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Post-Dredging Nitrogen Dynamics at the Sediment–Water Interface : the Shallow, Eutrophic Mogan Lake, Turkey

Topçu Akasya, Atlığ Seda

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 1

124--136

EN

The sedimentation and resuspension of various forms of nitrogen in wetlands determines the direction of the nitrogen dynamics. Mogan Lake, in the Gölbaşı Special Environmental Protection Area, is one of the most important Ramsar-nominated wetlands in Turkey. Lake management applications have been performed by the local managers since 2008, including sediment cleaning activities such as dredging. In this context, the aim was to quantitatively predict the nitrogen dynamics (ammonium and nitrate release/uptake in the positive and/or negative direction) at the sediment–water interface, which has not been addressed in the eutrophication and sediment-related studies conducted to date on the lake in question. Sediment ammonium and nitrate flux were estimated to be between −9.16 and 0.36 µg m−2 d−1 and between −67.2 and 35.16 µg m−2 d−1, respectively. The estimations for sediment nitrogen flux in Mogan Lake did not show a regular seasonal or spatial fluctuation. Our results demonstrate that low nitrogen release levels in Mogan Lake do not pose a threat to its nutrient level. In conclusion, both monitoring and reducing external loading is still the top priority for a long-term recovery of water quality in the process of freshwater ecosystems.

2

Biometric relation between body size and otolith size of Cyprinion kais and C. macrostomum collected from Tigris River, Şirnak Province, Türkiye

Dörtbudak Muhammed Yaşar, Jawad Laith A., Yalçin Hamza, Park Joo Myun

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 2

221-227

EN

One hundred and twenty asterisci were obtained from 30 specimens each of Cyprinion kais and Cyprinion macrostomum. Significant relationships between otolith mass and the three fish lengths (TL, SL, and FL) were attained for C. kais. Similar associations were obtained for OL and the three fish lengths of C. macrostomum. For C. kais,the highest in the relation between otolith mass, hereafter referred to as OM, and fish fork length, henceforth knownas FL (0.5894). The lowest coefficient of determination wasobserved between otolith width, hereafter called OW, and standard fish length, hereafter referred to as SL (0.2861). For C. macrostomum, the highest coefficient of determination was attained for the relation between OL and FL (0.7280) and the lowest for the relationship between OM and TL (0.1717).The analysis shows that evaluations of the body size of the two fish species investigated through biometric studies ofotoliths are trustworthy.

3

The analysis of the El Niño phenomenon in the East Nusa Tenggara Province, Indonesia

Karuniasa Mahawan, Pambudi Priyaji Agung

Journal of Water and Land Development

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2022

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no. 52

180--185

EN

Climate change causes various events, such as El Niño , and we experience their larger frequency. This study based on a quantitative approach uses observation data from the Umbu Mehang Kunda Meteorological Station and the Ocean Niño Index (ONI). As a result, East Sumba, which has an arid climate, has more challenges in dealing with drought and water deficits during El Niño. This study identifies rainfall when the El Niño phenomenon takes place in East Sumba through data contributing to the ONI value and dry day series from 1982 to 2019. The analysis was carried out by reviewing these data descriptively and supported by previous literature studies. The research found that there was a decrease in the accumulative total rainfall in El Niño years. The annual rainfall in the last six El Niño events is lower than the annual rainfall in the first six El Niño events. The dry day series is dominated by an extreme drought (>60 days) which generally occurs from July to October. This drought clearly has a major impact on livelihoods and causes difficulties in agriculture as well as access to freshwater. This results in crop failure, food shortages, and decreased income. The phenomenon triggers price inflation in the market and potential increase in poverty, hunger, and pushes the country further away from the first and second Sustainable Development Goals. This phenomenon and problems related to it need to be dealt with by multistakeholders.

4

Distribution of Didymosphenia, Gomphonema and Gomphosphenia diatoms (Bacillariophyta) in Turkish inland waters

Solak Cüneyt Nadir, Wojtal Agata Z., Rybak Mateusz, Yılmaz Elif

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 2

198--219

EN

In this study, a total of 53 taxa were identified from 13 catchments in Turkey. Gomphonema affine var. rhombicum E.Reichardt, G. angusticephalum E.Reichardt & Lange-Bertalot, G. calcifugum Lange-Bertalot & E.Reichardt, G. elegantissimum E.Reichardt & Lange-Bertalot, G. exilissimum (Grunow) Lange-Bertalot & E.Reichardt, G. graciledictum E.Reichardt, G. italicum var. densistriatum Levkov, Mitic-Kopanja & E.Reichardt, G. linearoides Levkov, G. megolobrebissonii D.A.Chudaev, Kociolek & M.A.Golobova, G. minusculum Krasske, G. minutum f. syriacum Lange-Bertalot & Reichardt, G. reediae Levkov, Mitic-Kopanja & E.Reichardt, G. sarcophagus W.Gregory, G. subcapitatum (Grunow) E.Reichardt & Levkov and Gomphosphenia holmquistii (Foged) Lange-Bertalot were recorded for the first time in Turkey. Of the identified taxa, Didymosphenia geminata (Lyngbye) M.Schmidt, Gomphonema acuminatum Ehrenberg, G. affine Kützing, G. angustatum (Kützing) Rabenhorst, G. augur Ehrenberg, G. micropus Kützing, G. minutum (C.Agardh) C.Agardh, G. olivaceum (Hornemann) Brébisson, G. parvulum (Kützing) Kützing and G. truncatum Ehrenberg are common in the waters. G. angustius E.Reichardt, G. insignaffine Reichardt, G. insigne W.Gregory, G. italicum Kützing, G. laticollum E.Reichardt, G. pumilum var. rigidum E.Reichardt & Lange-Bertalot, G. stonei E.Reichardt, G. supertergestinum E.Reichardt and G. vibrio Ehrenberg have been recently recorded from the Turkish waters. The genus Gomphosphenia in Turkey has so far been represented only by G. grovei (M.Schmidt) Lange-Bertalot.

