Life on the Rocks: Climate Change and Antarctic Biodiversity

By now, it’s a familiar story: climate change is melting glaciers in Antarctica, revealing an increasing proportion of ice-free terrain. The consequences of this melt are manifold, and one may be surprising: as more ground is bared, Antarctic biodiversity is expected to increase.

Currently, most of the terrestrial biodiversity— microbes, invertebrates, and plants like grasses and mosses— occurs in the less than one percent of continental Antarctica that is free of ice. A recent Nature article predicted that by the end of the 21st century, ice-free areas could grow by over 17,000 square kilometers, a 25 percent increase.

Members of the shrinking Torgersen Island Adélie colony (Source: Rachel Kaplan).

This change will produce both winners and losers in Antarctica’s ecosystems, according to Jasmine Lee, lead author on the above paper, and the game will be problematic. “Some of the winners are likely to be invasive species, and increasing invasive species could negatively impact the native species,” Lee told GlacierHub. “More isn’t necessarily better if new species are alien species.”

The Antarctic Peninsula, an 800-mile projection of Antarctica that extends towards South America,  is one of the fastest-warming places on Earth, and 80 percent of its area is covered by ice. The many outlet glaciers of the Antarctic Peninsula Ice Sheet primarily shrink through surface melting, which reduces volume, while tidal action spurs calving. Lee and her coauthors constructed two models based on two Intergovernmental Panel on Climate Change (IPCC) climate forcing scenarios. Under the strongest IPCC scenario, ice-free areas in the peninsula are expected to increase threefold, and Lee expects biodiversity changes in this region to be obvious by the year 2100. She predicts that some native species will expand their ranges south in response to the creation of new habitat and milder conditions, and invasive species will thrive for the same reasons.

This pattern is already apparent in the distribution of a number of penguin species. As climate warms, sea ice-obligate species like Adélie and Emperor penguin are shifting and contracting their ranges southward, seeking sea ice. Likewise, ice-intolerant gentoo and chinstrap penguins, typical of the Subantarctic latitudes, are moving south as the ocean becomes increasingly free of ice. As temperatures continue to rise, this biogeographic chess will play out increasingly across Antarctica.

Glaciers in the Antarctic Peninsula converge into one calving front (Source: NASA ICE/ Flickr).

“The greater the degree of climate change, the greater the biodiversity impacts,” predicted Lee. She added that counting an Adélie colony in a “real-life ice-free area” was a highlight of her fieldwork.

Interestingly, Lee and her coauthors found that higher biodiversity in the short-term may yield greater homogeneity in the long-term, as invasive species become established and potentially out-compete native species. It’s hard to know how to feel about these ecosystem-wide transitions, said Lee. “The fact that we are driving these changes through anthropogenic climate change should remind us that our actions impact the entire earth, even in what we consider the remotest and most pristine regions. I think we should feel accountable and know that because humans have the power to change the earth, we should do our best to look after it,” she said.

Curious Adélie penguins assess Lee on Siple Island (Source: Jasmine Lee/Twitter).

On June 1, President Donald Trump made a speech announcing the United States’ exit from the Paris climate agreement, obfuscating international cooperation on climate change mitigation. Lee feels this decision sends the wrong message to the rest of the world, but she hopes that the United States will find a way to continue meeting the environmental standards set forth. “America should be a leader in renewable energy technology and policy. However, I am also hopeful that the American businesses and states can reach the Paris accord milestones for America in spite of Trump. And this will show that every city, state or business can have a positive impact regardless of governance,” she said.

No matter the ebb and flow of the political tide, the Antarctic Peninsula is changing. As Antarctic glaciers melt and biodiversity changes, mitigation will require the cooperative efforts of the world.

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Explore the Homeland of the Emperor Penguin

Each winter, thousands of Emperor Penguins leave the ocean and start marching to a remote place in Antarctica for their breeding season. Blinded by blizzards and strong winds, only guided by their instincts, they march to an isolated region, that does not support life for most of the year…

March of the Penguins

The famous documentary March of the Penguins, directed by Luc Jacquet, earned the emperor penguin fanfare and admiration around the world. With their charismatic shape and loving nature, emperor penguins reside on the ice and in the ocean waters of Antarctica for the entirety of their lifespan, living on average from 15 to 20 years. 

Satellite data has been used to help researchers better understand emperor penguin populations and how they respond to environmental variability, including the threat of a rapidly warming planet. But the information gleaned so far remains too limited to significantly help conservation efforts. Enter André Ancel, a researcher who led a team on a mission to study the remaining areas where emperor penguins might breed. His team recently published their findings in the journal Global Ecology and Conservation.

March of the Penguins Official Trailer:

 

Photos of emperor penguins taken close to Dumont d’Urville station (source: André Ancel).
Photos of emperor penguins taken close to Dumont d’Urville station (source: André Ancel).
“The climate of our planet is undergoing regional and global changes, which are driving shifts in the distribution and phenology of many plants and animals,” Ancel writes in his paper. “We focus on the southern polar region, which includes one of the most rapidly warming areas of the planet. Among birds adapted to live in this extreme and variable environment, penguin species are the best known.”

Even with their extreme adaption capabilities, emperor penguin breeding colonies are impacted by the fact that chicks often succumb to Antarctic elements. “Though they are one of the tallest and heaviest birds in the world, the survival rate of newborn emperor penguins is really low, only about 19 percent,” Shun Kuwashima, a PhD student at UCSC and self-declared penguin lover, explained. The purpose of Ansel et al.’s research was to predict how the species responds to climate change and to better understand the penguins’ biogeography, or geographical distribution.

