In this work, we assessed the impacts of aqueous methanolic extracts of laurel (Laurus nobilis) leaves (D), black mustard (Brassica nigra) seed (SH) and fenugreek (Trigonella foenum-graecum L.) seed (C) seeds on growth related parameters, immune parameters, cytokine gene expression, and bacterial infection resistance in rainbow trout (Oncorhynchus mykiss). Experimental diets containing each extract at 0.1, 1, or 5 g/kg-1 were administered to fish for 45 days, alongside a control diet. Growth, NBT activity, lysozyme, myeloperoxidase, and expression of TGF-β, IFN-1, TNF-α and IL-1β were assessed every 15 days. After feeding, fish were exposed to Yersinia ruckeri, Aeromonas salmonicida and Vibrio anguillarum. No statistically significant differences were observed in growth parameters among the groups (P > 0.05). The highest NBT activity occurred in D5 on day 15 and SH5 on day 30 (P<0.05). No alteration in lysozyme activity was observed, while myeloperoxidase exhibited higher values in SH1 on day 15 (P<0.05). Gene expression varied significantly (P<0.05). Fenugreek at 1 and 5 g/kg-1 enhanced immune responses and survival, especially against Aeromonas salmonicida and Vibrio anguillarum.
This study aimed to evaluate the therapeutic potential of banana stem powder (BSP) supplementation in the diet of Pacific white shrimp (Litopenaeus vannamei) challenge with Vibrio parahaemolyticus. Shrimp (3.15±0.10 g) were reared in glass aquaria (60×30×40 cm3; 45L) at density of 3 L-1. After acclimation, shrimp were intramuscularly injected with V. parahaemolyticus (106 CFU mL-1), while the negative control (NC) gropu received phosphate-buffered saline only. Following the challenge, shrimp were fed experimental diets supplemented with BSP for 30 days, whereas positive control (PC) and NC group received diets without BSP supplementation. BSP supplementation at a dose of 2 g kg-1 significantly improved survival rate and immune response, including total haemocyte count, phagocytosis activity, respiratory burst, and phenoloxidase, compared to the PC group (p<0.05). in addition, BSP was associated with reduced inflammation, as indicated by lower TRAF6 gene expression, decreased V. parahaemolyticus abundance in the hepatopancreas and the intestine, and improved histological condition of these tissues. These result indicate that BSP supplementation may enhance shrimp resistance to V. parahaemolyticus infection.
Mussel aquaculture is often considered environmentally sustainable due to its potential to filter particles and recycle nutrients, yet its large-scale influence on coastal water quality remains difficult to quantify, especially in complex and highly variable systems such as the Sea of Marmara. Here, an installation-based analytical framework was implemented to evaluate potential mussel farm associations with turbidity and chlorophyll dynamics using Sentinel-2 satellite observations processed in Google Earth Engine. Twenty-one mussel farms in the southern Sea of Marmara were confirmed and digitized from high-resolution Google Earth imagery (most recent imagery year: 2025), and approximate installation years were assigned using time-series imagery interpretation supported by administrative information. Control areas were defined as a 1–3 km ring buffer around each farm to improve interpretability. Turbidity (B3/B2) and the Normalized Difference Chlorophyll Index (NDCI) were derived from annual and monthly median Sentinel-2 surface reflectance composites for 2018, 2020, 2022, and 2024. Annual-scale analyses (ANOVA and linear regression) detected no statistically significant pre- vs post-installation differences (p>0.05) and no significant relationships with time since installation. However, seasonal comparisons during the spring bloom period (March–May) revealed a recurrent negative chlorophyll difference in farm areas relative to controls, although the magnitude was limited and not consistently statistically strong. Overall, results indicate that mussel-related signals in the Sea of Marmara are scale- and season-dependent: patterns that may be consistent with filtration-related processes were more apparent under high-productivity conditions but are largely masked by strong regional variability and mixing, as well as known uncertainties in coastal optical remote sensing.
