Arctic Tipping Points

Presentation at a recent ASLO session “Impacts of Global Warming on Polar Ecosystems”, in Nice, France, co-chaired by the ATP team members Susana Agusti and Mikael Sejr, will result in two specific volumes. A Feature Section on impacts of climate warming on marine and freshwater polar ecosystems, containing a set of 4-5 synthesis and review papers, will be published in the journal ECOSYSTEMS. A special issue reporting original research on impacts of climate warming on marine and freshwater polar ecosystems to be published in the journal POLAR BIOLOGY. Both volumes will be coordinated by S. Agustí, M. Sejr, and C. M. Duarte.

More than half of the 22 invited and contributed manuscripts are partly or entirely derived from the ATP project. The manuscript will be submitted from September 20th to October 30th 2009.

S. Agusti, C. Duarte, M. Sejr and P. Wassmann convened at the Cape de Salines Lighthouse Field Station on Mallorca in order to work on the volume and to write one of the contributions for the feature section for Ecology: Footprints of climate change in the Arctic Marine Ecosystem

We, Núria and Dorte, joined MS FRAM on a 2-week cruise from Kangerlussuaq to Qaanaaq (Thule) and beyond – to the furthest north the sea ice allowed passage. The ship, built in 2007, is a very modern version of Frijof Nansens old FRAM expedition vessel from the late 19^th century. Though it is a luxury cruiser for tourists, ATP has the privilege to use it as research vessel! Hurtigruten which runs MS FRAM is part of the advisory panel of ATP and offered the project a cabin on each of the two Thule expeditions this summer and also a cabin on a cruise next summer. For ATP this is a great opportunity to do fieldwork along the western coast of Greenland and disseminate research on climate change. FRAM is also interested in having scientists on board and thereby offering the opportunity for the passengers to follow the sampling activities and listen to lectures on climate change and the Arctic marine ecosystem.

Our scientific aim on the cruise was to assess how the growth of kelp changes along the climatic gradient from south to north Greenland and use this information to provide a hint on how a future warming might affect the kelp communities in the north, assuming that current climate conditions in the south may move northwards.

The itinerary of FRAM with many stops along a wide latitudinal gradient is well suited for this purpose. We had planned a sampling scheme that was feasible during the relatively short time available at the stops in the settlements along the route, and which did not require fancy sampling and laboratory equipment. We needed a zodiac with GPS and depth sensor, a driver, an underwater video to explore the life on the seabottom, a rake to sample the kelp, plastic bags, ruler, pen, space to measure the several meter long kelp, and access to a freezer. FRAM provided us boat and skilled drivers at every stop as soon as the passengers had been brought to the shore. William and his colleagues became an important part of the team not solely by driving the zodiac but also by ensuring the best catches of kelp! Moreover, the bridge provided us temperature data, tidal tables and all kinds of logistic arrangements for the entire cruise, and the expedition team leader, Anja, settled the practicalities for sampling and lectures on board with her great organisational skills.

Since we did not know the sites in advance, we sought local knowledge on good places to sample. As soon as FRAM arrived at a settlement, we went to the shore and asked inhabitants for advice on where to find kelp. People were very helpful and also shared information with us about local ice conditions across the year. This help on kelp was very valuable and rendered the samplings quite efficient.

We got the opportunity to process the kelps at the sailors working space on deck 2 as well as next to the “Salon Panoramique” (deck 7) outdoors protected by the transparent wind screen across which we could admire the icebergs, glaciers, sea ice and occasionally a whale while navigating on a flat sea usually in sunshine… While working, the passengers and crew often approached us and inquired about the sampling and also shared experiences related to kelp and/or science with us. For example, a Greenlandic woman explained us how her family used kelp in their diet: they ate the big brown kelp, winged tangle (Alaria alata) and the red kelp Palmaria palmata prepared either as a soup or raw as a salad. Her favourite serving was freshly chopped Palmaria palmata with fresh mussels and seal blubber! Climate change also became a hot topic on board. Discussions took place in many languages: Scandinavian, English, French, Italian, German and we had to supplement our vocabulary with signs and body language. Parts of the discussions will even be translated into Czech when Czech TV releases a film about this trip.

In between the measurements we stored the algae cold in our minibar. Though we were eager to empty this minibar every night, we sometimes had to restrain ourselves and save some for the next day!

