Freshwater Water Research Articles

Improvement of In Vivo Fluorescence Tools for Fast Monitoring of Freshwater Phytoplankton and Potentially Harmful Cyanobacteria.

The use of multi-wavelength spectrofluorometers for the fast detection of algal taxa, based on chlorophyll a (Chl-a) emission spectra, has become a common practice in freshwater water management, although concerns about their accuracy have been raised. Here, inter-laboratory comparisons using monoalgal cultures have been performed to assess the reliability of different spectrofluorometer models, alongside Chl-a extraction methods. Higher Chl-a concentrations were obtained when using the spectrofluorometers than extraction methods, likely due to the poor extraction efficiencies of solvents, highlighting that traditional extraction methods could underestimate algal or cyanobacterial biomass. Spectrofluorometers correctly assigned species to the respective taxonomic group, with low and constant percent attribution errors (Chlorophyta and Euglenophyceae 6-8%, Cyanobacteria 0-3%, and Bacillariophyta 10-16%), suggesting that functioning limitations can be overcome by spectrofluorometer re-calibration with fresh cultures. The monitoring of a natural phytoplankton assemblage dominated by Chlorophyta and Cyanobacteria gave consistent results among spectrofluorometers and with microscopic observations, especially when cell biovolume rather than cell density was considered. In conclusion, multi-wavelength spectrofluorometers were confirmed as valid tools for freshwater monitoring, whereas a major focus on intercalibration procedures is encouraged to improve their reliability and broaden their use as fast monitoring tools to prevent environmental and public health issues related to the presence of harmful cyanobacteria.

Genome-wide identification of fatty acid synthesis genes, fatty acid profiles, and life parameters in two freshwater water flea Daphnia magna strains.

The freshwater water flea Daphnia magna is a planktonic animal belonging to the Cladocera. To evaluate differences between two D. magna strains (KIT and NIES) in terms of life parameters and fatty acid profiles, we examined several endpoints. In the D. magna KIT strain, the numbers of total and cumulative offspring were lower at 23 °C and higher at 14 °C than in the D. magna NIES strain. However, at 14 °C, the D. magna KIT strain showed an increased lifespan. Although the n-3/n-6 polyunsaturated fatty acids (PUFA) ratio was always decreased at a low temperature, the PUFA ratio in the KIT strain had a higher value on day 3 than the NIES strain, which gave it higher adaptability to low temperature. In addition, we identified the elongation of very long chain fatty acids (elovl) and fatty acid desaturase (fad) genes, which are involved in fatty acid biosynthesis pathways, in the genomes of both D. magna KIT and NIES. The Elovl and Fad genes in both D. magna strains were highly conserved, including tandem duplicated Elovl 1/7 genes. This study provides new information about the molecular basis for the difference in temperature sensitivity between two strains of D. magna.

Episodic volcanic eruption and arid climate during the Triassic-Jurassic transition in the Qiangtang Basin, eastern Tethys: A possible linkage with the end-Triassic biotic crises

During the Triassic-Jurassic (Tr-J) transition, a negative basin inversion, massive volcanic eruption and biological crises occurred in the Qiangtang Basin (eastern Tethys), while the volcanic eruption phases and the paleoenvironment characteristics during this transition were paid little attention. Here we present petrology, whole-rock geochemistry and zircon U-Pb isotopes data from the continuous Triassic-Jurassic sedimentary strata in the northern Qiangtang Basin, in order to reveal the volcanic eruption episodes, paleoenvironment characteristics during this transition, and to discuss the possible linkage with the biological extinction event. Our results show that the Late Triassic volcanic event displays episodic eruption process and contains about four phases. Zircon U-Pb ages of four tuff samples from the Quemo Co south section are, from bottom to top, 220.4 ± 1.1 Ma, 210.9 ± 0.9 Ma, 208.3 ± 0.8 Ma, and 202.9 ± 1.1 Ma, respectively. Statistical analysis of the zircon ages of the Late Triassic suggests that the age of the Late Triassic magmatic event ranges from 227 Ma to 201 Ma and shows about five age peaks. The Tr-J boundary is suggested to be located between the E’erlongba and Quemo Co formations in the eastern Qiangtang Basin. Geochemical indicators such as CIAcorr, C-value, Sr/Cu, and Rb/K ratios indicate that a moderate to high chemical weathering condition, semi-arid to semi-humid climate and normal marine water condition before the Tr-J transition, and suddenly changed to be low chemical weathering, arid to extreme arid climate, and freshwater water environment during the Tr-J transition, and then rebounded to be moderate to high chemical weathering and semi-humid to humid climate after the Tr-J transition. These evidences suggest that the basin inversion, significant paleoenvironment shift and regional regression occurred nearly coincidentally during the Tr-J transition. The extreme arid climate (probably cool) and ocean acidification may play an important role in the end-Triassic mass extinction in the eastern Tethys.

