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Photo of Borgthor Magnusson Island Life --
Borgthor Magnusson and Sigurdur Magnusson

How does life develop on a new part of the Earth? Find out more from two plant ecologists who study the once-sterile landscape of Surtsey: Borgthor Magnusson and Sigurdur Magnusson.

QWhat parts of the island had the first plant life and why? Do those areas still have the most plant life today?

(Sigurdur Magnusson) The areas of the island which first became colonized by plants were the sandy and unstable habitats close to the seashore. These habitats are still very poor in plant species and extremely low in cover, mainly due to the repeated disturbance from the sea. However, the main plant colonization started in an area not very far from the seashore but out of the range of the disturbing effects of the Atlantic waves, in a place covered by volcanic sand. At that site two species (Sea Sandwort and Lyme-grass) became established and mainly from that foci they have been able to spread to most other parts of the island. As the time has passed several other species have also been able to establish themselves on the island, but that initial spot still has less than 20 percent plant cover.

QDo you believe that the Island will one day be overgrown with plants and animals or not, and why?

(Sugurdur Magnusson) I believe that most of the island will become covered by plants, but that will certainly take a long time, probably more than a century or two. The breeding birds will aid the vegetation colonization by fertilizing the soils. The island will, however, never be totally overgrown with vegetation due to the high disturbance from the sea. The seashore and the sea-cliffs will always be relatively poor in plant cover.

The number of animal species like birds, soil animals and flying insects will probably increase in number when new habitats are formed on the island. The puffin will probably colonize the island when suitable nesting habitats have been formed (relatively deep soil covered by grass sward). Habitats now found on the island will probably change with time; therefore, some of the animals now found on the island will very likely be reduced in number.

QWhy did you stake out the different plots to study plants? How did you initially decide where to place them?

(Sigurdur Magnusson) During the first years after the formation of the island every plant found on Surtsey was marked and given a number in order to follow the plant colonization and establishment. With time more and more plants became established and therefore this method was no longer feasible. Therefore, we decided to establish several permanent plots in different parts of the island in order to study the plant succession and to follow how plant species interact. The plots were placed subjectively in what was considered representative for different vegetation and habitat types on the island, e.g. lava vs. ash substrate, inside/outside gull colony.

Q Do scientists take precautions not to bring seeds or life to Surtsey? If so, what are these precautions?

(Borgthor Magnusson) Yes, we take precautions and try to avoid all accidental introduction of plants or other life by man to Surtsey. We do this by checking our clothes, footwear and other gear very carefully before visiting the island. We recommend that clothes are washed and all dirt brushed from footwear to remove any soil or plant material. Then we must take care not to walk or wander though vegetated areas before leaving for the island. Although we take these precautions, introduction of plants by man to Surtsey can not be ruled out. However, we have not found any direct evidence of plant introduction by man to the island. The main transport agents of plant seeds or spores to Surtsey have been the sea-currents, the wind and the birds.

Q Has the atmosphere warmed enough in the past 25 years to affect the plant life found on Surtsey?

a(Borgthor Magnusson) We believe that global atmospheric warming has not affected plant life on Surtsey to any degree in the past 25 years. The climate on Surtsey is rather mild with a mean July temperature of 10 deg. C and a frost-free period from early May to mid October. The young and rapidly developing plant life on Surtsey is not the best to study the effects of climatic change. What has been of much greater significance in the last years is the effect the sea-gulls are having on the plants with their addition of nutrients to the soils of Surtsey.

Q How long do you think it will it take before Surtsey is completely eroded by the Atlantic Ocean?

(Borgthor Magnusson) At the end of the eruption in Surtsey in 1967, the island had reached a size of 2.7 sq. km or 270 hectares. Now half of that has been eroded away by the ocean and the island is only about 1.3 sq. km. During the first years Surtsey decreased annually by 3-20 hectares, but in the last years the erosion has slowed down and it has been about 1 hectare annually. The inner core of Surtsey is formed of palagonite tuff which is harder and more resistant to the oceanic waves than the outer lava which is now being eroded. Therefore, Surtsey will gradually, perhaps over a 2 to 3 centuries time, take the shape of the small nearby islands which where also formed in similar eruptions after the last ice age. These islands, which are stacks with steep cliffs and abundant bird life, are only 2 to10 hectares in size. The islands are known to be several thousand years old. Therefore, my prediction is that Surtsey will be there for the next thousand years at least.

