Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe

In this study, were determined on nutritional characteristic and property of made fish ball of tench

As material, tench ball were obtained from local processing firms. The chemicâl compositions and sensual analysis of obtained fish balls were made. in addition, On the lst, 4th, 7th,and 10th days tiobarbutiric acid (TBA), total volatile basic nitrogen, (TVBN) and pH parameters and total mesophilic aerobic bacteria (MAB), total psycrophilic bacteria (TPA), coliform and yeast-mould counting were made. According to the results of the sensual analysis tench fish ball was enjoyed so much. For the values TBA, TVB-N, pH and microbial analysis related to storing, it has been determined a tendency tovards spoilage depending on time. It has been concluded that tench could be used as aiming support to the economy by making fısh balls. The shelf life of fısh ball obtained was 7th days and spoiled after 10th.Bu arastırmada, kadife balığının (Tinca tinca L., 1758) balık köftesi yapımına uygunluğu ile isleme sonrası besinsel özelliklerindeki değisimler belirlenmistir. Temin edilen balık materyalleri kıyıldıktan sonra çesitli katkı maddeleri ilavesiyle köfte haline getirilmistir. Balık kıyması ve elde edilen köftelerin kimyasal kompozisyonları ile organoleptik analizleri yapılmıstır. Ayrıca +4±1 °C'de depolanmıs olan köftelerin 1,4,7ve10,. günlerde tiobarbutirik asit (TBA), toplam uçucu bazik azot (TVB-N) ve pH parametreleri ile toplam mezofilik aerob bakteri(TMA), psikrofilik bakteri(TPA), koliform grubu bakteri ve maya-küf sayımları gerçeklestirilmistir. Organoleptik analiz bulgularına göre kadife köftesi oldukça çok beğenilmistir. Depolamaya bağlı TBA, TVB-N, pH değerleri ve mikrobiyolojik analiz sonuçlarında zamana bağlı olarak bozulmaya doğru bir gidis tespit edilmistir. Kadife balığından köfte yapılarak ekonomiye katkı amaçlı kullanılabileceği sonucuna varılmıstır. Elde edilen köftelerin +4± 1 °C'de 7. güne kadar iyi kalite özelliklerini koruduğu 10. günden sonra bozulmus nitelik kazandığı tespit edilmistir

In this study, were determined on nutritional characteristic and property of made fish ball of tench

As material, tench ball were obtained from local processing firms. The chemicâl compositions and sensual analysis of obtained fish balls were made. in addition, On the lst, 4th, 7th,and 10th days tiobarbutiric acid (TBA), total volatile basic nitrogen, (TVBN) and pH parameters and total mesophilic aerobic bacteria (MAB), total psycrophilic bacteria (TPA), coliform and yeast-mould counting were made. According to the results of the sensual analysis tench fish ball was enjoyed so much. For the values TBA, TVB-N, pH and microbial analysis related to storing, it has been determined a tendency tovards spoilage depending on time. It has been concluded that tench could be used as aiming support to the economy by making fısh balls. The shelf life of fısh ball obtained was 7th days and spoiled after 10th.Bu arastırmada, kadife balığının (Tinca tinca L., 1758) balık köftesi yapımına uygunluğu ile isleme sonrası besinsel özelliklerindeki değisimler belirlenmistir. Temin edilen balık materyalleri kıyıldıktan sonra çesitli katkı maddeleri ilavesiyle köfte haline getirilmistir. Balık kıyması ve elde edilen köftelerin kimyasal kompozisyonları ile organoleptik analizleri yapılmıstır. Ayrıca +4±1 °C'de depolanmıs olan köftelerin 1,4,7ve10,. günlerde tiobarbutirik asit (TBA), toplam uçucu bazik azot (TVB-N) ve pH parametreleri ile toplam mezofilik aerob bakteri(TMA), psikrofilik bakteri(TPA), koliform grubu bakteri ve maya-küf sayımları gerçeklestirilmistir. Organoleptik analiz bulgularına göre kadife köftesi oldukça çok beğenilmistir. Depolamaya bağlı TBA, TVB-N, pH değerleri ve mikrobiyolojik analiz sonuçlarında zamana bağlı olarak bozulmaya doğru bir gidis tespit edilmistir. Kadife balığından köfte yapılarak ekonomiye katkı amaçlı kullanılabileceği sonucuna varılmıstır. Elde edilen köftelerin +4± 1 °C'de 7. güne kadar iyi kalite özelliklerini koruduğu 10. günden sonra bozulmus nitelik kazandığı tespit edilmistir

A comparison of the size-composition of the Turkish Crayfish (Astacus leptodactylus Eschscholtz, 1823) inhabiting Eğirdir Lake vs Keban Dam Lake

Objective: Turkish (Narrow-clawed) Crayfish (Astacus leptodactylus Eschscholtz, 1823) is the most important shellfish in Turkey in both economic and ecological sense. It is an important export product with high commercial value and is also an important source of revenue for fishermen. Although it is an important species a lot of bio-ecological features of it remain unknown. In this study, some morphometric features of two important A. leptodactylus population of Turkey have been compared on length to length relation for each length category. Methods: In this study, the sizes of total length (TL), carapace length (CL), carapace width (CW), abdomen length (AL), abdomen width (AW), chela length (ChL), and chela width (ChW) were compared separately for each length category obtained from two different habitats. In calculations, a total of 1328 crayfish from Lake Eğirdir (♀:555, ♂:773) and 2045 from Keban Dam Lake (♀:868, ♂:1177) were used. The field studies in Lake Eğirdir were carried out in three different stations, in a period of July-2010 and June-2011 with monthly period. Field works in Keban Dam Lake were carried out in 6 different stations in a period of January-2012 and December-2012. In the comparing body section of crayfish that in different sex groups and same length category in each catching ground the t-test was used. Statistical calculations were made on significance of P<0.05 and P<0.001. For all statistical calculations R Studio (V.0.99.463) computer software was used. Results and Discussion: . The correlation relations between compared parameters were so high. According to linear regression analysis while the highest relation was between TL and AL (R2=0.987) of the female in Eğirdir Lake and the weakest relation was between AW and ChL’s (R2=0.084) of male+female in Keban Dam Lake. As a result, it was determined that the biometric features of A. leptodactylus populations in Eğirdir Lake and Keban Dam Lake were different and while these differences were insignificant in small and larger lengths, it was significant in mid- length groups

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.Peer reviewe

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature