Ecological Gradients of Epimegafaunal Distribution along The Sectors of Gulf of İzmir, Aegean Sea

Abstract

During 2009During -2010 epifaunal materials were collected seasonally with a beam trawl from seven fixed stations in the infralittoral of Gulf of Izmir to study spatiotemporal distribution of megabenthic fauna and their ecology. A total 153 megafaunal species were identified belonging to nine phyla, comprised mostly of 54 molluscans, 43 chordates (mostly fish), 20 arthropods, and 18 echinoderms. Nine alien species were recorded. Four species (two fish species, one gastropod and one Asteroidea species) were constant species and 16 species were common species in the study area. Lesueurigobius friesii, Buglossidium luteum, Turritellinella tricarinata and Astropecten irregularis were the most frequently occurred, and Lesueurigobius friesii, Varicorbula gibba, Anomia ephippium, Turritellinella tricarinata and Dentalium sp were the most abundantly occurred species. Excluding the evenness index, faunistic characteristics tended to increase as a factor of depth. Seasonal density (abundance and biomass) was minimal in April and maximal in February, followed by November having 2-fold higher abundance than that inJuly. Faunal assemblages were correlated with regions of the gulf and habitat type. Buglossidium luteum overspread the entire gulf excluding the inner gulf. Varicorbula gibba and Fulvia fragilis, a pollution indicator predominated the inner gulf. Hydrographical parameters and depth were associated to dictate faunal assemblages with difference among the sectors and habitats.

Seasonal Macro-Floral Distribution on Soft Bottoms in a Gulf of a Metropolitan Providence, İzmir, Aegean Sea

“…Especially in the northern part of the bay, where there are wide shallows, opportunistic macroalgae species cause blooms in certain seasons (such as spring and late summer), causing undesirable results. Similar case was observed for the megabenthic fauna for a bad or moderate ecosystem of the inner and middle sectors of Izmir Gulf [27].…”

“…Ulva spp blooms seen at various eutrophic places; Venice lagoon, North-western Mediterranean, Quequen Argentina, Brittany coast [62, 63 and 65]. Similar ecosystem status occurred based on the megabenthic fauna in the inner gulf of Izmir [27]. However, the macrophyte communities or assemblages oriented primarily with the sectors corresponding to the seafloor depths on the CCA plot (Table 4 and Figure 5).…”

“…Therefore, this phenomenon threatens the human activities, commercial fishing and ecosystem biodiversity [17, 15, 12, 24, 14, 21, 25, 16, 13, 18 and 26]. Similar effects were observed for the megabenthic fauna for a bad or moderate ecosystem, such as inner gulf of Izmir [27].…”

“…The study area was well described with environmental measures in time and space by Mutlu [27]. The study area included the infralittoral zone of the Gulf of İzmir, Aegean Sea (Figure 1).…”