On the role of the architecture for spring discharge prediction with deep learning approaches

AbstractUnderstanding karst spring flow is important to accommodate the increasing water demand caused by the population growth and manage the freshwater water resource effectively. However, due to the spatial and temporal heterogeneity and complex hydrological processes in karst systems, predicting karst spring discharge remains challenging. In this study, three deep learning‐based models, including long short‐term memory (LSTM), gated recurrent unit (GRU) and simple recurrent neural network (RNN), are framed with an encoder–decoder architecture to provide multiple‐step‐ahead spring discharge prediction. The encoder–decoder architecture includes an encoder that reads and encodes the input sequence into a vector and decoder that deciphers the vector and outputs the predicted sequence. Three hybrid models called LSTM‐ED, GRU‐ED and simple RNN‐ED are compared with single‐step models and multiple‐step models without the encoder–decoder architecture to investigate the role of the encoder–decoder architecture on multi‐step‐ahead prediction. The sensitivity of the selection of input time and lead time steps on the karst spring discharge prediction is evaluated. The predicted results are compared with the observed spring discharge. It implies that: (1) LSTM‐ED, GRU‐ED and RNN‐ED models obtain similar results on predicting karst spring discharge multiple time steps ahead; (2) three hybrid multiple‐step models outperform the single‐step models in making consistent and accurate spring discharge predictions; (3) the multiple‐step models framed with an encoder–decoder architecture obtain better spring discharge prediction results than the single‐step models and multiple‐step models without the encoder–decoder structure; (4) the LSTM‐ED, GRU‐ED and simple RNN‐ED models are sensitive to the selection of lead time and insensitive to the selection of input time step. A short lead time typically yields a more accurate spring discharge prediction.

A miniaturized electrothermal array for rapid analysis of temperature preference behaviors in ecology and ecotoxicology

Due to technical limitations, there have been minimal studies performed on thermal preferences and thermotactic behaviors of aquatic ectotherm species commonly used in ecotoxicity testing. In this work, we demonstrate an innovative, purpose-built and miniaturized electrothermal array for rapid thermal preference behavioral tests. We applied the novel platform to define thermal preferences in multiple invertebrate and vertebrate species. Specifically, Dugesia notogaea (freshwater planarians), Chironomus tepperi (nonbiting midge larvae), Ostracoda (seed shrimp), Artemia franciscana (brine shrimp), Daphnia carinata (water flea), Austrochiltonia subtenuis (freshwater amphipod), Physa acuta (freshwater snail), Potamopyrgus antipodarum (New Zealand mud snail) and larval stage of Danio rerio (zebrafish) were tested. The Australian freshwater water fleas, amphipods, snail Physa acuta as well as zebrafish exhibited the most consistent preference to cool zones and clear avoidance of zones >27 °C out of nine species tested. Our results indicate the larval stage of zebrafish as the most responsive species highly suitable for prospective development of multidimensional behavioral test batteries. We also showcase preliminary data that environmentally relevant concentrations of pharmaceutical pollutants such as non-steroidal anti-inflammatory drug (NSAID) ibuprofen (9800 ng/L) and insecticide imidacloprid (4600 ng/L) but not anti-depressant venlafaxine (2200 ng/L) and (iv) anticonvulsant medications gabapentin (400 ng/L) can perturb thermal preference behavior of larval zebrafish. Collectively our results demonstrate the utility of simple and inexpensive thermoelectric technology in rapid exploration of thermal preference in diverse species of aquatic animals. We postulate that more broadly such technologies can also have added value in ecotoxicity testing of emerging contaminants.

Emerging biological archives can reveal ecological and climatic change in Antarctica.

