The threats behind the plight of the puffin


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Louise Gentle, Nottingham Trent University

Puffins are facing a perilous future. Population numbers have fallen sharply, and there are even fears the sea bird could be heading towards extinction within the next 100 years.

A much loved and enigmatic creature, puffins are easily identified by their wonderfully coloured beaks. They waddle around in a characterful fashion and make the strangest of noises. Their endearing features have been used as the symbol of children’s books, and to illustrate many stamps – but they are now also appearing on lists of endangered species.

On Britain’s Farne Islands, numbers have gone down 12% on average over just five years, with one island’s population falling by 42%.

The common puffin, named after its puffed-up swollen appearance (although its scientific name, Fratercula arctica, arises from its resemblance to a friar wearing robes) has an extensive range across the northern hemisphere, with breeding colonies from Norway to Newfoundland.

Around 90% of the global population is found in Europe, with 60% of the population breeding in Iceland (which is also home to a tradition which involves children rescuing young, wayward puffins – “pufflings” – and returning them to the safety of the sea). The UK is home to 10% of the global puffin population, breeding on many islands and mainland coastal areas.

Although there are around 450,000 puffins in the UK, the species is threatened with extinction due to their rapid and ongoing population decline. Recent surveys of the Farne Islands revealed that despite a steady increase over the previous 70 years, numbers have declined by as much as 42% over the past five years.

Unfortunately, we know very little about the ecology of the puffin outside the breeding season. Although the birds amass in large numbers to breed, they spend two-thirds of their life alone, out in the north Atlantic sea. Consequently, they are very difficult to monitor.

What’s causing the decline?

Firstly, although puffins live for a fairly long time (the oldest recorded so far reached the age of 34), their breeding population is limited to a small number of sites. They also have a low reproductive rate, laying just one egg a year, which makes them particularly vulnerable to adverse changes in the environment and means they can take a long while to recover from negative impacts.

They are also hunted – by humans and other animals. Smoked or dried puffin is considered a delicacy (or a flavouring for porridge) in some places, such as Iceland and the Faroe Islands. But although they were once over harvested by people, hunting is now maintained at a sustainable level.

During the breeding season, puffins nest in burrows on clifftops. Although this offers the nest protection from aerial predators, such as gulls, chicks and eggs are not safe from mammals, including weasels and foxes. On Lundy Island in the Bristol Channel, the population of puffins fell to just 10 pairs, but since the eradication of rats there, things are looking up. Nevertheless, the Arctic skua can be a particular problem as it steals food from adult puffins which is intended for their young.

Living on the open ocean makes the puffin highly susceptible to pollution such as oil spills. After the Torrey Canyon oil spill in 1967, the number of puffins breeding in France the following year decreased by a massive 85%.

The puffin feeds almost entirely on small fish, including sandeels, herring and capelin, which make up over 90% of the diet of pufflings.

The birds have a specialised beak with backwards facing spines, which prevents their prey (up to around 60 fish at a time) from falling out of their mouths when foraging. But in years where the main food source is low, many chicks starve to death.

Puffins have also suffered increased mortality from the rising frequency and intensity of extreme weather events associated with climate change. A recent succession of severe storms caused 54,000 seabirds, half of which were puffins, to be washed up along coasts. Starvation was cited as the main cause of death.

On a cliff edge

Sea temperatures have increased over the past 30 years, causing indirect effects on puffin survival. The rise in temperature decreases the abundance of plankton, which in turn leads to a reduction in the growth and survival of young sandeel and herring on which the puffins rely, particularly during the breeding season. Conditions in the North Sea are even causing some puffins to travel into the Atlantic, rather than the North Sea, in search of food – a perilous trek involving greater distances and different habitats.

It seems that a combination of factors are to blame for the decline in puffins, but the reduction in their food supply, particularly as a result of increased sea temperatures, appears to be the main culprit.

The ConversationWe need to continue monitoring puffins worldwide to better understand factors affecting populations. Hopefully, we can put measures in place to minimise pollution, reduce introduced predators and promote sustainable harvesting to try and ensure that the fate of this wonderful bird is not the same as that of the dodo.

Louise Gentle, Senior Lecturer in Behavioural Ecology, Nottingham Trent University

This article was originally published on The Conversation. Read the original article.

