Meriç Albay - Academia.edu (original) (raw)

Papers by Meriç Albay

Research paper thumbnail of Current Approaches to Cyanotoxin Risk Assessment, Risk Management and Regulations in Different Countries

Research paper thumbnail of Microplastic pollution in seabed sediments at different sites on the shores of Istanbul-Turkey: Preliminary results

Journal of Cleaner Production, 2021

Research paper thumbnail of Monitoring of freshwater toxins in European environmental waters by using novel multi-detection methods

Environmental toxicology and chemistry / SETAC, Mar 9, 2016

Monitoring the quality of freshwater is an important issue for public health. In the context of t... more Monitoring the quality of freshwater is an important issue for public health. In the context of the European Project µAqua (FP7-KBBE-2010-4, 265409) a total of 150 samples were collected from several waters in France, Germany, Ireland, Italy and Turkey over two years. These samples were analyzed using two multi-toxin detection methods previously developed: (i) a microsphere-based method coupled to flow-cytometry and (ii) an Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method. The presence of microcystins (MCs), nodularin (NOD), domoic acid (DA), cylindrospermopsin (CYN) and several analogues of anatoxin-a (ATX-a) was monitored. No traces of CYN or DA were found in any of the environmental samples. MC-LR and MC-RR were detected in two samples from Turkey and Germany. In the case of ATX-a derivatives, 75% of samples contained mainly H2 -ATX-a and small amounts of H2 -homo-ATX-a, whereas ATX-a and homo-ATX-a were found only in one sample. From these res...

Research paper thumbnail of The Effects of Climate Change on Aquatic Ecosystems in Relation to Human Health

Aquatic sciences and engineering, Apr 7, 2022

The effects of climate change on aquatic ecosystems in relation to human health. Aquatic Sciences... more The effects of climate change on aquatic ecosystems in relation to human health. Aquatic Sciences and Engineering, Advance online publication.

Research paper thumbnail of SPATIAL AND TEMPORAL DISTRIBUTION OF PHYTOPLANKTON IN LAKE GALA (Edirne/TURKEY)

Trakya University Journal of Natural Sciences, 2016

This study was performed from March 2004 to February 2005 in 4 stations in Gala Lake, a shallow l... more This study was performed from March 2004 to February 2005 in 4 stations in Gala Lake, a shallow lake located inside Gala Lake National Park in Meriç Delta. Water samples were taken from the lake in order to determine the phytoplankton present in the lake and to perform physicochemical analysis. A total of 112 taxa from 5 divisio were identified during the study period. Chlorophyta was the most diversed group in the lake with 47 taxa and diatoms were found to have the highest cell counts with a mean value of 670011 cell L-1. The general pattern of seasonal succession in phytoplankton of the lake was represented with Chlorophyta in June and with Cyanophyta in September and Diatoms were the dominant group of the lake in all other months. A spatial heterogeneity was observed in the lake where a slight Microsystis spp. increase occurred in early autumn months. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of...

Research paper thumbnail of The First Report of Geosmin and 2-METHYLISOBORNEOL Producer Cyanobacteria from Turkish Freshwaters

Trakya University Journal of Natural Sciences, 2021

Water users consider the safety of water according to its aesthetic properties, primarily taste a... more Water users consider the safety of water according to its aesthetic properties, primarily taste and odour. Geosmin (GEO) and 2-methylisoborneol (MIB) are the most common taste and odour compounds in freshwaters which cause an earthy and musty odour in water. Since human nose can detect these compounds in concentrations as low as 10 ng/L, it is essential to monitor drinking waters before consumer complaints and to produce a timely solution. Therefore, it is necessary to identify GEO and MIB producers to manage the problem at its source. Cyanobacteria are one of the main producers of these compounds in freshwater ecosystems. In this study, we analyzed 13 samples (9 cyanobacteria cultures from Bafa Lake, Elmalı Dam Lake, İznik Lake, Küçükçekmece Lake, Manyas Lake and Taşkısığı Lake, and 4 environmental water samples from Erfelek and Günpınar Waterfalls and Ömerli Dam Lake) for GEO and MIB production by HS-SPME (Head space-solid phase microextraction) coupled with GC-MS (gas chromatography-mass spectrometry). The presence of Cyanobacteriaspecific GEO and MIB synthase genes were also analyzed by PCR (Polymerase Chain Reaction). Taste and odour production was confirmed in 2 samples by GC-MS while 4 samples yielded positive results by PCR. All positive samples were environmental samples (3 samples from waterfalls from Günpınar and Erfelek Waterfalls, 1 sample from Ömerli Dam Lake-a drinking water reservoir) which were dominated by Nostoc Vaucher ex Bornet & Flahault, Phormidium Kützing ex Gomont and Pseudanabaena Lauterborn. This is the first report of GEO and MIB producing cyanobacteria in Turkish freshwaters by combining microscopy, analytical and molecular techniques. Özet: Su kullanıcıları, suyun güvenli olup olmadıklarına öncelikle onun tat ve kokusu gibi estetik özelliklerine bakarak karar vermektedir. Geosmin (GEO) ve 2-methylisoborneol (MIB), tatlısularda en yaygın olarak görülen tat ve koku bileşikleridir ve suyun toprak ve küf kokmasına neden olurlar. İnsanlar <10 ng/L gibi düşük konsantrasyonlarda dahi bu kokulara hassas olmalarından dolayı bu bileşiklerin içme sularında tüketici şikayetleri oluşmadan önce izlenmesi ve sorunun çözülmesi oldukça önemlidir. Bu sebeple, problemin kaynağında çözümlenebilmesi için GEO ve MIB üreticilerinin tespit edilmesi gereklidir. Tatlısu ekosistemlerinde bu bileşiklerin başlıca üreticilerinden biri siyanobakterilerdir (Cyanobacteria). Bu çalışmada 13 örnek (9 siyanobakteri kültürü, Bafa Gölü, Elmalı Baraj Gölü, İznik Gölü, Küçükçekmece Gölü, Manyas Gölü, Taşkısığı Gölü'nden ve 4 çevresel su örneği, Günpınar, Erfelek şelaleleri ve Ömerli Baraj Gölü'nden) GEO ve MIB üretiminin tespiti için HS-SPME (Tepe Boşluğu-Katı Faz Mikro Ekstraksiyon) GC-MS (Gaz Kromatografi-Kütle Spektrometresi) yöntemi kullanılarak analiz edilmiştir. Ayrıca siyanobakterilere özgü GEO ve MIB sentaz genlerinin varlığının tespiti için PZR (Polimeraz Zincir Reaksiyonu) yöntemi kullanılmıştır. İki örnekte GC-MS ile tat ve koku üretimi tespit edilmiş ve 4 örnekte de PZR ile pozitif sonuç alınmıştır. Pozitif sonuç elde edilen örnekler Nostoc Vaucher ex Bornet & Flahault, Phormidium Kützing ex Gomont ve Pseudanabaena Lauterborn cinslerinin baskın olduğu çevresel örneklerdir (3 şelale, 1 içme suyu kaynağı örneği). Bu çalışma Türkiye tatlısularındaki tat ve koku üreticisi siyanobakterilerin mikroskobik, analitik ve moleküler yöntemler birlikte kullanılarak tespit edildiği ilk kayıttır.

