The link below is to an article reporting on the collapse of the world’s largest King Penguin population.
Fishing nets pose a serious risk to the survival of penguin species, according to a new global review of the toll taken by “bycatch” from commercial fishing. Fourteen of the world’s 18 penguin species have been recorded as fishing bycatch.
Among the species under threat are Tasmania’s little penguins and New Zealand’s yellow-eyed penguins, as detailed in a review, published in the journal Endangered Species Research.
The review shows the level of bycatch is of greatest concern for three species: Humboldt and Magellanic penguins, both found in South America, and the endangered New Zealand yellow-eyed penguins.
On New Zealand’s South Island, yellow-eyed penguins are down to fewer than 250 nests. Previous population strongholds have declined by more than 75%. Conservative population models predict local extinction of yellow-eyed penguins by 2060, if not earlier.
Penguins are among the world’s most iconic and loved birds, despite the fact that many people never get to see one in the wild. Indeed, the opportunities to do so are diminishing, with ten of the 18 penguin species threatened with extinction. After albatrosses, penguins are the most threatened group of seabirds. And, like albatrosses, bycatch is thought to be a serious issue for some species.
On land, many penguins are now well protected, thanks to the efforts of conservation researchers, government agencies, community groups and tourism operators. Where many penguins were once vulnerable to attack from introduced predators, or to habitat loss from farming or development, today the biggest worry for many penguin chicks is how to get more food out of their parents.
But below the waves it’s a different story. Over thousands of years, these keen-eyed seabirds have evolved to catch food in the depths, while avoiding natural predators such as seals and sharks. But they cannot see the superfine nylon fishing nets invented in the 1950s which fishers now set in penguin foraging areas.
Little penguins, whose scientific name Eudyptula minor literally means “good little diver”, typically forage in the upper 20 metres of the ocean, with each dive lasting about 90 seconds. The larger yellow-eyed penguin – Megadyptes antipodes, the “big diver of the south” – prefers to hunt on the seafloor some 80-90m down, holding their breath for 2-3 minutes before coming up for air. If they do not encounter a fishing net, that is.
Gillnets (also called set nets) in particular are very dangerous for penguins. These nets are set in a stationary position rather than being dragged through the water. They are designed to catch fish around their gills, but can just as easily snare a penguin around its neck.
If it gets tangled in a net, a penguin will panic and drown in minutes. In Tasmania, nets with more than 50 drowned little penguins have been found washed ashore. Other penguins are found on beaches with characteristic bruising from net entanglement around their necks.
When a penguin is killed at sea, this has knock-on effects back at the nest. The chicks will die of hunger or fledge underweight, with little chance of surviving their first year at sea.
The breeding partner left behind will probably skip a breeding season; some penguins never find another partner after losing their mate. I have seen them calling plaintively from their nest, or even going down to the shore in the evening to look out to sea, before returning to their nest all alone.
In New Zealand, the endangered yellow-eyed penguin is declining. Current population models predict their extinction on the New Zealand mainland by 2060, or potentially even earlier. Yellow-eyed penguins are facing many threats mostly because they are simply living too close to humans.
Whereas threats on land are reasonably well managed, threats at sea need urgent attention. Marine habitat degradation by industries that damage the seafloor will take decades to recover. Similarly, pressures from climate change will not have a quick enough fix to save yellow-eyed penguins from local extinction.
There is one thing, however, we can change immediately: the needless death of penguins in fishing nets. This will give already struggling penguin populations a bit of a breather and maybe even the resilience required to deal with the many threats they face in their daily fight for survival.
Judging by the number of penguins washed ashore with net injuries, many fishers simply discard penguins’ carcasses at sea rather than reporting bycatch or working towards solutions to mitigate it.
Do we really want penguins to drown for our treat of fish and chips? Less destructive fishing methods are available that do not cause penguin bycatch and the death of other protected species.
But these more selective fishing methods would require fishers to change gear, which costs money. Currently, there is very little legal or commercial incentive for fishers to do anything about penguin bycatch.
But there are a couple of things you can do. Please do not just buy any fish with your chips – ask which species it is and how it has been caught. You can use a sustainable seafood guide, such as New Zealand’s Best Fish Guide or Australia’s Sustainable Seafood Guide. That way you can help the penguins snag a safe fish supper of their own.
Penguin numbers exploded in East Antarctica at the end of the last ice age, according to research published today in BMC Evolutionary Biology. Despite their image as cold-loving creatures, the increase in Adélie penguin numbers seems to be closely linked to shrinking glaciers, raising the possibility the these penguins could be winners from current climate change.
Adélie penguins are one of only two penguin species that live on the Antarctic continent. Their cousins, emperor penguins, may be the movie stars, but it is the Adélies that are the bigger players in the Southern Ocean. They outnumber emperors by more than ten to one, with a population of over 7.5 million breeding adults and counting.
Given the abundance of Adélie penguins and their crucial role in Southern Ocean ecosystems, there has been a great deal of interest in understanding how the species is likely to respond to future climate change.