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Why remote Antarctica is so important in a warming world


Chris Fogwill, Keele University; Chris Turney, UNSW, and Zoe Robinson, Keele University

Ever since the ancient Greeks speculated a continent must exist in the south polar regions to balance those in the north, Antarctica has been popularly described as remote and extreme. Over the past two centuries, these factors have combined to create, in the human psyche, an almost mythical land – an idea reinforced by tales of heroism and adventure from the Edwardian golden age of “heroic exploration” and pioneers such as Robert Falcon Scott, Roald Amundsen and Ernest Shackleton.

Recent research, however, is casting new light on the importance of the southernmost continent, overturning centuries of misunderstanding and highlighting the role of Antarctica in how our planet works and the role it may play in a future, warmer world.

Heroic exploration, 1913.
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What was once thought to be a largely unchanging mass of snow and ice is anything but. Antarctica holds a staggering amount of water. The three ice sheets that cover the continent contain around 70% of our planet’s fresh water, all of which we now know to be vulnerable to warming air and oceans. If all the ice sheets were to melt, Antarctica would raise global sea levels by at least 56m.

Where, when, and how quickly they might melt is a major focus of research. No one is suggesting all the ice sheets will melt over the next century but, given their size, even small losses could have global repercussions. Possible scenarios are deeply concerning: in addition to rising sea levels, meltwater would slow down the world’s ocean circulation, while shifting wind belts may affect the climate in the southern hemisphere.

In 2014, NASA reported that several major Antarctic ice streams, which hold enough water to trigger the equivalent of a one-and-a-half metre sea level rise, are now irreversibly in retreat. With more than 150m people exposed to the threat of sea level rise and sea levels now rising at a faster rate globally than any time in the past 3,000 years, these are sobering statistics for island nations and coastal cities worldwide.

An immediate and acute threat

Recent storm surges following hurricanes have demonstrated that rising sea levels are a future threat for densely populated regions such as Florida and New York. Meanwhile the threat for low-lying islands in areas such as the Pacific is immediate and acute.

Much of the continent’s ice is slowly sliding towards the sea.
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Multiple factors mean that the vulnerability to global sea level rise is geographically variable and unequal, while there are also regional differences in the extremity of sea level rise itself. At present, the consensus of the IPPC 2013 report suggests a rise of between 40 and 80cm over the next century, with Antarctica only contributing around 5cm of this. Recent projections, however, suggest that Antarctic contributions may be up to ten times higher.

Studies also suggest that in a world 1.5-2°C warmer than today we will be locked into millennia of irreversible sea level rise, due to the slow response time of the Antarctic ice sheets to atmospheric and ocean warming.

We may already be living in such a world. Recent evidence shows global temperatures are close to 1.5°C warmer than pre-industrial times and, after the COP23 meeting in Bonn in November, it is apparent that keeping temperature rise within 2°C is unlikely.

So we now need to reconsider future sea level projections given the potential global impact from Antarctica. Given that 93% of the heat from anthropogenic global warming has gone into the ocean, and these warming ocean waters are now meeting the floating margins of the Antarctic ice sheet, the potential for rapid ice sheet melt in a 2°C world is high.

In polar regions, surface temperatures are projected to rise twice as fast as the global average, due to a phenomenon known as polar amplification. However, there is still hope to avoid this sword of Damocles, as studies suggest that a major reduction in greenhouse gases over the next decade would mean that irreversible sea level rise could be avoided. It is therefore crucial to reduce CO₂ levels now for the benefit of future generations, or adapt to a world in which more of our shorelines are significantly redrawn.

This is both a scientific and societal issue. We have choices: technological innovations are providing new ways to reduce CO₂ emissions, and offer the reality of a low-carbon future. This may help minimise sea level rise from Antarctica and make mitigation a viable possibility.

The ConversationGiven what rising sea levels could mean for human societies across the world, we must maintain our longstanding view of Antarctica as the most remote and isolated continent.

Chris Fogwill, Professor of Glaciology and Palaeoclimatology, Keele University; Chris Turney, Professor of Earth Sciences and Climate Change, UNSW, and Zoe Robinson, Reader in Physical Geography and Sustainability/Director of Education for Sustainability, Keele University

This article was originally published on The Conversation. Read the original article.