Lake Ladik Research Articles

Evaluation of Potential Flood Areas in the Basin of Lake Ladik through AHP and GIS Integration, (Samsun, Türkiye)

Floods are a problem of many countries on a global scale. In Türkiye, especially in the summer months, large floods occur in the Black Sea Region coastal belt. The number and the destructive power of experienced floods are increasing day by day. It is not possible to prevent the occurrence of floods. But it is possible to take the necessary measures to prevent it from turning into a disaster. Recently, susceptibility analyses have been carried out for floods and similar natural disasters and the results help decision-makers. Within the scope of this study, flood susceptibility analysis was carried out by using multiple geographical factors together in the Basin of Lake Ladik of Samsun Province in the Black Sea Region. In the study, Analytical Hierarchy Process (AHP), Geographic Information Systems (GIS) and Remote Sensing (RS) techniques were used, which are multi-criteria decision-making methods. In this context, flood susceptibility analysis of the basin was carried out by using nine (9) different geographical factors (slope, aspect, lithology, soil, basin size, land use, landforms, precipitation, and drainage density). As a result of the study, for floods, there were identified four (4) different levels as low, medium, high, and very high; and 36.77% of the basin was found to be low, 30.03% was medium, 11.43% was high and 21.77% was found to be sensitive to possible floods at a very high level. The results of the study are also important for decision-makers to make flood risk planning.

Samsun İli (Türkiye)’ndeki dört lentik habitattan örneklenen gümüşi havuz balığının (Carassius gibelio (Bloch, 1782)) vücut uzunluğu ile otolit ölçümlerinin ilişkilerinde alansal varyasyon

This study aimed to disclose the spatial variability in the lagenar otolith (asteriscus) dimensions-total length relationships generated for four Prussian carp, Carassius gibelio (Bloch, 1782) populations (Altınkaya Dam Lake, Bafra Fish Lakes, Lake Ladik and Lake Simenit) in Samsun Province, Türkiye. Relationship between length and weight of the fish was also described for each population. Samples were obtained from commercial fishermen in different periods between February 2017 and March 2018. The length, height, and weight of each otolith were determined. A non-linear function was used to define allometric relationships between asteriscus measurements and body size. The slopes of the regressions acquired for the right and left otoliths at each sampling site did not show any significant difference. All of the relationships were found to be statistically significant (P<0.001). The r2 values ranged from 0.61 to 0.95, and the mean values of the percent prediction error varied from 3.10 to 7.45. The ANCOVA test determined significant spatial differences in regression slopes for the three otolith variables. Our findings revealed that otolith development reflected somatic growth, but this varied by sampling area.

Stock Discrimination of Northern Pike Esox lucius L., 1758 Inhabiting Lakes Simenlik and Ladik (Samsun-Turkey) Using Otolith Biometry and Shape Analysis

This study was carried out to investigate the relationships between total length and otolith dimensions and to detect the otolith shape index values of Northern pike (Esox lucius) which has high economic value, sampled from Ladik and Simenlik Lakes. A total of 140 specimens (Lake Ladik: 82 individuals, Lake Simenlik: 58 individuals) were sampled. Otolith height, length, perimeter, and area were determined by Imaging Software. Nonlinear and linear models were applied to estimate the relationships between the otolith measurements and total length. Form factor, circularity, roundness, rectangularity, aspect ratio, and ellipticity were used for otolith shape analyses. It was found that the relationship between the total length-otolith length was found to have the highest r2 value (Lake Ladik r2=0.949, Lake Simenlik r2=0.914) among the total length-otolith morphometrics at both localities. Otolith shape indices were calculated by using otolith measurements. As a result of comparing shape indices, it was found that there was a significant difference in two localities using roundness, ellipticity, and aspect ratio (P <0.05). The results indicated otolith shape indices could be used as a suitable tool to discriminate Northern pike populations.