Anthropogenic climate change is causing observable changes in Antarctica and the Southern Ocean including increased air and ocean temperatures, glacial melt leading to sea-level rise and a reduction in salinity, and changes to freshwater water availability on land. These changes impact local Antarctic ecosystems and the Earth's climate system. The Antarctic has experienced significant past environmental change, including cycles of glaciation over the Quaternary Period (the past ~2.6 million years). Understanding Antarctica's paleoecosystems, and the corresponding paleoenvironments and climates that have shaped them, provides insight into present day ecosystem change, and importantly, helps constrain model projections of future change. Biological archives such as extant moss beds and peat profiles, biological proxies in lake and marine sediments, vertebrate animal colonies, and extant terrestrial and benthic marine invertebrates, complement other Antarctic paleoclimate archives by recording the nature and rate of past ecological change, the paleoenvironmental drivers of that change, and constrain current ecosystem and climate models. These archives provide invaluable information about terrestrial ice-free areas, a key location for Antarctic biodiversity, and the continental margin which is important for understanding ice sheet dynamics. Recent significant advances in analytical techniques (e.g., genomics, biogeochemical analyses) have led to new applications and greater power in elucidating the environmental records contained within biological archives. Paleoecological and paleoclimate discoveries derived from biological archives, and integration with existing data from other paleoclimate data sources, will significantly expand our understanding of past, present, and future ecological change, alongside climate change, in a unique, globally significant region.

INVESTMENT DOMINANTS OF THE IMPLEMENTATION OF THE INNOVATIVE MODEL OF SUSTAINABLE USE OF FRESHWATER RESOURCES AT THE NATIONAL AND REGIONAL LEVELS

Of course, in addition to an effective system of control and administration of water resources, essential factors in the implementation of an innovative model of sustainable use of freshwater resources in the regions are the introduction of new technologies aimed at cleaning freshwater water bodies and promoting the rational use of water resources. The activation of such works requires sufficient funding and the attraction of additional investments in the industry. The article aims to research investment dominants in implementing an innovative model of sustainable use of freshwater resources at the national and regional levels. An analysis of investment support for developing the freshwater resource management system in Ukraine was carried out. The analysis showed that over the past ten years, the number of investments increased by 115%, which positively affected the state of water bodies and contributed to the reduction of water consumption in the economy. However, given the high level of wear and tear of the water management infrastructure, which according to the State Statistics Service, is an average of 63% of the available investments, it is not enough for the transition of water management to an innovative model of sustainable development. In addition, the conducted studies showed that more than 98% of investments are directed primarily to eliminating current problems in water management, reorganizing the industry, and partial modernization of water treatment facilities and centralized water supply systems. Almost no funds are invested in developing innovative activities in this area. The main areas of improvement of the system of investment support for innovative development of water management systems in the region are outlined, including improvement of regulatory and legal support and development of public-private partnership, in particular in the form of ESCO contracts; the use of freshwater resources for aquaculture production, which will increase the economic efficiency of the use of surface water bodies, will contribute to the attraction of investments in the industry and strengthening of food security; creation of conditions for attracting foreign investments, in particular in the construction and modernization of infrastructure; intensification of work in the direction of attracting international finances: grants, participation in international programs for the protection and restoration of water resources, etc.

INFLUENCE OF BENTHIC FAUNA ON HYDROCHEMISTRY ANDSEDIMENT IN SASTHAMKOTTA LAKE IN SOUTHERN KERALA, INDIA

Sasthamkotta Lake is the largest freshwater water body of Kerala with great ecological significance, playing also pivotal role in the supply of water for drinking, agriculture, fishery exploitation, industrial activities, frivolous navigation and water tourism. Due to their importance, the environmental conditions in the Sasthamkotta lake have engrossed an better public attention in present society. The concentrations of various physico-chemical parameters of water and sediment are not exceeding environmental standards. Benthic samples revealed 8 species belonging to Order Diptera, Order Trichoptera and Order Tubificida. The results obtained from the study showed good ecological condition despite numerous local and regional natural and anthropogenic interventions.

First complete mitochondrial genome from family Moinidae, Moina macrocopa (Straus, 1820) (Cladocera; Moinidae)

We sequenced and annotated the complete mitochondrial genome for the freshwater water flea Moina macrocopa (Straus, 1820). This is the first mitogenome for the family Moinidae. The complete mitogenome of M. macrocopa is 16,072 bp, with 35.8% A, 17.6% C, 12.8% G, and 33.8% T. The mitogenome comprises 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a non-coding region. Phylogenomic analysis based on 28 in-group taxa belonging to the orders Anostraca, Diplostraca, and Notostraca is congruent with published phylogenetic relationship for cladocerans, with M. macrocopa being grouped with members of the Daphniidae. This mitogenome resource will be useful for future phylogenetic studies of water fleas.

