An investigation on alien invasive seaweeds around Aegean sea coasts

As a result of the present study, among the alien and invasive species Caulerpa racemosa var. cylindracea was observed to be distributed intensly along the southern half of the Aegean Sea. In this study, because this species creates problems with regard to biodiversity special emphasis was given to it. Three base stations where this species show an intense distribution were determined in the northern, central and southern Aegean Sea respectively. The biometric measurements of the seasonal samples taken from these 3 stations were carried out. In additon to these, the distribution of the species at these sites were mapped with the aid of GPS. While because of its tropical origin Stypopodium schimperi?s northernmost distribution range was Çeşme coasts, subtropical Halophila stipulacea showed more northernly range until Dikili coasts. When the spreading characteristics of these three species were compared, while Caulerpa racemosa var. cylindracea was determined to be the fastest spreading weed, Stypopodium schimperi was markedly faster, and Halophila stipulacea was reasonably faster. While first two species affects the biota and biodiversity of the site that they occur greatly, Halophia stipulacea was found be spreading without affecting the surrounding biota. When the spreading kinetics were taken into account, Caulerpa racemosa var. cylindrecea has the capacity to influence the whole Turkish Medeiterranean coasts. Furthermore, with such kind of distribution and spreading mechanism, the eradication of the species has not been foreseen. Under the light of the present information, the distribution of this algea should be monitored with a big scale programme.