title: ALien Biotic IndEX (ALEX) - a new index for assessing impacts of alien species on benthic communities.
abstract: Biotic indices are mainly aimed at assessing levels of deterioration caused by chemical or organic pollution. However, no biotic index to date has been developed to detect impacts of alien species on benthic communities. In this paper, a new biotic index, namely ALEX, is proposed to address the objectives of the Water Framework Directive and was tested in Mersin Bay (Levantine Sea, Turkey). Species were divided into four biogeographic groups, namely native species, casual species, established species and invasive species, and the metric considers the relative importance of these groups in samples. The index classified the ecological status of some stations which are shallow, and close to harbor and river mouths as bad or poor in February and October. The ALEX values were positively and significantly correlated with total nitrogen, silicate and silt percentage in sediment, and negatively correlated with depth and the distance from the harbor.
authors.affiliation: Ege University, Faculty of Fisheries, Dept. of Hydrobiology, 35100 Bornova, İzmir, Turkey. Electronic address: melih.cinar@ege.edu.tr.
authors.forename: Melih Ertan
authors.initials: ME
authors.lastname: Çinar
authors.affiliation: Ege University, Faculty of Fisheries, Dept. of Hydrobiology, 35100 Bornova, İzmir, Turkey.
authors.forename: Kerem
authors.initials: K
authors.lastname: Bakir
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D058865:Introduced Species; D009792:Oceans and Seas; D045483:Rivers; D014421:Turkey
keywords: Alien species; Benthic communities; Biotic index; Eastern Mediterranean; Impacts of alien species