 Subjects -> WATER RESOURCES (Total: 160 journals)
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- Benthic Macroinvertebrate Fauna (Clitellata and Chironomidae) of Lake
Limni, Gümüşhane, Turkiye
Authors: Deniz MERCAN
Abstract: Benthic macroinvertebrate groups, which have adapted to life in a wide variety of aquatic habitats from fresh to saltwater, are often used as bioindicators to determine the status of aquatic ecosys-tems. Streams and lakes face the dangers of pollution due to anthropogenic impact, especially due to recreational uses. So far, a total of 262 protected nature parks have been declared in Türkiye, one of which is Lake Limni, the area under study. Lake Limni is located in the province of Gümüşhane in the Eastern Black Sea Basin. No studies were previously conducted to determine the macroinvertebrate fauna in the lake. To fill this gap, sampling was carried out from 2 stations in 2020 to determine the macroinvertebrate fauna of the lake. As a result of laboratory studies, 25 species belonging to 18 genera were identified. It was determined that the zoobenthic community of the lake consisted of Clitellata and Chironomidae individuals and that the dominant taxon of the lake was Limnodrilus hoffmeisteri from Oligochaeta with 14.71% dominancy. The high population density of Oligochaeta and Chironomidae individuals in the study area and the low species diversity indicate poor water quality. It is also possible to say that the water quality of Lake Limni has changed from eutrophic to hypereutrophic.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- A Comprehensive Review on Microplastic Pollution in Aquatic Ecosystems and
Their Effects on Aquatic Biota
Authors: Duygu SAZLI; Danial NASSOUHİ, Mehmet Borga ERGÖNÜL, Sibel ATASAGUN
Abstract: Plastic wastes released into the environment break down into fine particles due to exposure to meteorological events such as wind, precipitation, UV radiation, and abrasion. These smaller plastic particles, ranging between 1 µm and 5 mm, are called microplastics and they can be transported over longer distances with the aid of erosion, waste water discharges, winds, and currents. Aquatic habitats are the final sink for many pollutants including heavy metals, pesticides, nanoparticles, and microplastics released into environment. Thus, these pollutants are considered a major threat to aquatic life. In this study, we reviewed studies i: focusing on the type, size and the quantity of microplastics observed in freshwater and marine ecosystems, and ii: studies on the effects of microplastics on aquatic organisms. The data gathered clearly indicates that microplastics are quite abundant in freshwater and marine ecosystems. Furthermore, nearly in all studies reviewed, microplastic uptake and alterations in several biochemical parameters depending on microplastic exposure are recorded. The studies also point out that microplastics will become a global serious health concern both for human beings and aquatic organisms in the near future.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- What Reference Genome Assemblies Tell Us and How to Detect the Best
Available Version: A Case Study in Trout
Authors: Münevver ORAL
Abstract: Genomic studies have largely been accelerated by the advances of next generation sequencing technologies since the beginning of the millennium. This, in turn, has motivated the generation of more reference genome assemblies not only in model organisms but also in species of scientific interest. In the present study, we employed a comparison study between the two different reference genome assemblies available for the same species, Salmo trutta, in GenBank. The results indicated an overall 90% similarity index between the two assemblies. Furthermore, the inversion regions of which assembly needs corrections were detected. Taking into account the whole genome duplication origin of the Salmonidae family, both assemblies were of good quality. However, the updated version of the Wellcome Sanger Institute assembly (fSalTru_1.2) outperformed the Norwegian assembly and was detected as the best available reference genome assembly in Salmo trutta.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- Dose Selection for Induced Breeding and Larval Development of Indigenous
Ornamental Fish Puntius chola (Hamilton, 1822)
Authors: Godhuli SİT; Arun JANA, Angsuman CHANDA, Sanjat Kumar SAHU
Abstract: Puntius chola (Hamilton, 1822) is a small freshwater indigenous fish with food and ornamental value belonging to the family Cyprinidae found in Pakistan, India, Nepal, Bangladesh, Myanmar, and Sri Lanka. Due to the selective exotic species and the culture of Indian big carp, the species have gradually diminished in India. Evaluating P. chola's optimum selection, induced breeding, embryonic, and larval development is the goal of the current study. The optimum dose was selected through the trial-and-error method applied 5 doses (0.25 ml/kg, 0.50 ml/kg, 1 ml/kg, 1.5 ml/kg, 2 ml/kg body weight) of synthetic hormone, ovatide to both sexes. The study reveals that the optimum dose of synthetic hormone ovatide @ 1.5 ml/kg body weight for females and males is effective for induced breeding of Puntius chola. At the optimum dose, fecundity, fertilization, and hatching rates were 106308±3075, 79.28±0.589%, and 78.03±0.495%, respectively. The physicochemical parameters of water have been enlisted for proper induced breeding. The outcomes of this research will enable P. chola to have a more decorative design and assist in its protection by encouraging it to reproduce and survive on its own in the wild. Additionally, the study will aid in community members' economic development.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- Catch Composition of Different Bottom Trawl Cod-ends in the Western Black
Sea
Authors: İbrahim Tamer EMECAN; Taner YILDIZ, Uğur UZER, Ahmet ÇATAL, Hamdı MOUSSA, Celalettin AYDIN, Firdes Saadet KARAKULAK