Q I was wondering what species of gulls originally populated Surtsey. I was also wondering if any more species of birds had come since and if these birds had brought more species of plants. Thank you for your time.

(Borgthor Magnusson) There are eight species of birds breeding on Surtsey now. These are the Fulmar and the Black Guillemot (from 1970), Great Black-Back Gull (1974), Kittiwake (1975), Herring Gull (1981), Lesser Black-Back Gull (1985), Glaucous Gull (1993) and Snow Bunting (1996). A Raven has built a nest on Surtsey, but it has bred there. A nest of an Arctic tern has once been found but the species has not established itself on the island. The most abundant breeding birds now are the Lesser Black-Back, the Fulmar and the Herring Gull.

The Great Black-Back was the first gull species to start breeding in Surtsey. The number of pairs has increased to about 40 now. The Great Black-Back is spread over the island and the nests are far apart. We have found no direct evidence of plant introductions to the island with this species. However, plant growth is enhanced around the nests. Often the nests are in the middle of Sea Sandwort or Lyme-grass plants. In roosting areas frequently used by the Great Black-Back near edges of cliffs Scurvygrass became established in the early years of Surtsey. It is possible that the seeds were carried to the island by the birds.

The Fulmar, Black-Guillemot and Kittiwake breed in the sea cliffs which are very unstable and erode from one season to the next. Vegetation has not become established at their nesting sites on the cliffs. There are some Fulmar nests upon the island and vegetation cover has increased close to the nests. We have, however, not found any new plant species associated with the Fulmar nests.

In 1986 we noticed that the Lesser Black-Back and Herring Gull were forming a breeding colony on the southern part of the island. At that time the breeding pairs were less than 10, but now the number has reached over 200. The breeding colony has expanded greatly in range. A few pairs of Glaucous Gull have also joined in.

After the formation of this gull colony on Surtsey the number of new plant introductions has increased greatly and most of the new species have been found and become established within the colony. These gulls build more delicate nests than the Great Black-Back and they may have brought in nesting material from neighbour islands which could be a source of new seeds. Also they feed more on insects and earthworms and are more likely to pick up seeds and bring them to Surtsey. On the island the vegetation cover and species richness is now greatest within the gull colony.

In the summers of 1996 and 1997 we have seen one pair of Snowbuntings feeding their fledglings on Surtsey. A nest has not been found yet but we assume that the birds are breeding on the island. This is the first land bird to breed on Surtsey, feeding on the insects found there. The increase in vegetation and insect life following the formation of the gull colony has probably enabled the Snowbunting to establish itself on Surtsey. We know that these birds can transport seeds. Viable seeds were found in the stomachs of migrating Snowbuntings collected on Surtsey a few years after the formation of the island. However, we have no direct evidence that Snowbuntings are responsible for introducing new plant species to Surtsey.

Q You provided the meaning of the name "Surtsey" on the program but I did not catch it all. Would you please provide it again?

(Borgthor Magnusson) The island is named after the fire-giant SURTUR. The word Surts-ey, means "the Island of Surtur,"as the word "ey" is the same as island in English.

Q Is there any sign that the volcano that formed Surtsey could erupt again in the near future?

(Borgthor Magnusson) No, there are no signs of that. Geological research on the island shows that Surtsey has gradually been cooling down since the eruption ended in 1967. However, it cannot be ruled out that Surtsey will erupt again, but there are no indications that it will do so in the near future. Surtsey is the southernmost of the Westman Islands off the south coast of Iceland. The islands are all spread along a 25 km long SW-NE tectonic fissure, which is part of the Atlantic ridge. The islands have probably all been created by volcanic activity towards the end of and after the last Glaciation. Some of them were formed in the same way as Surtsey. The biggest of these islands is Heimaey (Home-island) and it is the only of them that is inhabited. Heimaey has been formed in several eruptions with thousands of years between them. The last eruption there was in 1973, adding considerable new land to the island (for more information check At that time Heimaey had been dormant for some 5000 years and it was generally believed that it would not erupt. The Surtsey and the Heimaey eruptions have shown us that there is still volcanic activity in the Westman Islands area, but we cannot tell when or where the next eruption will be.

Q Can you tell us how you are going to use the information you are learning by studying new life on Surtsey?

(Sigurdur Magnusson) The results from Surtsey can be used in several ways. The information can help us to predict how natural plant succession will proceed in other places under similar circumstances, e.g., on new lava fields, on eroded land or following retreat of glaciers. Also, the information on the succession in Surtsey is very important as it can be used to make better restoration plans for severely disturbed areas which are of similar character as Surtsey.