All in all we sampled 8 sites along the route. The preliminary results indicate that as we move northwards marine vegetation belts are narrower, the algae grow slower and some macroalge species disappear. These findings most probably reflect different climatic conditions. Ice cover persists longer towards the north, and laves less light for the macroalgae at the sea bottom and, concomitantly, seawater temperature decreases by several degrees during summer from southern to northern Greenland. With global warming we therefore expect southern kelp species to migrate further north and vegetation belts to expand.The two week cruise also offered many other highlights and set several northern records:

• we sampled the northernmost population of knotted wrack (Ascophyllum nodosum) at Qeqertarsuaq (Disko Island) , which we found thanks to the guidelines that Poul Møller Pedersen from the University of Copenhagen provided us
• we visited the northernmost settlement in the world, Siorapaluk, and
• we reached the northernmost latitude ever by this FRAM vessel: 79˚49’!

We have now left FRAM and are on our way home while we write this final blog on the 5-week field campaign in Greenland in 2009. Thank you for your interest!

Núria Marbà and Dorte Krause-Jensen

A couple of weeks have passed and much has happened since the last blog. We have finalised our temperature experiments in the Royal Arctic Laboratory. Our simple temperature control system worked perfectly well and maintained our aquaria with kelp and eelgrass at temperatures of 10 (in situ), 12, 14, 16 and 19˚C. We grew 3 species of algae having different geographical distribution ranges, some extending to the south/mid coast of Greenland, others extending further north. During the last days in Nuuk we harvested the vegetation and measured survival, growth, photosynthesis and respiration.

The preliminary results show that some species like it hot while others do not! For example the intertidal kelp, knotted wrack (Ascophyllum nodosum) which has a geographical distribution range extending from Portugal in the south to Disko Bay on Greenlands midwest coast in the north, grew markedly faster when temperatures were raised (see figure below). Eelgrass also thrived at the warmer temperatures.

By contrast the subtidal kelp, longstiped tangle (Laminaria longicruris), which has a geographical distribution range extending to the north of Greenland, grew only slowly at the high temperatures (see figure) and some individuals died.

Since the temperature experiment ran well and took care of itself, the weeks in Nuuk also allowed time for field sampling. We sampled longstiped tangle and measured annual growth. Since the algae produce a new blade every year the growth can be assessed by the end of the growth season by measuring the sixe of the blade, and this was what we did. Some individuals had monster sizes (see photo).

We also sampled eelgrass and knotted wrack and measured biomass, density, growth and for knotted wrack also assessed age and population structure. Both species leaves marks that reveal their past growth. The underground rhizomes of eelgrass leave a mark for each blade that is produced and since the distance between marks is short in winter and long in summer it is possible to count the number of blades produced in a year. Knotted wrack produces a bladder every year so by counting the number of bladders we could assess the approximate age and by measuring the distance between bladders, we could assess growth. This demanded a lot of work and long days. Luckily we were 4 of us; Birgit had to go home to teach but Kitte came and assisted us with a lot of organisational skills and laboratory experience.
We now aim to compare the growth of these species in Nuuk with the growth at other latitudes in order to assess how growth varies along a climatic gradient and thereby get an indication of the response of the vegetation in the north to a future warming.

We packed down the royal laboratory and sent the equipment back home, but the work had not yet finished. The next leg of the program is that Nuria & Dorte join a 2-week cruise along Greenlands westcoast with MS FRAM, where they can sample during stops in settlements along the route. Peter joins another 2-week cruise in the Disko Bay with 3 colleagues to do vegetation and fauna surveys.

Historical examination has shown that climate-induced ecosystem change, for example that reported in the waters around Greenland, have major consequences for fish catches. In a situation where the status of many living marine resources is precarious, abrupt ecosystem change may have major socio-economic impacts on local communities (e.g. Inuits) dependent, both culturally and for subsistence, on these natural resources. Economic activities dependent upon marine ecosystem services, such as Arctic tourism, may also be vulnerable to abrupt, climate-driven changes to marine ecosystems, and face major challenges in adapting to the new conditions. In the high North, management of fisheries and marine food-web exploitation by native peoples, tourism, and oil and gas extraction is nested within larger, global-scale initiatives, reducing the ability of Arctic states to adapt to change. The development of a management plan for activities in the Arctic seas represents a major institutional experiment on how to address abrupt changes in the Arctic marine ecosystem. The challenge lies in developing managerial models than can help discount anticipated risks and at the same time profit from emerging opportunities. Lessons could be drawn from other management systems that have experienced major shifts in recent history (for example the Northwest Atlantic and Bering Sea areas). The success of these new models is dependent on three key factors, the availability of reliable scientific forecasts on the future changes of Arctic marine ecosystem in response to climate change, the development of regionally focused resource-use models, and communication conduits to efficiently and reliably transfer this knowledge into managerial and political frameworks.

