-author Stephanie Jenouvrier told ABC News. "But changes that may seem small to humans are not small to species, and may affect the entire ecosystem."
To make their projections, the U.S. scientists used data from several sources, including climate models, sea ice forecasts, and a demographic model that they created of the Emperor penguin population at Terre AdÃ©lie.
“If you want to study the effects of climate on a particular species, there are three pieces that you have to put together,” Hal Caswell, a WHOI senior mathematical biologist and collaborator on the paper, said in a recent statement.
New research also shows that climate change is the culprit behind the 36 percent decline in the chinstrap penguin population over the last 20 years.
The penguins, which are named after the black strip of feathers that run underneath their chin, depend on krill as their main source of food.
The shrimp-like creatures reside in chunks of ice in the Antarctic ocean, but as the ice melts, the krill population melts away with it, the researchers wrote in the journal Polar Biology.
Natural History Museum in Madrid researchers counted chinstrap penguins in Antarctica's South Shetland Islands in 1991 and 1992, then again in 2008 and 2009.
The team found a tremendous drop in the population of the flightless birds, which also coincided with the drop in the amount of krill.
Caswell said rising temperature changes in the Antarctic is not just a problem penguins are having to face, but could affect other marine environments as well, and even humans.
“We rely on the functioning of those ecosystems,” he said. “We eat fish that come from the Antarctic. We rely on nutrient cycles that involve species in the oceans all over the world. Understanding the effects of climate change on predators at the top of marine food chains–like emperor penguins–is in our best interest, because it helps us understand ecosystems that provide important services to us."