“There are only about 54 known breeding colonies,” notes Ancel, “many of which have not yet been comprehensively studied.”

Location of the 54 emperor penguin breeding colonies around the Antarctic continent (source: Ancel et al.).
Location of the 54 emperor penguin breeding colonies around the Antarctic continent (source: Ancel et al.).
But finishing the research was a problem, considering that access to emperor penguin colonies remains limited. Getting accurate measurements on the size and location of the colonies relies on ground mapping and aerial photographs, which is “laborious, time consuming and costly,” according to Ancel. Even with the help of satellites, heavy cloud cover in the winter degrades the quality of images. Not to mention, the lack of light further complicates the collection of accurate data. In addition, the break-out of sea ice at the end of the breeding season can reduce the probability of detecting breeding colonies.

Although the authors did not actually conduct any exploration or examine remote sensing data to locate new emperor penguin colonies, they used data on the location of known colonies to make their findings. Based on the behavioral patterns of penguins, including movement and dispersal, and on the availability of food, the researchers found “six regions potentially sheltering colonies of emperor penguins.”

“What a big ship” (source: Arctic Al / Flickr).
“What a big ship!” (source: Arctic Al /Flickr).
It is true that scientists have looked for emperor penguin colonies with satellite data in the past, but the method was limited. To make improvements and find potentially missing colonies, the team developed an approach for calculating separation distance between colonies.

The approach determined the loxodromic separation distance (the shortest distance between two points on the surface of a sphere) between each pair of geographically adjacent colonies. Then, based on the fact that a breeding adult can travel 100 km from the colony during the breeding period, assuming a circumpolar distribution, the researchers pinpointed the potential areas where emperor penguin colonies might exist or could settle.

Emperor penguins with a chick (source: André Ancel).
An emperor penguin with a chick (source: André Ancel).
“Based on distances between existing colonies, we found six regions potentially sheltering colonies of emperor penguins,” Ancel explained to GlacierHub. “Some of the regions are located near glaciers.”

The regions identified by Ancel et al. do not fundamentally differ from the areas of other known colonies, which makes it possible that there are more than 54 colonies. It is similarly plausible that emperor penguins are adapting to new conditions through behavioral changes, Ancel indicated.

Safe harbor for an emperor penguin chick (source: Ignacio Nazal / Flickr).
Safe harbor for an emperor penguin chick (source: Ignacio Nazal/Flickr).
He expressed anxiety about climate change, noting that emperor penguins do not appear to show much flexibility in this regard. Emperor penguins live on sea ice off the coast, with some living near glaciers, including by Taylor Glacier, Mertz Glacier and Dibble Glacier. They require a proper amount of ice: not too much, so they can walk to the sea and hunt for food, but also not too little, so they can stay away from predators.

“Emperor penguins, like many other sea animals, are critically influenced by the harmful effects of global warming,” Kuwashima told GlacierHub in a recent interview. “The entire emperor penguin population could decrease by a third by the end of the century due to the inadvertent effect of climate change.”

It is heartbreaking to imagine that we may no longer be able to see the adorable emperor penguin chicks in Antarctica, but emperor penguins are in danger. As research conducted by Trathan et al. in 2011 showed, “In the Antarctic Peninsula region, one of the most rapidly warming parts of the planet during the latter part of the 20th century, one emperor colony has disappeared.”

Emperor penguin chicks at play (source: Ian Duffy / Flickr).
Emperor penguin chicks at play (source: Ian Duffy/Flickr).
Ancel concluded, “Our analysis highlights a fundamental requirement, that in order to predict how species might respond to regional climate change, we must better understand their biogeography and the factors that lead to their occupation of particular sites.” Armed with this knowledge, we might still be able to protect this beautiful species.

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Roundup: Penguins, Antarctica, and Geological Games

Roundup: Penguins, Antartica, and Geology Board Games

Looking for New Emperor Penguin Colonies

From ScienceDirect: “Knowledge about the abundance and distribution of the emperor penguin is far from complete despite recent information from satellites. When exploring the locations where emperor penguins breed, it is apparent that their distribution is circumpolar, but with a few gaps between known colonies. The purpose of this paper is therefore to identify those remaining areas where emperor penguins might possibly breed. Using the locations of emperor penguin breeding colonies, we calculated the separation distance between each pair of geographically adjacent colonies. Based on mean separation distances between colonies following a circumpolar distribution, and known foraging ranges, we suggest that there may yet be six undiscovered breeding locations with half of these in Eastern and the remainder in Western Antarctica.”

Read more about it here.

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A group of Emperor penguins and their chicks (Source: Jenny Varley/Creative Commons).

 

Patterns of Plant Succession in Antarctica

From Infona: “Maritime Antarctica is severely affected by climate change and accelerating glacier retreat forming temporal gradients of soil development. Successional patterns of soil development and plant succession in the region are largely unknown, as are the feedback mechanisms between both processes. Here we identify three temporal gradients representing horizontal and vertical glacier retreat, as well as formation of raised beaches due to isostatic uplift, and describe soil formation and plant succession along them.”

Learn more about it here.

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King George Island, Antartica (Source: Acaro/Creative Commons).

 

19th Century Geology Board Game

From : “Wonders of Nature in each Quarter of the World was an early nineteenth century educational board game designed to teach children about some of the natural wonders of the world, such as volcanoes. The game was produced at a time of advances in geological thinking and geographical expeditions and this study places such changes and events within the context of the pastime, and presents an interesting window on the way geology was perceived almost two centuries ago.”

Learn more here.

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A view of the Wonders of Nature board game (Source: Jane Dove/Geology Today).
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