Research paper thumbnail of Basic Guide to Detection and Monitoring of Potentially Toxic Cyanobacteria

Handbook of Cyanobacterial Monitoring and Cyanotoxin Analysis, 2017

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

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.

Research paper thumbnail of Spatial Variations of the Bacterial Diversity in an Alkaline Lake

ARPHA Conference Abstracts, 2021

Lake Iznik is one of the largest lake of Turkey covering 308 km2 surface area with 65 m max. dept... more Lake Iznik is one of the largest lake of Turkey covering 308 km2 surface area with 65 m max. depth. The lake has alkaline characteristics (Akcaalan et al. 2014). It is a mesotrophic lake that becomes stratified between June-September and well mixed between October-April. Although there are almost 200 lakes in Turkey, there is very little published research focused on the bacterial diversity structures (Ozbayram et al. 2020.) The specific objective of this study was to evaluate the bacterial community profile in the surface water and sediment of the alkaline lake during the winter turnover. For this purpose, the samples were collected from 6 stations (5 on the shore and 1 in the middle of the lake) in February 2020 when the lake was completely mixed. In addition to the surface water and sediment samples, a sample was also collected from the depth of 40 m from the station located in the mid-lake. The water samples were filtered from a 0.22 µm filter and the sediment samples were taken...

Research paper thumbnail of Contrasting the Water Quality and Bacterial Community Patterns in Shallow and Deep Lakes: Manyas vs. Iznik

Environmental Management, 2020

The objectives of this study are to monitor the physicochemical properties of two freshwater lake... more The objectives of this study are to monitor the physicochemical properties of two freshwater lakes with different chemical characteristics and trophic status over a year (2019) and assess the bacterial diversity by a high-throughput sequencing method for a certain time. Carlson Trophic Index analysis revealed that, whereas the deep lake, Iznik Lake, (TSI mean = 48.9) has mesotrophic characteristics, the shallow lake Manyas Lake (TSI mean = 74.2) was found at a hypertrophic status. The most important parameters controlling water qualities in the lakes were temperature, alkalinity, and phosphate levels. Although the bacterial communities were dominated by the same phyla (Cyanobacteria, Bacteroidetes, Actinomicrobia, Proteobacteria, and Verrucomicrobia) in both lakes, the communities differed distinctly at the lower levels. Whereas Sporichthyaceae in Manyas Lake accounted for 10% of the total reads, the major share of the sequences was assigned to Cyanobacteria Family I (8%) in Iznik Lake. The hypertrophic Manyas Lake had a more diverse bacterial community rather than Iznik Lake and contained higher numbers of unique Operational Taxonomic Units.

