During a a joint venture project of Australian, French, and Japanese researchers scientists found that there were twice as many Adélie penguins as originally thought. They observed a 5000km long coastal stretch in the East Antarctic. Instead of the expected 3.6 million birds they observed almost 6 million Adélie penguins in the study area. This would lead to an overall estimate of 14-16 million Adelie penguins world-wide.
This has, amongst others, implications on antarctic krill and other fisheries, as such a great number of penguins eats about 200,000t krill and 19,000t fish during one breeding season in the East Antarctic alone. The data were determined over several years by means of satellite technology, individual tagging and automatic camera monitoring.
Wind may be the great and so-far strongly underestimated factor when it comes to melting of large masses of glacier ice in Antarctica. Changing wind patterns are now receiving more attention from scientists.
Researchers have so far mostly focusses on oceanic currents. Warm water masses are melting ice shelves and glaciers from the bottom. This leads to enormous quantities of glacier ice being lost – for the Totten Glacier in eastern Antarctica alone, the loss is estimated at an incredible 63-80 billion tons of ice. Per year! Totten Glacier is the largest one, but it is not alone.
The scenario gains even more horror because of the subglacial topography on a continental scale. The surface of the bedrock under the ice is sloping downwards as you get away from the coast and into the continent, not upwards as with all other continents. This is due to the heavy ice load. This means that warmer sea water, as soon as it has overcome the ice-bedrock-boundary on the edge between the (floating) ice shelf and the glacier (resting on the ground), may penetrate much more easily as it is actually moving downhill, and that’s what water likes to do. The process may accordingly accelerate significantly as it is progressing.
Now, wind is coming in as an additional factor, making the whole system much more complicated. But the result is most likely to be yet another increase of ice loss due to basal melting. Normally, there is a rather thin layer of meltwater on top of the water column of the Southern Ocean near the antarctic coast. This meltwater layer is quite thin, but due to its low salinity it has a sharp boundary to underlying warmer waters and it tends to be quite stable. It provides a thermal buffer between the cold atmosphere or glacier ice/shelf ice masses on top and warmer waters underneath.
Strong winds can, however, disturb this relatively thin, cold layer of meltwater, making the way free for more temperate water masses from greater depth to come to the surface, where they have a warming effect on ice and air.
Strong winds are expected to increase in frequency and force in decades to come in the west wind zone in the Southern Ocean. This implies more frequent weather situations that may help warmer water masses to come to the surface, where they can melt the overlying glacier ice including ice shelves.
Robust modelling and substantial prediction of this extremely complex system will require a lot of further research work and computer processing power. Nevertheless, it may be fair to draw the following conclusions, which may not actually surprise you: 1) take climate change seriously and get something done about it ASAP 2) further research is needed …
Tabular iceberg in the Ross Sea, Antarctica: symbol of disintegrating ice shelves.
When you are talking about the “slow recovery of whale population after industrial whaling”, then the emphasise is on “slow” rather than on “recovery”, depending on the species. All large baleen whale species where hunted intensively with industrially brutal methods in the southern hemisphere, mostly between 1890 and 1970, although whaling (mainly by Japanese whalers) is still an ongoing fact, as most readers will be aware of. Natural, pre-whaling populations were reduced to fractions. The actual size of the original populations can only be estimated.
With today’s knowledge of reproduction, food resources etc., predictions of the future development of whale populations can be made. Of course, there are uncertainties inherent as with any model-based (or other) prediction, but some trends are nevertheless quite clear.
Humpback whale in Gerlache Strait: back to a natural population size around 2050?
Results vary, depending on the species, as a recent study by Australian biologists shows. Humpback whales may be back to a natural population level, estimated near 100,000 individuals, as “soon” as around 2050. Currently, there is only a third of that number around, but humpback whale cows may give birth to a calf every year and they are benefitting from a solid nutrition base.
The larger species such as fin, blue and southern right whales will take more time. Their females five birth only once in 2-3 years. Recovery is accordingly much slower, and population levels may not be more than half of the original size in 2100, more than 100 years after whaling mostly came to an end. Factors like climate change and its influences on the marine food web and the potential threat of more whaling in the future bring additional uncertainty.
Australian researchers report in the journal PLOS ONE, that they were able to determine the exact age of Krill for the first time. As known from lobsters and crabs, the age of Antarctic krill can now also be determined by the bright and dark rings of their eye stalks. So far, krill that were older than two years could not longer be determined by their size, since environmental conditions and food supply were responsible for their growth or even shrinking. If it is possible to determine the age groups of swarms of krill the CCAMLR (Convention for the Conservation of Antarctic Marine Living) would be able to determine catch limits more precicely. Since the scientists can use the same method to age determine krill in scientific collections and museums, they soon will be able to compare the age composition of past and present krill swarms.
