Bilir, Batıkan
It is known that the temperature change in water resulted by the strength and direction of cold winds varying from year to year has an effect on the distribution of small pelagics which have yearly migration cycles in semi-closed systems such as Black Sea. However, how small pelagic species wintering in the southern Black Sea have adopted to this situation has not yet been elucidated. The aim of this study is to determine how the wintering distributions of three small pelagic fishes, Black Sea Anchovy (Engraulis encrasicolus ponticus), Mediterranean Horse Mackerel (Trachurus mediterraneus) and Sprat (Sprattus sprattus), dominant in the southern Black Sea region change in two different years with different cooling rate and direction from a rational point of view. To this end, the region between 28°E and 42°E longitudes of the southern Black Sea was examined to the limit of the exclusive economic zone. The surveys carried out in 2011 and 2016 was funded by TUBITAK (The Scientific and Technological Research Council of Turkey) for the project titled “Determination of Anchovy Stocks in the Black Sea by Acoustic Method and Setting of Continuous Monitoring Model” within the scope of 1007 projects. Within the scope of these expeditions; CTD, trawl and acoustic data were collected simultaneously. Then, CTD data were analyzed for two separate years to determine the thermocline line and implied to the acoustic data. As a result of this process, the shapes of horse mackerel schools were determined and the structure (height, weight, energy distribution etc.) of these schools were quantified before separating the cold water species, sprat and warm water species, anchovy. For this procedure, schools verified as horse mackerel were used. The schools in the rest of data set were determined according to ranges of these parameters. Afterwards, horse mackerel schools were removed from the data set and the acoustic data which were divided into two separate layers were analyzed for anchovy and sprat. According to the results, all three small pelagic species settled in the wintering area due to cooling resulted from northern winds. In detail, while the adults of anchovy and horse mackerel, which are hot lovers, are mostly observed on the shore, juvenile individuals which have tolerance colder waters, of the same species and sprat were more intense in the open sea. Regarding the coastal zone, anchovy was observed in the eastern, and horse mackerel spread in the western part of the central and eastern parts of the southern Black Sea in 2011. This shows that cold water tolerance of the horse mackerel were more than anchovy in the year 2011. As a result of north-south cooling in 2016, anchovy was distributed in the west and about 10-fold less than that in the east which are probably came from north. Similar to the state of anchovy, horse mackerel was concentrated in the west in 2016. It was finally observed that sprat prefers open waters in winter and the density which is less on the coasts increases in colder regions.


Effect of temperature on clearance rate daily ration and digestiontime of Mnemiopsis leidyi from the southern Caspian Sea
M,, Rowshantabari; Finenko, Ga; Kıdeyş, Ahmet Erkan; Kiabi, B. (University of Guilan, 2012-06-01)
The effect of temperature on the main feeding parameters of Mnemiopsis leidyi from the southern Caspian Sea was studied in 2002. The clearance rates and daily rations were estimated from laboratory experiments in a wide range of temperatures from 12 to 27 ?C for M. leidyi of 12?17 mm in length. Clearance rate values changed from 52.5 to 107.3 ml ind-1 h-1. The coefficient Q10 in temperature 12 - 20 ?C was higher than that in 20 - 27 ?C (3.81 and 1.91, respectively). The specific daily ration changed from 1....
Effect of tectonic processes on biosphere-geosphere feedbacks across a convergent margin
Fullerton, Katherine M.; et. al. (2021-04-01)
The subsurface is among Earth's largest biomes, but the extent to which microbial communities vary across tectonic plate boundaries or interact with subduction-scale geological processes remains unknown. Here we compare bacterial community composition with deep-subsurface geochemistry from 21 hot springs across the Costa Rican convergent margin. We find that cation and anion compositions of the springs reflect the dip angle and position of the underlying tectonic structure and also correlate with the bacter...
Impacts of climatic variables on water-level variations in two shallow Eastern Mediterranean lakes
Yagbasan, Ozlem; Yazıcıgil, Hasan; Demir, Vahdettin (2017-08-01)
Variations in temperature and precipitation have direct impacts on the physical, chemical and biological characteristics of the shallow lakes. This paper examines the possible linkages between climate variables and the water levels of shallow interconnected Lakes Mogan and Eymir, located 20 km south of Ankara in Central Anatolia. The variations in the lakes' water levels during 1996-2015 are studied and the impacts of climate variables on the lake levels are assessed to address the long-term consequences. T...
Effect of meteorological parameters on fine and coarse particulate matter mass concentration in a coal-mining area in Zonguldak, Turkey
TECER, LOKMAN HAKAN; Suren, Pinar; Alagha, Ömer; KARACA, FERHAT; Tuncel, Süleyman Gürdal (2008-04-01)
In this work, the effect of meteorological parameters and local topography on mass concentrations of fine (PM2.5) and coarse (PM2.5-10) particles and their seasonal behavior was investigated. A total of 236 pairs of samplers were collected using an Anderson Dichotomous sampler between December 2004 and October 2005. The average mass concentrations of PM2.5, PM2.5-10, and particulate matter less than 10 mu m in aerodynamic diameter (PM10) were found to be 29.38, 23.85, and 53.23 mu g/m(3), respectively. The ...
Role of Saharan dust on phytoplankton dynamics in the northeastern Mediterranean
Eker-Develi, Elif; Kıdeyş, Ahmet Erkan; TUĞRUL, SÜLEYMAN (2006-01-01)
Effects of atmospheric deposition and other environmental factors on phytoplankton dynamics were evaluated from an open (having offshore characteristics) and a coastal station in the northeastern Mediterranean between December 2000 and December 2001. Data on phytoplankton, chlorophyll a, nutrients, temperature and salinity were obtained at bi-weekly or more intense intervals during 1 yr, whilst transport of Saharan dust towards the sampling region was monitored daily by SeaWiFS (sea-viewing wide field-of-vi...
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