Yilmaz, Elif
Three areas of different ecosystem characteristics in the Northern Levantine Basin is compared using a 1-D multicomponent lower trophic level ecosystem model developed by SALIHOĞLU, B. et al. (2009) (NAGEM). Main focus was to analyze and compare the carrying capacity (PP) and regulatory mechanisms of the nutrients on lower trophic levels. 26 years’ of historical data obtained from METU-IMS data inventory and CORIOLIS was used to form a climatology, to introduce boundary conditions to the model as well as to carry out model skill analyses. At the three sites (Erdemli Times Series, that represents a coastal system, Mersin Bay, that represent offshore waters and Rhodes upwelling area) vertical mixing in winter and stratification in summer are found to play a major role in the distribution of nutrients in the water column resulting shift in ecosystem structure. Furthermore, model results suggest distinct mechanisms that control phytoplankton biomass in each region. In Rhodes upwelling area, highest annual primary production values calculated due to nutrientrich, deep water carried into the euphotic zone throughout the year. On the other hand the strongest and deepest spring bloom occurred at Erdemli coasts which are attributed to increasing riverine input to the area in early spring. the strongest and deepest spring bloom occurred at Erdemli coasts which are attributed to increasing riverine input to the area in early spring. Offshore waters of Mersin Bay have the lowest productivity throughout the year with minor pulses during winter and spring seasons. The model also suggests alterations on limiting nutrients due to changing nutrient budgets among sites. Even though all areas are found to be limited by phosphate, offshore waters of Mersin Bay are also co-limited by nitrogen for autotrophic eukaryotes and diatoms in the summer season. This limitation also occurs in ETS station for diatom species.


Ecosystem and primary production interactions in three contrasting sites in thenorthern levantine basın
Yılmaz, Elif; Salihoğlu, Barış; Uysal, Zahit; Yumruktepe, Veli; Tezcan, Devrim; Örek, Hasan; Tuğrul, Süleyman (null; 2016-09-16)
To determine the effects of different nutrient dynamics in the Levatine Basin a 1-D multi component lower trophic ecosystem model is used and the carrying capacity and regulatory mechanisms of the nutrients on upper trophic levels at three contrasting marine sites in the Northeastern Mediterranean is assessed. Offshore waters of Mersin Bay, coastal sites of Erdemli and Rhodes Gyre is chosen as they represent distinctive characteristics in terms of nutrients dynamics. Model results suggest distinct mechanism...
Simulations of phytoplankton species and carbon production in the equatorial Pacific Ocean 2. Effects of physical and biogeochemical processes
Salihoğlu, Barış (2007-03-01)
A one-dimensional multi-component lower trophic level ecosystem model that includes detailed algal physiology is used to investigate the response of phytoplankton community and carbon production and export to variations in physical and biochemical processes in the Cold Tongue region of the equatorial Pacific Ocean at ON, 140W. Results show that high-frequency variability in vertical advection and temperature is an important mechanism driving the carbon export. Filtering out low frequency physical forcing re...
Changes of Eutrofication Indicator Parameters (TP, DIN, Chl-a and TRIX) in the Cilician Basin (Northeast Mediterranean)
TUĞRUL, SÜLEYMAN; Uysal, Zahit; Erdogan, Emine; Yucel, Nebil (2011-01-01)
Eutrophication processes and changes in coastal ecosystem are determined by the coastal/open sea interactions and rates of nutrient pollution. The Cilician Basin shelf waters are affected not only by intense industrial activities and increased population, but also by complex atmosphere-sea-land interactions. There is a recognizable difference between water qualities of Mersin bay coastal and the Cilician open waters depleted in nutrients. Eutrophic conditions have developed in the eastern bay shallow waters...
Evaluation of salt tolerance in sto transformed Arabidopsis thaliana and Nicotiana tabacum plants
Selçuk, Feyza; Yücel, Ayşe Meral; Department of Biology (2004)
Salinity is one of the limiting factors of crop development. Together with causing water loss from plant tissues, salinity also leads to ion toxicity. Under salt stress, increase in Ca+2 concentration in cytosol can decrease the deleterious effects of stress. The binding of Ca+2 to calmodulin initiates a signaling cascade involving the activation of certain transcription factors like STO and STZ. This signal transduction pathway regulates transport of proteins that control net Na+ influx across the plasma m...
Quantification of the Synergistic Effects of Eutrophication, Apex Predator Pressure, and Internal Processes on the Black Sea Ecosystem
Salihoğlu, Barış (2013-12-01)
In the present study, a model of the lower-trophic pelagic food web of the Black Sea is considered in order to provide a quantitative understanding of the marked changes in the food web structure in response to changing top-down and bottom-up control mechanisms due to eutrophication, overfishing, and climatic changes. The simulations consider three particular parameters controlling the changes in the ecosystem structure due to these stressors; (i) the magnitude of the nitrate flux into the euphotic layer fr...
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