Age, Growth and Reproductive Biology of the Common Two-Banded Seabream (Diplodus vulgaris Geoffroy Saint-Hilaire, 1817) from the Northern Aegean Sea, Turkey

2019 ◽  
Vol 35 (2) ◽  
pp. 679-688 ◽  
Author(s):  
Ali Ismen ◽  
Ismail Burak Daban ◽  
Mukadder Arslan Ihsanoglu ◽  
Cahide Cigdem Yıgın ◽  
Koray Cabbar ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Aegean Sea ◽  
The Common ◽  
Northern Aegean Sea

scholarly journals Some reproductive characteristics of the blotched picarel Spicara maena (Perciformes: Centracanthidae) from Saros Bay, Northern Aegean Sea, Turkey

2019 ◽  
Vol 54 (2) ◽  
pp. 174
Author(s):  
Özgür Cengiz
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Aegean Sea ◽  
Reproductive Characteristics ◽  
Absolute Fecundity ◽  
Northern Aegean Sea

This study was carried out, monthly, in the Saros Bay (Northern Aegean Sea, Turkey) between January 2015 and December 2015. The gonadosomatic index (GSI) and absolute fecundity (Fa) of the blotched picarel (Spicara maena) were analyzed . The present study contributes to the reproductive biology of S. maena by reporting the first data about the fecundity of the species for the Aegean Sea

Genetic studies in four populations of the Northern Aegean Sea, Greece

1989 ◽  
Vol 78 (1) ◽  
pp. 89-106
Author(s):  
R. Schliwa ◽  
Angela Dannewitz ◽  
K. Gilbert ◽  
H. Walter
Keyword(s):  
Aegean Sea ◽  
Genetic Studies ◽  
Northern Aegean Sea

Abundance and population structure of the blue crab Callinectes sapidus (Decapoda, Portunidae) in Thermaikos Gulf (Methoni Bay), northern Aegean Sea

Crustaceana ◽  
2018 ◽  
Vol 91 (6) ◽  
pp. 641-657 ◽  
Author(s):  
Kosmas Kevrekidis ◽  
Chryssanthi Antoniadou
Keyword(s):  
Population Structure ◽  
Blue Crab ◽  
Callinectes Sapidus ◽  
Carapace Width ◽  
Seawater Temperature ◽  
Aegean Sea ◽  
Cold Season ◽  
Mean Size ◽  
Northern Aegean Sea ◽  
Fyke Nets

Abstract The blue crab Callinectes sapidus is an alien decapod established in the Mediterranean Sea. Since 2007, increased abundance has been reported from the northern Aegean Sea sustaining local scale fishery. The present work aims to assess the abundance and population structure of C. sapidus in Thermaikos Gulf using fyke nets. Population abundance, estimated as CPUE, exhibited strong temporal variability with decreased values in the cold season; this pattern was correlated with seawater temperature. Females exhibited also spatial differences with increased abundance close to the Aliakmon estuary. In total, 543 individuals were measured for carapace width. Males prevailed in the population; however, mean size was similar between sexes. Larger individuals were caught from deeper waters and the estuarine areas, whereas mean size decreased temporally. The fyke nets used proved to be size-selective, thus preventing fisheries mortality for juveniles. However, recurrent monitoring is necessary for a sustainable management of blue crab fisheries in the gulf.

scholarly journals Temporal variations of the fractal properties of seismicity in the western part of the north Anatolian fault zone: possible artifacts due to improvements in station coverage

1995 ◽  
Vol 2 (3/4) ◽  
pp. 147-157 ◽  
Author(s):  
A. O. Öncel ◽  
Ö. Alptekin ◽  
I. Main
Keyword(s):  
Fault Zone ◽  
Statistical Significance ◽  
Rock Fracture ◽  
Aegean Sea ◽  
B Value ◽  
Temporal Variations ◽  
North Anatolian Fault ◽  
North Anatolian Fault Zone ◽  
The North ◽  
Northern Aegean Sea

Abstract. Seismically-active fault zones are complex natural systems exhibiting scale-invariant or fractal correlation between earthquakes in space and time, and a power-law scaling of fault length or earthquake source dimension consistent with the exponent b of the Gutenberg-Richter frequency-magnitude relation. The fractal dimension of seismicity is a measure of the degree of both the heterogeneity of the process (whether fixed or self-generated) and the clustering of seismic activity. Temporal variations of the b-value and the two-point fractal (correlation) dimension Dc have been related to the preparation process for natural earthquakes and rock fracture in the laboratory These statistical scaling properties of seismicity may therefore have the potential at least to be sensitive short- term predictors of major earthquakes. The North Anatolian Fault Zone (NAFZ) is a seismicallyactive dextral strike slip fault zone which forms the northern boundary of the westward moving Anatolian plate. It is splayed into three branches at about 31oE and continues westward toward the northern Aegean sea. In this study, we investigate the temporal variation of Dc and the Gutenberg-Richter b-value for seismicity in the western part of the NAFZ (including the northern Aegean sea) for earthquakes of Ms > 4.5 occurring in the period between 1900 and 1992. b ranges from 0.6-1.6 and Dc from 0.6 to 1.4. The b-value is found to be weakly negatively correlated with Dc (r=-0.56). However the (log of) event rate N is positively correlated with b, with a similar degree of statistical significance (r=0.42), and negatively correlated with Dc (r=-0.48). Since N increases dramatically with improved station coverage since 1970, the observed negative correlation between b and Dc is therefore more likely to be due to this effect than any underlying physical process in this case. We present this as an example of how man-made artefacts of recording can have similar statistical effects to underlying processes.

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