Food composition and feeding strategies of an invasive species, Carassius gibelio (Bloch, 1782) inhabiting a eutrophic lake in Middle Black Sea region

Diet composition and feeding features of the Prussian carp Carassius gibelio (Bloch, 1782) were studied by analysing the stomach content of 155 fish specimens sampled from Lake Ladik during November 2009-October 2010. Five of the specimens had empty stomachs. A total of 29 prey taxa belonging to eight major groups comprising aquatic insects, Copepoda, Cladocera, Rotifera, Bacillariopyhta, Chlorophyta, Cyanobacteria and fish eggs were identified in 150 full stomachs. Diet composition showed slight seasonal variation. Cladocera was the most important prey item in all seasons, with peak abndance in spring. Feeding intensity exhibited seasonal change and was maximum in summer. Summer and autumn diets of this species showed the highest similarity. The study indicated that the Prussian carp in Lake Ladik showed both omnivorous and opportunistic feeding habits, exhibiting specialised feeding strategy on Cladocera, while they showed generalised feeding strategy on most prey items. The wide dietary plasticity of invasive Prussian carp can help their population to expand rapidly in different aquatic ecosystems. Keywords: Alien species, Diet composition, Feeding habits, Lake Ladik, Prussian carp

The effect of ontogenetic diet shifts on sagittal otolith shape of European perch, Perca fluviatilis (Actinopterygii: Percidae) from Lake Ladik, Turkey

European perch undergoes several ontogenetic dietary shifts during its lifetime. The present study focused on the variability in otolith shape caused by ontogenetic dietary changes in this species. A total of 172 specimens (7.5 to 27.5 cm TL) were caught by local fishermen in Lake Ladik from April to November 2019. Shape indices (SIs) and elliptic Fourier coefficients (EFCs) were calculated for each otolith. To detect ontogenetic changes in otolith shape, SIs and EFCs were compared among the three defined size classes (I, II, and III). Size-related groups were distinguished by both SIs and EFCs. Otolith shape analysis was more effective than morphometric analysis in distinguishing ontogenetic groups. Simultaneous use of both methods improved the classification success of each method alone. This study demonstrated that otolith shape of European perch is influenced by ontogenetic changes in diet. However, sexual maturity of the fish is also responsible for these variations in otolith shape.

Ladik Gölü (Samsun)’nde Yaşayan Turna Balığı (Esox lucius L., 1758)’nda Yaş Tayini İçin Farklı Kemiksi Yapıların Değerlendirilmesi

Different bony structure of pike, Esox lucius L., 1758 individuals caught from Lake Ladik between November 2009 and October 2010 were examined for age determination. Scale, vertebra, otolith (sagitta) and cleithrum were removed from 204 individuals. Before age determination, all hard structures are subjected to prior review. After preliminary examination, it was decided that vertebra, sagittal otoliths and cleithra structures were not usable for age estimation. Therefore, these bony structures were not used in age analysis. It was concluded that scale is the most suitable bony structure for age determination in Lake Ladik population of this species. The scales were only analyzed three times by one reader. As a result, mean ages, percent agreement (3/3), average percent error, coefficient of variation were calculated as 3.18, 57.35 %, 6.14, 13.99, respectively in reading scale.

Biological Characteristics of European Perch (Perca fluviatilis L., 1758) Inhabiting Lake Ladik (Samsun, Turkey)

Abstract The aim of this study was to determine the growth features of European perch (Perca fluviatilis L., 1758) inhabiting Lake Ladik. A total of 858 individuals were caught. The total length and weight ranged from 8.2 to 27.5 cm and from 7.16 to 365.20 g, respectively. The age of the females ranged between 1 and 7 years and the age of the males ranged from 1 to 5 years. The female to male ratio was 1:0.19. The von Bertalanffy growth equation parameters were determined as L ∞=41.27 cm, W ∞=1251.40 g, K=0.10 (year−1), t 0 (year)=−1.98 for all samples. Length-weight relationship was calculated as W=0.0047TL 3.358 for all specimens. Length-length relationships (total length-standard length, total length-fork length, standard length-fork length) were highly significant (r2>0.98). The mean condition factor value was obtained as 1.28 for all fish. Condition factor showed statistically significant increase according to length classes.