Q Can you tell us how you are going to use the information you are learning by studying new life on Surtsey?

(Borgthor Magnusson) Findings of the research carried out on Surtsey have been published in scientific reports, papers and books. Also the general public has been informed though articles in newspapers, magazines, TV programs and other media. I would say that this the most important use of the information from Surtsey. But the research also has practical aspects and reference to the land reclamation work that is carried out in many areas of Iceland, where we are trying to revegetate barren land which has lost its vegetation and soil cover. By studying natural plant colonization on Surtsey we also obtain useful information for the reclamation of similar habitats on the mainland.

Q Could the new plants now growing on Surtsey help slow down the rate of erosion of the island?

(Sigurdur Magnusson) No, the main eroding factor, the waves of the Atlantic ocean, are so powerful that the small plants now growing on Surtsey have no effect to slow down the rate of erosion.

Q Are only plant scientists studying Surtsey? Or are other scientists also looking at how birds, animals and insects are colonizing the island?

(Borgthor Magnusson): The plant ecologist keeps an eye on the birdlife but it is also followed by ornithologists. The development of insect and other invertebrate fauna has also by studied by specialists in that field but not in the same detail as the plant succession. Colonization of the subtidal zone by marine life has been studied from the first years of the island and the sampling carried out at intervals of a few years.

All geological and biological research on Surtsey is organized by the Surtsey Research Society (P.O. Box 354, Reykjavik, Iceland, Telefax: 562-0815), which looks after the island for the Icelandic Nature Conservancy. The Society organizes expeditions to the island every year. Scientists who are interested in carrying out research on the island have to apply for research permission to the Society. Tourist visits to the island are not allowed. The Surtsey Research Society has its own publication "Surtsey Research Progress Report" which is published in English. The Society will soon open a homepage on the web and it will have an English version.

Q Is Surtsey the first time you've had a chance to study how plants colonize "new" land? What is the most surprising thing you have learned there?

(Sigurdur Magnusson) No, we have also been studying plant colonization on eroded land on the mainland of Iceland. Although there are many similarities between the conditions on eroded land and Surtsey (unstable and low nutrient content of soils), they also differ greatly. On eroded land the distance to the nearest seed sources is only few hundred meters but Surtsey is an isolated island and therefore the plants have to overcome that barrier to colonize the island.

There are several surprising things we have learned from our studies.

We find it very interesting to follow how effective the Sea Sandworth (Honkenia peploides) has been in colonizing the island, in spite of the harsh conditions like the abrasion from wind blown material and the low soil nitrogen content. This species is by far the most successful colonist on Surtsey and has now spread over the whole island.

Quite surprising for us is also the fact that the vascular plants are the dominant colonists on Surtsey, but not the lichens or mosses which usually dominate young lava fields in southern Iceland. The main reason for the low cover of mosses and lichens compared to vascular plants might be the drifting sand and ash. These plants are known to be very sensitive to accumulation and abrasion by wind born material. It is also possible that the colonization by these plants is retarded in some way by surface characteristics of the lava fields.

We also find it very interesting to see how the sea gulls have affected plant succession on the island. In the gull colony, which started forming on the island in 1986, there has been a great increase in the number and cover of vascular plants, probably due to increased dispersal to the island and fertilization by the birds.

I was wondering what species of gulls originally populated Surtsey. I was also wondering if any more species of birds had come since and if these birds had brought more species of plants. Thank you for your time.

Q Did the Chernobyl nuclear incident affect the island in any way?

(Sigurdur Magnusson) No, the radioactive deposition from Chernobyl was very low in Iceland, and in Surtsey we have no indication of negative effects from that incident.

Q Can you make any predictions about the next plants, insects and birds you will see on Surtsey? Could mammals survive there one day?

(Borgthor Magnusson) Yes, I think we can make some predictions about what species are likely to colonize Surtsey in the near future. I will only comment on the plants and the birds as my knowledge of insects is very limited. There are several plant species which are common on the mainland of Iceland or the nearby islands that we have not found on Surtsey yet, although the habitat is similar. Examples of these are Wild Thyme, Moss Campion, Sea Plantain, Viviparous Fescue, Alpine Bistort and Roseroot. They are among the species we expect to find on Surtsey in the future.

