Arctic Tipping Points

Archive for the ‘ATP experiment July 2009’ Category

The University Center of Svabard (UNIS) in winter. Please remark the magic light environment that ic characterstic for the return of day light (4 months of darkness).

In the early morning hours of June 29 Jan Mayen arrived at Longyearbyen on Spitsbergen to bring scientists, equipment, Arctic water and zooplankton to the site of an experiment that will last 4 weeks.  Large amounts of equipment were transported to the University Center on Svalbard (UNIS, www.unis.no).  The samples and water were stored in the cooling rooms.  Since then a team of about 25 participants from 5 nations have unpacked the equipment, installed the temperature controlled water baths and taken care of organisms.  At times the confusion was immense, but with the right spirit and the ability to improvise and find solutions most of the activity is now shaping up.

The logistics of such an experiment are remarkable.  After all entire laboratories have to be shipped from 5 European institutions to 78 °N and running in 1-2 days.  The right water and organisms have to be sampled, the cool rooms have to have the right temperature, affordable housing has to be found, transportation and storage of piles of boxes and containers have to sorted out etc.

This blog will at irregular time intervals report from the experiment.  It will discuss a few scientific details that are of general interest throughout the experimental period.  And it will add description of the Longyearbyen settlement, important facts and communicate some of the history of the place and Svalbard.

Before we do so we have to look in more detail on the ATP experiment that now takes place.  The work is part of Workpackage 4 (WP4), Experimental exploration of climatic tipping points for Arctic marine ecosystem components.  What are the objectives of WP4? It aims to supply Workpackage 5, Future trajectories of Arctic ecosystems (WP5) with climatic thresholds and tipping points for key Arctic ecosystem components and processes, as well as to validate those identified in Workpackage 3, Extraction of Arctic regime shifts and tipping points from time series records (WP3). Ecological modelling and experimentation work best in an iterative manner, where each informs subsequent activities by the other. Therefore, experiments to be conducted under WP4 will also be used to test climatic thresholds and tipping points hypothesised from model outputs (WP5).

Climatic thresholds and tipping points will be identified through a series of concerted experiments and comparative analyses across the full range of Arctic warming expected under the scenarios developed by the regional-specific projections. Experimental work in the laboratory and the field will be conducted using experimental and/or natural temperature gradients. The response variables will include ecosystem and organism processes and traits, and the treatment variables will include pressures associated with Arctic climate change, as well as the interactions between these pressures. Research on acidification impacts will focus on testing for interactions with warming, thereby avoiding overlap with studies of direct effects of acidification, which are the subject of research (e. g. FP7 EPOCA). The experiments will also be used to develop early warning of climatic thresholds and tipping points to Arctic organisms and ecosystems. In particular, genomic markers of climate-driven stress will be developed using experiments to investigate whole-genomic responses to climatic changes.

Svalbard reindeer can be seen all over Longyearbyen. Photo R. van Meurs

Over the years the largest settlement on Svalbard, Longyearbyen, has developed from an isolated mining place to on of the best-connected and visited place in the High Arctic.  Spitsbergen is not a country, but an archipelago with a specific governing structure.  It flies the Norwegian flag, but has a governor, natural resources on land can be exploited by the signatory powers that signed the Svalbard convention, and it is not part of Schengen etc.  Svalbard has thus no capital, but Longyearbyen with its 1700 permanent inhabitants is the centre of the archipelago.  It is here the airport is situated, the governor’s office is located and most shops to be found.  It was founded in Adventfjord by the US-American entrepreneur John Munro Longyear in 1905 and started as coal mine.  Over the decades several coalmines have been developed and exploited.  Now coal is only exploited in a smaller mine close to Longyearbyen and is only used for the local power plant, the only major power plant based on coal (or gas) in Norway, which receives its electricity exclusively from hydropower.  Over the years Longyearbyen, the settlement Ny Ålesund and the coal mine Svea developed into a society that is based on three foundations: coal mining, tourism and science.  In Longyearbyen we find the University Center in Svalbard (UNIS; www.unis.no), which is a most important education and research facility in the High North.  UNIS has about 350 students, half of them are foreigners.  It is in these facilities some of the ATP the experiments are carried out.  Other important facilities are EISCAT (European Incoherent Scatter; www.eiscat.com), Svalbard Science Forum (ssf.npolar.no/pages/start.htm) and the Kjell Henriksen Observatory Svalbard 78°N (http://kho.unis.no).