This study examines the effects of physicochemical variables on phytoplankton functional groups (FGs) in seven lentic ecosystems, including one natural lake (Akgöl) and six artificial water bodies comprising five reservoirs (Gezende, Alaköprü, Berdan, Bağbaşı, and Ermenek) and one pond (Sarıveliler), in the Eastern Mediterranean River Basin (Türkiye), representing Mediterranean and semi-arid climatic conditions. Phytoplankton and environmental data were collected seasonally (spring and autumn) during 2020–2021 from 18 sampling stations. Strong spatial and temporal heterogeneity was observed among lakes. The shallow, saline-influenced Akgöl Lake showed low functional diversity and dominance of benthic and tychoplanktonic diatoms (codon MP), associated with sediment resuspension and unstable mixing. In contrast, deeper stratified reservoirs (Gezende, Berdan, Ermenek) were dominated by motile dinoflagellates (codon L0), particularly in spring under stable, oxygenated conditions. Seasonal dynamics structured FG composition, with spring assemblages favoring mixing- and oxygen-adapted groups, whereas autumn assemblages shifted toward taxa tolerant of higher turbidity and organic enrichment. Redundancy analysis revealed that salinity, turbidity, suspended solids, and total organic carbon were the main drivers of FG distribution, while nutrients had comparatively weak explanatory power. Together, these variables define a clear mineralization–organic matter–turbidity gradient controlling phytoplankton structure across the basin. Mesotrophic functional groups dominated overall, although their relative contributions varied with local environmental conditions. The results demonstrate that phytoplankton FGs are reliable indicators of ecological status and spatial variability in Eastern Mediterranean lakes. Importantly, the system is structured by a pronounced hydrological degradation gradient driven by coupled salinity, organic matter, and turbidity dynamics, which emerges as the dominant organizing environmental framework. This highlights the need to integrate hydrological regulation, sediment dynamics, and organic matter processes with nutrient management under increasing anthropogenic and climatic pressures.
Co-occurring ectoparasites represent a challenge in intensive aquaculture; however, quantitative tools to assess how parasite species partition their temporal niches remain limited. The seasonal dynamics of two coexisting gill ectoparasites, Diplectanum aequans and Lernanthropus kroyeri, infecting farmed European seabass (Dicentrarchus labrax) were evaluated using two complementary indices: a Seasonal Niche-Decoupling Index (D) and a standardized Thermal Alignment Score (S). The D index quantified temporal separation in parasite dominance, while S was defined as the Pearson correlation coefficient between seasonal parasite abundance and water temperature. Although both parasites were present year-round, their population dynamics exhibited contrasting seasonal patterns. D. aequans peaked in spring, whereas L. kroyeri predominated in winter, resulting in a pronounced but incomplete temporal separation (D = 0.483). Standardized thermal alignment analysis indicated that D. aequans exhibited a strong negative alignment (S = −0.76), whereas L. kroyeri showed a weak positive alignment (S = +0.19). These findings suggest that temporal niche partitioning may facilitate the coexistence of ectoparasites under continuous infection pressure in intensive aquaculture systems. Under projected warming scenarios, the seasonal window of D. aequans may contract, whereas L. kroyeri may expand its temporal niche. The applied indices provide a practical and transferable framework for evaluating seasonal parasite dynamics and may support improved parasite management strategies in aquaculture.
The fact that Clostridioides difficile, known as a nosocomial pathogen, causes infections in individuals lacking traditional risk factors raises the possibility that its source may not be confined to hospital environments. In this context, investigating food matrices and accurately identifying presumptive isolates are important for understanding the possible foodborne relevance of this bacterium. This study comparatively evaluated two selective supplement systems, Dcycloserine- cefoxitin (CC) and moxalactam-norfloxacin (MN), for the recovery of presumptive C. difficile isolates from 536 mussels collected from nine sites in & Ccedil;anakkale, Turkey, together with seawater samples obtained from the same locations. Presumptive isolates were further examined using MALDITOF MS (Bruker and VITEK MS), RAPID ID 32 A, and multiplex realtime PCR. Considerable discrepancies were observed among the identification methods. In particular, one isolate recovered from mussels was identified as C. bifermentans by MALDITOF MS but as C. difficile by RAPID ID 32 A; however, this result was not confirmed by PCR. Overall, none of the presumptive isolates from mussel or seawater samples were confirmed as C. difficile by multiplex realtime PCR. These findings demonstrate that detection outcomes are strongly influenced by both the isolation strategy and the identification method used. They also indicate that presumptive recovery and preliminary identification do not necessarily correspond to confirmed C. difficile detection in complex food and environmental matrices. Therefore, molecular confirmation remains essential, and further methodological improvements are needed to improve the reliable detection of C. difficile in food samples.