Samples of the study yielded ages between one and five years, but the main point of the study was to establish the technique and not to actually describe the age of krill.
A glimpse into Australia’s Antarctic Science programs: Changing phytoplankton in a changing climate: href=“http://www.antarctica.gov.au/news/2017/big-changes-predicted-for-the-smallest-southern-ocean-species“ target=“_blank“>In a review on antarctic polar science projects in recent years the authors conclude that climate change also alters the composition, the distribution and the growth of phytoplankton.
Since this phytoplankton binds carbon dioxide from the air or produces chemical substances that contribute to the formation of clouds, a change in the composition and occurrence of these tiny algae could have significant influence on the future climate as well. Glacial melting and sea ice thinning favor tiny flagellate algae, while the major diet of the Antarctic krill, the diatoms, will lose their optimal habitat. The scientists need to do more work to understand how fast and how long the phytoplankton species can adapt to their new environmental conditions.
Algae – here terrestrial ones on Petermann Island – are influenced by climate change, but this is not a one way road.
Both trips in early 2018 with SY Anne-Margaretha to Antarctica and, respectively, Patagonia are mostly fully booked, but there are some last opportunities. There is one female seat in a twin cabin on the journey to Antarctica and one twin cabin still available in Patagonia due to a cancellation. Get in touch with me for further questions or with the Geographische Reisegesellschaft for reservation and booking. Please note that these trips will be German speaking! For this reason, the detailed descriptions are only available in German.
In the middle of the Southern Ocean there is a great wildlife paradise: South Georgia. The archipelago is well known for the large numbers of sea birds and seals that are breeding here. The land is home for four species of penguins: King penguins, Gentoo penguins, Chinstrap penguins and Macaroni penguins.
The scientists found a trend in a well doing Gentoo population versus a less well doing Macaroni population. They describe the Gentoo as a generalist species, feeding in the pelagic zone as well as at the sea bottom close to the coast. The Macaroni is described as a specialist species feeding all kind of crustaceans close to the shelf-break region. However, the most important and energy rich main food of both penguin species is the Antarctic krill (Euphausia superba). But while the Macaroni penguin sticks to crustaceans, the Gentoo is preferring various fish species especially during the breeding season. One important source is the commercially used Mackerel icefish (Champsocephalus gunnari) .
Life is not distributed evenly in the oceans. Water masses are complex and water fronts are of high importance. An important convergence zone is situated North of South Georgia. Here a layer of cold, oxygen-rich surface water from the South meets warm, oxygen-poor surface water from the North and sinks underneath it, before the cold water continues its way northward as intermediate water layer. Such zones can be found anywhere in the world. Here, the water masses mix. They create a corridor full of life where tiny crustaceans feed on algae and are eaten by other species like fish or sea birds. This zone is so important for the southern marine ecosystem, because it is not interrupted by any land masses. It also defines the northern boundaries of the Southern Ocean. Depending on the prevailing winds, winter sea ice distribution or the amount of large icebergs in the area, this rich mixing zone moves further to the North or to the South. Interestingly, the richest Sub-Antarctic Islands are situated within this productive belt.
Penguins swim different distances to find their food. The energy intake has to be balanced. The food of a foraging bout must cover both the energy consumption during the hunting trip as well as the time the bird spends on shore. During the breeding season the food for the offspring has to be accounted for as well. If the balance is correct, the population is doing well. If the prey changes its whereabout due to changes in its habitat (water temperature, salinity, commercial fishing), the penguins have to swim further to reach their prey or they will switch to alternative prey, with less energy outcome. The energy brought along may not be sufficient enough for the offspring to survive.
Both discussed species differ clearly in their way looking for food. The Gentoo penguins with their two chicks are often staying close to the coast. They usually return to the nest after one day foraging. The Macaroni penguins use to swim about 150 kilometers for several days to catch enough food for themselves and their single chicks. Both species have the same prey species on the menu. But if they breed together, like on Bird Island, then the Gentoo prefer various kind of fish near the coast and the Macaroni catch different crustaceans on the shelf edge.
The scientists of the study would now like to understand, how changes in the diet composition of the penguins reflect changes in the marine ecosystem. Krill and fish stocks are playing a major role in this food web, since both are resources for the animal predators and the fishing industry.