Research paper thumbnail of Zooplankton Biodiversity in Reservoirs of Different Geographical Regions of Turkey: Composition and Distribution Related with Some Environmental Conditions

Aquatic Sciences and Engineering, 2019

The zooplankton fauna and the relationship with their environmental variables were investigated o... more The zooplankton fauna and the relationship with their environmental variables were investigated on the epilimnion layer of the seven reservoirs (Demirdöven, Devegeçidi, Menzelet, Sır, Ömerli, Porsuk, Tahtalı) of different regions (Marmara, Aegean, Mediterranean, Central Anatolia, Eastern Anatolia, Southeastern Anatolia) throughout the summer months (2015) in Turkey. According to the trophic conditions reservoirs varied between oligo-and eutrophic status. Chlorophylla concentration, measured for the estimation of primary production, was determined considerably high along the investigation period. A total of 62 zooplankton species were identified with the contribution of 44 rotifers, nine cladocerans and nine copepods. Except one reservoir, all of the others were dominated by rotifera group, and also in each study site dominant taxa were changed at species level. On the other hand common dominant taxa for all reservoirs was the rotifer Polyarthra vulgaris Carlin, 1943 with 95 % frequency. In terms of zooplankton species, most of the studied reservoirs showed less than 50% similarities, due to their different limnological conditions and different geographic locations. Reservoirs in high trophic conditions in the present study were represented by low species diversity. Water quality in the reservoirs with respect to biological data were determined as ß-mesosaprobic. The using limnological and biological indices to determine water quality were consistent. Densities of main zooplankton groups, and also frequent species of the reservoirs correlated with epilimnion layer depths and total phoshorus concentrations significantly. On the other hand rotifera variation was affected mainly by physical variables (pH, temperature, dissolved oxygen concentration, conductivity), and crustacean variations were related with total phoshorus. The comperative assessment between limnological variables and zooplankton community in this reservoirs was studied for the first time.

Research paper thumbnail of Bacterial Community Composition of Sapanca Lake During a Cyanobacterial Bloom

Aquatic Sciences and Engineering, 2020

Microbial community compositions and functions of freshwater ecosystems vary due to the environme... more Microbial community compositions and functions of freshwater ecosystems vary due to the environmental parameters and water chemistry. Transient bloom events play a crucial role on the community profiles. In this study, a specific focus was set to provide a snapshot of the bacterial community composition in Lake Sapanca, associated with cyanobacterial bloom by high throughput sequencing method. For this purpose, a sample was collected in the shore of Lake Sapanca during a cyanobacterial bloom, and the bacterial community profile was examined by 16S rRNA amplicon sequencing using the Illumina MiSeq platform. Cyanobacteria represented 94% of the all reads. The bacterial community was recalculated to evaluate the bacterial diversity in detail by filtering cyanobacterial sequences. The community was dominated by Proteobacteria (44%) and Bacteroidetes (33%) species which are abundant in freshwater ecosystems having an ability to degrade complex organics. Among the classified genera, Flavobacterium and Rheinheimera dominated the bacterial community suggesting a strong link between those species and the cyanobacterial bloom. The experimental work presented here provides one of the first investigations of total bacterial communities in Lake Sapanca by the high throughput sequencing method. Further work is needed with more sampling points and time series to fully understand the bacterial diversity and dynamics.

Research paper thumbnail of Composition and Distribution of Benthic Diatoms in Different Habitats of Burdur River Basin

Turkish Journal of Water Science and Management, 2020

Diatoms constitute an essential component for biomonitoring studies to determine the ecological q... more Diatoms constitute an essential component for biomonitoring studies to determine the ecological quality of waterbodies. In this study, benthic diatoms of Burdur River Basin were investigated as a consequence of a project on river basin management plan. This is the first detailed taxonomical study of diatoms taken from 13 streams, 4 lakes and 6 reservoirs of Burdur River Basin and a total of 223 taxa have been observed. Among genera, Navicula Bory (27) and Nitzschia Hassal (27) were represented with the highest numbers of taxa and followed by Gomphonema Agardh with a total of 22 species. Navicula antonii Lange-Bertalot and Nitzschia palea var. debilis (Kützing) Grunow had the highest relative abundance with 17.1% and 15.5% respectively. As a closed basin, salinity varied greatly from fresh to saline water between the sampling stations and diatom composition contained species with a different tolerance level. Navicula antonii and Nitzschia frustulum (Kützing) Grunow observed in all habitats indicating their euryhaline characters; however Navicula digitoconvergens was only detected in saline Acıgöl lake with a high relative abundance (38%) in autumn. Other two dominant species were Halamphora coffeiformis (Kützing) Levkov and Navicula cincta (Ehrenberg) Ralfs in Acıgöl lake showing their tolerance to high salt content as a brackish species. According to first results, 11 species were new records for Turkish diatom flora. The high biodiversity of diatoms revealed the presence of different habitat characteristics within the basin. These results are an important contribution of Turkish diatom flora and could be useful for monitoring specific areas like Burdur River Basin.

Research paper thumbnail of A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Scientific data, Jan 23, 2018

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ... more 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 3...

Research paper thumbnail of Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Toxins, Apr 13, 2018

Insight into how environmental change determines the production and distribution of cyanobacteria... more 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 sta...

