Nilsun Demir | Ankara University (original) (raw)

Papers by Nilsun Demir

Tarım Bilimleri Dergisi, 2003

Afşin Elbistan A termik santraline so ğ utma suyu temin eden P ı narba şı Göleti'nde a şı rı su b... more Afşin Elbistan A termik santraline so ğ utma suyu temin eden P ı narba şı Göleti'nde a şı rı su bitkisi geli şimi görülmektedir. Bu sorunun tespiti ve çözümü amac ıyla, gölette bitki biyokütlesinin en fazla oldu ğu Ağ ustos, Eylül 2000 ayları nda su kalitesi, sediment yap ı sı ve bitki kompozisyonu incelenmi ştir. Göletin kaynak k ı sm ı nda bulunan Groenlandia densa (L.) Fourr., Nasturtium officinale R. Br. gibi su bitkilerinin yerlerini göletin geni şledi ğ i kesimde Myriophyllum spicatum L. ve Chara globularis Thuill. gibi bitkilerin ald ığı belirlenmi ştir. Gölette su yüzeyini kaplayarak çirkin bir görüntü olu şturan bitki ise Cladophora fracta (Dillw.) Kuetz. türüdür. Bu bitki gölet yüzey alan ı n ı n yaklaşı k % 42'sini kaplamaktad ı r. Gölette bulunan toplam bitki kuru madde a ğı rl ığı n ın ise 27 t oldu ğ u tahmin edilmi ştir. Bu makalede, bitkilerin yönetimi için göletin su kalitesi ve yap ısı na uygun olabilecek metotlar tart ışı lm ıştı r.

Ziraat mühendisliği, 2011

Ekoloji, 2011

The determination of the spatial and temporal variations of phytoplankton populations contribute ... more The determination of the spatial and temporal variations of phytoplankton populations contribute to set up lake management strategies. It was aimed to investigate the biomass of phytoplankton of large and shallow Lake Beysehir. The lake was sampled monthly from four selected stations and surface, mid and deep layers between March and December 2007. The phytoplankton biomass was estimated from counted cell size. A total of 119 phytoplankton species from Bacillariophyta (42), Chlorophyta (48), Chrysophyta (1), Cryptophyta (4), Cyanobacteria (9), Pyrrophyta (5) and Euglenophyta (10) were identified. Total phytoplankton biomass consisted of Bacillariophyta (53%), Chlorophyta (27%), Chrysophyta (3%), Cryptophyta (2%), Cyanobacteria (10%), Pyrrophyta (4%) and Euglenophyta (2%). Mean values of chlorophyll a, total phosphorus and Secchi depth were measured as 8.24±2.08 mg/m3, 10.46±6.20 mg/m3 and 1.08±0.35 m, respectively. Dissolved oxygen was measured between 6.36±0.06 and 11.63±0.06 mg/l....

Bu calismada, sig bir gol olan Mogan Golu’nde sucul makro tlere gore ekolojik kalitenin tahmin ed... more Bu calismada, sig bir gol olan Mogan Golu’nde sucul makro tlere gore ekolojik kalitenin tahmin edilmesi amaclanmistir. Makro tlerin bollugu, 2003 ve 2013 yillarinda incelenmistir. Mogan Golu’nde sualti makro tlerden 5 tur ( Ceratophyllum demersum L., Chara vulgaris L., Najas marina L., Myriophyllum spicatum L. ve Stuckenia pectinata (L.) Borner) teshis edilmistir. Mogan Golu’nde Makro t Indeksine gore ekolojik kalite Temmuz 2003’de orta olarak tahmin edilirken, Temmuz 2013’de kotu olarak bulunmustur.

