Arda özen | Cankiri Karatekin University (original) (raw)

Papers by Arda özen

Journal of Bryology, 2021

Md N. Aziz, V. A. Bakalin , G. Bergamo Decarli, M. Boiko, N. Zagorodniuk, L. M. Boiko, E. A. Boro... more Md N. Aziz, V. A. Bakalin , G. Bergamo Decarli, M. Boiko, N. Zagorodniuk, L. M. Boiko, E. A. Borovichev, G. Brusa, M. J. Cano, J. A. Jiménez, S. S. Choi, I. Draper , F. Lara, M. V. Dunlin, J. Enroth, T. Ezer, V. E. Fedosov, E. Fuertes, R. Garilleti , B. Albertos , S. R. Gradstein, A. Graulich, V. Hugonnot, C. W. Hyun, M. Kırmacı, F. Filiz, U. Çatak, N. A. Konstantinova, A. N. Savchenko, M. Kropik, J. Kučera, H. Kürschner, E. Yu. Kuzmina, N. S. Liksakova, D. Maity, P. Martin, T. T. McIntosh, H. M. H. van Melick, B. Moncada, Cs. Németh, S. V. O’Leary, G. F. Peñaloza-Bojacá, S. A. Maciel-Silva, S. Poponessi, A. Cogoni, R. D. Porley, A. D. Potemkin, M. Puglisi, S. Sciandrello , K. K. Rawat, V. Sahu, R. R. Paul, M. Ryan, P. Saha, D. S. Salas, J. G. Segarra-Moragues, F. Sguazzin, N. R. Shafigullina, J. R. Shevock, S. Ștefănuţ, A. Uygur, S. Karaman Erkul, S. Ursavaş, A. Özen, H. G. Zechmeister and R. H. Zander

In this study, the hydrology and physical, chemical and biological variables of a shallow lake sy... more In this study, the hydrology and physical, chemical and biological variables of a shallow lake system including the Lakes Mogan and Eymir between 1997-2005 were evaluated. In Lake Eymir, a biomanipulation study was conducted between August, 1998 December, 1999. Upon biomanipulation, Lake Eymir shifted to clearwater state with submerged vegetation domination during 2000-2003. However, in 2004, the lake shifted back to algae-dominated turbid state since the buffer mechanisms provided by submerged plants were absent. In the summer of 2005, fish kills were observed due to algal bloom. However, due to increasing hydraulic residence time in the lake, internal processes became more important for nutrients. Lake Mogan faces seasonal and interannual water level fluctuations. During the low water levels experienced in 2001 and 2005, which coincided with the high hydraulic residence times, the in-lake phosphorus amount was controlled by internal processes rather than external loading. Moreover...

... Page 6. vi ÖZ AYNI HAVZADAKĐ SIĞ GÖLLERĐN EKOLOJĐK YAPISININ ... Special thanks to Burcu Kara... more ... Page 6. vi ÖZ AYNI HAVZADAKĐ SIĞ GÖLLERĐN EKOLOJĐK YAPISININ ... Special thanks to Burcu Karapınar, Özge Karabulut, Ceran Şekeryapan, Gizem Bezirci, Korhan Özkan and Onur Kerimoğlu for their help in the field and in the laboratory. ...

Bu çalışma, 25-28 Ağustos 2014 tarihleri ​​arasında Bursa Türkiye'de düzenlenen “6. Ulusal Li... more Bu çalışma, 25-28 Ağustos 2014 tarihleri ​​arasında Bursa Türkiye'de düzenlenen “6. Ulusal Limnoloji Sempozyumu” nda sunulmuştur.Minimum lake-level has important impacts on lake ecology (such as submerged plant growth, in-lake nutrients concentrations, physicochemical properties of lakes, lake biodiversity and lake primary production). However, prediction of lake water levels is important in watershed management for planning, design, construction, and operation of lakeshore structures and also in the management of freshwater lakes for water supply purposes. In the present paper, autoregressive moving average (ARMA) techniques were applied to test the power of predictability of models for minimum lake-level variations in Lake İznik. The measurements at the Lake Iznik in Bursa, for the period of 1955-2002 were used for training, testing, and validating the employed models (AR,MA and ARMA). The results obtained by the ARMA (2,2) model indicated that it performs better than other mo...