Research paper thumbnail of Molecular detection of hepatotoxic cyanobacteria in inland water bodies of the Marmara Region, Turkey

Advances in Oceanography and Limnology, 2017

Blooms of cyanobacteria are an increasingly frequent phenomenon in freshwater ecosystems worldwid... more Blooms of cyanobacteria are an increasingly frequent phenomenon in freshwater ecosystems worldwide as a result of eutrophication. Many species can produce hepatotoxins that cause severe health hazards to humans. The aim of this study was to identify the bloom forming cyanobacteria species by molecular methods and to amplify genes responsible for hepatotoxin biosynthesis from the environmental samples and isolated strains of cyanobacteria from Küçükçekmece Lagoon, Sapanca, İznik, Manyas and Taşkısı Lakes. A total of 10 bloom samples and 11 isolated strains were examined and Microcystis spp., Planktothrix spp., Nodularia spumigena, Anabaenopsis elenkinii, Sphaerospermopsis aphanizomenoides, Cylindrospermopsis raciborskii were identified. Hepatotoxin genes were detected in 60% of the bloom samples and 45% of the strains. Two Microcystis strains were obtained from Küçükçekmece Lagoon. While the strain assigned to Microcystis flosaquae was non-toxic, Microcystis aeruginosa strain produced microcystin. According to PCR results, the M. aeruginosa and Planktothrix agardhii bloom samples of Küçükçekmece Lagoon contained the microcystin synthetase gene E (mcyE) indicative of microcystin production, however, no microcystin was detected by HPLC. The mcyE gene was also found in Microcystis wesenbergii isolated from Taşkısı Lake, and in all Planktothrix rubescens bloom samples from Sapanca Lake. To our knowledge, this is the first detailed study for identifiying different toxic cyanobacteria species and their hepatotoxin production from several waterbodies in Turkey using molecular methods.

Research paper thumbnail of A New Rotifer Species for Turkish Inland Waters

Journal of Limnology and Freshwater Fisheries Research, 2015

The zooplankton fauna of Lake Sapanca (Turkey) was studied during January 2009-May 2010 of monthl... more The zooplankton fauna of Lake Sapanca (Turkey) was studied during January 2009-May 2010 of monthly intervals. One Rotifera species, Ploesoma truncatum (Levander, 1894) is a new record for the Turkish inland waters fauna.

Research paper thumbnail of Seasonal Variations of Water Quality Parameters and Algal Flora of Tundzha (Tunca) River (Edirne, Turkey)

Open Journal of Ecology, 2014

In this study which was performed in order to determine the seasonal variations of water quality ... more In this study which was performed in order to determine the seasonal variations of water quality parameters and algal flora of Tundzha River, samplings were made monthly from 5 different stations along the river. A total of 138 taxa from Chlorophyceae (65 taxa), Bacillariophyceae (46 taxa), Euglenophyta (13 taxa) and Cyanophyta and Charophyta (7 taxa) were found to represent the algal flora of the river. Diatoms were recorded to be the dominant group throughout the year in terms of biovolume. Station I was the richest station during the whole study in terms of species diversity and composition. The maximum abundance of phytoplanktonic community within this station was 3,459,313 cells•L −1 , and Station IV was found to be richest station in terms of biovolume, with 2028.8 µg•L −1. The water quality of the river was found to be close to the 2nd and 3rd quality levels. 2nd and 3rd, and 1st and 3rd stations were found to be most similar to each other in terms of floristic compositions biovolume, respectively.

Research paper thumbnail of Planktothrix rubescens: a perennial presence and toxicity in Lake Sapanca

TURKISH JOURNAL OF BOTANY, 2014

Introduction Climate variability is expected to have a significant impact on inland waters, inclu... more Introduction Climate variability is expected to have a significant impact on inland waters, including lakes. It is widely accepted that water temperature is a key parameter in most biological systems, directly influencing water chemistry, biochemical reactions, and aquatic biota. Increasing water temperatures can change the hydrodynamics and expand the thermal stratification period of lakes (Komatsua et al., 2007). On the other hand, climatic effects on phytoplankton are also of considerable importance, since the composition and quantity of phytoplankton are important parameters of water quality (Shams et al., 2012) and a good indicator of the ecological status of water bodies (Demir et al., 2014). Regional impacts of climate warming on water ecosystems represent a new and growing threat (Liboriussen et al., 2005). Climate change has been considered a potential tool for the further expansion of harmful cyanobacterial blooms, particularly in eutrophic waters with rising temperatures, enhanced stratification, increased residence time, and high nutrient loading all favoring cyanobacterial dominance (

Research paper thumbnail of First Report of Cylindrospermopsin Production by Two Cyanobacteria (Dolichospermum mendotae and Chrysosporum ovalisporum) in Lake Iznik, Turkey

Toxins, 2014

Cylindrospermopsin (CYN) is a cytotoxic alkaloid produced by cyanobacteria. The distribution of t... more Cylindrospermopsin (CYN) is a cytotoxic alkaloid produced by cyanobacteria. The distribution of this toxin is expanding around the world and the number of cyanobacteria species producing this toxin is also increasing. CYN was detected for the first time in Turkey during the summer months of 2013. The responsible species were identified as Dolichospermum (Anabaena) mendotae and Chrysosporum (Aphanizomenon) ovalisporum. The D. mendotae increased in May, however, C. ovalisporum formed a prolonged bloom in August. CYN concentrations were measured by LC-MS/MS and ranged from 0.12 µg• mg −1 to 4.92 µg• mg −1 as dry weight, respectively. Both species were the only cyanobacteria actively growing and CYN production was attributed solely to these species. Despite CYN production by C. ovalisporum being a well-known phenomenon, to our knowledge, this is the first report of CYN found in D. mendotae bloom.

