densest cover between below sea level. 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 carcasses washed up on the island. When a large, grass-covered tussock 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. 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. The first earthworm was found in a soil sample in 1993, probably carried over from Heimaey by a bird. However, the next year no earthworms were found. 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. Human impact The only significant human impact is a small prefabricated hut which is used by researchers while staying on the island. The hut includes a few bunk beds and a solar power source to drive an emergency radio and other key electronics. There is also an abandoned lighthouse foundation. All visitors check themselves and belongings to ensure no seeds are accidentally introduced by humans to this ecosystem. It is believed that some boys who sneaked over from Heimaey by rowboat planted potatoes, which were promptly dug up once discovered. An improperly managed human defecation resulted in a tomato plant taking root, which was also destroyed. In 2009, a weather station for weather observations and a webcam were installed on Surtsey. See also Geography of Iceland List of islands of Iceland List of new islands List of volcanoes in Iceland Volcanism of Iceland References External links The Surtsey Research Society Weather observations on Surtsey Webcam on Surtsey Aerial photos, maps and volcanic geology of Surtsey. Visit Westman Islands Surtsey Topography The Surtsey Research Society , which administers the island A notice from the Environmental & Food Agency declaring Surtsey a protected