Higher temperature could have severe impact on ecosystem function as consequences of community ch... more Higher temperature could have severe impact on ecosystem function as consequences of community changes. Thus lakes are very sensitive to warming. We assessed the effects of nutrient and water level changes on zooplankton community composition and size structure in different climate zones by running a standardised controlled six-month experiment in six countries. The mesocosms were established with two different nutrient levels and two depths, all run with four replicates. We analysed pooled zooplankton samples originating from monthly samplings of each mesocosm throughout the study period. We found a significant effect of temperature on the community composition and size structure of the zooplankton. However, no water depth and nutrient effect appeared. In all countries except for Greece, zooplankton community biomass was mostly dominated by cladocerans. The normalised size spectrum (NSS) slope increased with temperature but did not differ among depths or nutrient levels. The slope ...

Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pat... more Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities. The current study comprised of a comparative study of the microbial food web community along north to south latitudinal gradient using space for time susbtitute, monitoring and mesocosms experiments with contrasting nutrient and predation states. We investigated effect of fish predation through different zooplankton taxa on microbial loop community with in situ food web experiments in 14 lakes along north to south latitudinal gradient. The effect of seasonality was also determined by monitoring in Lakes Eymir and Mogan between 2010 and 2011. Effects of hydrology and fish through microbial community was studied in mesocosms in Lake Eymir. An implication of global warming along with eutrophication on microbial community was further explored in warmed and nutrient enriched artificial ponds duri...

TÜBİTAK ÇAYDAG15.03.2011Bacteria, nanoflagellates and ciliates constitute the microbial loop and ... more TÜBİTAK ÇAYDAG15.03.2011Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities. Relations between bacteria and bacterivores are not fully understood, especially lakes in Mediterranean climate zone, in respect to their changes with the eutrophication and hydrological changes. Despite their abundance and likely importance in shallow lake ecosystems, little is known about the microbial communities, their interactions and their response to environmental changes. Most of studies were done in temperate and tropical climatic zones. We comprised a comparative study of the microbial food web community along north to south latitudinal gradient with contrasting nutrient and predation states. Little is known about the impact of trophic cascade on microbial loop and often the results are contradictory. We investigated effect of different zooplankton taxa on m...

Journal of Ecological Engineering, 2020

Journal of the Entomological Research Society, 2018

Deronectes toledoi Fery, Erman and Hosseinie, 2001 (Dytiscidae) is an endemic aquatic beetle only... more Deronectes toledoi Fery, Erman and Hosseinie, 2001 (Dytiscidae) is an endemic aquatic beetle only known from Turkey (Erzurum, Toprakkale). Relatively little has been learned about this beetle since it was discovered. We conducted a study to determine some bio-ecological characteristics of D. toledoi and determine the impact of physico-chemical parameters on aquatic Coleoptera species diversity. Mature specimens of aquatic Coleoptera were collected once a month from vegetated part of the brook running parallel to the Erzurum-Ispir road around Erzurum, Aziziye district, Toprakkale Village during March November 2009 period and were assessed in relation to environmental variables. Redundancy Analysis (RDA) showed that water temperature, dissolved oxygen and calcium explained 82 % of the taxa variance of the creek. Not only these parameters but also air temperature and precipitation were also found out to be important factors for the ecology of D. toledoi. Higher evenness in the creek sh...

The aim of this study was to assess the current status of inland aquaculture in Cankiri province ... more The aim of this study was to assess the current status of inland aquaculture in Cankiri province by using the SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis technique and to provide recommendations for making aquaculture to be more effective in the future. SWOT analysis was based on the data that was obtained from interviews with the owners of the aquaculture facilities, literature data and observations from field studies. Establishing fisheries cooperatives, subsidizing the fish production costs of fish farms, preparing province scaled management and production plans for fisheries, monitoring water resources for securing the water quality, changing consumer`s preferences are necessary for improving the Cankiri aquaculture sector. The results further showed that, Cankiri province has a high potential for the inland aquaculture sector in the future if strengths and opportunities are used effectively and internal weaknesses are improved by reducing the impact of t...

Inland freshwater lakes are sensitive to climate change and human activities. The current situati... more Inland freshwater lakes are sensitive to climate change and human activities. The current situation of these lakes should be identified and the changes should be determined in order to correct management of freshwater lakes. In this study, Turkey’s biggest three inland freshwater lakes (Beysehir,Egirdir and Iznik) surface area changes were estimated from 1980 to 2015 and possible factors causing the water level changes were also discussed. Lake surface area estimation was done using unsupervised classification of LANDSAT images and lakes water level data were gathered from General Directorate of State Hydraulic Works. Coastline change of lakes identified by using algorithms of change. The change algorithm involves initially classification of remote sensing images for each period. Employing the pixel -based classification, the images has been cross -classified in order to identify the "where to where" change. The type, rate, and pattern of the changes among studied time is ...