Research paper thumbnail of Current Approaches to Cyanotoxin Risk Assessment, Risk Management and Regulations in Different Countries

Research paper thumbnail of Microplastic pollution in seabed sediments at different sites on the shores of Istanbul-Turkey: Preliminary results

Journal of Cleaner Production, 2021

Research paper thumbnail of Monitoring of freshwater toxins in European environmental waters by using novel multi-detection methods

Environmental toxicology and chemistry / SETAC, Mar 9, 2016

Monitoring the quality of freshwater is an important issue for public health. In the context of t... more Monitoring the quality of freshwater is an important issue for public health. In the context of the European Project µAqua (FP7-KBBE-2010-4, 265409) a total of 150 samples were collected from several waters in France, Germany, Ireland, Italy and Turkey over two years. These samples were analyzed using two multi-toxin detection methods previously developed: (i) a microsphere-based method coupled to flow-cytometry and (ii) an Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method. The presence of microcystins (MCs), nodularin (NOD), domoic acid (DA), cylindrospermopsin (CYN) and several analogues of anatoxin-a (ATX-a) was monitored. No traces of CYN or DA were found in any of the environmental samples. MC-LR and MC-RR were detected in two samples from Turkey and Germany. In the case of ATX-a derivatives, 75% of samples contained mainly H2 -ATX-a and small amounts of H2 -homo-ATX-a, whereas ATX-a and homo-ATX-a were found only in one sample. From these res...

Research paper thumbnail of The Effects of Climate Change on Aquatic Ecosystems in Relation to Human Health

Aquatic sciences and engineering, Apr 7, 2022

The effects of climate change on aquatic ecosystems in relation to human health. Aquatic Sciences... more The effects of climate change on aquatic ecosystems in relation to human health. Aquatic Sciences and Engineering, Advance online publication.

Research paper thumbnail of SPATIAL AND TEMPORAL DISTRIBUTION OF PHYTOPLANKTON IN LAKE GALA (Edirne/TURKEY)

Trakya University Journal of Natural Sciences, 2016

This study was performed from March 2004 to February 2005 in 4 stations in Gala Lake, a shallow l... more This study was performed from March 2004 to February 2005 in 4 stations in Gala Lake, a shallow lake located inside Gala Lake National Park in Meriç Delta. Water samples were taken from the lake in order to determine the phytoplankton present in the lake and to perform physicochemical analysis. A total of 112 taxa from 5 divisio were identified during the study period. Chlorophyta was the most diversed group in the lake with 47 taxa and diatoms were found to have the highest cell counts with a mean value of 670011 cell L-1. The general pattern of seasonal succession in phytoplankton of the lake was represented with Chlorophyta in June and with Cyanophyta in September and Diatoms were the dominant group of the lake in all other months. A spatial heterogeneity was observed in the lake where a slight Microsystis spp. increase occurred in early autumn months. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of...

Research paper thumbnail of The First Report of Geosmin and 2-METHYLISOBORNEOL Producer Cyanobacteria from Turkish Freshwaters

Trakya University Journal of Natural Sciences, 2021

Water users consider the safety of water according to its aesthetic properties, primarily taste a... more Water users consider the safety of water according to its aesthetic properties, primarily taste and odour. Geosmin (GEO) and 2-methylisoborneol (MIB) are the most common taste and odour compounds in freshwaters which cause an earthy and musty odour in water. Since human nose can detect these compounds in concentrations as low as 10 ng/L, it is essential to monitor drinking waters before consumer complaints and to produce a timely solution. Therefore, it is necessary to identify GEO and MIB producers to manage the problem at its source. Cyanobacteria are one of the main producers of these compounds in freshwater ecosystems. In this study, we analyzed 13 samples (9 cyanobacteria cultures from Bafa Lake, Elmalı Dam Lake, İznik Lake, Küçükçekmece Lake, Manyas Lake and Taşkısığı Lake, and 4 environmental water samples from Erfelek and Günpınar Waterfalls and Ömerli Dam Lake) for GEO and MIB production by HS-SPME (Head space-solid phase microextraction) coupled with GC-MS (gas chromatography-mass spectrometry). The presence of Cyanobacteriaspecific GEO and MIB synthase genes were also analyzed by PCR (Polymerase Chain Reaction). Taste and odour production was confirmed in 2 samples by GC-MS while 4 samples yielded positive results by PCR. All positive samples were environmental samples (3 samples from waterfalls from Günpınar and Erfelek Waterfalls, 1 sample from Ömerli Dam Lake-a drinking water reservoir) which were dominated by Nostoc Vaucher ex Bornet & Flahault, Phormidium Kützing ex Gomont and Pseudanabaena Lauterborn. This is the first report of GEO and MIB producing cyanobacteria in Turkish freshwaters by combining microscopy, analytical and molecular techniques. Özet: Su kullanıcıları, suyun güvenli olup olmadıklarına öncelikle onun tat ve kokusu gibi estetik özelliklerine bakarak karar vermektedir. Geosmin (GEO) ve 2-methylisoborneol (MIB), tatlısularda en yaygın olarak görülen tat ve koku bileşikleridir ve suyun toprak ve küf kokmasına neden olurlar. İnsanlar <10 ng/L gibi düşük konsantrasyonlarda dahi bu kokulara hassas olmalarından dolayı bu bileşiklerin içme sularında tüketici şikayetleri oluşmadan önce izlenmesi ve sorunun çözülmesi oldukça önemlidir. Bu sebeple, problemin kaynağında çözümlenebilmesi için GEO ve MIB üreticilerinin tespit edilmesi gereklidir. Tatlısu ekosistemlerinde bu bileşiklerin başlıca üreticilerinden biri siyanobakterilerdir (Cyanobacteria). Bu çalışmada 13 örnek (9 siyanobakteri kültürü, Bafa Gölü, Elmalı Baraj Gölü, İznik Gölü, Küçükçekmece Gölü, Manyas Gölü, Taşkısığı Gölü'nden ve 4 çevresel su örneği, Günpınar, Erfelek şelaleleri ve Ömerli Baraj Gölü'nden) GEO ve MIB üretiminin tespiti için HS-SPME (Tepe Boşluğu-Katı Faz Mikro Ekstraksiyon) GC-MS (Gaz Kromatografi-Kütle Spektrometresi) yöntemi kullanılarak analiz edilmiştir. Ayrıca siyanobakterilere özgü GEO ve MIB sentaz genlerinin varlığının tespiti için PZR (Polimeraz Zincir Reaksiyonu) yöntemi kullanılmıştır. İki örnekte GC-MS ile tat ve koku üretimi tespit edilmiş ve 4 örnekte de PZR ile pozitif sonuç alınmıştır. Pozitif sonuç elde edilen örnekler Nostoc Vaucher ex Bornet & Flahault, Phormidium Kützing ex Gomont ve Pseudanabaena Lauterborn cinslerinin baskın olduğu çevresel örneklerdir (3 şelale, 1 içme suyu kaynağı örneği). Bu çalışma Türkiye tatlısularındaki tat ve koku üreticisi siyanobakterilerin mikroskobik, analitik ve moleküler yöntemler birlikte kullanılarak tespit edildiği ilk kayıttır.