A recent long-term study reports on the development of the three brush-tailed penguins: Adélie, Chinstrap and Gentoo penguins on the South Orkney Islands. The study compares their situation with the population development around the Antarctic Peninsula. The scientists can look back on a continuous census data set of 38 years, since 1978/79. Previously only sporadic counts were done. While the populations of Adélie and Gentoo penguins were subject to regular fluctuations, the number of Chinstrap penguins decreased steadily. However, the Adélie penguin colonies were also decreasing. The Gentoo penguins did relatively well over the years, their numbers were increasing – a trend that is also observed at the Antarctic Peninsula. The researchers explain the observed fluctuations with a lively exchange of nesting birds between colonies of the archipelago. At present, Adélie, Chinstrap and Gentoo penguin populations at the South Orkneys are estimated to be about 200,000, 600,000, and 5000-10,000 breeding pairs, respectively.
Today it is assumed that a change in population size can be a good indicator of changes in the ecosystem. This is researched in a number of krill-eating species, e. g. also the brush-tailed penguins. The Commission for the conservation of Antarctic marine living resources (CCAMLR) uses this data to monitor the marine Ecosystem. With that they can set catch limits for the krill and fish fisheries.
All three species are breeding together on Signy Island, South Orkney Islands. While the breeding success of all species is equally good or bad over the years in the observed period, the population development is different. Since the beginning of the continuous census Adélie penguins decreased by 42% and Chinstrap penguins by 68%. In the same period, the originally much smaller Gentoo penguin population increased by 255%! Historical data show a completely different trend between 1947 and 1978: the numbers of the first two species increased enormously during this early period.
According to some scientists, the population development seems to be correlated to the regional decline in sea ice extent and the long-term warming of the region. However, the researchers of the present study are looking a bit deeper into the context, because ice-loving Adélie penguins and ice-avoiding chinstrap penguins are subject to the same decline. They point out that the survival rate of the young penguins during their first winter, the access to krill stocks and the increase in fur seal numbers and whales as food competitors in the area, also seem to play a major role. Between 1977 and 1994, the number of fur seals increased tenfold at Signy Island.
In order to gain a better understanding for the decline of one species and the success of another, researchers have to look into the dynamics of the system even deeper. Their long-term data of the last decades and data from other field of subjects are important components for future models and understanding of the processes observed.
Many antarctic visitors have enjoyed the hospitality of the Ukrainian Vernadsky Base. Now you can visit Vernadsky without actually traveling to Antarctica: there is now a new, complete panorama tour of the base on this website, from selected scientific working areas to the famous Faraday Bar. Click here and have fun!
North-West of the Antarctic Peninsula the South Shetland Islands are situated. Here research stations of many countries are gathering, because some of the islands are easy to reach by ship and there are relatively large ice free areas. During the last decades the climate has become noticeable warmer inWest-Antarctica, particularly at the Peninsula. Some people are comparing the summer weather of the South Shetland Islands already with the summer weather at the Falkland Islands.
The largest island of the South Shetlands is King George Island. It is approximately situated 1000 km South of Cape Horn. One-tenth of the island is free of ice and offers sufficient space for 24 research stations and refuges of 12 nations. 8 stations are operated all year long. German researchers are regularly in the area during summer time. On King George Island, many biologists tend to work. They observe the scarce plant life. Others analyse terrestrial-maritime food chain connections or study marine habitats. Ornithologists usually work with penguins or skuas. But all scientists usually also have an eye for unusual occurrences.
Polish researchers have been studying birdlife at the South Shetland Islands for almost 40 years, since their station opened for the first time in 1977. In 1981, White-rumped sandpipers (Calidris fuscicollis) were observed for the first time on Ardley Island, a small tidal island in Maxwell Bay. However, this does not mean that this species has not visited the area before. The observation program only got started in 1977. Since then small groups or single birds have appeared in the region. Over an period of 30 years, these small waders were observed during twelve years. In eight of these cases spring was warmer than usual.
White-rumped sandpipers are migratory birds of superlatives, like the Arctic tern. They breed in the Arctic tundra of North America. Within a month, the birds migrate in big flocks to the South, almost without rest. Reaching the coast of Suriname, they then turn in to the continental route and cross the Brazilian Amazon region. In October they arrive in their wintering areas in Argentina and Chile. The most restless individuals continue further and spend the winter in Tierra del Fuego or the Falkland Islands. Why some individuals would head for islands in the cold Antarctic waters, such as South Georgia, South Orkney, or South Shetlands, the researchers begin to understand slowly.
In contrast to other regions of the Antarctic continent, the Antarctic Peninsula experiences a rapid, dramatic warming. Measurements of average summer temperatures resulted in an increase of 2 degrees, the average temperatures for the winter are yet 5-6 degrees higher than 50 years ago. Lower winter temperatures and the existing hole in the ozone layer are responsible for less frequent but stronger periodical westerlycyclone systems. They transfer warm, moist, maritime air to the coast of the Peninsula including a number of feathered vagrants.