Sensitivity to sea ice
Breeding colonies have been monitored for decades to determine the effects of a changing environment on the penguins. A common finding of many of these studies is that Adélies are highly sensitive to sea ice conditions.
Unlike emperor penguins, Adélies do not nest on the sea ice, but they must cross it to reach their nests on land. As everyone knows, penguins are not the most efficient walkers, and in years with a lot of sea ice their journeys to and from the ocean to feed their chicks can become lengthy. With a longer wait between meals chicks are less likely to survive.
In an extreme case, extensive sea ice at one breeding colony had a devastating impact in 2014, and not a single chick survived.
Based on these observations over years and decades, there has been concern that changing sea ice conditions, including increases in certain parts of Antarctica, could have a serious impact on Adélie penguin numbers in the future.
Short-term vs long-term climate change
However, the climate change that is taking place now is not a decadal trend. Rather, the shrinking glaciers and ice sheets, changing sea ice conditions, and shifting currents and weather patterns represent a global change to a new climate.
We therefore set out to understand how Adélie penguins in East Antarctica were affected by the last big shift to a different climate: the ending of the last ice age.
Following similar methods to our previous study on emperor penguins, we used genetic data to uncover the trend of the Adélie population in East Antarctica over the past 22,000 years.
The end of the ice age
We found that, as for the emperor penguins, Adélies were far less common during the ice age. This is not at all surprising since most of their nesting sites would have been covered with glaciers and their feeding grounds encased in sea ice that never melted.
Following the end of the ice age 20,000 years ago, temperatures increased slowly, and after a few thousand years of warming the glaciers and ice sheets began to shrink. Fast forward to 10,000 years ago and the annual sea ice melting cycle that we see today was established.
Given the sensitivity of Adélie penguins to sea ice changes today, we predicted that Adélie numbers would remain very small until 10,000 years ago when sea ice conditions became similar to what they are now.
However, the penguins surprised us again. We found that the number of Adélies exploded by around 135-fold, but the expansion pre-dated the sea ice change by at least 3000 years.
The proliferation of Adélie penguins in East Antarctica began during a period of ice sheet and glacier retreat, which would have increased the amount of ice-free ground available for nesting.
A study of Adélie penguins at the Scotia Arc, on the opposite side of the continent, found that numbers in this region rose 17,000 years ago. That expansion was several thousand years before the growth of the East Antarctic population, but coincided with the shrinking of glaciers in the Scotia Arc. This lends further support to our conclusion that it was glacier retreat, rather than changing sea ice conditions, that caused the hike in Adélie penguin numbers after the last ice age.
This is an important finding, as it suggests that the effects of climate change on a species over thousands of years can be quite different to the effects over years or decades. Given the long-term nature of contemporary climate change, we suggest that it is critical to consider millennial-scale trends alongside decadal ecological studies when predicting the effects of climate change on a species.
Could penguins benefit from future climate change?
Glaciers and ice sheets in Antarctica will continue to shrink. As this happens, ground that was previously covered in ice will become suitable for Adélie penguin nesting. In regions with adequate food supplies and where sea ice conditions remain favourable, Adélie penguin numbers may continue to grow.
A recent study using satellite images showed that one breeding colony in the Ross Sea grew by 84% between 1983 and 2010, as a direct result of a glacier shrinking by 543 m and uncovering new nesting sites.
While it seems that East Antarctic Adélie penguins might come out on top as climate change winners, it is important to keep in mind that for penguins to flourish their food supplies must be plentiful enough to meet the demands of a growing population. Whether this will be the case in the future remains to be seen, as Adélie penguin prey species, such as Antarctic krill, are threatened by both climate change and commercial fisheries.
The link below is to an article that appeared for World Penguin Day, but it is still a great article to read today.
The weather in England is famously dreary, and this winter it’s been worse, not only dismal but windy and stormy. Humans have developed ways to cope with this — pajamas, whiskey, Law & Order marathons — but penguins, even ones living in relative comfort in captivity, aren’t so lucky. And the ones at the Sea Life Center in Scarborough are getting downright depressed.
Scarborough’s Humboldt penguins really ought to be able to tough out winter weather; their native habitat in coastal Peru and Chile does get extreme weather events. But the British winter has been relentless and the penguins are having none of it:
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Being a baby penguin is no easy ride. To survive, the chicks must escape starvation, the jaws of predators, and being beaten or pecked to death by other penguins. Now, on top of these dangers, there comes evidence the baby birds are facing another challenge to their existence: climate change, which is making their habitats increasingly deadly.
Scientists have known for a while that the warming atmosphere is changing the global food chain, and that these alterations can starve seabirds. But a team of researchers that has been monitoring penguins since the 1980s alleges that more extreme weather is directly responsible for killing these birds, mainly through abnormal heat and powerful rainstorms. These worsening environmental stresses can decimate as much as half of a penguin-chick population in a year, they say in a new study in PLOS ONE.
The scientists, led by University of Washington biology professor Dee Boersma…
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