Applied Ecology and Environmental Research, 2018

In this study, the seasonal succession of the diatoms on Phragmites australis community was inves... more In this study, the seasonal succession of the diatoms on Phragmites australis community was investigated in Lake Mogan (Turkey), and the epiphytic diatom community was used to estimate the ecological condition of the lake. Five stations were chosen in the littoral region of the lake, and diatom samples were taken from the P. australis monthly between January and November 2013. Two stations were selected in the pelagial region and chlorophyll a concentrations were determined. Lake water temperature, pH, dissolved oxygen concentration, conductivity and Secchi depths were measured, and total nitrogen, total phosphorus and silicate were analyzed. A total of 61 epiphytic diatom species were identified in Lake Mogan. The dominant species were those with tolerance to α-β mesosaprobic conditions. According to the mean Secchi depth, chlorophyll and total phosphorus concentrations, the lake was eutrophic. The IDG, IPS, DESCY, WAT, IDP and TDI indices, calculated according to epiphytic diatoms, indicated an ecological quality between medium and poor (classes III-IV). Among them, IDG and IPS are recommended for monitoring of ecological status in the lake because these indices also integrated all diatom taxa within the samples. The occurrence of pollution-tolerant species and the fact that most indices showed an ecological quality of medium or poor indicated an increase of organic matter and eutrophication in Lake Mogan.

Israeli Journal of Aquaculture - Bamidgeh

This study was carried out to evaluate the growth performance and nutritive value of carp fed die... more This study was carried out to evaluate the growth performance and nutritive value of carp fed diets containing moderate levels of sunflower seed meal (SFM) as a partial replacement of fishmeal. Four diets were formulated as isocaloric and isonitrogenous at incorporation levels of 0% (control), 15%, 30% and 45% SFM and were fed to triplicates group of carp (993.82±11.68 g). Growth, as assessed using a range of biometric parameters and nutrient utilization was determined by muscle content, fatty acids and electrophoretic protein profiles of tissues. Condition factor (CF) and survival (Surv) were unaffected by levels of SFM inclusion though a significant decline in weight gain (WG), protein efficiency rate (PER), absolute (AGR) and specific growth rate (SGR) was observed with increasing inclusion levels of SFM. Feed conversion ratio (FCR) was negatively correlated with SGR and also reflective of feed intake. No significant effects of inclusion were noted among treatments on protein, li...

Journal of Aquatic Plant Management, 2004

The effects of the grass carp (Ctenopharyngodon idella Val.) on aquatic plant biomass, water qual... more The effects of the grass carp (Ctenopharyngodon idella Val.) on aquatic plant biomass, water quality, phytoplankton, chlorophyll a , zooplankton and benthic fauna were investigated between May and September 2000 in earthen ponds at Cifteler-Sakaryabasi Aquaculture and Research Station. Four earthen ponds with an area of 100 m 2 were used and one of them was selected as control. The other ponds were stocked at rates of 200, 400 and 600 fish per ha in May. The survival rate of harvested grass carp was 100% in September and the highest weight gain of 428 g occurred at the minimum stocking rate. Cladophora and Zygnema species of aquatic plants were consumed in June by grass carp; however, Chara was eliminated completely by August. At the end of the stocking period, Phragmites was the only plant not consumed by the grass carp. Plant biomass increased 1.4 times in the pond without grass carp but was decreased 2.5 times in the ponds stocked with 200 and 400 grass carp per ha and 4 times in the pond stocked with 600 grass carp per ha. The lowest values of nitrite-nitrogen, nitrate-nitrogen, and total phosphate were measured in the pond without grass carp (p < 0.05). The highest values of phytoplankton, zooplankton, benthic fauna abundance and chlorophyll a were found in the ponds with fish (p < 0.05).

Su Ürünleri Dergisi, 2015

Turkish Journal of Water Science and Management, 2021

We explained the methodology used in setting the basic and supplementary measures for diffuse pol... more We explained the methodology used in setting the basic and supplementary measures for diffuse pollutants at Küçük Menderes Basin. As the majority of diffuse pollutants arise from livestock breeding and agricultural activities, we focused to propose measures regarded with tackling the pollution from agricultural activities. The types and distribution of diffuse loads were expressed by total nitrogen and phosphorous parameters. We used the results of a yearlong surface water quality monitoring involving physico-chemical, chemical and biological parameters with specific pollutants and priority substances, set in the European Union Water Framework Directive as the AquaTool input data. The AquaTool model was run for attaining the outcomes of a series of measures determined according to the ecological sensitivity of each water body. The removal efficiency of pollution loads provided by the best management practices in agricultural activities and livestock breeding were compiled from literature, and typical removal rates were further determined for the basin. We produced nine alternative scenarios at first cycle for determining compliance measures for mitigating point and diffuse sources of pollution 231

In this study, carp were fed for 12 weeks with experimental diets incorporated with different rat... more In this study, carp were fed for 12 weeks with experimental diets incorporated with different ratios of sunflower seed meal and the alterations in biochemical parameters of carp fillets during 6 months of frozen storage at -18 °C were determined. In this context, 4 diets were prepared comprising incremental levels of sunflower seed meal (0%-K, 15%-AT15, 30%-AT30, 45%-AT45). Furthermore, the mineral composition (P, Ca, K, Na, Mg, Zn) of experimental diets and fish flesh was assessed and it was concluded that the difference observed in diets regarding with mineral content did not affect the flesh. Through 6 months of storage, TBA, TVB-N and FFA values were determined monthly and TBA, TVB-N and FFA values were increased in all groups corresponding to storage (P<0.05).

