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.
