As Daphnia have an important role in freshwater food webs, it is important to understand how environmental stressors affect their survival and life history traits. Daphnia pulex were first acutely exposed to a combination of NaCl salinities (0.00-10.0 g/L) and fish-exuded kairomone. The 24 and 48 hour LC50 values were 0.401 and 0.159 g/L in kairomone-absence and 1.962 and 1.007 g/L in kairomone-presence. Hence, survival decreased with increasing salinity, while the kairomone enhanced daphnid resistance to salinity below 2 g/L. During the chronic exposure to salinity (0.00-1.5 g/L) combined with the fish-exuded kairomone, impacts of temperature and food were also investigated. Survival decreased significantly with increased salinity, while the kairomone had a positive impact on survival at intermediate salinity levels, suggesting an antagonistic relationship. Temperature alone had a significant negative impact on survival and its combined effect with salinity and fish kairomone was synergistic. However, the impact of food limitation was insignificant. Life history parameters were affected by both salinity and the fish-exuded kairomone, the combination of which significantly decreased the body length: width ratio. Egg number/individual decreased with salinity and increased in the presence of the fish kairomone. In conclusion, the combined impact of salinity and fish-exuded kairomone significantly affected daphnid survival and life history traits in a non-linear manner, such that fish kairomone enhanced daphnid resistance to intermediate salinity levels. Moreover, the combined effect of salinity, temperature and fish kairomone on daphnid survival was also significant.

The aim of this study was to determine the habitat features affecting nest site selection and breeding success of the endangered Egyptian Vultures (Neophron percnopterus) breeding around the town of Beypazari. We searched and monitored nest sites in the study area (750 km2) for the years 2010 and 2011. The differences in terms of habitat features between nest sites and random points distributed along cliffs, and between successful and failed nest sites were investigated using both parametric approaches and machine learning methods with 21 habitat variables. The size of the Beypazari population of Egyptian Vultures was estimated to be 45 pairs. Seventeen nests in 2010 and 37 nests in 2011 were found and monitored. The breeding success of the population was estimated to be 100% in 2010 and 70% in 2011. Random Forests was the modeling technique with the highest accuracy and the modeling process chose 6 and 4 variables affecting nest site selection and breeding success of the species, respectively. Results showed that human impact was a potential factor governing the distribution of nest sites in the area and increased the probability of breeding failure as vultures clearly preferred to nest away from nearby villages, towns and roads, and nests on lower cliffs and nests that are close to the dump site (therefore the town center) was prone to failure. Utilization of elevation gradient and aspect showed trends similar to other populations of the species, with probability of nesting increasing at lower altitudes and for south facing cliffs. The overall results emphasize the potential conflict between human presence and the population of Egyptian Vultures in the area. Continuous monitoring of the nest sites and conservation activities towards raising public awareness are advised.

White Stork ( Ciconia ciconia, Linnaeus, 1758) is a summer visitor and passage migrant in Turkey. Although being widespread in summer near wetlands of Turkey, except for the eastern and western parts of the Black Sea Region, there has been no research on this species involving regular monitoring of nests. In this study, breeding success and survival of nestlings in a population in Kizilcahamam-Ankara as well as behavioral differences among nests and their probable consequences on breeding success were studied. Regular field observations throughout six-month long breeding seasons between 2003 and 2006 were carried out to determine parent and young behavior patterns at nest. Clutch size, and numbers of chicks hatched and fledged fluctuated throughout 2003-2006 for pairs that bred while fledgling success (average fledgling per successful nests with egg laid) were 2.63 in 2003, 3.82 in 2004, 1.89 in 2005 and 3.13 in 2006. These values are in good agreement with those recorded in northern Europe. The relationship between beginning date of incubation and both clutch size and brood size were found to be different for 2004 and 2005. Such a relationship may be significant in breeding seasons colder than usual. For 2004 and 2005, the amount of food brought and caring towards young by parents were compared with breeding success (proportion of hatched young that were fledged), and breeding success was found to increase with increasing amount of food provisioning. However, this result may be suggested to be related with weather conditions. In conclusion, Kizilcahamam White Stork population has been found to be not restricted by food or nest site availability and with a reproductive output above the European average, although annual climatic stochasticity was found to affect reproductive output.

Shallow lake wetlands, for which aquatic plants (macrophytes) and water clarity are the key indicators of ecological status, provide valuable services to wildlife and humanity. Conservation of these ecosystems requires development of rapid and large scale monitoring strategies, where remote sensing and Geographic Information Systems (GIS) can be advantageous. In this study, high spatial resolution Quickbird and IKONOS and medium spatial resolution Landsat and Aster images were used for monitoring the aquatic plants and water clarity in Lakes Mogan and Eymir. Classification of emergent plants with high spatial resolution data yielded overall accuracies greater than 90% for both lakes, while overall accuracies obtained from the medium spatial resolution data ranged between 80% and 93% for Lake Mogan and between 70% and 78% for Lake Eymir. It was found that there was 23ha reed bed loss in Lake Mogan between 2002 and 2005 and an additional 14ha was lost between 2005 and 2006. In Lake Eymir, no significant change in reed bed area was detected from high spatial resolution images / however medium spatial resolution images revealed 8ha of change which was attributed to the presence of mixed pixels due to low resolution. The overall accuracies for submerged plant coverage classification from Quickbird images in Lake Mogan were 83% (2005) and 79% (2006) and for classification of submerged plants species were 72% (2005) and 69% (2006). Moreover, it was found that blue band together with the ratio of red band to blue band, were the best predictors of Secchi disc depth.