This study was carried out to evaluate the phenological changes resulting from external impacts o... more This study was carried out to evaluate the phenological changes resulting from external impacts on Posidonia oceanica meadows along the Aegean coast. Triplicate samples were collected from 17 stations at 8 and 10 m depths by SCUBA diving between April and June 1999. The water temperature was measured and sediment type was determined in the stations. The phenological parameters; shoot density, leaf number, leaf area index, leaf surface area, brown tissue surface area and total biomass were investigated. One of the most important descriptors of Posidonia, shoot density, showed supranormal values at the seven of the meadows while only two of them showed abnormal values. Beside the natural factors such as water temperature and sediment types, the possible environmental or antrophogenic impacts on phenological characters of Posidonia meadows were discussed.

The flowering and fruiting of Halophila stipulacea (Forsskål) Ascherson were followed on the Turk... more The flowering and fruiting of Halophila stipulacea (Forsskål) Ascherson were followed on the Turkish coasts of the Aegean Sea, and both male and female flowers were recorded at the same location for the first time. Male and female flowers were found between mid-April and late September. In shallow coastal water, male flowers were fewer than female flowers, while in deep zones, female flowers were fewer than male flowers. The female flowers of H. stipulacea had three styles, but four styles of flowers were also found exceptionally. At the research stations, the plants and flowers showed a lower limit of 30 m depth and an upper limit of between 1 and 8 m. The upper limit of female plants was 4 m, and that of male plants was 6 m. Besides, flowering was recorded generally in very dense populations.

Bu calismada, farkli oranlarda aycicegi tohumu kuspesi iceren deneme yemleri kullanilarak 12 haft... more Bu calismada, farkli oranlarda aycicegi tohumu kuspesi iceren deneme yemleri kullanilarak 12 hafta sure ile beslenen sazan baliklari, derili fileto halinde 6 ay boyunca -18 oC’de depolanmis ve depolama suresince biyokimyasal parametrelerdeki degisimler belirlenmistir. Bu amacla, artan oranlarda aycicegi tohumu kuspesi iceren (%0-K, %15-AT15, %30-AT30, %45-AT45) 4 adet yem hazirlanmistir. Ayrica, deneme yemlerinde ve balik etinde mineral madde icerigi (P, Ca, K, Na, Mg, Zn) belirlenmis ve deneme yemlerinde mineral madde icerigi bakimindan gozlenen farkliligin balik etine yansimadigi gorulmustur. Donmus depolama suresince TBA, TVB-N ve SYA degerleri aylik olarak degerlendirilmis ve tum gruplarda TBA, TVB-N ve SYA degerlerinde artis tespit edilmistir (P<0.05).

Limnology and Oceanography, 2021

Author Contribution Statement: D.D. analyzed and worked on data visualization, coordinated feedba... more Author Contribution Statement: D.D. analyzed and worked on data visualization, coordinated feedback from coauthors, and wrote the manuscript. E.M. coordinated the EMLS, collected data, curated the dataset, analyzed the data, and contributed to writing the manuscript. B.I. conceived the idea for the EMLS, contributed to discussions throughout the study and to the writing of the manuscript. D.

