on the island has both relied on and helped to advance the spread of plant life. Birds use the plants for nesting material, but also continue to assist in the spreading of seeds, and fertilize the soil with their guano. Birds first began nesting on Surtsey three years after the eruptions ended, with fulmar and guillemot the first species to set up home. Twelve species are now regularly found on the island. A gull colony has been present since 1984, although gulls were seen briefly on the shores of the new island 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 nesting Atlantic puffins, which are abundant 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 Europe and Iceland. Species that have been seen briefly on the island include whooper swans, various species of geese, and common ravens. Although Surtsey lies to the west of the main migration routes to Iceland, it has become a more common stopping point as its vegetation has improved. In 2008, the 14th breeding bird species was detected with the discovery of a common raven's nest. According to a 30 May 2009 report, a golden plover was nesting on the island, with four eggs. 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 harbour seals, but both are now well established. The presence of seals attracts orcas, 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