LIFE ON THE SHORE AND IN THE SEA
Among the first colonists of Surtsey’s coastal environment were diatoms discovered on the sandy beach in August 1964.
The dispersal methods used by marine organisms to reach Surtsey are numerous. Algae have planktonic spores, and many marine animals have planktonic larvae that are dispersed by ocean currents. Such organisms are dispersed over long distances. Marine animals that give birth to living offspring that are similar in appearance to their parents are usually not dispersed by way of ocean currents but must crawl or swim to new destinations. Colonization of new habitats is difficult for such organisms. Animals that had a sessile larval stage and lived on the bottom of the sea nearby when the eruption began had an advantage compared to other benthic species. They were able to colonize the new land as soon as the eruption subsided and the ash no longer covered them. In addition, it may be possible that birds carried spores and larvae of marine animals in their feathers, as most seagulls and wading birds look for food in the sublittoral zone.