(CNN) About 150,000 penguins have died since being stranded by a vast iceberg that became lodged off the coast of Antarctica six years ago, according to the journal Antarctic Science.
Combined with expanding ice, the B09B iceberg, which at 1,120 square miles is almost the size of Rhode Island, has cut off the Adelie penguins' food supply and changed the landscape of their home, according to a February report in the peer-reviewed journal published by Cambridge University Press.
The towering mass of water ice first ran aground into the penguins' habitat of Cape Denison in Commonwealth Bay in 2010. Before that it was floating along the coast for nearly 20 years before colliding into the bay. The iceberg essentially has landlocked the penguins, forcing the animals to trek across a desolate stretch of nearly 40 miles to find food.
Around the globe, penguins are at risk of extinction due to overfishing and man-made changes to their breeding grounds.
Ben Adkison is a freelance photographer based in Montana. His photos from remote corners of the world can be found on Facebook and his website.
There are 17 species of penguin, with emperor penguins being the largest. They weigh up to 45 kilos (100 pounds) and grow to 120 centimeters (48 inches) tall. These three are pictured on sea ice at McMurdo Sound in Antarctica.
Emperors can be seen along the coast of Antarctica. Breeding colonies are often the destination for cruises and scenic flights. Penguin species can also be spotted in South Africa, Chile, Argentina, Australia and New Zealand.
As with most polar species, penguins are feeling the effects of climate change. Ice melt is changing their breeding grounds and overfishing and ocean acidification is affecting their food sources of fish, squid and krill.
Emperors have an awkward, waddling gait on land, but are graceful in the water. These birds can dive more than 550 meters (1,800 feet) and stay under for up to 20 minutes.
Less than half the size of an emperor penguin, Adelie penguins are one of the smallest of the Antarctic penguin species. Each October, they build nests of rocks on land near open water.
Adelies are one of the most abundant of the penguin species. They can be found in large colonies and on icebergs and coastal areas in Antarctica waters.
Adelie penguins face the same climate change dangers as emperors, such as reduced habitat and a diminishing food supply. However, due to their larger population, they're currently less at risk.
The south polar skua is the Adelie's only land predator. It will attempt to steal penguin eggs and attack young chicks. Penguins work together to fight off the vicious skuas.
The warmer climes of coastal South Africa and Namibia are home to the African or jackass penguin. Boulders Beach near Cape Town, South Africa, is a popular destination for penguin spotting.
Unlike the highly mobile penguins in Antarctica, African penguins breed, nest and feed in the same area instead of traveling hundreds of miles between sites. They build nests under boulders or bushes or burrows dug from their own guano.
African penguins are listed as an endangered species. Their decreasing population is spurred by loss of nesting grounds due to guano removal by humans, as well as a decreasing food supply as a result of overfishing.
The little penguin, also known as the fairy or blue penguin, can be found on the coasts of New Zealand and southern Australia. They're the smallest of all penguins, weighing just a kilo or two and topping out at just over 30 centimeters tall.
The once 160,000-strong colony has now dwindled to 10,000 penguins.
"The arrival of iceberg B09B in Commonwealth Bay, East Antarctica... has dramatically increased the distance Adélie penguins breeding at Cape Denison must travel in search of food," said researchers in the report.
Since 2011, the colony's population has fallen dramatically, according to the Climate Change Research Center at Australia's University of New South Wales.
The outlook for the Cape Denison Adelie penguins remains dire. Unless the colossal iceberg is broken up by sea ice, scientists predict the colony will disappear in 20 years.
About 5,500 pairs are still breeding in the area, but there has been a significant decline in their population compared with a century ago, according to estimates based on satellite images and a census in 1997.
Effects of global warming around the world
The consequences of climate change go far beyond warming temperatures, which scientists say are melting the polar ice caps and raising sea levels. Click through the gallery for a look at 10 other key effects of climate change, some of which may surprise you.