Management of big wildlife such as bears can be a difficult task, especially in the face of human-wildlife conflict and demands of the hunting industry. The Brown Bear (Ursus arctos) population at Yusufeli County (Artvin, northeastern Turkey) has recently been the focus of scientific, social and economic concerns. This study population of c. 140 individuals occurs within 800 km2 of forested and alpine land. Legal hunting of male bears was allowed in 2007 after an interval of four years. This study aims to find out through a population viability analysis the level and frequency of trophy hunting this population can tolerate for the next 50 years. A matrix model with six age-classes for each sex was constructed using observed and literature-based parameter values. RAMAS Metapop was used to simulate four different scenarios where numbers of hunted bears and hunting frequency changes. The model was highly sensitive to maximum growth rate and adult survival. Interval extinction probabilities for the next 50 years ranged between 0% and 26% depending on the scenario. Viable scenarios (with an extinction probability &lt / 0.05) were only possible with either no trophy hunting or hunting of 4 subadult/adult males and 1 adult female every other year. Legal and illegal hunting jointly impact the bear population in a strong way, and when they occur simultaneously every year, they lead to extinction in the long run. Avoidance of illegal killing and a close supervision of trophy hunting are crucial in the management of this bear population.

There is considerable need for higher-tier aquatic risk assessment and information on toxicant-induced molecular alterations in lower aquatic invertebrates. Thus the current study&rsquo / s priorities were two-fold: a novel approach utilizing higher-tier ecotoxicity bioassay-guided ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared) spectroscopy to better understand the impact of the presence of fish predation pressure &ndash / mimicked by predator-exuded info-chemicals &ndash / on cypermethrin or salinity toxicity to Daphnia pulex &ndash / key-stone species in lake ecosystems &ndash / and ultimately better assess toxicant-induced alterations at both organismal and molecular levels. This approach indicates that even low concentrations of cypermethrin/salinity had significant molecular and organismal effects on daphnids. Fish kairomone acted as a major factor affecting toxicant severity, interacting antagonistically below a threshold and synergistically above. Moreover, molecular ATR-FTIR spectroscopic results, clearly consistent with organismal responses, showed that both cypermethrin and salinity lead to decreased contributions of lipid and proteins to the investigated daphnid systems. It is further suggested that the action mechanism of the fish-exuded kairomone occurs via the lipid metabolism of Daphnia. Hence, infrared spectroscopic results enabled detection of early molecular alterations, whose effects might not always be observable at the organismal level. The results of this study clearly indicate that the simplistic nature of standard ecotoxicology tests hinders a precise judgment of threats imposed by chemicals of interest. Furthermore, it has been shown that ATR-FTIR spectroscopy has considerable potential for studies on daphnid responses to varying environmental conditions. Thus, this study presents a starting point for increasing the environmental realism of aquatic risk assessment.

Since submerged macrophytes are a key primary producer of shallow lakes and are sensitive to environmental changes, macrofossils of them can be used in investigations of past environmental conditions, to infer human introduced environmental impacts (e.g. eutrophication) and to determine past macrophyte communities. The present study includes twenty six shallow lakes, which were chosen along a latitudinal gradient ranging from the North (41&deg / 52&acute / N, 27&deg / 58&acute / E) to the South (37&deg / 06&acute / N, 29&deg / 36&acute / E) in Turkey. Sampling for environmental variables and sediment was carried out using a snap-shot sampling protocol (developed within the framework of the EU FP6 project &lsquo / Eurolimpacs&rsquo / ) during the summers of three consecutive years (2006-2008). Surface sediment, short core and long core samples were retrieved from the lakes. The aims of this study were i. to compare the surface sediment plant macrofossils with present day macrophyte taxa of the lakes, ii. to determine the environmental variables potentially influencing the temporal changes in macrophyte communities, and iii. to assess vegetation community dynamics in dated short and long cores. Comparison of plant macrofossil assemblages in surface sediment with present day macrophyte coverage revealed that approximately 41% of the modern taxa were represented among the surface sediment macrofossils. Redundancy analysis (RDA) was carried out for surface macrofossil data with corresponding environmental data. RDA revealed relation of plant species and environmental variables (e.g. Salinity and Najas marina L.). Changes in plant species assemblages in short and long cores from eight lakes chosen along a latitudinal gradient ranging from North to South Turkey is discussed in relation to the RDA results.

