Effects of inorganic arsenic species on the antioxidant enzyme system of the Amazon Sword Plant (Echinodorus amazonicus Rataj).

This study aims to examine the effects of Arsenite (As+3) and Arsenate (As+5) on the aquatic macrophyte Amazon Sword Plant (Echinodorus amazonicus Rataj). To this aim, different concentrations of As+3 and As+5 (0, 6, 18 and 54 µM) were analyzed. At the end of the trail, photosynthetic pigment contents, total protein amounts, the enzymatic antioxidants superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) activities and the amount of malondialdehyde (MDA) in the leaf samples of E. amazonicus were investigated. The antioxidant enzyme activities increased at low concentrations (32.13% for SOD, 185% for CAT and 201.5% for POX in the groups of 6 µM As+5), but decreased at high concentrations (64.98% for SOD, 21.64% for CAT and 21.29% for POX in the groups of 54 µM As+3). MDA increased in all the treatment groups. The highest MDA contents were observed as 96% for 54 µM As+3 and 71.50% for 54 µM As+5. Photosynthetic pigment contents and the amount of protein were decreased with higher concentrations. The most significant decreases in protein content were 65% for 54 µM As+3 and 34.9% for 54 µM As+5. As a result, the toxicity of As+3 was higher and the toxic effect increased at higher concentrations.

Mitigating Dietary Microplastic Accumulation and Oxidative Stress Response in European Seabass (Dicentrarchus labrax) Juveniles Using a Natural Microencapsulated Antioxidant.

Aquafeed's contamination by microplastics can pose a risk to fish health and quality since they can be absorbed by the gastrointestinal tract and translocate to different tissues. The liver acts as a retaining organ with the consequent triggering of oxidative stress response. The present study aimed to combine the use of natural astaxanthin with natural-based microcapsules to counteract these negative side effects. European seabass juveniles were fed diets containing commercially available fluorescent microplastic microbeads (1-5 µm; 50 mg/kg feed) alone or combined with microencapsulated astaxanthin (AX) (7 g/kg feed; tested for half or whole feeding trial-30 or 60 days, respectively). Fish from the different dietary treatments did not evidence variations in survival and growth performance and did not show pathological alterations at the intestinal level. However, the microplastics were absorbed at the intestinal level with a consequent translocation to the liver, leading, when provided solely, to sod1, sod2, and cat upregulation. Interestingly, the dietary implementation of microencapsulated AX led to a mitigation of oxidative stress. In addition, the microcapsules, due to their composition, promoted microplastic coagulation in the fish gut, limiting their absorption and accumulation in all the tissues analyzed. These results were supported by in vitro tests, which demonstrated that the microcapsules promoted microplastic coagula formation too large to be absorbed at the intestinal level and by the fact that the coagulated microplastics were released through the fish feces.

The Promising Role of Synthetic Flavors in Advancing Fish Feeding Strategies: A Focus on Adult Female Zebrafish (Danio rerio) Growth, Welfare, Appetite, and Reproductive Performances.

The present study aimed to test over a six-month period different synthetic flavors in zebrafish (Danio rerio) as an experimental model. Specifically, two attractive and one repulsive synthetic flavors were added (1% w/w) to a specific zebrafish diet, which was administered to the fish during the whole life cycle (from larvae to adults), to evaluate their physiological responses, emphasizing fish welfare, feed intake, growth, reward mechanisms, and reproductive performances. Fish welfare was not affected by all tested flavors, while both attractive flavors promoted fish feed ingestion and growth. The results were supported by both molecular and immunohistochemical analyses on appetite-regulating neurohormonal signals, along with the influence of the feed hedonic properties induced by the brain reward sensation, as demonstrated by the dopamine receptor gene expression. Finally, the present study demonstrated that a higher feed intake also had positive implications on fish reproductive performances, suggesting a promising role of synthetic flavors for the aquaculture industry. In conclusion, the results highlighted the potential of synthetic flavors to improve fish feeding strategies by providing a consistent and effective alternative to traditional stimulants, thereby reducing dependence on natural sources.

Macro- and microplastic abundance from recreational beaches along the South Aegean Sea (Türkiye).

This study aimed to evaluate the abundance and diversity of macro- and microplastics in sand samples collected during summer and winter from eight different beaches used for recreational purposes located on the South Aegean coasts of Türkiye. According to the results, microplastic in fiber shape was dominant on all the beaches. The highest microplastic abundance was determined at Ölüdeniz Kumburnu Beach (360.00 ± 237.66 particles kg-1 dw) in summer and at Aktur Beach (358.33 ± 397.24 particles kg-1 dw) in winter. A significant positive correlation was found in the winter between microplastic amounts and wind speed. The study area is an important touristic center faraway from major cities and industrial areas. Thus, plastic pollution in this area may be the result of tourism activities in the summer, discharge waters from wastewater treatment plants or transportation by meteorological factors (like waves, wind or river flows).

