Abstract 
 
 Population changes of top predators can provide key indications of environmental quality. In the Antarctic ecosystem, population dynamics of top predators like penguins may yield important information about how the environment is changing. From 1991–1992 to 2008–2009 censuses of the chinstrap penguin (Pygoscelis antarctica), breeding population of Vapour Col in Deception Island (South Shetlands Islands) were carried out. Censuses were conducted on 19 sub-colonies, mainly in December around the time of peak hatching. Nest counts were taken from photographs that were recorded from a standard location. Some censuses were also made in mid-January in 1999, 2006, 2007 and 2008. Our results reveal that the population has declined by 36 % when comparing data from 1991 with those from 2008. The strongest decline occurred since 2000. No temporal trends were detected in reproductive success. Declines of Chinstrap penguin populations constitute a general pattern in the South Shetlands, and it has been suggested to be related to climate change through effects of reduction in sea-ice extent during winter and a consequent decline in the abundance of krill. 

 A population of chinstrap penguins is feeling the heat, with more than one-third of a breeding colony lost in the past 20 years, new research finds. 
 
 A warming planet, which is causing sea ice in Antarctica (and elsewhere) to melt, may ultimately be to blame for the plummeting penguin population, the researchers said. That's because the chinstraps' main food, shrimplike creatures called krill, depend on algae that attaches to that ice. 
 
 "Actually, in the '90s it was thought that the climate change would favor the chinstrap penguin, because this species prefers sea waters without ice, unlike the Adélie penguin, which prefers the ice pack," study researcher Andres Barbosa told LiveScience. He added that at the time, chinstraps, named for the thin black facial line from cheek to cheek, seemed to increase in numbers, with some new colonies being established. 
 
 The sea-ice decline in the winter, however, has become so big that it is now impacting krill populations, said Barbosa, of the National Museum of Natural Sciences in Madrid. 
 
 Counting chinstraps 
 
 Barbosa and his colleagues tallied chinstrap penguins (Pygoscelis antarctica) in the Vapour Col colony of Deception Island, in the Antarctic's South Shetland Islands in 1991-92 and 2008-09. They photographed nests in 19 subcolonies, mainly in December when chicks were hatching. [ See Photos of Chinstrap Penguins on Deception ] 
 
 Results, which ended up including just 12 of the subcolonies due to availability of data, showed the occupied nests had declined by 36 percent between 1991 and 2008. 
 
 Barbosa and colleagues ruled out research activity as the cause for the loss since both studied populations and those used as controls showed similar patterns of decline. 
 
 Tourism is also not a likely culprit. Deception Island, built on a volcano, is one of the most visited places in Antarctica ; the 2007-08 year saw some 25,000 visitors, according to the International Association of Antarctica Tour Operators (IAATO). Meanwhile, the nearby chinstrap penguin colony of Bailey Head, which is usually visited by 2,000 to 3,500 people every season, showed a decline of about 50 percent. 
 
 Rather, a dip in the krill population may be to blame, an idea supported by the fact that Adélie penguin population (P. adeliae) in the region is also declining, while the gentoo penguin population (P. papua), which has a more variable diet, is not. 
 
 (The chinstrap, gentoo and Adélie penguins are the three pygoscelid species (in the Pygoscelis genus) that inhabit the Antarctic Peninsula, the region of the Antarctic continent where the effects of climate change are more evident, the researchers noted.) 
 
 Saving penguins 
 
 But Barbosa says the chinstraps aren't a lost cause. 
 
 "This is an example of how the human activity far from the poles can affect the life at thousands of kilometers far from our homes," Barbosa told LiveScience. "Therefore, a more responsible use of the energy and the fossil fuels is necessary to preserve the planet and then the Antarctica." 
 
 In addition, he said, to protect the organisms that call the Antarctic home, we need to reduce human impact by reducing overfishing, tourism and even research activity. 
 
 The research was detailed online May 22 in the journal Polar Biology. 
 
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– More than a third of a major Antarctic penguin colony has been decimated, and researchers believe it's due to warmer temperatures and disappearing ice and food. The colony of chinstrap penguins relies for food on krill, which depend on algae that attach to ice, which is rapidly disappearing, scientists note. The team from Madrid's National Museum of Natural Sciences tallied chinstrap penguins in the Vapour Col colony of Deception Island in the Antarctic's Shetland Islands, and photographed nests in 19 subcolonies from 1991 to 2009. The number of occupied nests in that time period plummeted by 36%, with the steepest declines occurring since 2000. The population of a nearby chinstrap colony on Bailey Head has plummeted by 50%, according to the team's findings in Polar Biology. The population declines "constitute a general pattern" in the South Shetlands, and are particularly troubling as "population changes of top predators provide key indications of environmental quality," writes lead researcher Andres Barbosa. "This is an example of how the human activity far from the poles can affect life thousands of kilometers far from our homes," he tells MSNBC. "A more responsible use of the energy and fossil fuels is necessary to preserve the planet, and Antarctica."