Interaction Between Brackish Water Intermittent Infiltration and Cultivated Soil Environment: A Case Study From Arid Piedmont Plain of Northwest China

Brackish groundwater was widely used in arid areas which may cause soil salinization and groundwater environmental declines. To ensure the sustainable development of agriculture in arid areas, brackish water intermittent infiltration experiments were conducted in Southern Xinjiang, Northwest China between June to September 2018, and Hydrus-2D numerical simulation was used to analyze the underground pipe drainage systems. The field experiments were carried out during cotton growth stages after the first freshwater flood infiltration and salt washing. Two control experiments were, respectively, designed as freshwater (0.68 g/L) and brackish water (1.66 g/L) with water amount of 1.0 Q = 572 mm. Other eight groups (1.05–1.40 Q) were compared to analyze the effect of soil salt leaching by increasing the brackish water amount. The results showed that the soil moisture content was almost less than the field capacity of 0.203 at depth of 0–60 cm before each infiltration due to roots water uptake, and the soil water holding capacity rate was lower than 0.2 after 5 days under 1.20–1.40 Q brackish water treatments. Variation of EC1:5 at depth of 0–30 cm was less than 0.5 dS/m. Salt mainly accumulated at the depth of 40–60 cm whether the water amount was excessive or insufficient even under the fresh water infiltration. The optimal brackish water amount was 1.15 Q = 657.8 mm, and the soil total salinity was less than 0.55 dS/m (EC1:5) and reached mild salinization degree. Numerical simulations were used based on the 2018 field experimental results and extended by another 10 years. The soil salt accumulated to 1.10–2.99 dS/m (EC1:5) at the depth of 40–60 cm during 0–30 days. The no salinization area expanded to depth of 40–45 cm after 120 days and reduced during non-infiltration period due to evaporation effect. The soil salt was gradually leached and less than 0.55 dS/m (EC1:5) after 10 years. The optimized leaching–drainage system could not only provide a low salinity soil condition for cotton growth and realize sustainable cultivation but also greatly protect the soil and groundwater environment.

Coral-like hierarchically nanostructured membrane with high free volume for salt-free solar-enabled water purification

Solar evaporation presents a sustainable means to alleviate global water shortages. Varying photothermal materials have been designed to enhance evaporation performance. However, the critical technology gap is their low efficiency due to the severe salt crystallization and organic pollution. Here, we proposed a coral-like polypyrrole (PPy)-based photothermal membrane by the interface modification of d-glucitol (DG) and tetrakis (hydroxymethyl)phosphonium chloride (THPC). The designed PPy@DG/THPC membrane exhibited a wide range of sunlight absorption capacity with an efficiency of ∼97.6% due to its hierarchical nanostructure. Moreover, this membrane displayed superhydrophilicity and rich charges, giving it a superior salt-resistance property. Furthermore, molecular dynamics simulations indicated that this membrane exhibited a high free volume to inhibit salt crystallization. Hence, the evaporation rate of the PPy@DG/THPC membrane reached 1.46 ± 0.02 kg/m2/h in simulated brine (3.5 wt% NaCl) under 1-sun illumination. Besides, it exhibited exceptional anti-fouling ability under the synergy of hydration and charge effects. Overall, this membrane can achieve effective and sustainable solar evaporation to produce freshwater water to meet drinking-water standards. This work will offer a new approach to developing efficient solar evaporation for water remediation.

Climate Change and Human Impact on Freshwater Water Resources: Rivers and Lakes

In this Special Issue, we have included articles focusing on disturbances of hydro-ecological conditions and availability of water resources stored in rivers and lakes due to climate change and human activity [...]

