Community structure of deep-sea demersal fish in the North Aegean Sea (northeastern Mediterranean)
Labropoulou, M.; Papaconstantinou, C. (2000). Community structure of deep-sea demersal fish in the North Aegean Sea (northeastern Mediterranean), in: Jones, M.B. et al. Island, Ocean and Deep-Sea Biology: Proceedings of the 34th European Marine Biology Symposium, held in Ponta Delgada (Azores), Portugal, 13-17 September 1999. Developments in Hydrobiology, 152: pp. 281-296. https://dx.doi.org/10.1007/978-94-017-1982-7_26 In: Jones, M.B. et al. (2000). Island, ocean and deep-sea biology: Proceedings of the 34th European Marine Biology Symposium, held in Ponta Delgada (Azores), Portugal, 13-17 September 1999. European Marine Biology Symposia, 34. Developments in Hydrobiology, 152. ISBN 978-0-7923-6846-5; e-ISBN 978-94-017-1982-7. XII, 391 pp. https://dx.doi.org/10.1007/978-94-017-1982-7, more In: European Marine Biology Symposia., more |
| Keywords | Dimensions > Depth
Distribution > Geographical distribution > Zonal distribution
Species diversity
Marine/Coastal |
| Authors | | Top | - Labropoulou, M.
- Papaconstantinou, C.
| | |
| Abstract | The spatial structure and seasonal changes of the demersal fish assemblages on the continental shelf (100-200 m) and upper slope (200-500 m) in the North Aegean Sea (Northern Aegean and Thracian Seas, northeastern Mediterranean, Greece) were analysed. Seasonal experimental trawl surveys, carried out from summer 1990 to autumn 1993, provided a total of 151 demersal fish species. Analysis of 259 bottom trawls showed the existence of four groups associated with the continental shelf and the upper slope; each group was dominated by a small number of species. The bathymetric distribution of the species, established using measures of the centre of gravity and habitat width, revealed that most of the species had a wide distributional range within the study area, although a few were restricted to the greatest depths. Density, biomass, species richness and diversity decreased significantly with depth, and were also indicative of distinctive characteristics between these fish assemblages. Mean fish weight exhibited two different trends: a bigger-deeper phenomenon at the continental shelf and a smaller-deeper phenomenon at the upper slope. The variability in assemblage structure was determined mainly by depth and, to a lesser extent, by season and geographical location. For some species, results suggest a pattern of gradual species replacement along the depth gradient coupled with ontogenetic habitat shifts. |
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