In addition, the season with sea-ice cover is about 90 daysshorter than 4 decades ago. At the Antarctic Peninsula, the sea ice arrives later and disappears earlier. All this are preconditions for faunal and floral change over the coming decades. This is especially the case for the most northerly spur of the Antarctic: the South Shetland Islands.
So it is no big surprise that even during in January this year, attentive guides and tourists at King George Island have been spotting a small flock of White-rumped sandpiper. They report them “foraging on mud in the outflow stream from a meltwater pond. The amount of time they spent resting calmly and preening suggested that they were not desperate for food.” (Stephen F. Bailey auf M/V Akademik Sergey Vavilov, in: IAATO-Newsletter)
A great trip to round the season off, with a lot of activities all the way down south to the polar circle. We had groups on board specializing in kayaking and diving, and their stories and photos were very impressive – yes, diving, that would be something, one day … The weather was pretty much on our side, we had some very nice antarctic late summer days and no extreme weather. Yesterday we were sunbathing on deck in the Drake-Passage, can you believe it? Ok, we got blown out of Whalers Bay in Deception Island the other day, but that’s part of the game down here. We could not land on Detaille Island, the kombination of poor visibility, drifting ice near all possible landing sites and wind was just too much. But the Zodiac cruise around the island was good stuff!
Plenty of humpback whales, as one might wish for in the late season, and maybe not as many penguins as might have been some weeks earlier, but still quite a lot of them on shore, more than enough for heart and soul, eye and camera.
After a rather calm crossing of the Drake-Passage, our first exposure to Antarctica was to happen in the South Shetland Islands. And quite likely our only chance to see Chinstrap penguins.
And a good opportunity to get an impression of Antarctica’s wild weather. From zero to more than 40 knots within half an hour. Our afternoon landing in Deception Island was quickly turned into a ship cruise.
Even 32 days in Antarctica will finally come to an end. The South Shetland Islands are the last stop of our Antarctic Odyssey, before we set course northwards, to more civilized latitudes. We do not have too much time left, but enough for an early morning landing. The weather is on our side, which is good for a visit to a small island on the edge of the Drake-Passage.
At least in comparison, it seems to be a tropical rain forest. Well, almost. There are some green patches, something we have not seen in a while. With the Chinstrap penguins, we can add yet another species to our species list, which is already quite impressive.
Then back to the open sea. A good two days across the Drake-Passage until we have reached southernmost South America. We pass Cape Hoorn in distance and darkness without taking too much notice of it, before we approach the Beagle-Channel in the company of dolphins. Then it is time to say goodbye to our good helicopter crew, pilots and mechanics, six of them in total, who take off in their birds and quickly disappear in the distance, not without a fine farewell to Ortelius.
Gallery – South Shetland Islands to Ushuaia – March 15-18, 2017
Click on thumbnail to open an enlarged version of the specific photo.
And while we are at it, we keep saying goodbye to many good people the next day in the morning. The very last day of a voyage is never a highlight, and port days are always very busy. But on the other side … if it is hard to leave a trip and associated people behind, then I guess it must have been pretty good 🙂
Too few short hours later, we are on our way again. Hasta la vista, Antarktis!
It is nice, for the difference, not to cover a large distance from one day to the next one. To wake up where we fell asleep. To calm down a bit, geographically, in a way.
We are in the Errera Channel as we wake up, just around the corner from Andvord Bay. And soon we are standing in a little antarctic penguin paradise. Gentoo penguins, gentoo penguins, gentoo penguins. Not in thousands anymore, but in hundreds, as they are standing on snow and rocks, looking a bit scruffy. They are moulting, probably annoyed by the itching of the feathers that are about to fall off and to be replaced by nice, new ones. Some are very curious and come close to have a look at these funny, colourful visitors.
Click on thumbnail to open an enlarged version of the specific photo.
Also the humpback whales in the Errera Channel and neighbouring waters are now in late summer mood. They have been feeding for weeks and months in productive antarctic waters. Now they are merely moving, snoozing and sleeping at the surface without doing much at all. Soon it is time to move northwards to warmer waters, also for them.
Seeing Antarctica from a bird’s perspective is a dream that we wanted to realize today. That was easier said than done. We had to abort the first attempt in the rather early morning and we spent good part of the day searching for a place where the wind was not howling with 30-40 knots. Not easy.
Click on thumbnail to open an enlarged version of the specific photo.
But then it worked. Conditions were ideal and everybody could once again board the helicopters to enjoy grand vistas of Andvord Bay and Paradise Harbour. The photos (there will be more and higher res pics after the trip) will tell the story!