All our incubators are now installed and the instruments are running.  Not all is developing as planned, but we are confident.  The zooplankton groups work not only with feeding and egg production, but also with zooplankton development experiments.  We have full access to the UNIS building and in the light summer nights we can work whenever we wish or have to in full daylight.  We are planning to replenish our living zooplankton stocks with new animals tomorrow.

Sorting zooplankton in a small vessel. Photo K. Solovyev

Which of the fours spellings is the correct one?  It were the Vikings that discovered a “cold edge” (sval bard) during a journey northwards in 1194.  It is assumed that they found Svalbard, i.e. parts of the archipelago.  In 1596 the Dutch Willem Barents, on a mission to find the Northeast Passage and to sail to the rich Asian markets, discovered and mapped the islands that today are called Svalbard.  Barents explored in particular the island of Spitsbergen and because of his Dutch Spitsbergen is written with an s.  At this time it was believed that Spitsbergen was a part of Greenland and from the British side the term Greenland instead of Spitsbergen was applied for a long time, first of all for political reasons.  They did not want to acknowledge that the Dutch “discovered” the island.

Barents failed to find a passage to Asia, but he and those that came after him discovered the Svalbard archipelago, the isolated island in the Norwegian Sea, Jan Mayen, and Novaja Zelmja.  Further, they found the rich feeding grounds of whales and this induced a period of significant Dutch presence on Svalbard.  There are, however, rumours that the Dutch employed Basques that were skilful in whaling.  There were many settlements and at times people even overwintered.  The reason for the frenzy for whaling was lamp oil.  All over Europe whale oil was the main light source in the 16th and 17th century.  After the depletion of the whale stocks hunters turned for a long time to walrus hunting because the ivory of their sizeable teeth was of great value.

The Pomors, hunters and farmers form northern Russia, in particular from the White Sea region, visited Svalbard and settled there.  They called Svalbard for Grumant, which is possible based on the term Greenland.  This name is not common anymore, but one of the former Russian coalmines in Isfjord is called Grumantbyen.  A German that visited the islands in 1675 introduced the German spelling Spitzbergen and various English writers also adopted this term.  In 1925 the Norway were granted sovereignty over the islands and used the opportunity to introduce the old Norse term Svalbard, which not only includes Bjørnøya (Bear Island) and Kvitøya.  Officially the name is now Svalbard, but in every day language the region is usually called Spitsbergen or Spitzbergen.  The four terms thus reflect the history of this archipelago.

Yesterday we used the UNIS ship Polarsirkel to cross Isfjord to sample zooplankton in Burebukta on the northern shores.  The weather was fine, but easterly winds picked up in the middle of the fjord and made the crossing a rather cool and refreshing experience, in particular with an outboard motor of 200 horse power and top speed of 40 nm per hour!  However, in Borebukta the weather calm and sunshine and work with the zooplankton net resulted in that we had to get rid of clothing under our survival dresses.  We found a good sample of zooplankton with lots of the Arctic form Calanus glacialis present.  We did not find adult females, but so called CV 5 stages, specimens that prepare for overwintering at depth and which will come to the surface as mature adults and spawn during next years spring bloom.

Grey skies of Longyearbyen and the Adventfjord. Photo Jesus M. Arrieta.

The first experimental results indicate that changes in response to varying temperature are relatively slow, involving shifts in the composition of algae, reaching maximum abundance at intermediate temperatures, of about 4-6  °C, and a stronger response of bacteria and protozoans, which abundance increases with increasing temperature, thereby rendering the community more dominated by consumers, that release CO2 instead of capturing it, with warming.  A second experiment to examine the response of the microbial planktonic community to warming will be initiated with a community adapted to warmer, 6.2 º C, Atlantic water. This experiment should allow us to resolve the contrasts in the response to warming between these two communities and make inferences on how each will respond to warming.

In order to do so, a fast, 200 hp engine, boat from UNIS was used to reach the centre of Isfjorden, where about 600 L of warm, 6.2 °C, water, including its plankton community, was pumped and distributed into 60 L carboys, that were transported and stored in cooling units at UNIS awaiting for the experiment to be initiated.  The work was done on a cloudy day and choppy conditions.

After succesfully sampling in the centre of Isfjord Carlos Duarte smiles. Photo Jesus M. Arrieta.

As mentioned earlier tourism, science and coalmining are the three activities that the Svalbard society is based upon.  Tourism and science are clearly on the rise.  In an sensitive, arctic environment there is a continues debate how much activity should be the maximum impact of human activities and this discussion does not exclude science.  The governor of Svalbard and the Norwegian government observe the human impact on Svalbard and set restrictions when a limit is reached, also for science.  Never-the-less, scientific activities on Svalbard are a crucial segment of today’s human activity.  With major players such as the Norwegian Polar Institute, the University Centre in Svalbard and the Kings Bay in Ny Ålesund, Svalbard is the most important region for science in the Arctic.  While scientific activities in other parts of the Arctic Ocean, in particular in Arctic Canada, are on the rise, science on Svalbard will also in the future play a most important role.