Feeding ecology and prey selection of European perch, Perca fluviatilis inhabiting a eutrophic lake in northern Turkey

ABSTRACTFeeding habits and prey selection of European perch (Perca fluviatilis) were examined in Lake Ladik between November 2009 and October 2010. Stomach contents of 308 individuals ranging in size from 73 to 275 mm total length were analyzed and 55.2% were empty. The fullness index indicated that feeding intensity of this species was the highest in summer and the lowest in winter. European perch feeds on prey fish and macroinvertebrates. The most important food items were Scardinius erythrophthalmus and Perca fluviatilis, followed by chironomidae larvae. Diet composition and feeding habits varied seasonally and ontogenetically. Macroinvertebrates were only consumed by small individuals, while prey fishes were only eaten by large individuals. S. erythrophthalmus, P. fluviatilis, and Blicca bjoerkna were positively selected but their selection indexes were not statistically significant (p > 0.05). This prey selection is important for combating eutrophication. Abramis brama constitute 24.03% of all fish species in this lake; however, it was a negatively selected prey item (Va = −0.198, χ2 = 7.86, p < 0.05). Esox lucius, Squalius cephalus, Chondrostoma regium, and Carassius gibelio inhabiting this lake were not preferred by European perch. Cannibalism rate was 12.3%.

Ladik Gölü (Türkiye)’ndeki Tahta Balığı, Blicca bjoerkna (L., 1758)’nın Yaşı, Büyümesi ve Üreme Dönemi

The white bream, Blicca bjoerkna (L., 1758) specimens ( n =434) were collected from Lake Ladik between November 2009 and October 2010 in order to determine the age, growth, and reproductive season. Fork lengths and weights of these samples varied between 11.5-24.3 cm and 22.80-259.00 g, respectively. Age estimates obtained from scales and vertebrae were compared to determine the most reliable bony structure for ageing. The precision analyses indicated that scales were the most appropriate hard structures for determining the age of white bream. Ages of all the specimens ranged from I to VI years and age group III was dominant. The parameters of the von Bertalanffy growth equations were calculated as L ∞ = 32.85 cm, W ∞ = 707.76 g, k = 0.11 year -1 and t 0 = -2.64 year, and the growth performance index ( Φ' ) value was computed as 2.074 for combined sexes. Fork length-weight relationship was found to be W = 0.0066 FL 3.317 . The mean condition factor was the highest in August and the lowest in October. The gonadosomatic index values showed that the reproduction occurred between May and June.

Ladik Gölü (Samsun, Türkiye)'ndeki kızılkanat balığı (Scardinius erythrophthalmus L., 1758) populasyonunda en güvenilir yaş tayini yönteminin belirlenmesi

Ladik Gölü’nden Şubat-Mart 2010 tarihlerinde yakalanan 260 adet kızılkanat balığı ( Scardinius erythrophthalmus L., 1758) bireyinde pul, omur, operkül, utrikular (lapillus) ve lagenar (asteriskus) otolitlerden okunan yaşlar en güvenilir yaş tayini yönteminin belirlenmesi amacıyla karşılaştırılmıştır. Her bir kemiksi yapı için bir okuyucu tarafından üç okuma yapılmıştır. Tüm kemiksi yapılar için ortalama yaş bulunmuş ve tekrarlı okumalarda elde edilen yaş verilerinin uyumu yüzde uyum (YU), ortalama yüzde hata (OYH) ve değişim katsayısı (DK) hesaplamalarıyla değerlendirilmiştir. En yüksek YU (% 71.71), en düşük OYH (% 2.71) ve DK (% 3.56) değerinden dolayı, türün Ladik Gölü populasyonunda yaş tayini için en güvenilir kemiksi yapının lapillus olduğu sonucuna varılmıştır. Lapillus yaşları diğer kemiksi yapılarla kıyaslandığında, en yüksek uyumun lapillus-asteriskus yaş okumaları arasında olduğu gözlenmiştir.

