Atlantis Online
October 21, 2019, 05:55:13 pm
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Ruins of 7,000-year-old city found in Egypt oasis
http://news.yahoo.com/s/afp/20080129/wl_mideast_afp/egyptarchaeology
 
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Surtsey

Pages: [1]   Go Down
  Print  
Author Topic: Surtsey  (Read 2420 times)
Adam Hawthorne
Superhero Member
******
Posts: 4250



« on: April 14, 2007, 05:21:35 pm »

The settlement of life

A classic site for the study of biocolonisation from founder populations that arrive from outside (allochthonous), Surtsey was declared a nature reserve in 1965 while the eruption was still in active progress. Today only a small number of scientists are permitted to land on Surtsey; the only way anyone else can see it closely is with a small plane.


Plant life

Life began to settle on the island. The first life to appear was moss and lichen, which began to appear on the island as early as 1965. Mosses and lichens now cover much of the island. During the island's first 20 years, 20 species of plants were observed at one time or another, but only 10 became established in the nutrient-poor sandy soil.

As birds began nesting on the island, soil conditions improved, and more advanced species of plants were able to survive. In 1998, the first bush was found on the island a Salix phylicifolia bush, which can grow to heights of up to 4 metres. In total at least 60 species of plant have been found on Surtsey, of which about 30 have become established. More species continue to arrive, at a typical rate of roughly 25 new species per year.[3]




The first puffin nests were found on Surtsey in 2004


Birds

The expansion of bird life on the island has both relied on and helped to advance the spread of plant life. Birds use plants for nesting material, but also assist in the spreading of seeds, and fertilise the soil with their guano. Birds began nesting on Surtsey three years after the eruptions ended, with fulmar and guillemot the first species to set up home. Eight species are now regularly found on the island.

A gull colony has been present since 1986, although gulls were seen briefly on the shores of the new island only weeks after it first appeared. The gull colony has been particularly important in developing the plant life on Surtsey, and the gulls have had much more of an impact on plant colonisation than other breeding species due to their abundance. An expedition in 2004 found the first evidence of Atlantic Puffins nesting on the island. Puffins are extremely common in the rest of the archipelago.

As well as providing a home for some species of birds, Surtsey has also been used as a stopping-off point for migrating birds, particularly those en route between the British Isles and Iceland. Species that have been seen briefly on the island include whooper swans, various species of goose, and ravens. Although Surtsey lies to the east of the main migration routes to Iceland, it has become a more common stopping point as its vegetation has improved.[4]


Marine life

Soon after the island's formation, seals were seen around the island. They soon began basking there, particularly on the northern spit, which grew as the waves eroded the island. Seals were found to be breeding on the island in 1983, and a group of up to 70 made the island their breeding spot. Grey seals are more common on the island than common seals, but both are now well established. The presence of seals attracts killer whales, which are frequently seen in the waters around the Vestmannaeyjar archipelago and now frequent the waters around Surtsey.

On the submarine portion of the island, many marine species are found. Starfish are abundant, as are sea urchins and limpets. The rocks are covered in algae, and seaweed covers much of the submarine slopes of the volcano, with its densest cover between 10 and 20 metres below sea level.[5]


Other life

Insects arrived on Surtsey soon after its formation, and were first detected in 1964. The original arrivals were flying insects, carried to the island by winds and their own power. Some were believed to have been blown across from as far away as mainland Europe. Later insect life arrived on floating driftwood, and both live animals and corpses washed up on the island. When a large, grass-covered tussock was washed ashore in 1974, scientists took half of it for analysis and discovered 663 land invertebrates, mostly mites and springtails, the great majority of which had survived the crossing [3].

The establishment of insect life provided some food for birds, and birds in turn helped many species to become established on the island. The bodies of dead birds provide sustenance for carnivorous insects, while the fertilisation of the soil and resulting promotion of plant life provides a viable habitat for herbivorous insects.

Some higher forms of land life are now colonising the soil of Surtsey. The first earthworm was found in a soil sample in 1993, probably carried over from Heimaey by a bird. Slugs were found in 1998, and appeared to be similar to varieties found in the southern Icelandic mainland. Spiders and beetles have also become established.[6][7]

Report Spam   Logged


Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy