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A study on silver scabbardfish (Lepidopus caudatus) distribution and demographic structure was carried out in northern Aegean Sea from bottom trawl surveys (MEDITS: Mediterranean International Bottom Trawl Survey) during1996-2006. The surveys were performed each year (except in 2002) between June and July. Approximately 65 hauls were carried out in total, at depth range between 10 and 800 m. The sampling design adopted was random-stratified including five depth zones: 10-50, 50-100, 100-200, 200-500 and 500-800 m. Data of biomass (kg/km2) and abundance (N/km2) were investigated in order to describe the geographical and bathymetric distribution. Scabbardfish was more frequently found in the area of Lesvos Island between depths of 340 and 370 m. The hotspots of scabbardfish biomass coincided with the longitudinal thermal front that is generated between the eastern (colder) and the western (warmer) surface water masses during the summer months. The aim of this research was to analyze the distribution and demographic structure of L. caudatus and the associated species assemblages in the northern Aegean Sea. [ABSTRACT FROM AUTHOR]

The article presents a study on the stomach contents of a Mediterranean monk seal in the Aegean Sea. It mentions that the cause of its death is the accidental entanglement in the fishing net. It also notes that Monk seal and fishery interactions could hamper the conservation of these kinds of species.

The population characteristics of four deep-water pandalid shrimps (Decapoda: Caridea) were studied in the northern Aegean Sea in samples collected annually (1997-2000) in summer, through experimental trawl, at depths down to 600 m. Females were larger than males in Plesionika martia and Plesionika heterocarpus; no significant differences in size of males and females were found in Chlorotocus crassicornis and Plesionika antigai. A trend of increasing size with depth was observed, as well as a linear increase in the proportion of females with increasing size. Sex ratio was skewed towards females at all depths in P. antigai, while in P. heterocarpus and C. crassicornis males dominated the intermediate depths. Negative allometries were apparent in the carapace length-weight relationships in males of all species. Isometric relationships were found in females apart from in P. heterocarpus. The population patterns conform to relevant Mediterranean reports. However, some population differences exist that may reflect the distinct environmental conditions prevailing in the study area. [ABSTRACT FROM AUTHOR]

Abstract: The recently launched Daily Egg Production Method (DEPM) surveys to estimate the spawning stock biomass (SSB) of the northern Aegean Sea anchovy stock are presented and variability in plankton and adult parameters is analyzed for the yearly applications of 2003, 2004, 2005, 2006 and 2008. Anchovy spawned mainly over the continental shelf of the Thracian Sea in the east (directly affected by Black Sea waters), and the semi-enclosed Thermaikos Gulf and Evoikos Gulf in the west. The surveyed area was therefore post-stratified into an eastern and western region and DEPM parameters, which, in certain years, differed markedly between the two areas, were estimated separately for the two strata. To increase precision of the daily egg production estimates, both eggs and yolk sac larvae were used assuming that the mortality rate does not change between the egg and yolk sac larval stage. Embryonic mortality increased as a power function of temperature. The estimation of spawning fraction was based on the postovulatory follicles (POFs) method and was particularly complicated due to the presence of strong thermoclines and diel vertical migration of the fish: POF absorption was very fast during the night, when fish were located above the thermocline (>20°C), but relatively slow during the day, when fish were close to the bottom at ∼14–15°C. Mean relative batch fecundity was significantly related to somatic condition (energy reserves) whereas spawning frequency was related to liver condition (presumably, direct food intake). In comparing daily specific fecundities (DSFs) with concurrent estimates of mesozooplankton biomass and total anchovy biomass (independently derived from acoustic sampling) evidence for strong density-dependence in DSF emerged. Density-dependent use (expansion–contraction) of the spawning habitat (SA), indexed by the ratio CV(SA)/CV(SSB), was relatively low but density-dependency of egg production CV(DSF)/CV(SSB) was particularly high in the N. Aegean Sea compared to the more productive Bay of Biscay or upwelling regions. [Copyright &y& Elsevier]

Abstract: The development of a periodic, spatially structured population matrix model for the study of North Aegean Sea anchovy population structure and dynamics is presented on the basis of its life-cycle, and the ecosystem environmental features. System heterogeneity and species life-cycle leaded to model development on seasonal scale and sub-regional basis, incorporating survival, fecundity and migration rates. Several methodological aspects concerning the periodic dynamics on a seasonal basis combined with the existence of spatial heterogeneity and age—season specific migration patterns are examined and discussed. Special attention is devoted to a possible inflow of recruits originated from Black Sea Waters, introducing a “source-sink” effect in the model and resulting in reducible projection matrices. The model also accounts for a possible outflow from the study area, structurally implemented by another virtual “sink” sub-area incorporation. A first attempt was made to calibrate the model using parameters provided by older studies and original data provided by the ANREC project focused on the anchovy—environment interactions and carried out in the area. Then the model was used to check the efficiency of various fishing limitations in space and/or time and the results confirmed the importance of the fishing activity over the spawning grounds. [Copyright &y& Elsevier]