Performances of Boro Rice as Affected by Different Concentrations of Marine Water

Salinity is one of the most devastating abiotic stresses limiting crop production. Considering this issue, a pot experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the boro season (2017-2018) using two rice(Oryza sativa L.) varieties, namely BRRI dhan28 (salt sensitive) and BRRI dhan47 (salt tolerant),to assess the effects of varied salinity levels on the growth and the performance of the rice varieties under salt stress conditions. Four salinity treatments were used in this experiment, viz. control S0 (only freshwater), quarter-strength marine water S1 (three-parts freshwater and one-part marine water; 7.5 ds m−1), half-strength marine water S2 (half freshwater and half marine water; 15 ds m−1), and full-strength marine water S3 (only marine water; 30 ds m−1).These mixtures were used for irrigation purposes throughout the life cycle of the plants. Salt stress significantly decreased the plant height, relative water content (RWC) of leaves, number of effective tillers hill−1, number of filled grains panicle−1, 1000-grain weight, grain yield, straw yield, and biological yield of the rice. In both rice types, plant growth and yield were reduced as the salinity level increased. Grain yields decreased by 50, 90, and 100% in BRRI dhan28 when irrigated with quarter strength, half strength, and full-strength seawater, respectively, but decreased by 27, 50, and 72%, respectively, in BRRI dhan47. Similarly, other yield attributes had higher reductions in BRRI dhan28 under salt stress conditions than BRRI dhan47. However, irrigation with marine water in rice might lead to some straw yield but produced little to no grain.

Fire Test Performance of Eleven PFAS-Free Class B Firefighting Foams Varying Fuels, Admixture, Water Types and Foam Generation Techniques

The firefighting performance of eleven PFAS-free firefighting foams was evaluated using different fuels (Jet A1, commercial heptane and diesel) and types of water (freshwater and synthetic sea water). Moreover, different firefighting foam generation techniques and application methods were evaluated. The firefighting foams were generated as aspirated foams or as compressed air foams (CAFs). The results for CAF showed a higher performance, with respect to extinction time and burn-back resistance, compared to the foam generated using a UNI 86 nozzle. The CAF was not optimised, indicating a further potential of this foam generation technique. The results indicate that the time to fire knockdown decreases with decreasing foam viscosity. The heat flux was shown to be small, although the entire fuel surface was involved in the fire. The tests showed a dependence on fuel type; different products performed differently depending on the fuel. Tests using sea water showed that addition of salt to the foam solution generally prolonged the extinction time, although for one of the firefighting foams a shorter extinction time was observed. Out of the eleven evaluated PFAS-free products there was no product that outperformed the rest. None of the products in the study met the fire test performance requirements in all the referenced standards. Instead, the products seem to have different niches where they perform best e.g., with different types of fuel or water.

Rapidly Deployable Algae Cleaning System for Applications in Freshwater Reservoirs and Water Bodies

Occurrence of large-scale harmful algal blooms (HABs) in our reservoirs and water bodies threaten both quality of our drinking water and economy of aquaculture immensely. Hence, rapid removal of HAB biomass during and after a bloom is crucial in protecting the quality of our drinking water and preserve our water resources. We reported here a rapidly deployable algae cleaning system based on a high-capacity high-throughput (HCHT) spiral blade continuous centrifuge connected with inlet and effluent water tanks and a series of feed-in and feed-out pumps as well as piping, all fitted into a standard 20 feet metal shipping container. The system separates algal biomass from algae-laden water with a maximum flow rate of 4000 L/h and a centrifugal force of 4500× g. Cells collected by the system are still intact due to the low centrifugal force used. We showed that after HCHT centrifugation, cellular contents of HAB biomass were not found in the effluent water, and hence, could be discharged directly back to the water body. Furthermore, the addition of flocculants and chemicals prior to the separation process is not required. The system could operate continuously with proper programmed procedures. Taken overall, this system offered a much better alternative than the traditional flocculation- and sonication-based methods of HAB removal in a freshwater environment. This deployable system is the first of its kind being built and had been field-tested successfully.

Diversity of freshwater fish and water quality parameters associated threats of commercially important freshwater species caught by bottom trawl and mid-water trawl from the various habitat

Diversity of freshwater fish and water quality parameters associated threats of commercially important freshwater species caught by bottom trawl and mid-water trawl from the various habitat

Theoretical and experimental investigation on a novel design of wick type solar still for sustainable freshwater production