POPULATION STRUCTURE AND GROWTH OF RUDD Scardinius erythrophthalmus (L., 1758) FROM A EUTROPHIC LAKE IN NORTHERN ANATOLIA

A total of 1329 samples were collected from monthly sampling between November 2009 and October 2010 in order to analyze growth features and population structure of rudd Scardinius erythrophthalmus living in Lake Ladik which has eutrophic character. The fork length (FL) ranged from 9.8 to 21.4 cm and the body weight (W) ranged from 13.62 to 200.68 g. Based on lapillus readings, the maximum age was 7 years. The overall ratio of female to male was 1:0.16. The von Bertalanffy growth equation parameters were calculated as L∞ = 39.32 cm, W∞ = 1504.92 g, k = 0.08, t0 = -1.08 for females, and L∞ = 28.19 cm, W∞ = 448.03 g, k = 0.13, t0 = -1.19 for males. Length-weight relationship for females and males was found as W = 0.0060 FL3.386 and W = 0.0078 FL3.282, respectively. The Fulton’s condition factor (K) showed an upward trend with reference to age and length groups in both sex. The value of mean K was computed as 1.737 for females, 1.667 for males and 1.727 for combined sexes. This study provides the initial data on population structure, growth features and condition of rudd in Lake Ladik. Obtained data have shown that population is comprised of young individuals and that the growth rate of the species is slow.

Relationships between fish length and otolith size for five cyprinid speciesfrom Lake Ladik, Samsun, Turkey

The relationships between size (length and width) of the lagenar (asteriscus) and the utricular (lapillus) otoliths and body length for five cyprinid fish species, freshwater bream Abramis brama, white bream Blicca bjoerkna, Prussian carp Carassius gibelio, brond-snout Chondrostoma regium, and rudd Scardinius erythrophthalmus, collected from Lake Ladik from November 2009 through October 2010, are presented. The right and left side measurements of otoliths were pooled in all cases except asteriscus length in Prussian carp. Nonlinear and linear functions provided the best fit for 80% and 20% of all species, respectively. All relationships were highly significant (P < 0.001, R2 > 0.71) and the mean percent prediction errors were less than 10%. The results showed that reliable original size estimates of all species studied are obtainable from their otolith biometrics. The regressions from this study can be useful for investigators examining food habits of piscivorous fauna and sizes of these fishes in archaeological samples.

The zooplankton composition of Lake Ladik (Samsun, Turkey)

The zooplankton composition of Lake Ladik, located in Samsun Province in northern Turkey, was investigated monthly between November 2009 and October 2010. Some physicochemical parameters such as temperature of surface water, pH, dissolved oxygen, salinity, conductivity, and total dissolved solids were also evaluated. A total of 29 zooplankton species were identified. These species were represented by three main groups: Rotifera (59%), Cladocera (24%), and Copepoda (17%). The maximum and minimum numbers of species were found in July and October, respectively. Bosmina longirostris, Keratella quadrata, Asplanchna priodonta, Cyclops abyssorum, Polyarthra dolichoptera, Brachionus calyciflorus, Keratella cochlearis, Brachionus angularis, and Chydorus sphaericus were the dominant species of the lake. According to the Brachionus:Trichocerca quotient (QB/T), the trophic level of the lake is eutrophic.

Some of the biological features of the Brond-snout (Chondrostoma regium, Heckel, 1843) living in Lake Ladik (Samsun, Turkey)

Ladik Gölü’nden Ocak 2010-Mart 2010 tarihleri arasında yakalanan 164 adet kababurun balığı, Chondrostoma regium (Heckel, 1843) bireyinin yaş ve eşey kompozisyonu, boy ve ağırlık dağılımları, yaş, boy, ağırlık ilişkileri ve kondisyon faktörü gibi bazı biyolojik özellikleri incelendi. Yaş tayini pullardan yapıldı ve balıkların yaşlarının 2 ile 5 arasında değiştiği belirlendi. Örneklerin total boy ve ağırlıkları sırasıyla 16,5-25,4 cm ve 40,04-192,42 g arasındaydı. Eşey oranı (D/E) 1/0,29 olarak tespit edildi. Tüm örnekler için von Bertalanffy büyüme denklemi parametreleri L∞ = 28,15 cm, W∞ = 254,16 g, k = 0,30 yıl-1 ve t0 = -1,23 yıl ve büyüme performans indeks değeri (Ø') 2,38 olarak hesaplandı. Boy-ağırlık ilişkisi W = 0,0029 TB3.41 şeklinde elde edildi. Ölçülen farklı boy uzunlukları arasında kuvvetli ilişkiler belirlendi (p<0,001, r2 > 0,98). Fulton’un kondisyon faktörü değeri tüm bireyler için 1,01±0,09 olarak tespit edildi