Abstract: Across the Mediterranean and the Black Sea, an improvement in technological adoption which optimizes the environmental benefits of fisheries is needed. The testing of quality standards in trawl fishing is one of the essential components. In an experiment, we tested four bottom trawl cod-ends in the western Black Sea to determine the characteristics of the catch composition. Fishing trials were conducted by 40 mm diamond (40D), 44 mm diamond (44D), 40 mm square (the 40S), and 40 mm 90-degree turned (40T) mesh cod-ends for 31 bottom trawling hauls. The multivariate analysis of catch composition indicated a significantly higher differentiation between 40D and 40T cod-ends, mainly characterized by five species: Merlangius merlangus, Mytilus galloprovincialis, Trachinus draco, Mullus barbatus, and Uranuscopus scaber. The difference in the shape of cod-end meshes reflected the variation in the catchability and catch composition. However, the 40S and 40T showed 80% similarity in catch composition. Among cod-ends, 40T yielded in lowest catch per unit effort for both commercial and other species. Adoption of gear specially made to catch more target species can help bottom trawl fisheries further improve their ecological and economic sustainability.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- Green Synthesized Nanoceria Applied as a Fenton-Like Catalyst for
Degrading Methylene Blue
Authors: Dilek ÖZYURT; Fatos Ayca OZDEMİR OLGUN, Birsen DEMİRATA, Mustafa Reşat APAK
Abstract: Nanomaterials are preferred for scientific studies due to their spectral properties and perfect surface appearance. This study aims to introduce a novel, environmentally friendly, photocatalytic method for degrading methylene blue (MB) in aqueous solutions. With this purpose in mind, the study synthesizes nanoceria particles and coats them with zahter (Thymbra spicata; zahter-coated nanoceria, ZCNC) following the main outlines of green chemistry as characterized by SEM and FTIR analyses. The study proposes this new nanoparticle (with the aid of H2 O2 and UV combinations) as an alternative to iron in Fenton-type reactions for enabling MB degradation. The maximum efficiency was observed through the ternary combination of zahter-coated nanoceria, UV light, and H2 O2 at 63% concentration. The degradation of the MB solution was achieved by installing a small amount of ZCNC (0.1g), after which the absorbance values were measured at 664 nm. According to the possible reaction kinetics discussed within the study, the reaction rate was calculated at 1.49 × 10-2 min -1, thus enabling a faster reaction for a better evaluation of the reaction mechanism compared to other degradation processes that have been previously investigated.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- Effects of Size Grading on Growth Performance, Survival Rate and
Cannibalism in Russian Sturgeon (Acipenser gueldenstaedtii) Larvae Under
Small-Scale Hatchery Conditions
Authors: Kübra AK
Abstract: Sturgeon aquaculture is important due to the value of their caviar and meat as well as its ecological importance. The current study focused on the effects of different size groups on the final mean weight, specific growth rate, survival rate and cannibalism of Russian sturgeon (Acipenser gueldenstaedtii) larvae. The groups were graded with homogeneous small-size larvae in the first group, 50% small and 50% large-size heterogeneous larvae in the second group, and homogeneous large size larvae in the third group. The highest specific growth rates in each group occurred between days 28-35. After 35 days, the specific growth rate (SGR) in all groups dramatically reduced compared to the first week. The SGR of the larvae were not significantly affected by size (p>0.05). Mortalitiy were high during the first week in all groups, but, decreased as the larvae grew larger during the fourth weeks. At the end of the study, the survival rates were 30% for the small-size, 53% het-erogeneous-size, and 64% for the large-size groups. The highest cannibalism rate in the present study occurred in heterogeneous-size group. However, the literature shows cannibalism rates to not be high for any groups of sturgeon. Size grading in the early period may negatively affect the survival rate and growth performance of larvae. Therefore, maintaining optimum larval rearing conditions such as stocking density, and feeding strategy may support higher survival and growth performance, in larvae that are newly acclimated to exogenous feeding.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
- The Effect of Improper Packaging on Moisture and Fatty Acid Composition in
Frozen Bluefin Tuna (Thynnus Thynnus)
Authors: Abdullah ÖKSÜZ; Şenay Burçin ALKAN, Elif Didem ÖRS
Abstract: This article investigates the effect of improper packaging and freezer burn on the moisture content and fatty acid profile of frozen bluefin tuna. Improper packaging caused serious freezer burn on the surface of a bluefin tuna slice during frozen storage. The moisture content of the surface affected from freezer burn and an inner part of the tuna slice was analysed. Visual examination showed that the surface of the tuna slices were dried and different from normal flesh colour. Moisture content of the frozen tuna slices dropped significantly on the surface compared to the inner part unaffected by freezer burn. Direct methylation method was successfully achieved on the sample without any lipid extraction. Separation of fatty acid methyl esters of the bluefin tuna was successfully achieved by using GC-FID 100 m column in 65 minutes. Significant changes were observed in saturated and polyunsaturated fattyacids, whereas monounsaturated fatty acids remained the same. The level of polyunsaturated fatty acids reduced by half on the surface of the flesh compared to the inner part. Among the PUFA, n3 and n6 fatty acids were greatly reduced, but more intense in n3 fatty acids.
PubDate: Tue, 24 Jan 2023 00:00:00 +030
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