Jellyfish have the potential to be a good alternative solution to the problems we may encounter in the future. It is important to use this potential effectively and obtain environmentally friendly results. Superabsorbents, which come across us in many forms from diapers to oil traps, have their own supply and demand today. In this study, the use of Aurefia aurita and Rhizostoma pufmo jellyfish, which are frequently encountered in the Marmara Sea, as superabsorbent materials was investigated. After drying and grinding these simple organisms, which contain over 95% water, their potential as superabsorbent materials was examined both directly and in hydrogels. By incorporating jellyfish tissue into hydrogels, which are traditionally chemically crosslinked polymeric 3D network structures, transparent hydrogels with high strength and water capacity, where both physical and chemical bonds are effective, were characterized within the scope of the study. These hydrogels, which have the capacity to hold more than 1000 times their dry weight in water, have a promising potential for use, especially in agriculture and health applications.
In Indonesia, particularly on the island of Tanakeke, Kappaphycus afvarezii cultivation is an aqua culture product that is a source of carrageenan for the food industry. However, this region has limited cultivation technology and still uses local seeds. Therefore, this study aims to compare the specific growth rate and carrageenan content of K. afvarezii from tissue culture seeds and local seeds. Using initial weights of 50 g, 75 g, and 100 g for each seed type with a completely randomized factorial design, the seeds were grown for 45 days (6 weeks). This study found that K. afvarezii from tissue culture with an initial seed weight of 50 g had the highest average specific growth rate of 15.52 (SD 43%). The greatest average carrageenan content was obtained under this treatment (54.29%, SD 0.63%). However, its broader environmental effects, including potential impacts on biodiversity, remain to be examined.
This study examines the short-term vertical redistribution of Microcystis aeruginosa under controlled conditions, focusing on the combined effects of light attenuation, thermal gradients, and low-energy wind-powered aeration. Laboratory experiments were conducted in a stratified tank system designed to simulate simplified mixing processes in lakes and reservoirs. Following biomass introduction, light penetration decreased markedly, with reductions of 23% at the surface and 83.7% in deeper layers due to biomass concentration. Under unstratified conditions, cyanobacterial biomass accumulated primarily at depths of 40-60 cm above the tank bottom. However, the establishment of thermal gradients induced biomass consolidation at depth between (30-50 cm), corresponding to a temperature range of 18-19 degrees C which is the same temperature interval that was seen in unstratified conditions. Mechanical aeration weakened the vertical temperature gradient and induced a further upward redistribution of biomass toward the surface, showing a clear physical control on buoyancy-driven positioning. Mechanical aeration significantly redistributed the biomass, leading to a 106.4% increase at the surface while reducing concentrations in the previously stable mid-layers by up to 27.3%, effectively disrupting the thermal gradient-induced niche of M. aeruginosa. Overall, aeration destabilized the vertical biomass structure by neutralizing thermal stability and shifting depth preferences. These findings demonstrate that low-energy, renewablepowered mixing effectively counteracts cyanobacterial buoyancy, providing mechanistic evidence that aeration can disrupt bloom formation.
The discharge of synthetic dyes into aquatic environments without adequate treatment constitutes a serious environmental problem due to their toxicity, chemical stability, and resistance to biodegradation. Among these contaminants, Malachite Green (MG), a commonly used cationic dye, has attracted considerable attention because of its harmful effects on both aquatic ecosystems and human health, thereby emphasizing the necessity for efficient and sustainable remediation approaches. In recent years, biochar produced from lignocellulosic biomass has gained increasing interest as a potential adsorbent owing to its low production cost and environmentally friendly nature. In this study, biochar derived from Cupressus sempervirens (CSb) and its iron modified form (CSmb) were investigated for the removal of MG from aqueous solutions. The structural and surface properties of the adsorbents were characterized using FT-IR, XRD, and SEM-EDS analyses, which revealed noticeable alterations in surface morphology and functional groups after the modification process. Batch adsorption experiments were carried out to examine the effects of various parameters, including pH, temperature, initial dye concentration, contact time, and adsorbent dosage. The kinetic results indicated that the adsorption of MG onto both adsorbents was best described by the pseudo-second-order model. Thermodynamic analysis further suggested that the adsorption process is spontaneous and endothermic. Equilibrium data were best fitted by the Langmuir isotherm model, with maximum adsorption capacities of 33.670 mg g-1 for CSb and 38.462 mg g-1 for CSmb. Overall, the results indicate that biochar derived from Cupressus sempervirens, particularly after iron modification, can serve as an effective and economically feasible adsorbent for the treatment of dye contaminated wastewater.