Kizilirmak Nehri’nin Avanos Ilcesi (Nevsehir) icinden gecen bolumunde Mart 2010-Aralik 2010 tarih... more Kizilirmak Nehri’nin Avanos Ilcesi (Nevsehir) icinden gecen bolumunde Mart 2010-Aralik 2010 tarihleri arasinda yurutulen bu calismada, sualti bitki tur/turleri incelenmistir. Sucul makrofit ornekleri, 4 istasyondan ayda bir defa, uc tekrarli olmak uzere alinmistir. Ayrica su derinligi, Secchi derinligi, su sicakligi, cozunmus oksijen, pH ve elektrik iletkenligi yerinde olculmustur. Arastirma alaninda sualti bitkilerinden Stuckenia pectinata (L.) Borner (Taraksi Su Sumbulu) turunun baskin olarak bulundugu tespit edilmis, nadir olarak Ceratophyllum submersum turunun bulundugu belirlenmistir. Sualti bitki biyokutlesi Mart ayindan itibaren artis gostermis, en yuksek degerine (1086 kuru agirlik/m2) Kasim ayinda ulasmis ve ortalama bitki biyokutlesi 720,9± 287,9 kuru agirlik/m2 olarak tahmin edilmistir. Calisma suresince ortalama su derinligi 2,21± 0,45 m, Secchi derinligi 0,90 ± 0,19 m, su sicakligi 10,19 ± 3,33 °C, cozunmus oksijen 12,45 ± 1,0 mg/l, pH 8,01 ± 0,3, elektrik iletkenligi 1178 ± 67 µS/cm olarak olculmustur. Taraksi Su Sumbulunun asiri gelisiminde Kizilirmak Nehri’nde baraj yapimi sonrasinda olusan mudaheleli akim kosullarinin baslica etken oldugu dusunulmektedir. Abstract In this study, submerged plant species were investigated in the part of river Kizilirmak passing through Avanos town (Nevsehir) between March 2010 and December 2010. Aquatic macrophytes were sampled by three replicates once a month from four stations. .Furthermore, water depth, Secchi depth, water temperature, dissolved oxygen, pH and conductivity were measured in situ. The dominant submerged plant in the research area was identified as Stuckenia pectinata (L.) Borner (Sago Pond Weed), Another submerged plant which existed rarely was Ceratophyllum submersum. The underwater plant biomass was increased from March, reached its highest level as 1086 dry weight/ m2 in November and the average plant biomass was estimated as 720,9± 287,9 dry weight/ m2. Throughout this study, the average water depth, Secchi depth, water temperature, dissolved oxygen, pH and conductivity were measured as 2,21± 0,45 m, 0,90 ± 0,19 m, 10,19 ± 3,33 °C, 12,45 ± 1,0 mg/l, 8,01 ± 0,3, 1178 ± 67 µS/cm, respectively. The modified stream course which was occurred after the dam construction in Kizilirmak River could be the main reason of the excessive growth of Sago Pondweed.

Ankara Üniversitesi Çevrebilimleri Dergisi, 2011

Baraj gölleri; enerji üretimi, içme suyu kaynağı sağlama, sulama ve taşkın koruma gibi çeşitli am... more Baraj gölleri; enerji üretimi, içme suyu kaynağı sağlama, sulama ve taşkın koruma gibi çeşitli amaçlarla akarsular üzerine inşa edilen yapay göllerdir. Bu yapay göller, akarsu ve durgun su ekosistemleri arasında geçiş gösteren ve her ikisinin de özelliklerini taşıyan ekosistemlerdir. Baraj gölleri, morfometrik ve fiziko-kimyasal özellikleri bakımından doğal göllerden farklılıklar gösterir. Baraj gölleri akarsular ile beslendiğinden besin maddesi açısından oldukça zengindir ve bazı baraj göllerinde akarsuyun taşıdığı besin maddeleri nedeniyle hızlı bir ötrofikasyon görülmektedir. Ötrofikasyonun bir göstergesi olan, ani mavi-yeşil alg artışları ise özellikle içme su kaynağı olarak kullanılan baraj göllerinde insan sağlığı açısından risk oluşturabilir. Ülkemizde 277 adet baraj bulunmakta ve halen bazı baraj göllerinin inşası devam etmektedir. Bu barajlardan 52'si içme su temini amacıyla kullanılmaktadır. Bu çalışmada baraj göllerinde fitoplanktona ilişkin 19 yayın değerlendirilmiştir. Ötrofik baraj göllerinde zaman zaman aşırı artışlar gösteren toksik Microcystis, Anabaena, Aphanizomenon ve Oscillatoria cinslerine ait mavi-yeşil türlerinin bulunduğu bildirilmektedir. Ancak toksik alg artışlarının izlenmesine yönelik çalışma bulunmamaktadır. Bu çalışmada, olası toksik Cyanobacteria artışlarının izlenmesi ve alınması gereken önlemler tartışılmıştır.