Research paper thumbnail of Basic Guide to Detection and Monitoring of Potentially Toxic Cyanobacteria

Handbook of Cyanobacterial Monitoring and Cyanotoxin Analysis, 2017

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

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.

Research paper thumbnail of Spatial Variations of the Bacterial Diversity in an Alkaline Lake

ARPHA Conference Abstracts, 2021

Lake Iznik is one of the largest lake of Turkey covering 308 km2 surface area with 65 m max. dept... more Lake Iznik is one of the largest lake of Turkey covering 308 km2 surface area with 65 m max. depth. The lake has alkaline characteristics (Akcaalan et al. 2014). It is a mesotrophic lake that becomes stratified between June-September and well mixed between October-April. Although there are almost 200 lakes in Turkey, there is very little published research focused on the bacterial diversity structures (Ozbayram et al. 2020.) The specific objective of this study was to evaluate the bacterial community profile in the surface water and sediment of the alkaline lake during the winter turnover. For this purpose, the samples were collected from 6 stations (5 on the shore and 1 in the middle of the lake) in February 2020 when the lake was completely mixed. In addition to the surface water and sediment samples, a sample was also collected from the depth of 40 m from the station located in the mid-lake. The water samples were filtered from a 0.22 µm filter and the sediment samples were taken...

Research paper thumbnail of Contrasting the Water Quality and Bacterial Community Patterns in Shallow and Deep Lakes: Manyas vs. Iznik

Environmental Management, 2020

The objectives of this study are to monitor the physicochemical properties of two freshwater lake... more The objectives of this study are to monitor the physicochemical properties of two freshwater lakes with different chemical characteristics and trophic status over a year (2019) and assess the bacterial diversity by a high-throughput sequencing method for a certain time. Carlson Trophic Index analysis revealed that, whereas the deep lake, Iznik Lake, (TSI mean = 48.9) has mesotrophic characteristics, the shallow lake Manyas Lake (TSI mean = 74.2) was found at a hypertrophic status. The most important parameters controlling water qualities in the lakes were temperature, alkalinity, and phosphate levels. Although the bacterial communities were dominated by the same phyla (Cyanobacteria, Bacteroidetes, Actinomicrobia, Proteobacteria, and Verrucomicrobia) in both lakes, the communities differed distinctly at the lower levels. Whereas Sporichthyaceae in Manyas Lake accounted for 10% of the total reads, the major share of the sequences was assigned to Cyanobacteria Family I (8%) in Iznik Lake. The hypertrophic Manyas Lake had a more diverse bacterial community rather than Iznik Lake and contained higher numbers of unique Operational Taxonomic Units.