In parallel with the increase in the need for raw materials used in industry, the area and amountof use of Rare Earth Elements are also increasing. Yttrium (Y), which is used as a raw material source, is thought to form residues in the environment. Gammarus pufex individuals were selected as a model organism to investigate the effects of Yttrium on the environment and aquatic organisms. G. pufexes were exposed to Y at different temperatures (16, 18, and 20 degrees C) and concentrations (25, 100, and 500 & micro;g/L) for 96 hours and samples were taken at24 and 96 hours for biochemical analyses. For biomarker analysis, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, thiobarbituric acid (TBARS) and glutathione (GSH) levels were performed using CAYMAN ELISA kit. Study data revealed that SOD and CAT activities increased significantly with increasing temperature and exposure concentration, while GPx activity showed an irregular response; in contrast, no significant change was observed in TBARS levels at 16 degrees C, while the increase in TBARS and significant changes in GSH levels at 18 and 20 degrees C indicate that oxidative stress becomes more pronounced at high temperatures.
In this study, the physical properties and nutrient salt composition of coastal waters affected by De & gbreve;irmendere along the Trabzon coast of the Southeastern Black Sea were compared with stations representing open sea conditions relatively independent of river influence. Fieldwork was planned for March and August 2025 to capture two contrasting hydrographic conditions; sampling was carried out at depths of 0-200 m along the river-influenced TM (Trabzon-Center; TM1-TM4) line and the reference TY (Trabzon-Yomra; TY1-TY4) line. Temperature, salinity, and density profiles of the water column were obtained using CTD; dissolved inorganic nitrogen species (nitrate, nitrite, ammonium), orthophosphate, reactive silicate, and total nitrogen and total phosphorus concentrations were measured using an auto-analyzer and statistically evaluated using the Month & times;Line approach. In March, a cold and vertically well-mixed water column of 9 degrees C was observed in both channels, while in August, a warmer and less dense layer developed at the surface and a distinct thermocline/pycnocline formed between 20 and 40 m. While no significant difference was observed between TM and TY in terms of salinity and density, nutrient salts showed a significant change from the coast to the open sea and from the surface to the depths. Near the coast, TM showed a higher tendency for ammonium and total nitrogen, while total phosphorus and silicate were relatively higher in TY in most cases. The effects of month, line, and interaction were pronounced on total nitrogen, with enrichment being more prominent in TY in March and in TM in August. DIN:PO43-ratios above the Redfield ratio generally indicate phosphorus limitation; although De & gbreve;irmendere increases enrichment near the coast, this effect weakens within a few nautical miles, indicating that the trophic status of the region remains relatively balanced in terms of eutrophication. This study provides a local reference dataset that comparatively documents river effects during two distinct periods rather than representing an annual cycle.
The cephalopod diversity, fishery, and market value remain underexplored in the Bicol Region despite its increasing significance in local livelihood. This study conducted a market survey from June to July 2025 on selected landing sites of Asid Gulf, Lagonoy Gulf, and Ragay Gulf. A standardized survey protocol adopted from del Norte-Campos (2019) with criteria for ranking cephalopod species [commercial value (40%), catch rates (20%), sources of threats (20%), frequency in the markets and source sites (10%), and literature available (10%)] was used. Results revealed a total of ten (10) cephalopod species documented belonging to Order Teuthida, Octopoda, and Sepiida with day octopus (Octopus cyanea), broadclub cuttlefish (Sepia latimanus), bigfin reef squid (Sepioteuthis lessoniana), and swordtip squid (Uroteuthis edulis) present across all three gulfs. Based on Jaccard Similarity Index (presence or absence of cephalopods), Lagonoy Gulf and Ragay Gulf exhibited highest similarity (67%), while Asid Gulf and Ragay Gulf showed the least similarity (44%) relative to cephalopod composition. Species ranking varied across all gulfs, attributed to variation in fishing gears, catch rates, and market demand. Survey data revealed declining trend in catch volume with an increasing market value demand over the past five years, indicating heightened market value amid reduced stock availability. The findings underscore the growing economic importance of cephalopods in the Bicol Region while raising concerns about potential overexploitation driven by increasing market demand. These trends highlight the need for strengthened fisheries monitoring, sustainable harvest, and management strategies for long-term viability of cephalopod resources and the livelihoods dependent on them.
