Effects of habitat and substrate complexity on shallow sublittoral fish assemblages in the Cyclades Archipelago, North-eastern Mediterranean Sea

Abstract

This is the first study to explore fish community structure and its relations to habitat and topographic complexity in the shallow coastal waters of the Cyclades Archipelago, North-eastern Mediterranean Sea. In situ visual surveys were carried out at 233 sampling sites in 26 islands of the Cyclades Archipelago. Fish community parameters and biomass were estimated across seven substrate types: sand, seagrass, vertical walls, boulders, horizontal/subhorizontal continuous rock, rocky substrate with patches of sand, and rocky substrate with patches of sand and Posidonia oceanica. Topographic complexity and percentage of algal cover were estimated on hard substrate. Substrate type was found to be a determining factor affecting the structure and composition of fish assemblages. Species number, abundance and biomass were significantly lower in sandy areas and always higher on hard substrates, with seagrass habitats presenting intermediate values. Topographic complexity in rocky bottoms did not seem to affect species richness, density or biomass. This study provides a baseline for future evaluation of changes produced by potential management actions such as the creation of marine protected areas in the study region.

Setting an ecological baseline prior to the bottom-up establishment of a marine protected area in Santorini island, Aegean Sea

“…We focused our research on infralittoral rocky reefs and Posidonia oceanica seagrass meadows (Habitat Types 1170 and 1120 respectively, sensu the EU Habitats Directive 92/43/EEC), as these habitats support the highest fish biomass in the Mediterranean (Harmelin-Vivien et al, 2005;La Mesa et al, 2011;Giakoumi & Kokkoris, 2013) and provide a wide array of marine ecosystem services (Salomidi et al, 2012). To assess the ecological status of these habitats, ad hoc indices and metrics were applied (Orfanidis et al, 2001;Boudouresque et al, 2006;Montefalcone et al, 2007), along the lines of the Habitats (92/43/EEC) and Water Framework (WFD, 2000/60/EE) EU Directives, taking into account the morphological, structural and life-history features of the habitat-forming macrophytes (macroalgae and P. oceanica).…”

“…Where values for a and b were not available, the parameters from congeneric species with similar shape and maximum total length were used. We chose the parameter values that best corresponded (Guidetti & Sala, 2007;Giakoumi & Kokkoris, 2013).…”

Assessment of coastal fish assemblages before the establishment of a new marine protected area in central Mediterranean: its role in formulating zoning proposal

“…Comparative studies have clearly demonstrated substantial differences in fish assemblage composition and structure among these habitats, mainly driven by interspecific differences in the habitat requirements of fishes (Guidetti, 2000;Tunesi et al, 2006;Giakoumi & Kokkoris, 2013). The spatial variability of fish assemblages observed within inshore habitats has been frequently ascribed to differences in depth range (Dufour et al, 1995;Reñones et al, 1997;Letourneur et al, 2003;Tunesi et al, 2006;La Mesa et al, 2010).…”

Fish community in a surf zone of the northern Sicilian coast (Mediterranean Sea): diversity and functional guild composition

“…Moreover, considering that the few studies conducted on Mediterranean surf zones have focused only on the macro-and supra-benthic communities (León & Corrales, 1995;Munilla et al, 1998;San Vicente & Munilla, 2000;Deidun & Schembri, 2006;Esposito et al, 2011;Esposito, 2013) or on fish assemblages of Adriatic or north-eastern Mediterranean Sea (Lipej et al, 2003;Giakoumi & Kokkoris, 2013) the specific objectives of this paper were: 1) to investigate, for the first time, the taxonomic composition of a fish assemblage in a surf zone of the Tyrrhenian Sea; 2) to assess the assemblage structure, with the aim of providing information on the functional aspects of this shallow water habitat for the ichthyofauna.…”