Data Descriptor : A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.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

levels of Turkish shallow lakes

Climate warming threatens the structure and function of shallow lakes, not least those in the Mediterranean climate. We used a space-for-time substitution approach to assess the response of trophic and community structures as well as the richness and evenness of multiple trophic levels to temperature, hydrological, and nutrient constraints. We selected 41 lakes covering wide climatic, hydrological, and nutrient gradients within a short distance for reducing the effect of biogeographical factors in the western Anatolian plateau of Turkey. Generalized linear model analyses revealed that temperature was overall the most important driving variable, followed by total nitrogen (TN) and salinity. The chlorophylla:total phosphorus ratio, the cyanobacteria:total phytoplankton biovolume ratio, the fish:zooplankton biomass ratio, the proportion of small fish, and fish richness increased with increasing temperature, whereas macrophyte plant volume inhabited (PVI, %), richness, and evenness decreased. Grazing pressure, macrophyte coverage, piscivore biomass, phytoplankton richness, and evenness decreased significantly with both increasing TN and temperature. Temperature and nutrients also separated the northern highland lakes from other lakes in a non-metric multidimensional scaling analysis. Additionally, salinity reduced richness and evenness of phytoplankton and zooplankton. Our results indicate major changes in lake structure and functioning with warming and eutrophication, and highlight the need for strict control of nutrients and water use.C1 [Beklioglu, Meryem; Bucak, Tuba; Levi, Eti E.; Erdogan, Seyda; Ozen, Arda; Filiz, Nur; Bezirci, Gizem; Cakiroglu, Ayse Idil; Tavsanoglu, U. Nihan; Ozkan, Korhan; Jeppesen, Erik] Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey.[Gokce, Didem] Inonu Univ, Dept Biol, Malatya, Turkey.[Demir, Nilsun] Ankara Univ, Fac Agr, Dept Fisheries & Aquaculture, Ankara, Turkey.[Ozulug, Mufit] Istanbul Univ, Fac Sci, Dept Biol, Istanbul, Turkey.[Duran, Mustafa] Pamukkale Univ, Fac Arts & Sci, Hydrobiol Lab, Denizli, Turkey.[Brucet, Sandra] Univ Vic, Aquat Ecol Grp, Cent Univ Catalonia, Vic, Spain.[Brucet, Sandra] ICREA, Catalan Inst Res & Adv Studies, Barcelona, Spain.[Levi, Eti E.; Jeppesen, Erik] Aarhus Univ, Dept Biosci & Arctic Res Ctr ARC, Silkeborg, Denmark.[Jeppesen, Erik] Sino Danish Ctr Educ & Res SDC, Beijing, Peoples R China.[Beklioglu, Meryem; Filiz, Nur] Middle East Tech Univ, Ctr Ecosyst Res & Implementat, Ankara, Turkey.[Bucak, Tuba] Nat Conservat Ctr DKM, Ankara, Turkey.[Erdogan, Seyda] Yozgat Bozok Univ, Fac Sci & Art, Dept Biol, Yozgat, Turkey.[Ozen, Arda] Cankiri Karatekin Univ, Dept Forest Engn, Cankiri, Turkey.[Bezirci, Gizem] British Embassy Sch, Ankara, Turkey.[Tavsanoglu, U. Nihan] Cankiri Karatekin Univ, Eldivan Vocat Sch Hlth Serv, Dept Environm Hlth, Cankiri, Turkey.[Ozkan, Korhan] Middle East Tech Univ, Inst Marine Sci, Mersin, Turkey

Determinants of firm competitiveness: case of the Turkish textile and apparel industry

This article explores different determinants of competitiveness in the booming textile and apparel industry of Turkey. By using focus groups, survey data, and explanatory factor analysis, we have identified 27 competitive items grouped into eight constructs. According to Turkish managers, the competitiveness of textile and apparel firm is heavily determined by product differentiation, efforts across foreign markets, and availability of government incentives. In contrast to existing studies, we find little evidence that networking in different forms, such as close relationship politicians and state employees, clustering, and participating in the industry associations, have a major impact on a firm competitiveness

Determination of Bioaccumulation of Heavy Metals and Selenium in Tissues of Brown Trout Salmo trutta macrostigma Duméril 1858 from Munzur Stream Tunceli Turkey

The objective of the present work was to determine the bioaccumulation of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), uranium (U) and selenium (Se) in gill, liver, and muscle tissues of the fresh water fish Salmo trutta macrostigma (Duméril, 1858) in Munzur Stream, Tunceli, Turkey. The highest concentrations of U (1.83 μg kg−1), Pb (119.84 μg kg−1) and Se (1.31 μg kg−1) were recorded in the gills of S. t. macrostigma. Concentrations of As (46.27 μg kg−1), Cd (109.19 μg kg−1), Hg (16.40 μg kg−1), Cu (18.19 μg kg−1) were recorded at highest levels in the liver. The results showed that there were significant differences in concentrations of As, Cd, Cu, Pb, Se, U and Hg in gill, liver and muscle tissue (p < 0.05). Heavy metals were within the edible parts of the investigated fish were in the permissible safety levels for human uses