The birdlife on Surtsey will change with increasing vegetation cover on the island. The Puffin, which is the most common breeding bird on the nearby islands, has not colonized Surtsey yet. The Puffin breeds in grassland where it digs a hole for the nest deep into the ground. On Surtsey grassland has started to form in the gull colony and with its further development breeding conditions for the Puffin may become favourable within the next twenty years. The Puffin is a seabird and will not have any problems with feeding its young on Surtsey. It is much more difficult for a landbird to start breeding on Surtsey as insects or other prey are not very abundant. A Raven has built a nest on Surtsey but it has not bred there, probably due to a lack of food (eggs and young of smaller birds) in early summer when the young hatch. It will probably be very difficult for the Raven to breed successfully on Surtsey in the future. A pair of Snowbuntings, which feed on insects, has however managed to breed on Surtsey in the last two summers. This species will probably continue to breed on the island as insects will become more abundant with increasing vegetation cover. The Meadow Pipit and the White Wagtail which also are small insectivorous landbirds and very common in Iceland might start breeding on Surtsey in the near future.

I don't think land mammals will ever colonize Surtsey. The Wood-mouse could probably survive there throughout the year when vegetation becomes more abundant but it will probably never find a way of getting to Surtsey across the sea.

Q Can you tell us more about the lava tunnel you were in on the show. How long is it? How did it form? Is it safe to climb in a lava tunnel?

(Borgthor Magnusson): That lava tunnel is about 200 m long. At the upper end it is like a big cave, about 5 meters wide and with 3-4 meters height to the roof, from there it becomes narrower and forms a tunnel all the way down to the sea-cliff below where it opens with a nice view over the ocean. In the eruption the tunnel was like a river of lava and when the crater stopped feeding it, the river ran dry, leaving behind the empty tunnel or riverbed. The roof of the tunnel was probably formed in a similar way as ice on a river that freezes over. In the river you will have a flow of water underneath. In the lava river the molten lava will cool at the top, harden and form a crust. Underneath it there will be a stream of lava as long as the crater feeds the tunnel. There are several lava tunnels or caves on Surtsey and this one is the most accessible and it is fairly safe. Most of the others are much bigger and they are not very safe places to visit. To do that people need ropes, helmets and special equipment. They have only been explored by cave geologists and enthusiasts.

Q How long would it take for an inch of soil to form on the new island?

(Borgthor Magnusson) The soil of Surtsey is still mostly made up of volcanic ash and sand and there has been a very limited build-up of organic matter. It has therefore not changed considerably from the first years after the formation of the island. In parts of the gull colony there is now dense vegetation cover of grass and herbs and underneath that soil formation is more apparent, with root mat and decomposing plant remains. These processes have not been studied in any detail on Surtsey but they are certainly very interesting and important in the developing ecosystem. My feeling is that it will take many years (30-50?) before we have an inch of soil with some decent organic matter content underneath vegetation sward on Surtsey.

Q The show said that the island, created by the volcanic rock, is about half the size it was when it started. If that's true, then why are continents like Australia still around? I mean didn't the continents start as lava and harden like the island? So why is Surtsey disappearing but North America never did?

(Borgthor Magnusson) The geologists would answer this question more fully but I will try. Surtsey is a very small island, surrounded by deep waters and exposed to strong southern winds blowing across the Atlantic. The basaltic lava layers that form the southern part of the island are very loose and more like a pile of huge stones than one concrete block. The oceanic waves break and erode the lava cliffs of Surtsey rather easily. Most of the broken material is carried to deeper waters by the waves but part of it is deposited on the northern or lee side of Surtsey, where a small ness has been formed. I doubt that the big continents were all formed in volcanic eruptions or under similar conditions as Surtsey. Their formation may partly have been caused by volcanic activity, but also by upheaval of the earth's crust and other forces. There is a great difference in the hardness of the bedrock and its resistance to erosive forces, e.g., oceanic waves. On the continents and bigger islands there are rivers and streams that bring material from hills and mountains down to the lowlands where it is deposited in estuaries and on shores. This may increase the land area or will maintain it. There is volcanic activity on some of the continents, e.g., in parts of North America, which brings up new material from the earth's crust. This will help to keep the balance with what is broken down along the coastline. I hope this answers some of your thoughts, but I suggest you point your question to a geomorphologist. Frontiers Forum Moderator adds: Viewers who want to learn more can visit Volcano World at Here you'll find information, photos and video clips of volcanoes around the world and also have an opportunity to send questions to a volcanologist.


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