Water scarcity is among the major crucial issues confronting humanity, caused by the world’s growth in population, the socio-economic development and the global climate change. Several desalination technologies are available to tackle the increased freshwater water demand. Therefore, the solar energy-driven distillation is among the most conceivable alternatives for supplying safe water with reducing the energy cost. The conventional solar distiller is a sustainable and economical process. However, the overall productivity is generally low. In this study, conceptual improvements on the design and distillation process of a wick type solar still are presented for the purpose of overcoming the low efficiency of the classic system. The novelty of this study is presented in combining three ideas to improve the still efficiency through creating an alternative mode of condensation based on forced convection, achieving a substantial gain in the specific weight and automating the distillation process. Hence, reducing the heat losses and enhancing the still productivity are achieved while maintaining the simplicity of the distiller and without calling for any complicated or cost-intensive technology. Furthermore, this investigation offers an innovative analytical process based on mathematical modelling tools as well as, an experimental approach. The results inferred that the advanced system produces significantly high distillate outputs of about 4.03 L.m−2.d-1 for an average of 380 W.m−2 of mean solar radiation. Thereafter, the numerical results were experimentally validated, and it was proven that the efficiency of the advanced solar still was enhanced by 32% in comparison to the conventional solar still. The physic-chemical and bacterial analysis of the produced water revealed that the improved solar still can supply good quality of drinking.

The freshwater water flea Daphnia magna NIES strain genome as a resource for CRISPR/Cas9 gene targeting: The glutathione S-transferase omega 2 gene.

The water flea Daphnia magna is a small freshwater planktonic animal in the Cladocera. In this study, we assembled the genome of the D. magna NIES strain, which is widely used for gene targeting but has no reported genome. We used the long-read sequenced data of the Oxford nanopore sequencing tool for assembly. Using 3,231 genetic markers, the draft genome of the D. magna NIES strain was built into ten linkage groups (LGs) with 483 unanchored contigs, comprising a genome size of 173.47 Mb. The N50 value of the genome was 12.54 Mb and the benchmarking universal single-copy ortholog value was 98.8%. Repeat elements in the D. magna NIES genome were 40.8%, which was larger than other Daphnia spp. In the D. magna NIES genome, 15,684 genes were functionally annotated. To assess the genome of the D. magna NIES strain for CRISPR/Cas9 gene targeting, we selected glutathione S-transferase omega 2 (GST-O2), which is an important gene for the biotransformation of arsenic in aquatic organisms, and targeted it with an efficient make-up (25.0%) of mutant lines. In addition, we measured reactive oxygen species and antioxidant enzymatic activity between wild type and a mutant of the GST-O2 targeted D. magna NIES strain in response to arsenic. In this study, we present the genome of the D. magna NIES strain using GST-O2 as an example of gene targeting, which will contribute to the construction of deletion mutants by CRISPR/Cas9 technology.

Geochemical characteristics and paleodepositional setting of coal-bearing strata in Konya-Karapınar Basin, Central Anatolia, Turkey

The Neogene coals of the Hotamış Formation in the Konya-Karapınar basin were examined, and the organic matter type, thermal maturity, paleodepositional environment, and Rock-Eval pyrolysis characteristic of coal samples obtained from boreholes. The total organic carbon (TOC) values of coal vary between 15.2 wt% and 47.0 wt% and the yield of extractable organic matter (EOM) values varies between 0.5% and 1.0% indicating a limited hydrocarbon production potential. Bitumen index (BI) and Quality index (QI) values were calculated for coal samples and vary from 1 to 13 mg HC/g TOC and from 75 to 260 mg HC/g TOC, respectively. Due to BI and QI values, coal samples have limited gas generation potential. The type of organic matter was determined as Type III kerogen according to Rock-Eval data. The coal samples have Tmax values between 414 and 443 °C, and huminite reflectance values with 0.20%–0.41% Ro indicating that they are in the immature-early mature stage. This is supported by biomarker maturity parameters 20S/(20S + 20R) (C29) sterane (0–0.59), ββ/(αα + ββ) (C29) sterane (0–0.58), MPI-1 (0.18, 0.31) and MPI-1* (0.21, 0.37). The relative abundance of C27–C28–C29 normal steranes and aromatic steroids and the abundance of partially low carbon number tricyclic terpanes of the Konya-Karapınar coals showed that the organic matter consisted of terrestrial higher plants with a small contribution of algae and microorganisms. Homohopane distributions, V/(V + Ni), V/Sc ratios show that organic matter accumulated in an environment that varies between oxic-anoxic conditions and that medium-high gammacerane index, C27–C28–C29 sterane distributions, and low DBT/P ratios are compatible with the weak brackish water-fresh water depositional environment of organic matter.

Sustainable aquafeed and aquaculture production systems as impacted by challenges of global food security and climate change

Sustainable aquafeed and aquaculture production systems as impacted by challenges of global food security and climate change