That has, however, not been the case all the time.  Traffic to the Arctic and economic activities strongly increased in the beginning of the last century.  Beside fishing and hunting, early settlers watched out for resources on land, such as gypsum, minerals and in particular coal.  When Norway was given the sovereignty over Svalbard by the predecessor of the United Nations, several signatory nations extracted coal: The Netherlands in Barentsburg, Norway in Longyearbyen and Sweden in Svea.  The Dutch company in Barentsburg finally sold the mine to Russia which after this purchase founded two additional settlements, all based upon coal mining:  Grumantbyen and Pyramiden in Isfjord.  Svea, to day a most significant coal mine in van Mijenfjord south of Isfjord, was bought by Norway.  From then on only Norway and Russia extracted coal and had permanent settlements on Svalbard.  On the background of the political differences between the two countries co-existence was complicated, but on the whole peaceful.  Even today there are conflicts between the Russian Trust Arktikugol that runs the last Russian settlement in Barentsburg and Norway.  Presently the right to fly helicopters except for mining related activities is a matter of dispute where Norway’s position is that helicopter traffic should be clearly limited to the transportation of personnel, science and rescue.  Visiting Barentsburg is an experience nobody should miss when visiting Svalbard.  With a few hundred people living there and the few tourists that daily visit the village the Russian governors building is impressively spacious.  In particular the 2 m high, high security fence surrounding the building astonishes.  What may the reason be?

Sampling new water for an expriment. It is the middle of summer and only light clothing is needed. Photo Jesus M. Arrieta.

About 800 litres of water collected during the ATP cruise on board Jan Mayen, entered the cold chambers at the University Center of the Svalvard (UNIS, ), in Longyearbyen, an Arctic town of 1,700 people at 78 º N 15 º E in the Svalvard Islands.

This volume was distributed in 20 llitre jars and installed into temperature controlled baths maintaining temperature at each of 7 different levels, ranging from 1 ºC to 9 ºC, increasing at 1.5 º C steps, thereby encompassing the range of warming expected to occur in the Arctic during the 21^st Century.

Experimental units enclosing Arctic communities

This experiment is one of the central activities of the ATP project. The goal is to experimentally establish the threshold of warming beyond which abrupt changes in the plankton community may occur. These changes are expected to affect the structure of the plankton community as well as its activity, and may involve a reorganization of the food web of the Arctic Ocean, affecting its capacity to act as sink for CO₂ as well.

It is evident that extrapolating from these experimental results of responses of microscopic planktonic organisms, with generation times in the order of 1 day, involving responses assessed over 10 days, to predict the changes that may occur during the coming decades involve importance uncertainties. Indeed, the goal is not so much to establish these predictions, but to provide a basis to test the predictions derived from models and theoretical frameworks developed within the ATP project.

The team involved in the experiments with microplankton includes 11 researchers, 9 spaniards, 1 swedish and one American, sharing the lab with a team of Norwegian, polish, rusian and german colleagues busy assessing responses of the large crustacean copepods present in Arctic waters. The activity in the laboratory does not stop around the clock.

That the days in the laboratory are endless is a more obvious truth in Longyearbyen than anywhere else, with the sun describing a circle, at an elevation of 30 to 50 º over our heads, 24 h a day. Moreover, the fog and low laying clouds that appear during the day often vanish at around midnight, leaving bright, sunny nights. The bright sunlight enters the window of the apartment I use at about 3 to 4 am. The apartment is so well insulated for the cold winter months than my apartment experiences a severe midnight greenhouse effect, with temperature mounting above 25 º C in the middle of the night.

Main street at Longyearbyen

In leaving my home in Majorca, Spain, to come for three weeks to the Arctic, I encountered consolation in the thought that I will encounter some consolation in avoiding the rigors of the warm summer temperatures. However, I find myself awake in the middle of the night, sweating on the warm room and watching through the landscape illuminated by the bright midnight sun. It is not only me who sweats: the snow field at the end of the valley where Longyearbyen is shines with the bright reflections of sunlight into the water dripping from the meted snow, feeding the streams, which discharge has increased since my arrival a week ago.

At 78 º N all of us sweat: my colleagues, insomniac in their bedrooms, the snow field at the top of the valley and, in the cold rooms at UNIS the Antarctic plankton subject to experimental warming.