Four-month mesocosm experiment from June 1st to September 25th, 2009, was conducted to determine the effect of water level dierence in combination with fish predation pressure, on submerged macrophyte development, in an eutrophic shallow lake. Effect of water level fluctuation was simulated by placing enclosures to the different water depths that included 0.8 m, 1.6 m and 2.3 m on Lake Eymir. These enclosures having a cylindirical shape and 1.2 m diameter, were open to sediment and atmosphere interaction. The highest water level mesocosms were cancelled after fifth sampling due to rapture in the bags, hence this thesis does not include the results of 2.3 m. At each depth, half of the enclosures were stocked with planktivo-omnivorous fish (Tinca tinca, Alburnus spp.) which are natural fauna of Lake Eymir. Before stocking of fish, ten shoots of Potamageton pectinatus were added to all of the enclosures in order to observe submerged macrophyte development. Sampling for physico-chemical parameters, zooplankton, chlorophyll a, PVI% and periphyton was conducted weekly for the first five weeks, last six samplings were done biweekly. Macrophyte harvesting for dry weight estimation was done at the end of the experiment. Throughout the experiment water level decreased 0.41 &plusmn / 0.06 m in each enclosures. Water level was so critical for macrophyte development that no significant macrophyte growth was observed in enclosures located at 1.6 m (HW). However, fish predation did not prevent the growth of macrophyte in enclosures located at 0.8 m (LW) but it was important in HW enclosure for affecting water clarity. Fish predation affected chlorophyll a, zooplankton and nutrient concentrations and the effect was mostly pronounced at LW enclosures. They had high chlorophyll a and nutrient concentrations but it did not repress macrophyte growth as in temperate lakes. Despite high water clarity in HW fishless enclosures, very low macrophyte biomass may be attributed to enhanced periphyton development. Zooplankton community shifted to small sized ones under fish predation while fishless enclosures had higher zooplankton /phytoplankton ratio for each depth. Hence, regarding these results it can be stated that decrease in water level can compensate the negative effects of fish predation on macrophyte growth in warm Mediterranean lakes.

A mesocosm experiment was conducted in Lake Eymir between June &ndash / September 2009 in order to elucidate the effects of water level changes and fish predation on periphyton growth and macroinvertebrates in semi-arid shallow lakes. Twenty four cylindrical enclosures, each with 1.2 m diameter, open to lake bottom and atmosphere, were placed at three different depths, i.e. 0.8 m (low water level, LW), 1.6 m (high water level, HW) and 2.3 m (however, data regarding the enclosures at 2.3 m were excluded in this study due to complications after fifth sampling) to simulate water level fluctuations. At each water level, four replicates were stocked with omnivorous&ndash / planktivorous fish (Tinca tinca and Alburnus escherichii) and the other four replicates were left fishless to observe the effect of fish predation. Ten shoots of submerged macrophytes (Potamogeton pectinatus) were planted and six polyethylene strips were hung in the water column in each enclosure to monitor macrophyte and periphyton growth. The mesocosms were sampled for physical, chemical and biological parameters weekly in the first month and fortnightly thereafter. Benthic macroinvertebrate samples were taken before the start, in the middle and at the end of the experiment with Kajak corer. Macrophytes were harvested after the last sampling for determination of dry weight, epiphyton, and the associated macroinvertebrates. All macroinvertebrate samples were sieved through 212 &mu / m mesh size before identification and counting. Over the course of the experiment, an average of 0.46 &plusmn / 0.03 m water level decrease in the mesocosms triggered submerged macrophyte growth in all LW enclosures, overriding the negative effects of fish predation. The results indicate that while fish predation pressure had negative influences on macroinvertebrate communities in terms of both abundance and richness, structural complexity created by dense vegetation in the LW mesocosms weakened the top-down effect of fish on macroinvertebrates by acting as a refuge in this semi-arid shallow lake.

In this study, annual total phosphorus (TP) budget and dissolved inorganic nitrogen (DIN) load were constructed for Lakes Mogan and Eymir for the period of eight years from 1997 to 2004 and the period of ten years covering from 1993 to 1995 and 1997 to 2004, respectively. Lake Mogan experienced seasonal and interannual water level fluctuations. Low water level experienced in 2001 led to decrease in the in-lake TP amount whereas 2-fold increase in the in-lake DIN amount was recorded. Also, high hydraulic residence time resulted in high TP and DIN amount in the lake. Increase in hydraulic residence time was due to management of the lake level. It seems that this practice deteriorates the water quality of Lake Mogan. In Lake Eymir, sewage effluent diversion undertaken in 1995 resulted in 2-fold and 11-fold decrease in TP and DIN amounts in the lake, respectively. High biomass of carp and tench were halved through selective removal during 1998-1999. A 2.5-fold and 1.5 fold decrease in the in-lake TP and DIN amounts, respectively, were recorded after the biomanipulation. In low water level years, the in-lake TP increased and the in-lake DIN amounts were high despite the fact that TP and DIN loads via inflows were significantly low. Therefore, the results showed that the in-lake phosphorus and nitrogen amount were controlled by internal processes rather than external loading in the years with low water levels which coincided with the high hydraulic residence times.