Microplastics (MPs) contamination has become a pressing issue in freshwater ecosystems, yet existingstudies in T & uuml;rkiye remain geographically uneven and concentrated in only a few basins. This study brings together data from previously published investigations to create a harmonized national-scale dataset of 79 sediment records, each containing regional, seasonal, and environmental descriptors. Sediments were chosen as the focus because they act as long-term sinks for MPs, offering a more stable and comparable basis than water or biota samples for assessing spatial and temporal pollution trends. By compiling information from different studies into a consistent format, the dataset allows more reliable cross-site evaluations of MPs contamination in freshwater ecosystems across T & uuml;rkiye. To explore predictive capacity, three machine learning (ML) algorithms (Ridge Regression, Random Forest, and Histogram-based Gradient Boosting Regressor) were applied. Model performance was assessed using both 5-and 10-fold cross-validation and independent test sets, evaluated with R2, RMSE, and MAE metrics. Among these, the Histogram-based Gradient Boosting Regressor showed the highestaccuracy (R2 = 0.77), successfully capturing nonlinear relationships even with the relatively small dataset. Interpretability analyses highlighted region and season as the strongest predictors. Elevated MP concentration was consistently found in the Marmara Region and during the summer, reflecting combined pressures from industrial activity, dense urbanization, and seasonal factors such as increased tourism and hydrological changes. Overall, this study provides the first harmonized dataset of MPs concentration in freshwater sediments in T & uuml;rkiye. It also demonstrates the usefulness of predictive modelling and explainable artificial intelligence (XAI) for understanding pollution dynamics and supporting evidence-based strategies for environmental monitoring and management.
The invasiveness of the fishes in the genus Pterygoplichthys poses a considerable environmental threat to native aquatic ecosystems worldwide. This disruption of natural biodiversity and fish ecosystems corresponds to changes in nutrient dynamics resulting from the impact of Pterygoplichthys, exploitation of benthic resources, and increased interspecific competition. Fish species from this genus have been reported from various places, including the Indian subcontinent. The present study aims to develop a rapid eDNA-based assay to detect the presence of Pterygoplichthys in the Bhima River, one of the major tributaries of the Krishna River system, located in the biodiverse northern Western Ghats of India. The qPCR method was optimised with newly designed Pterygoplichthys-specific primers. Subsequently, eDNA samples collected from the seven locations were analysed under these conditions. This advanced and suitable method can be applied in other regions of India as well as in neighbouring countries where an invasion is suspected or has already occurred. Our results confirmed the presence of Pterygoplichthys eDNA in four of the seven sites. This indicates the ongoing invasion throughout the region, which is one of the global freshwater ecoregions characterized by a high degree of endemism.
This study is the first to characterize the chromosomes and cytogenetic features of Merlangius merlangus (Linnaeus, 1758), a typical commercial marine species in the Black Sea and the sole member of the order Gadiformes, which first appeared around 16 million years ago. Samples were collected from professional fishermen working in the coastal waters of Fatsa in autumn 2023. Postmortem fish samples were stored in PB-MAX culture medium for 2.5 hours, after which slides were prepared by conventional air-drying. These slides were stained with Giemsa, C-, GTG-, and AgNO3, respectively. Metaphases were examined and analyzed using AKAS image analysis software. Results showed that Merlangius merlangus has a diploid number (2n) of20 chromosome pairs, with a karyotype comprising 18 pairs of bi-armed chromosomes (including five pairs of metacentric and four pairs of submetacentric) and 22 uni-armed chromosomes ( eight pairs of subtelocentric and three pairs of acrocentric). One metacentric chromosome with C+ regions, two different metacentric chromosomes with G+ regions, and one acrocentric chromosome with NOR regions were identified. The study aimed to determine the karyology and cytogenetic features of Merlangius merlangus, a species not previously studied cytogenetically, using sequential staining and banding techniques. As a migratory bottom-dwelling fish like other Gadidae, it is characterized by a high number of biarmed chromosomes and is consistently found in the Black Sea. This research will help identify 45S rDNA gene regions across populations from various geographic locations.