By Carlos M. Duarte, CSIC, Spain

By Carlos M. Duarte, ATP Project, CSIC, Spain

Our experimental mesocosms, consisting of replicated 20 L containers holding Arctic Ocean water continue exposed to increasing temperature, from 1 º C to 9 ºC in an attempt to elucidate the extent of warming beyond which abrupt changes in the plankton community may occur.  Each milliliter of the 20 L container is a precious item for the scientist involved to evaluate the reponses of planktonic communities to warming.

With these 20 L we must measure changes in over twenty different properties over time (from bacterial mortality to CO2 release by the planktonic community). One of our first tasks is to agree on how much water each of us can use for their measurements, so that we can sample with the higest possible frequency and yet leave sufficient water to terminate the experiment after 10 days of exposure to the experimental temperature treatments. This is no easy task an requires some degree of negotiation among the scientists, as each is convinced that her or his measurements will deliver the key result to the experiment. The colume of water each requires ranges from 2 L to measure changes in the structure of the silica valve of diatoms, to 10 m to assess bacterial abundance and production.

The reader will surely wonder what can be learn from a few mililiters of water?, how can the observation of a few milliliters of water deliver any meaningful insight into the effects of phenomena of planetary scale, such as climate change?

One milliliter is equivalent to about 20 drops, or if we prefer, 20 tears, as our tears have the same ionic composition as sea water. In fact, as the Spanish poet Federico García Lorca conveys in his poem “The Seawater Balad” (1919), we cry seawater:

“…
These salty tears,
Where do they come from, mother?

I cry, my Lord, the water
From the oceans.
….”

Twenty tear drops are as full of content and loaded with so much feeling and emotions as the information that 20 drops of water, one milliliter, contains about the ocean.

Twenty tear drops of seawater contain nearly 100 million virus, 1 million bacteria, 1,000 protists, 200 diatom algae, all embedded in an environment that, at the escale of these organisms, is viscous and contains particles, gels and polimers. Each of our 20 L experimental tanks contains a bacterial population four times greater than the number of human beind populating the entire Earth.

Diatoms dominate the photosynthetic plankton of the Polar Seas

Tiny as they are, planktonic microbes conceal many of the keys to how the functioning of the Earth’s biosphere will react to anthropogenic disturbances, such as climate change. Diatoms and other photosynthetic algae in the Arctic Ocean range from 1 micron to a tenth of a milimiter in length, but, through their photosynthetic activity, they can produce organic matter and remove CO2 from the atmosphere.  Indeed, diatom growth at the onset of the Arctic summer can reduce the partial pressure CO2 in seawater to four fold below atmospheric equilibrium, driving a large flux of CO2 from the atmosphere into the Arctic Ocean, contributing to remove some of CO2 delivered by human activity. Bacteria, along with protists, fulfill the opposite function, decomposing, through their respiratory activity, organic matter to release CO2 and consume oxygen.

The relative changes in the abundance and activity of algae, bacteria and protists in response to increased temperature in our experiments will allow us to confer if, as expected by models, CO2 release by bacteria and protists will increase more rapidly than its capture by plankton photosynthesis. The delicate balances between these important, but opposite processes determine to a large extent whether a warmer Arctic Ocean will continue to act as a sink for atmospheric CO2 or whether, to the contrary, it will act as a source of CO2 to the atmosphere.

By Carlos M. Duarte and Dolors Vaqué,  ATP-2010 experiment

The millions of organisms that thrive in our cultures of Arctic Ocean water are responsible, through the shear brute force of their overwhelming abundance in the biosphere, for driving much of its functioning. Their importance also rests in that their possible responses to warming will have a great bearing on the future of the Arctic ecosystem.

Through our experiments at the University Center of the Svalbard (UNIS, www.unis.no), in Longyearbyen, Svalbard Islands, we are trying to resolve the responses of planktonic organisms to warming.  However, important as they are, we have not yet properly introduced in this blog these key one-celled actors of the Arctic marine ecosystem.

Most abundant, virus, are relatively inert when isolated from their hosts, but can greatly constrain the population dynamic and fate of these, once infected. All organisms on Earth, not only flu-prone humans, are affected by virus, which in our case can drive the population and community dynamics of all the larger single-celled organisms in our experimental community.

Bacteria are modest in appearance and size, as most look like small spheres and rods under the microscope. However, they are greatly diverse in the functions they can perform, transforming and decomposing organic matter, so that key nutrients and gases can be recycled.