Research paper thumbnail of Zooplankton Biodiversity in Reservoirs of Different Geographical Regions of Turkey: Composition and Distribution Related with Some Environmental Conditions

Aquatic Sciences and Engineering, 2019

The zooplankton fauna and the relationship with their environmental variables were investigated o... more The zooplankton fauna and the relationship with their environmental variables were investigated on the epilimnion layer of the seven reservoirs (Demirdöven, Devegeçidi, Menzelet, Sır, Ömerli, Porsuk, Tahtalı) of different regions (Marmara, Aegean, Mediterranean, Central Anatolia, Eastern Anatolia, Southeastern Anatolia) throughout the summer months (2015) in Turkey. According to the trophic conditions reservoirs varied between oligo-and eutrophic status. Chlorophylla concentration, measured for the estimation of primary production, was determined considerably high along the investigation period. A total of 62 zooplankton species were identified with the contribution of 44 rotifers, nine cladocerans and nine copepods. Except one reservoir, all of the others were dominated by rotifera group, and also in each study site dominant taxa were changed at species level. On the other hand common dominant taxa for all reservoirs was the rotifer Polyarthra vulgaris Carlin, 1943 with 95 % frequency. In terms of zooplankton species, most of the studied reservoirs showed less than 50% similarities, due to their different limnological conditions and different geographic locations. Reservoirs in high trophic conditions in the present study were represented by low species diversity. Water quality in the reservoirs with respect to biological data were determined as ß-mesosaprobic. The using limnological and biological indices to determine water quality were consistent. Densities of main zooplankton groups, and also frequent species of the reservoirs correlated with epilimnion layer depths and total phoshorus concentrations significantly. On the other hand rotifera variation was affected mainly by physical variables (pH, temperature, dissolved oxygen concentration, conductivity), and crustacean variations were related with total phoshorus. The comperative assessment between limnological variables and zooplankton community in this reservoirs was studied for the first time.

Research paper thumbnail of Bacterial Community Composition of Sapanca Lake During a Cyanobacterial Bloom

Aquatic Sciences and Engineering, 2020

Microbial community compositions and functions of freshwater ecosystems vary due to the environme... more Microbial community compositions and functions of freshwater ecosystems vary due to the environmental parameters and water chemistry. Transient bloom events play a crucial role on the community profiles. In this study, a specific focus was set to provide a snapshot of the bacterial community composition in Lake Sapanca, associated with cyanobacterial bloom by high throughput sequencing method. For this purpose, a sample was collected in the shore of Lake Sapanca during a cyanobacterial bloom, and the bacterial community profile was examined by 16S rRNA amplicon sequencing using the Illumina MiSeq platform. Cyanobacteria represented 94% of the all reads. The bacterial community was recalculated to evaluate the bacterial diversity in detail by filtering cyanobacterial sequences. The community was dominated by Proteobacteria (44%) and Bacteroidetes (33%) species which are abundant in freshwater ecosystems having an ability to degrade complex organics. Among the classified genera, Flavobacterium and Rheinheimera dominated the bacterial community suggesting a strong link between those species and the cyanobacterial bloom. The experimental work presented here provides one of the first investigations of total bacterial communities in Lake Sapanca by the high throughput sequencing method. Further work is needed with more sampling points and time series to fully understand the bacterial diversity and dynamics.

Research paper thumbnail of Composition and Distribution of Benthic Diatoms in Different Habitats of Burdur River Basin

Turkish Journal of Water Science and Management, 2020

Diatoms constitute an essential component for biomonitoring studies to determine the ecological q... more Diatoms constitute an essential component for biomonitoring studies to determine the ecological quality of waterbodies. In this study, benthic diatoms of Burdur River Basin were investigated as a consequence of a project on river basin management plan. This is the first detailed taxonomical study of diatoms taken from 13 streams, 4 lakes and 6 reservoirs of Burdur River Basin and a total of 223 taxa have been observed. Among genera, Navicula Bory (27) and Nitzschia Hassal (27) were represented with the highest numbers of taxa and followed by Gomphonema Agardh with a total of 22 species. Navicula antonii Lange-Bertalot and Nitzschia palea var. debilis (Kützing) Grunow had the highest relative abundance with 17.1% and 15.5% respectively. As a closed basin, salinity varied greatly from fresh to saline water between the sampling stations and diatom composition contained species with a different tolerance level. Navicula antonii and Nitzschia frustulum (Kützing) Grunow observed in all habitats indicating their euryhaline characters; however Navicula digitoconvergens was only detected in saline Acıgöl lake with a high relative abundance (38%) in autumn. Other two dominant species were Halamphora coffeiformis (Kützing) Levkov and Navicula cincta (Ehrenberg) Ralfs in Acıgöl lake showing their tolerance to high salt content as a brackish species. According to first results, 11 species were new records for Turkish diatom flora. The high biodiversity of diatoms revealed the presence of different habitat characteristics within the basin. These results are an important contribution of Turkish diatom flora and could be useful for monitoring specific areas like Burdur River Basin.

Research paper thumbnail of A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Scientific data, Jan 23, 2018

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ... more 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 3...

Research paper thumbnail of Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Toxins, Apr 13, 2018

Insight into how environmental change determines the production and distribution of cyanobacteria... more 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 sta...

