Megabentic non-crustacean invertebrates which play crucial important role in the ecosystem were spatiotemporally studied in an oligotrophic water mass of the eastern Mediterranean shelf-shelf break. The samples were collected with an Otter fishery trawl on three regions, each having five different seafloor depths. The samplings were repeated seasonally in four different months during year 2014–2015, being aimed to provide baseline ecological information on their bathymetric and seasonal distribution and biodiversity patterns. A total of 7 megabenthic non-crustacean phyla were found including 90 species composed mainly of 38 mollusks, 20 echinoderms, and 12 sponges. Three non-crustacean species recorded alien species for the Mediterranean Sea. Number of species for each phylum changed with the seafloor depth. Number of species increased overall from the shallow water to the intermediate water, and then decreased down to the shelf break. The westernmost Mediterranean Sea was incomparable so rich and high in the number of species, biomass and abundance as compared with the easternmost Mediterranean Sea. In general, abundance and biomass increased in summer and decreased in winter in the Mediterranean Sea, particularly at the shallower waters, continental shelf depending mainly on a series variety of organisms' behaviors and environmental conditions. The abundance of epifauna was differentiated by the status of the grounds: fishing and non-fishing grounds. Conomurex persicus changed remarkably the spatiotemporal trends in contrast to no regular seasonal pattern in the faunistic characters in very shallow waters after its introduction. The depth-related gradient was owing to a number of biogeochemical and physical factors interacted with sedimentary characters, light intensity, nutritional condition availability, and temperature. With an exception of few species, the characteristic species for spatio-temporal similarities, the species composition were rather different between the easternmost and westernmost Mediterranean Sea.

Depth range
10- 300 m

Mesophotic “mentions”
0 x (total of 9797 words)

Classification
* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'temperate mesophotic ecosystem'

Fields
Biodiversity
Ecology
Community structure

Focusgroups
Fishes
Overall benthic (groups)

Locations
Turkey - Mediterranean Sea

Platforms
Acoustic Telemetry
Dredging / trawling
Surface-deployed sensors and samplers