Through scientific work, analysis of time series data and by communicating knowledge ATP wishes interested parties and stakeholders in Greenland and the pan-Arctic region (e.g. Inuit Circumpolar Conference).  ATP wishes also to reach relevant policy actors in Greenland and will search for possibilities to transfer knowledge.  Finally ATP wishes to convey results to the general public on this island.  This blog and the scientific work (see science blog on experimental work concurrently carried out in Greenland on the ATP web site) is a first step in this direction.  I wish to thank the ATP partner Hurtigruten ASA for the support during the expedition cruise to northern Greenland.

There is so much conflicting evidence regarding climate change in the Arctic.  What shall I believe?

Headlines and news regarding the climate and climate change have been regular event in recent years.  They hit us like ice grains during a hailstorm.  And many headlines hurt us.  Droughts, storms, heat waves, hurricanes, floods, melting sea ice, disappearing species, drinking water shortages etc.: we could list endless lists of miseries that befall the human race in recent decades of increasing climate change.  The media wishes to attract the attention of people and thus it is partly ourselves that “create” the frightening headlines.  If we would not be so, the number of climate related headlines would be much smaller and reserved for the big events that we call catastrophes.  I hesitate to use the word because it is so often misused.  Most of what often is called catastrophes are just events that are overexposed by the media.  This can create a dooms day scenario that upsets people.  In this manner media can keep the attention of people.  A balanced statement on sea level rising, ice-melt or fauna changes often do not make it to the main headlines, partly due to the cool, precise and unemotional nature of scientific communication.

Often the information presented is, over time, discussed by the media, which wishes to have debates about burning issues.  In order to commence a debate one or other person will be selected who has an opposite opinion to most scientists or an alternative explanation.  Here the media often make the mistake that they initiate a debate that is not based on opinions that are weighted, for which the journalist had to have very good scientific insight.  Often any opinion opposite to one launched by scientist is given as much space then science.  Some of the debates are net between scientists of different opinion, but scientists and politicians, members of environmental movements or others with critical opinions regarding mainstream science.  This can easily result in superficial debates that give the reader or listener the impression that scientists do not really know what they talk about.   Presented to the fear for the future and the insecurity that derives from – what I would call – unbalanced debates, people get tired and give up their “engagement”.  By which nothing has been gained.  In particular an important issue for the livelihood of mankind like the climate can suffer from that sequence of events, resulting in passivity and repression.

Hot debates in the media result in that important question are forgotten by the general public.  Is there no acid rain any more, much debated 30 years ago?  There is less acid rain now, but there is still the acid rain question that we never hear anymore about.  And what about dying woods, a major debate in central Europe 20 years ago.  Are the woods healthy now because we never hear about it?  No, the situation is as bad as before (except for specific regions with large industrial emission that have improve) or worse.  But the issue is “used up”, does not make it not the headlines anymore.  I can foresee a time, not far from now, where we will not hear anymore about melting sea ice anymore because it is not a hot issue anymore for the general public.  Already now journalists have to fight an decreasing interest in climate change issues in the Arctic by focussing upon them in particular manner, e.g. through personal interviews with scientists.

What shall we then believe when we have great interested in issues such the climate, the Arctic or ecosystems?  The core question will always be the following: “What is the quality of this information? Who has provided it?  Has it gone through an evaluation and referee process?”  The best one a do is to look for international reports such those from ACIA* and IPCC**.  Both reports have good and readable summaries that are written for the general citizen.   My answer to the question raised above is thus that one should not believe too much into the debates about climate change and the Arctic Ocean in the media, but go to the best available sources such as ACIA and IPPC.  Knowledge has magic qualities: it keeps the worries at a distance.  The future will be good one for many regions of the world, but reduced carrying capacity and climate change will result in lowered life quality

At the end I wish to launch a wish.  I notice a trend where some citizens believe that the ultra conservative ACIA and IPPC reports are documents of a environmentalist and scientific clique.  An elite that wish to indoctrinate citizens and limit democratic freedom (e.g. driving cars, protecting nature, introduce environmental taxes etc.).  These conspiration theories are wrong and dangerous.  They can easily become the place where we move in the political landscape because we do not wish to change our life style.  All reason tells us that we need a controlled lading after decades of overconsumption to omit the crash that will be the inevitable result of today’s life styles. ACIA and IPP do not wish to indoctrinate people and limit their freedom.