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Biodiversity of freshwater macroinvertebrates on Gökçeada Island (North Aegean Sea, Turkey)

Odabaşı Serpil

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 4

421--429

EN

Island ecosystems have attracted the attention of scientists since the early days of science because of their formation and biodiversity. Despite their abundant freshwater resources, data on freshwater diversity of Gökçeada are incomplete, especially for macroinvertebrates. This study was conducted in a wide range of freshwater ecosystems on Gökçeada between May 2016 and September 2018. Sampling of macroinvertebrates was performed using a hand net from 34 pre-selected sampling sites on the island. A total of 78 aquatic macroinvertebrate taxa were found, 46 of which are new records for the island. The most common species during the study were Gammarus komareki and Bythinella gokceadaensis with a frequency of 25.93%, followed by Tubifex tubifex, Gammarus sp. and Caenis sp. with a frequency of 22.22%. Endemic and invasive species on the island were assessed according to their presence and frequency values. Based on the results of the current study and previous data, it can be concluded that Gökçeada is characterized by a remarkable species diversity compared to aquatic macroinvertebrates on other Aegean islands.

6

Evaluation of the Distribution of Heavy Metals and Arsenic in Inland Wetlands (Peru) Using Multivariate Statistical Methods

Custodio María, Peñaloza Richard

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 3

104--111

EN

Heavy metals in the environment circulate among the different compartments and can accumulate, convert into organic complexes and biomagnify in the food chain. The objective of this study was to evaluate the distribution of heavy metals and arsenic in inland wetlands using multivariate statistical methods. Samples of water, sediment and aquatic vegetation were collected at 48 sampling sites established in the Paca and Tragadero lagoon wetlands. The determination of heavy metals and arsenic was carried out using the flame atomic absorption spectrophotometry method. The decreasing order of heavy metal and arsenic concentration in sediment was Fe>Zn>Pb>As, in water it was Zn>Fe>Pb>As and in S. californicus it was Zn>Fe>Pb>As. Redundancy analysis (RDA) indicated that there are significant differences in heavy metal and arsenic concentrations in sediment between ponds and between sampling sites. Generalized linear model (GLM) analysis on vegetables indicated that the concentrations of heavy metals and arsenic in the vegetable increase as a function of their concentration in sediment.

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Distribution of cyclopoid copepods in different subterranean habitats (southern Poland)

Kur Jarosław, Mioduchowska Monika, Kilikowska Adrianna

Oceanological and Hydrobiological Studies

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2020

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Vol. 49, No. 3

255--266

EN

The majority of Polish studies on freshwater cyclopoids focused on surface water fauna. There are relatively few data on copepods of subterranean waters. Thus, in our research, copepods were collected from 37 different, mostly groundwater-dependent habitats (i.e. caves, springs, wells, interstitial and overhead environments) over a period of five years between 2005 and 2010. A total of 22 species belonging to eight genera were found. Some species, previously not recorded or known only from a few sites in Poland, proved to be a frequent component of subterranean communities.

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Inter- and intra-specific variability in δ13C and δ18O values of freshwater gastropod shells from Lake Lednica, western Poland

Apolinarska K., Pełechaty M.

Acta Geologica Polonica

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2017

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Vol. 67, no. 3

441--458

EN

This study focuses on the inter- and intra-specific variability in δ13C and δ18O values of shells and opercula of gastropods sampled live from the littoral zone of Lake Lednica, western Poland. The δ13C and δ18O values were measured in individual opercula of Bithynia tentaculata and in shells of Bithynia tentaculata, Gyraulus albus, Gyraulus crista, Lymnaea sp., Physa fontinalis, Radix auricularia, Theodoxus fluviatilis and Valvata cristata. The gastropods selected for the study are among the species most commonly found in European Quaternary lacustrine sediments. The carbon isotope composition of the gastropod shells was species-specific and the same order of species from the most to the least 13C-depleted was observed at all sites sampled. Differences in shell δ13C values between species were similar at all sampling sites, thus the factors influencing shell isotopic composition were interpreted as species-specific. The δ18O values of shells were similar in all the species investigated. Significant intra-specific variability in shell δ13C and δ18O values was observed not only within the populations of Lake Lednica, which can be explained by heterogeneity of δ13C DIC, δ18O water and water temperature between the sites where macrophytes with snails attached were sampled, but also between individuals sampled from restricted areas of the lake’s bottom. The latter points to the importance of factors related to the ontogeny of individual gastropods.