Seasonal sampling between June and November 2023 revealed thatAurelia aurita was the only bloom-forming jellyfish species, exhibiting consistently high abundance at Izmit Bay stations throughout most of the sampling period, and reaching notably high biomass levels between August and October. Phytoplankton composition was dominated by diatoms, particularly Lepto cylindrus minimus, and showed high dinoflagellate diversity (Prorocentrum micans, Gonyaulax fragilis), with seasonal peaks driven by temperature and nutrient availability. Zooplankton community dynamics in the Sea of Marmara were shaped by strong seasonal forcing and episodic jellyfish occurrences, promoting a shift toward small filter-feeding taxa such as Cladocera and Appendicularia. Periodic increases in meroplanktonic larvae, particularly Bivalvia and Polychaeta, reflected active benthic recruitment and localized nutrient enrichment in coastal areas (especially at stations M1 and M2). It was determined that C/N ratio of particulate matter (PM) mostly varied between 10-12. This result shows that the source of PM is phytoplankton and therefore the primary production periods. Additionally, the isolation of certain pathogenic bacterial species exclusively from Aurelia aurita specimens suggests that A. aurita may act as a temporary microhabitatfor specific bacterial taxa. These findings highlight the critical need for long-term, multi-parameter monitoring of biological and physicochemical factors to improve our understanding and predictive capacity of future dynamics of plankton communities in the sensitive coastal ecosystem of the Sea of Marmara, especially under jellyfish pressure.
The present study aimed to investigate the effects of sex-related morphological differences in crayfish bodies on their escape rates from the fyke net used in fishing. The study, conducted in E & gbreve;irdir Lake (Isparta, T & uuml;rkiye) with a total of 20 fishing operations, utilized commercial crayfish fyke nets equipped with 34 mm diamond mesh size. Statistical differences were determined between the body parts of female and male crayfish within the same length classes among the 1,529 crayfish examined, ranging from 31.80 to 149.00 mm in total length. These observed differences were reflected in the catch comparison results; however, the difference was found to be statistically insignificant. According to the study results, the crayfish fyke nets commonly used in crayfish fisheries in T & uuml;rkiye, rigged with 34 mm diamond mesh, did not exhibit selectivity based on sex groups. In this context, it is considered that there is no need for any sex-specific regulation in crayfish fisheries in T & uuml;rkiye.
Mud crab (Scylla serrata) culture using recirculating aquaculture systems (RAS) with vertical crab boxes offers a sustainable model for urban aquaculture, particularly in land-limited coastal cities such as Jakarta, Indonesia. However, the dependence on wild-caught seeds from surrounding mangrove areas raises production costs and may affect seed quality due to variations in transport distance and handling. This research evaluated the production and economic performance of mud crab culture in RAS vertical boxes using seeds sourced from three coastal regions: Tangerang, Bekasi, and Subang, which represent different transfer distances. Ninety crabs (60-120 g/crab) were individually reared for 30 days following a completely randomized design with three treatments and three replications. Growth parameters (survival rate, daily growth rate, molting percentage, and feed conversion ratio) and profitability indicators (cost of goods sold, revenue cost ratio, and payback period) were analyzed. Production performance did not differ significantly among seed sources (p > 0.05), with survival rates ranging from 50-73% and daily growth rates from 0.60-0.69 g/ day. Nevertheless, profitability varied markedly: culture using Tangerang-sourced seeds achieved the highest economic return (profit = USD 153.4/year; R/C = 1.3; payback period = 6.8 years), while Subang-sourced seeds resulted in financial loss, primarily due to prolonged transport and lower seed vitality. Seed source influenced economic outcomes but not biological productivity. hatchery-based seed production is essential to strengthening the sustainability of urban mud crab aquaculture.