*ACIA (2004). Impacts of a warming Arctic: Arctic climate impact and assessment. Cambridge University Press, Cambridge 144 pp.

** IPCC (2007). Fourth Assessment Report: Climate Change 2007. http://www.ipcc.ch/publications_and_data/publications_and_data_reports.htm#1.

What will happen to life in the Arctic Ocean when the ice disappears?

With the long-term decrease of Arctic Sea ice since satellite measurement started in 1978 it has been predicted that the Arctic Ocean should be free of ice in summer around 2050.  The winter ice will still be in the same position, although annual, relatively thin ice will predominate.  However, after the dramatic decline of sea ice in summer 2007 many oceanographers fear that the Arctic Ocean development has entered a new phase; a tipping point may have been reached and passed.  Since 2007 the ice cover has not recovered and also in 2008 and probably also 2009 summer ice cover will be low.  What does all that mean for the ecology of the Arctic Ocean and humans that live in the Arctic realm?

It implies first of all that the primary production in the Arctic Ocean will increase and provide food for organisms that currently live under extreme food limitation.  It means also that organisms that hardly survive in the Arctic Ocean at present will experience good living conditions (e.g. zooplankton).  Capelin could be one these potential candidates.  That, in turn, will probably result in that fish will benefit from it and we may foresee an Arctic fishery in the future.  This new fishery has to be managed by the 5 Arctic states, Russia, USA, Canada, Greenland and Norway.  Lack of ice in the summer implies also that necessary substrate for organisms like seals and Polar Bears disappear in critical times of the year.  While the Polar Bear may learn to get back on land (from where he came some ten thousand years ago, developing from the Grisly Bear) and try to survive (as Polar Bears in the Hudson Bay region already do).  But what about seals?  It may look like that seals will suffer greatly from the loss of sea ice.  What the decline of the seal population will bring for the ecosystem is a matter of speculation.  Will there be less grazing pressure on capelin or leave the food to marine mammals that do not depend on ice as a substrate, e.g. whales.

For the only people that depend on the marine food web, i.e. the Inuit, all changes in climate and ecosystems have an immediate effect on their living conditions. Before modern times they were flexible in their manner to live.  They would move from winter to spring and summer places, according to the availability of prey animals.  Modern civilisation with schools, hospitals, infra structure etc. resulted in permanent settlements that cannot be easily changed when the food resource in the near by ecosystem is changing.  Let us, for example, look at the Inuits in the Thule region.  They live in this inhospitable region because of the North Water Polynya with its high productivity and the overwintering and sea mammals in the open water.  It may well be that the polynya will disappear as so many other polynyas have and will do.  In this case the main food source of the Thule Inuits will decline or move towards the Arctic Ocean, with negative ramifications for a population that is now geographically inflexible.  It would make life more difficult and probably depended on a different economy or support from the south.

For many other people living in the Arctic the situation is different.  Arctic agriculture and logging may in many cases profit from warming.  For reindeer herders the situation seems more difficult, but most probably they will experience more difficult times, with more ice in winter, invasion of woods from the south or the difficulties that arise when permafrost is melting.  For fishermen the situation may also get difficult with changing species composition, but new fishing fields in the north may compensate for different species and changes in ecosystem in the south.  For tourism and transportation a decrease of sea ice cover will be beneficial.  New and so far unreachable destinations may be in reach and the possibility to use the Northeast and Northwest Passage open up shorter transportation routes to important markets.  For the oil and gas industry less ice is a great advantage.  There will be strong arguments to explore the 25 % of the Worlds remaining gas and oil reserves that are expected present in the Arctic Ocean.  And with our seemingly inability to create and continue a prosperous life without the use of fossil fuels great pressure to extract oil and gas from the Arctic Ocean can be expected, in particular when receding ice eases the operational challenges.