Occurrence of Microplastics in Most Consumed Fruits and Vegetables from Turkey and Public Risk Assessment for Consumers.

Microplastics are transferred to humans through the food chain by consuming food contaminated with microplastics. However, the knowledge about the risks of dietary exposure for humans to these particles is very limited. Moreover, only a few studies on microplastic pollution in fruit and vegetables have been carried on. Thus, this study aims to investigate the presence of microplastics in some of the most consumed fruits and vegetables (pear (Pyrus communis), apple (Malus domestica), tomato (Solanum lycopersicum), onion (Allium cepa), potatoes (Solanum tuberosum), and cucumber (Cucumis sativus)) from Turkey and to evaluate the potential risk for consumers. Fruits and vegetable samples were purchased from different markets and fruiterer (two of each) in Mugla province, Southwest of Turkey. Microplastic extraction processes were carried out on the edible parts of the samples. According to the results obtained, a total of 210 particles (2.9 ± 1.6 particle g-1) were detected in all samples. Any significant difference occurred among the different markets. The maximum average amount of microplastic was determined in tomato samples (3.63 ± 1.39 particle g-1). The highest microplastic intake was with tomato (398,520 particles individual-1 year-1 for Estimated Annual Intake (EAI) and Estimated Daily Intake (EDI) for children 68.24 particles kg-1 day-1). The occurrence of microplastics of big size, that are not allowed to pass by plant xylem transport, suggests that fresh vegetables and fruits can be contaminated with plastic, especially during the production phase, during agricultural activities and during the marketing process (transport to the market and purchasing process).

Heavy metals in processed seafood products from Turkey: risk assessment for the consumers.

In this study, concentrations of 6 different elements (copper (Cu), tin (Sn), zinc (Zn), iron (Fe), cadmium (Cd) and lead (Pb)) in 9 different processed seafood (marinated and smoked mackerel, smoked mackerel, marinated octopus tentacles, marinated octopus salad, marinated squid salad, salted and dried mackerel, marinated and smoked anchovy, smoked salmon and smoked bonito) randomly taken from markets in Mugla province (West Anatolia, Turkey) were determined with the method of inductively coupled plasma mass spectroscopy (ICP-MS) after microwave wet digestion process. In addition, risk assessment for consumer health was conducted by the determination of estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ) and carcinogenic risk (CR). According to the obtained results, the seafood product samples with the highest concentrations of each metal were marinated and smoked anchovy for Fe (65.85 ± 16.03 mg kg-1), marinated and smoked anchovy for Zn (64.58 ± 25.16 mg kg-1), marinated octopus salad for Cu (26.33 ± 17.76 mg kg-1), smoked mackerel for Sn (0.42 ± 0.18 mg kg-1), smoked mackerel for Pb (0.28 ± 0.18 mg kg-1) and marinated squid salad for Cd (0.31 ± 0.12 mg kg-1). According to risk assessment for consumer health, it was found that EDI results did not exceed the tolerable daily intake (TDI) values. As a conclusion, any risk for consumer health in terms of CR, THQ and TTHQ values was not detected in the examined samples.

Microplastic pollution at the intersection of the Aegean and Mediterranean Seas: A study of the Datça Peninsula (Turkey).

This study aims to reveal microplastic pollution. It is the first to be conducted in the South Aegean Region and one of the limited numbers of such studies in Turkey. To this aim, in September 2018 microplastic particles (MP's) pollution was evaluated on the sandy beaches along the coastline of the Datça Peninsula (Southern Aegean coast of Turkey) located at the intersection of the Aegean and Mediterranean Seas. MP's were analyzed using standard operating procedure along with some experimental techniques. Prior to the identification process, microplastics ranging from 1 to 5 mm were exposed to an experimental pre-treatment and efficient polymer scanning. The results showed that fragments (72%) were the dominant category from all the beaches exposed to dominant winds and surface currents and that MP contamination in the Datça Peninsula was higher than that reported in the literature from similar locations around the world (1154.4 ±â€¯700.3 particles kg-1 dw). More specifically the highest contamination was found in Aktur Beach (2073.3 ±â€¯648.6 particles kg-1 dw) which could be considered as a hotspot for the whole region in terms of MP pollution. As a result of the study, as sampling stations are remote from major cities and industrial zones, maritime activities increase during summer season and tar has been observed on particles during analyses, it can be asserted that the pollution may be caused by marine resources.