In the coming decades climate change will unleash megadroughts lasting 10 years or more, according to
a new report by scholars at Cornell University, the University of Arizona and the U.S. Geological Survey. We're seeing hints of this already in many arid parts of the world and even in California, which has been rationing water amid record drought. In this 2012 photo, a man places his hand on parched soil in the Greater Upper Nile region of northeastern South Sudan.
There's not a direct link between climate change and wildfires, exactly. But many scientists believe the increase in wildfires in the Western United States is partly the result of tinder-dry forests parched by warming temperatures. This photo shows a wildfire as it approaches the shore of Bass Lake, California, in mid-September.
Scientists say the oceans' temperatures
have risen by more than 1 degree Fahrenheit over the last century. It doesn't sound like much, but it's been enough to affect the fragile ecosystems of coral reefs, which have been bleaching and dying off in recent decades. This photo shows dead coral off the coast of St. Martin's Island in Bangladesh.
A U.N. panel found in March that climate change -- mostly drought -- is already affecting the global agricultural supply and will likely drive up
food prices. Here, in 2010, workers on combines harvest soybeans in northern Brazil. Global food experts have warned that climate change could double grain prices by 2050.
Are you sneezing more often these days? Climate change may be to blame for that, too. Recent studies show that rising temperatures and carbon dioxide levels promote the growth of weedy plant species that produce allergenic pollen. The worst place in the United States for spring allergies in 2014, according to the Asthma and Allergy Foundation of America?
Louisville, Kentucky.
Climate change has not been kind to the world's
forests. Invasive species such as the bark beetle, which thrive in warmer temperatures, have attacked trees across the North American west, from Mexico to the Yukon.
University of Colorado researchers have found that some populations of mountain pine beetles now produce two generations per year, dramatically boosting the bugs' threat to lodgepole and ponderosa pines. In this 2009 photo, dead spruces of the Yukon's Alsek River valley attest to the devastation wrought by the beetles.
The snows capping majestic Mount Kilimanjaro, Africa's highest peak, once inspired Ernest Hemingway. Now they're in danger of melting away altogether. Studies suggest that if the mountain's snowcap continues to evaporate at its current rate, it could be gone in 15 years. Here, a Kilimanjaro glacier is viewed from Uhuru Peak in December 2010.
Polar bears may be the poster child for climate change's effect on animals. But scientists say climate change is wreaking havoc on many other species -- including birds and reptiles -- that are sensitive to fluctuations in temperatures. One, this golden toad of Costa Rica and other Central American countries, has already gone extinct.
It's not your imagination: Some animals -- mostly birds -- are migrating earlier and earlier every year because of warming global temperatures. Scholars from the University of East Anglia found that Icelandic black-tailed godwits have advanced their migration by two weeks over the past two decades. Researchers also have found that many species are migrating to higher elevations as temperatures climb.
The planet could see as many as 20 more hurricanes and tropical storms each year by the end of the century because of climate change, according to
a 2013 study published in the Proceedings of the National Academy of Sciences. This image shows Superstorm Sandy bearing down on the New Jersey coast in 2012.
However, it isn't the end for all Adelie penguins. About five miles from the Commonwealth Bay, another colony is thriving, which leaves scientists to conclude that the iceberg has had a direct impact of the species that is now landlocked. About 30% of the Adelie penguin population lives in East Antarctica.
Research on the iceberg's impact on the Adelie penguins can give scientists insight into the wider implications on the effects of increasing sea ice in the area.
Long-term environmental changes are projected for the Southern Ocean, which will likely affect marine predators, according to a 2015 report published the peer-reviewed journal BMC Evolutionary Biology. Environmental shifts because of climate change could also affect the breeding habitats of land creatures, finding food in a marine environment and the availability of prey for larger predators
Meet the man who spies on penguins for science
Deglaciation, the gradual melting of glaciers, is a key driver in the Adelie penguins' population over a millennium, according to scientists. But while changes in sea ice can directly affect the species, scientists say it's important to keep perspective on the penguins' population over a larger time frame.