In summary, there is no clear answer to the question of what will happen to life in the Arctic Ocean when the ice disappear in summer. The challenge to give answers is far too demanding for today’s scientists that work in the region.  Scientific knowledge from the Arctic is rather limited and the climatic development is too fast to give the clear answers that society provides.  Nobody suffers more for this weak answering capability then the scientist working in the Arctic Ocean.

Everything happening now to the climate is caused by humans

Off course not.  This is a statement that an environmental fundamentalist may provide.  There is a concomitant development of the climate having natural and man-made causes.  To distinguish between those two forcings is one of the big challenges for science.  Nothing is more difficult than to solve this question.  We would often need good and long time series data that are in short supply.

The UN climate panel (Intergovernmental Panel on Climate Change [IPPC]) works hard to provide the best possible evidence to give a balanced answer to the question if recent climate change is natural or man-made.  The conclusion of the IPPC is not to be taken lightly.  The panel summarises the evidence that science can provide. The answer - in a time when there is consensus that our society should be knowledge based – is a significant one.  When IPPC states “It is very likely that the emission of climate gasses by humans have caused most of the increase in global temperature during the last 50 years”, then they do not say that climate change is only due to humans.  They state that the emission of greenhouse gases is very likely (95 % probability that this is so) the cause for the recent warming.  The human contribution of global warming comes on top of the natural.  In fact, IPPC scientists have reason to believe that the natural global temperature should decline for the time being.  Which supports the argument that the observed warming is man-made.

Nothing that happens to the climate is caused by humans

Off course not.  The most advanced methods – that deal with the development of many types of observations in space and time – concluded that this hypothesis couldn’t be verified.  In other words (and to translate scientific jargon): human activity is very likely involved in global warming.

Climate change takes place and this will have consequences for the livelihood of the human race.  The changes in the climate that we will have in front of us will not be the start of the end.  In times when significant changes take place dooms day prophets make their appearance.  And the pessimistic among us may listen to these prophets and our expectations for a promising (but not uncomplicated) future will be coloured.  The optimistic among us may tend to the opposite direction and expose themselves to hybris, which in our times is often connected to a strong believe that technology will solve all our problems, also those of ecosystem feed-backs and resource overconsumption.

We live in a society based on the assumption that the base for our decision should be knowledge.  Due to that sciences, and in particular natural sciences, are highly prioritised.  When it comes to climate change, knowledge has magic qualities: it keeps the overwhelming threats and the doomsday prophesies at a distance. Knowledge is the ultimate weapon against foolishness, arrogance, apocalyptic attitudes, repression and doomsday prophets.  As in previous periods of history the future will be good, but the earths reduced carrying capacity and climate change will result in lowered life quality.

”Climate researchers just quarrel – they cannot agree on anything.  Basically we do know too little about the climate.”

Climate researchers do quarrel over details of their research and interpretation of results, but the majority does not quarrel about climate change and global warming.  In fact most congresses involve quiet and peaceful procedures.  Most of the quarrelling is not between active scientists, but between scientists and laypersons or politicians.  The quarrelling is clearly visible in media because they wish to have a ”balanced” debate.  A statement from a committee or scientists cannot remain alone.  It has to be contradicted to obtain at least a debate.  Anybody who contradicts a scientific position is then welcome.  If the scientific statement is supported by a large majority and contradicted by a small minority is not so important for the press.  Many journalists have too little time or too little specific education to launch weighted debates.  The quarrels addressed in the above statement are practically not visible in international journals and at conferences.

But, off course, there is a lot of uncertainty.  And there are alternative interpretations for which good data and arguments are always welcome.  Uncertainty should support the case of nature, not the man-made world, our culture.  At the end of the day we all depend on the good and services that Mother Nature provides us with.  The sustainability of nature must be our ultimate goal and all action that undermines sustainability is a threat to mankind.

It is not dangerous with an increase in temperature of 2-3 degrees

An increase of the average global temperature with 2-3 degrees above pre-industrial time will have more positive then negative effects in many regions of the word.  We have already a global temperature that is more then 1 degree above that during pre-industrial times.  For the time being the global temperature is not increasing so fast then during the last 10 years, but these changes go in cycles and we expect that it soon will pick up again so that we can soon experience that w ego through the upper limit of 3 degrees, as accepted by the EU.  Thus we could indeed agree with the above-cited statement.