Research paper thumbnail of Molecular detection of hepatotoxic cyanobacteria in inland water bodies of the Marmara Region, Turkey

Advances in Oceanography and Limnology, 2017

Blooms of cyanobacteria are an increasingly frequent phenomenon in freshwater ecosystems worldwid... more Blooms of cyanobacteria are an increasingly frequent phenomenon in freshwater ecosystems worldwide as a result of eutrophication. Many species can produce hepatotoxins that cause severe health hazards to humans. The aim of this study was to identify the bloom forming cyanobacteria species by molecular methods and to amplify genes responsible for hepatotoxin biosynthesis from the environmental samples and isolated strains of cyanobacteria from Küçükçekmece Lagoon, Sapanca, İznik, Manyas and Taşkısı Lakes. A total of 10 bloom samples and 11 isolated strains were examined and Microcystis spp., Planktothrix spp., Nodularia spumigena, Anabaenopsis elenkinii, Sphaerospermopsis aphanizomenoides, Cylindrospermopsis raciborskii were identified. Hepatotoxin genes were detected in 60% of the bloom samples and 45% of the strains. Two Microcystis strains were obtained from Küçükçekmece Lagoon. While the strain assigned to Microcystis flosaquae was non-toxic, Microcystis aeruginosa strain produced microcystin. According to PCR results, the M. aeruginosa and Planktothrix agardhii bloom samples of Küçükçekmece Lagoon contained the microcystin synthetase gene E (mcyE) indicative of microcystin production, however, no microcystin was detected by HPLC. The mcyE gene was also found in Microcystis wesenbergii isolated from Taşkısı Lake, and in all Planktothrix rubescens bloom samples from Sapanca Lake. To our knowledge, this is the first detailed study for identifiying different toxic cyanobacteria species and their hepatotoxin production from several waterbodies in Turkey using molecular methods.

Research paper thumbnail of A New Rotifer Species for Turkish Inland Waters

Journal of Limnology and Freshwater Fisheries Research, 2015

The zooplankton fauna of Lake Sapanca (Turkey) was studied during January 2009-May 2010 of monthl... more The zooplankton fauna of Lake Sapanca (Turkey) was studied during January 2009-May 2010 of monthly intervals. One Rotifera species, Ploesoma truncatum (Levander, 1894) is a new record for the Turkish inland waters fauna.

Research paper thumbnail of Seasonal Variations of Water Quality Parameters and Algal Flora of Tundzha (Tunca) River (Edirne, Turkey)

Open Journal of Ecology, 2014

In this study which was performed in order to determine the seasonal variations of water quality ... more In this study which was performed in order to determine the seasonal variations of water quality parameters and algal flora of Tundzha River, samplings were made monthly from 5 different stations along the river. A total of 138 taxa from Chlorophyceae (65 taxa), Bacillariophyceae (46 taxa), Euglenophyta (13 taxa) and Cyanophyta and Charophyta (7 taxa) were found to represent the algal flora of the river. Diatoms were recorded to be the dominant group throughout the year in terms of biovolume. Station I was the richest station during the whole study in terms of species diversity and composition. The maximum abundance of phytoplanktonic community within this station was 3,459,313 cells•L −1 , and Station IV was found to be richest station in terms of biovolume, with 2028.8 µg•L −1. The water quality of the river was found to be close to the 2nd and 3rd quality levels. 2nd and 3rd, and 1st and 3rd stations were found to be most similar to each other in terms of floristic compositions biovolume, respectively.

Research paper thumbnail of Planktothrix rubescens: a perennial presence and toxicity in Lake Sapanca

TURKISH JOURNAL OF BOTANY, 2014

Introduction Climate variability is expected to have a significant impact on inland waters, inclu... more Introduction Climate variability is expected to have a significant impact on inland waters, including lakes. It is widely accepted that water temperature is a key parameter in most biological systems, directly influencing water chemistry, biochemical reactions, and aquatic biota. Increasing water temperatures can change the hydrodynamics and expand the thermal stratification period of lakes (Komatsua et al., 2007). On the other hand, climatic effects on phytoplankton are also of considerable importance, since the composition and quantity of phytoplankton are important parameters of water quality (Shams et al., 2012) and a good indicator of the ecological status of water bodies (Demir et al., 2014). Regional impacts of climate warming on water ecosystems represent a new and growing threat (Liboriussen et al., 2005). Climate change has been considered a potential tool for the further expansion of harmful cyanobacterial blooms, particularly in eutrophic waters with rising temperatures, enhanced stratification, increased residence time, and high nutrient loading all favoring cyanobacterial dominance (

Research paper thumbnail of First Report of Cylindrospermopsin Production by Two Cyanobacteria (Dolichospermum mendotae and Chrysosporum ovalisporum) in Lake Iznik, Turkey

Toxins, 2014

Cylindrospermopsin (CYN) is a cytotoxic alkaloid produced by cyanobacteria. The distribution of t... more Cylindrospermopsin (CYN) is a cytotoxic alkaloid produced by cyanobacteria. The distribution of this toxin is expanding around the world and the number of cyanobacteria species producing this toxin is also increasing. CYN was detected for the first time in Turkey during the summer months of 2013. The responsible species were identified as Dolichospermum (Anabaena) mendotae and Chrysosporum (Aphanizomenon) ovalisporum. The D. mendotae increased in May, however, C. ovalisporum formed a prolonged bloom in August. CYN concentrations were measured by LC-MS/MS and ranged from 0.12 µg• mg −1 to 4.92 µg• mg −1 as dry weight, respectively. Both species were the only cyanobacteria actively growing and CYN production was attributed solely to these species. Despite CYN production by C. ovalisporum being a well-known phenomenon, to our knowledge, this is the first report of CYN found in D. mendotae bloom.