The Fatty Acid Composition and Cholesterol and Vitamin Contents of Different Muscles of Esox lucius (Linnaeus, 1758) Living in Lake Ladik

The Fatty Acid Composition and Cholesterol and Vitamin Contents of Different Muscles of Esox lucius (Linnaeus, 1758) Living in Lake Ladik

A 3000-Year Record of Ground-Rupturing Earthquakes along the Central North Anatolian Fault near Lake Ladik, Turkey

The North Anatolian fault (NAF) is a similar to 1500 km long, arcuate, dextral strike-slip fault zone in northern Turkey that extends from the Karliova triple junction to the Aegean Sea. East of Bolu, the fault zone exhibits evidence of a sequence of large (M(w) > 7) earthquakes that occurred during the twentieth century that displayed a migrating earthquake sequence from east to west. Prolonged human occupation in this region provides an extensive, but not exhaustive, historical record of large earthquakes prior to the twentieth century that covers much of the last 2000 yr. In this study, we extend our knowledge of rupture events in the region by evaluating the stratigraphy and chronology of sediments exposed in a paleoseismic trench across a splay of the NAF at Destek, similar to 6: 5 km east of Lake Ladik (40.868 degrees N, 36.121 degrees E). The trenched fault strand forms an uphill-facing scarp and associated sediment trap below a small catchment area. The trench exposed a narrow fault zone that has juxtaposed a sequence of weakly defined paleosols interbedded with colluvium against highly fractured bedrock. We mapped magnetic susceptibility variations on the trench walls and found evidence for multiple visually unrecognized colluvial wedges. This technique was also used to constrain a predominantly dip-slip style of displacement on this fault splay. Sediments exposed in the trench were dated using both charcoal and terrestrial gastropod shells to constrain the timing of the earthquake events. While the gastropod shells consistently yielded (14)C ages that were too old (by similar to 900 yr), we obtained highly reliable (14)C ages from the charcoal by dating multiple components of the sample material. Our radiocarbon chronology constrains the timing of seven large earthquakes over the past 3000 yr prior to the 1943 Tosya earthquake, including event ages of (2 sigma error): A. D. 1437-1788, A. D. 1034-1321, A. D. 549-719, A. D. 17-585 (1-3 events), 35 B. C.-A. D. 28, 700-392 B. C., 912-596 B. C. Our results indicate an average interevent time of 385 +/- 166 degrees yr (1 sigma).

Changes in the Lake Ladik fish community (1972-2004) and ichthyofauna of its inlet and outlet streams (Samsun, Turkey)

This research was conducted to record the fish species inhabiting Lake Ladik and its inlet and outlet streams between July 2003 and August 2004. Electrofishing equipment, fishing cast net, fisherman's dip net, and fishing nets with different scales were used to catch fish samples. As a result of evaluated samples caught from the research area, 12 species belonging to 4 families (Cyprinidae, Balitoridae, Esocidae, and Percidae) were identified.

Seasonal Variation of the Phytoplankton of Lake Ladik Samsun, Turkey

ABSTRACT The composition and seasonal variations of phytoplankton of Lake Ladik were studied between June 2000 and May 2001. The taxa identified included members of Cyanoprokaryota (8), Bacillariophyta (46), Chlorophyta (54), Euglenophyta (30), Cryptophyta (2), Dinophyta (1) and Xanthophyta (1). In the phytoplankton, Cyclotella ocellata, Aulacoseria distans, Trachelomonas hispida, T. volvocina var. punctata, Cryptomonas ovata, Pediastrum spp., and Scenedesmus spp. were common organisms. Seasonal variations in phytoplankton appeared to be related to availability of light and temperature rather than various measured nutrients.

A study of the composition and seasonal variation of the epilithic diatoms of Lake Ladik (Samsun, Turkey)

A study of the composition and seasonal variation of the epilithic diatoms of Lake Ladik (Samsun, Turkey)