However, the effects are unevenly distributed and while a rich country like Norway will not suffer others will.  For example: the Sahel region, countries of the Arabian Peninsula or northern Africa.  A global temperature increase is not a local and national matter, but a global one, i.e. the situation over the entire globe matters.  The climate problem infiltrates a suite of problems, such as heath, politics, economy and security.  All that has consequences for every country and every citizen.  How will the World society react to immigration of climate refugees from regions that have become unacceptably hot?  What about the advent of difficult to fight diseases such as malaria that is on the move into regions where it has long been forgotten to exist? An increase in temperature of 2-3 degrees is dangerous, if not for the region in which we live then as a consequence of the ramifications that a temperature increase has in other parts of the world.  A global economy implies also enduring the climate effects of the entire globe.

It has also been warmer earlier and the climate changes whatever we do. What is so different today?

We have detailed knowledge from how temperature varied in previous times.  We have a few continuous records since about 1850.  We have investigations of tree rings growth for a few hundred years.  We have data on the ocean temperature from sediment cores on a suites of time intervals, from hundred to several thousands of years.  The longest record we have come from ice cores in Antarctica where we have detailed knowledge about temperature down to 900.000 PP.  Most of these records do indeed show that there have been warmer and colder periods.  However, the alarming signs are a) that the global temperature is now higher than during any interglacial time, b) that the final increase comes during a short time interval (100 years) and c) that the tendency over the last 30 years is ever increasing (with some variability).  The conservative consensus of IPPC states that the warming this time is not only natural, but basically caused by humans.  Many indices tell us that we should be in a cooling  period, but we face basically the opposite (right now we have a slight decline).

In contradiction to former times when climate variation was natural IPPC thinks mankind can do something with it.  This is because climate warming is caused for the most by emission of greenhouse gasses.  Two of them, carbon dioxide and methane, have increased due to human activity with 38 and 148 % since the industrial revolution.  There exists enough knowledge to take action, but out hesitation to do so, probably based upon our unwillingness to change our resource overconsumption, results in that climate warming increases further.  Despite of setting an upper limit of + 2 degrees our lack of action implies that this limit seem to have become unrealistic already.  Scientists have not been able to convince the general audience.  Thus we, the people, do not comprehend the consequences of what we do.  What is different today compared with other time periods is that warming is manmade.  And these consequences, if not for us, then for people more exposed for warming.  Our production of green house gasses should be accompanied by willingness to accept climate refugees, but I am afraid this is not the case.

Our experimental campaign in Nuuk lasts 3 weeks. We live and work at the Greenland Institute of Natural Resources that also participates in the ATP project. Being located next to the sea with access to well-equipped and fast boats run by experienced boat drivers, a well-functioning laboratory, and inspiring and helpful employees, the place is ideal for studying the coastal ecosystem. Next to the laboratory is an annex building with apartments and individual rooms with common facilities for guest scientists and students. This is where we live during our stay.

The overall aim of our campaign is to obtain information on the growth of subarctic kelp forests and eelgrass meadows and their response to a future warmer climate where more light will reach the seabottom as the sea-ice retracts. Our activities incorporate field studies of the growth of kelp and eelgrass here in the north for comparison with that further south, since the present situation further south may simulate the future situation here in the north. We also conduct experimental studies of how kelps and seagrasses respond to increased seawater temperature.

For the experimental studies we have rented a cooling container from Royal Arctic Line and transformed it into a laboratory where we can grow seagrasses and kelp at temperatures ranging from the present summer seawater temperatures to temperatures up to +9 ˚C which covers the full range of projected scenarios for surface (air) temperatures in the Arctic by the end of the 21th century. The surface temperature of the coastal water around Nuuk is about 6˚ C in August and we had expected to use the temperature range 6-15 ˚C for our experiments. However, in the fjords where we sampled the vegetation the water temperature was typically around 10 ˚C so we decided to use the range 10-19 ˚C instead.

The container awaited us in front of the institute when we arrived. The first couple of days were spent equipping the container with shelves, aquaria, temperature control units, heating systems, lamps, pumps etc. that we had sent in advance – also by Royal Arctic Line. Now the aquaria are populated with eelgrass and 3 species of kelp which will grow there for almost two weeks before we examine their responses to the warming. We have selected small individuals for the experiment so that we can fit them in our aquaria. The largest ones in the field are far too big – the biggest we found are almost 6 meters long! The three kelp species we use in the experiments are among the most dominant algae here and the same species also grow further south so we expect they will grow faster at the higher temperature treatments –up to a certain limit.