Journal of Paleolimnology, 2014

Journal of Bryology, 2021

Md N. Aziz, V. A. Bakalin , G. Bergamo Decarli, M. Boiko, N. Zagorodniuk, L. M. Boiko, E. A. Boro... more Md N. Aziz, V. A. Bakalin , G. Bergamo Decarli, M. Boiko, N. Zagorodniuk, L. M. Boiko, E. A. Borovichev, G. Brusa, M. J. Cano, J. A. Jiménez, S. S. Choi, I. Draper , F. Lara, M. V. Dunlin, J. Enroth, T. Ezer, V. E. Fedosov, E. Fuertes, R. Garilleti , B. Albertos , S. R. Gradstein, A. Graulich, V. Hugonnot, C. W. Hyun, M. Kırmacı, F. Filiz, U. Çatak, N. A. Konstantinova, A. N. Savchenko, M. Kropik, J. Kučera, H. Kürschner, E. Yu. Kuzmina, N. S. Liksakova, D. Maity, P. Martin, T. T. McIntosh, H. M. H. van Melick, B. Moncada, Cs. Németh, S. V. O’Leary, G. F. Peñaloza-Bojacá, S. A. Maciel-Silva, S. Poponessi, A. Cogoni, R. D. Porley, A. D. Potemkin, M. Puglisi, S. Sciandrello , K. K. Rawat, V. Sahu, R. R. Paul, M. Ryan, P. Saha, D. S. Salas, J. G. Segarra-Moragues, F. Sguazzin, N. R. Shafigullina, J. R. Shevock, S. Ștefănuţ, A. Uygur, S. Karaman Erkul, S. Ursavaş, A. Özen, H. G. Zechmeister and R. H. Zander

In this study, the hydrology and physical, chemical and biological variables of a shallow lake sy... more In this study, the hydrology and physical, chemical and biological variables of a shallow lake system including the Lakes Mogan and Eymir between 1997-2005 were evaluated. In Lake Eymir, a biomanipulation study was conducted between August, 1998 December, 1999. Upon biomanipulation, Lake Eymir shifted to clearwater state with submerged vegetation domination during 2000-2003. However, in 2004, the lake shifted back to algae-dominated turbid state since the buffer mechanisms provided by submerged plants were absent. In the summer of 2005, fish kills were observed due to algal bloom. However, due to increasing hydraulic residence time in the lake, internal processes became more important for nutrients. Lake Mogan faces seasonal and interannual water level fluctuations. During the low water levels experienced in 2001 and 2005, which coincided with the high hydraulic residence times, the in-lake phosphorus amount was controlled by internal processes rather than external loading. Moreover...

... Page 6. vi ÖZ AYNI HAVZADAKĐ SIĞ GÖLLERĐN EKOLOJĐK YAPISININ ... Special thanks to Burcu Kara... more ... Page 6. vi ÖZ AYNI HAVZADAKĐ SIĞ GÖLLERĐN EKOLOJĐK YAPISININ ... Special thanks to Burcu Karapınar, Özge Karabulut, Ceran Şekeryapan, Gizem Bezirci, Korhan Özkan and Onur Kerimoğlu for their help in the field and in the laboratory. ...

Bu çalışma, 25-28 Ağustos 2014 tarihleri ​​arasında Bursa Türkiye'de düzenlenen “6. Ulusal Li... more Bu çalışma, 25-28 Ağustos 2014 tarihleri ​​arasında Bursa Türkiye'de düzenlenen “6. Ulusal Limnoloji Sempozyumu” nda sunulmuştur.Minimum lake-level has important impacts on lake ecology (such as submerged plant growth, in-lake nutrients concentrations, physicochemical properties of lakes, lake biodiversity and lake primary production). However, prediction of lake water levels is important in watershed management for planning, design, construction, and operation of lakeshore structures and also in the management of freshwater lakes for water supply purposes. In the present paper, autoregressive moving average (ARMA) techniques were applied to test the power of predictability of models for minimum lake-level variations in Lake İznik. The measurements at the Lake Iznik in Bursa, for the period of 1955-2002 were used for training, testing, and validating the employed models (AR,MA and ARMA). The results obtained by the ARMA (2,2) model indicated that it performs better than other mo...