Photosynthetic organisms fuel the whole ecosystem by using sunlight as an energy source to convert carbon and water into organic matter that is then channelled all the way to fuel the ecosystem, from the tiny bacteria to the largest Arctic whales. These key organisms, alike to the trees in forests, range greatly in size, from tiny Micromonas – a eukaryotic photosynthetic organisms of about 0.002 mm in size, to comparatively large diatoms, enclosed in beautiful glass cases (silicon valves), that can exceed 0.1 mm in size.

Protists include flagellates, small cells with a flagella, and ciliate, hairy cells, used their wipes and hairs for swimming and gathering food particles, in the viscous media water is at their tiny scale. These organisms, ranging from 0.002 to 0.2 mm in size, are key predators of bacteria and photosynthetic microrganisms, and also predate upon each other not always following strict size rules.

These one-celled organisms conform the microbial food web that remains hidden to the public, as the drama of their interactions (predators, preys, death, births, etc.) is not as colourful as that of the large, fury and feathery animals that perform this drama on TV screens.  Their drama occurs within drops of water, and is only disclosed to those, as our colleagues do, expending many hours observing this one-celled theatre.

Dynobrium sp., a colonial photosynthetic flagellate, photo D. Vaqué, CSIC

a Tintinnid shell, photo D. Vaqué, CSIC

A Phaeocystis colony. Dedicated to our leader, Paul Wassmann, by D. Vaqué

A Thalassiosira sp. chain. Photo D. Vaqué.

By Carlos Duarte, coordinator of the ATP experiment, CSIC

After a final sprint of 3 intense days of intense lab work topped by a session of packing the 100 or so parcels containing our equipment and cleaning of the labs to return them to their original state, the ATP 2009 Experiment has formaly ended.

The aim of the experiment was to evaluate predictions that there may be a threshold of warming, within the 9 º C range predicted by different projections by the end of the century, beyond which abrupt changes may take place in the Arctic Ocean ecosystem.

Dinobrion colony

The experiments conducted, where we have experimentally evaluated the response of the plankton community to warming, have allowed the test of various model predictions: (a) that the mortality of the organisms characteristic of the Arctic community increases rapidly with temperature. Among these, these predictions have been confirmed for the copepod (small crustacean) Calanus glacialis, which plays a key role in the food web of the Arctic ecosystem, the colonial falgellate Dinobryon, able to perform photosynthesis and predate in bacteria; (b) that the biomass and photosynthetic production of the photosynthetic plankton collapse at temperatures in excess of 5 º C; (c) that the respiration rate, and thus the biological production of CO2, by Arctic plankton increases rapidly with increasing temperature; and (d) that the Arctic plankton shifts from acting as a strong CO2 sink to acting as a CO2 source with warming.

Moreover, not only were we able to confirm these trends, but our experiments allowed us to identify the warming level at which these changes are expected, which modelling exericse could not achieve. Our results clearly show that the tipping point is to be expected at a warming of 3 º C y 5 º C above the reference level (1990). Since the Arctic is expected to experience a warming of up 9 º C along the 21st Century, these results show that abrupt changes in the ecosystem may be expected in the coming decades.

These conclusions are but the tip of the iceberg of the massive amount of data collected, which will require two full years of lab and computer work to fully extract the insights they contain on the response of the Arctic Ocean ecosystem to global warming.

All researchers involved, about 30 altogether, in the cruise and subsequent experiment reach this end exhausted after 14 days of work at sea on board R/V Jan Mayen followed by 21 days of intense lab work. We are nevertheless satisfied with what we can already observe on the results achieved. The last day of the experiment we improvised a mini-simposium (the root of the word simposium means “gathering of drinkers”) to share the results, for we had been so busy that we could hardly raise our eyes from the microscope, spectrofluorimeter, autotitrator- whatever the instruments each of us used – to consider the results.

Calanus glacialis is a major component of the Arctic food web

This mini-symposium was precedeed by a joint dinner, although our group was much too large to be acommodated on a single table, at Kroa, restaurant in Longyearbyen.

It only remains to thank all of those who help us conduct the ATP experiment and send this with you: the European Union, that funds the ATP project,  to the FBBVA foundation which collaborates with us in communicating the important changes taken place in the Arctic to society, to my colleagues at the ATP project, who have stood the intense pace of work and last to you for sharing with us this scientific adventure. Specially warm thanks go to Gunnar Sand, Director at UNIS, for hospitality at UNIS and the help and kindness of all UNIS staff, a superb facility for Arctic Research and Academic training.

Most of the components of the ATP experiment team

Now we travel home to meet again with the night…