Higher temperature could have severe impact on ecosystem function as consequences of community ch... more Higher temperature could have severe impact on ecosystem function as consequences of community changes. Thus lakes are very sensitive to warming. We assessed the effects of nutrient and water level changes on zooplankton community composition and size structure in different climate zones by running a standardised controlled six-month experiment in six countries. The mesocosms were established with two different nutrient levels and two depths, all run with four replicates. We analysed pooled zooplankton samples originating from monthly samplings of each mesocosm throughout the study period. We found a significant effect of temperature on the community composition and size structure of the zooplankton. However, no water depth and nutrient effect appeared. In all countries except for Greece, zooplankton community biomass was mostly dominated by cladocerans. The normalised size spectrum (NSS) slope increased with temperature but did not differ among depths or nutrient levels. The slope ...

Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pat... more Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities. The current study comprised of a comparative study of the microbial food web community along north to south latitudinal gradient using space for time susbtitute, monitoring and mesocosms experiments with contrasting nutrient and predation states. We investigated effect of fish predation through different zooplankton taxa on microbial loop community with in situ food web experiments in 14 lakes along north to south latitudinal gradient. The effect of seasonality was also determined by monitoring in Lakes Eymir and Mogan between 2010 and 2011. Effects of hydrology and fish through microbial community was studied in mesocosms in Lake Eymir. An implication of global warming along with eutrophication on microbial community was further explored in warmed and nutrient enriched artificial ponds duri...

TÜBİTAK ÇAYDAG15.03.2011Bacteria, nanoflagellates and ciliates constitute the microbial loop and ... more TÜBİTAK ÇAYDAG15.03.2011Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities. Relations between bacteria and bacterivores are not fully understood, especially lakes in Mediterranean climate zone, in respect to their changes with the eutrophication and hydrological changes. Despite their abundance and likely importance in shallow lake ecosystems, little is known about the microbial communities, their interactions and their response to environmental changes. Most of studies were done in temperate and tropical climatic zones. We comprised a comparative study of the microbial food web community along north to south latitudinal gradient with contrasting nutrient and predation states. Little is known about the impact of trophic cascade on microbial loop and often the results are contradictory. We investigated effect of different zooplankton taxa on m...

Journal of Ecological Engineering, 2020

Journal of the Entomological Research Society, 2018

Deronectes toledoi Fery, Erman and Hosseinie, 2001 (Dytiscidae) is an endemic aquatic beetle only... more Deronectes toledoi Fery, Erman and Hosseinie, 2001 (Dytiscidae) is an endemic aquatic beetle only known from Turkey (Erzurum, Toprakkale). Relatively little has been learned about this beetle since it was discovered. We conducted a study to determine some bio-ecological characteristics of D. toledoi and determine the impact of physico-chemical parameters on aquatic Coleoptera species diversity. Mature specimens of aquatic Coleoptera were collected once a month from vegetated part of the brook running parallel to the Erzurum-Ispir road around Erzurum, Aziziye district, Toprakkale Village during March November 2009 period and were assessed in relation to environmental variables. Redundancy Analysis (RDA) showed that water temperature, dissolved oxygen and calcium explained 82 % of the taxa variance of the creek. Not only these parameters but also air temperature and precipitation were also found out to be important factors for the ecology of D. toledoi. Higher evenness in the creek sh...

The aim of this study was to assess the current status of inland aquaculture in Cankiri province ... more The aim of this study was to assess the current status of inland aquaculture in Cankiri province by using the SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis technique and to provide recommendations for making aquaculture to be more effective in the future. SWOT analysis was based on the data that was obtained from interviews with the owners of the aquaculture facilities, literature data and observations from field studies. Establishing fisheries cooperatives, subsidizing the fish production costs of fish farms, preparing province scaled management and production plans for fisheries, monitoring water resources for securing the water quality, changing consumer`s preferences are necessary for improving the Cankiri aquaculture sector. The results further showed that, Cankiri province has a high potential for the inland aquaculture sector in the future if strengths and opportunities are used effectively and internal weaknesses are improved by reducing the impact of t...

Inland freshwater lakes are sensitive to climate change and human activities. The current situati... more Inland freshwater lakes are sensitive to climate change and human activities. The current situation of these lakes should be identified and the changes should be determined in order to correct management of freshwater lakes. In this study, Turkey’s biggest three inland freshwater lakes (Beysehir,Egirdir and Iznik) surface area changes were estimated from 1980 to 2015 and possible factors causing the water level changes were also discussed. Lake surface area estimation was done using unsupervised classification of LANDSAT images and lakes water level data were gathered from General Directorate of State Hydraulic Works. Coastline change of lakes identified by using algorithms of change. The change algorithm involves initially classification of remote sensing images for each period. Employing the pixel -based classification, the images has been cross -classified in order to identify the "where to where" change. The type, rate, and pattern of the changes among studied time is ...

Journal of Paleolimnology, 2014