The Use of Zebra Mussel (<i>Dreissena polymorpha</i>) as a Sentinel Species for the Microplastic Pollution of Freshwater: The Case of Beyhan Dam Lake, Turkey

The presence of microplastics (MPs) in several components of different ecosystems has aroused great concern and led to numerous studies on MP pollution. Although there has been an increasing number of these studies in aquatic ecosystems, no data about the MP pollution in zebra mussel (Dreissena polymorpha, Pallas 1771) living in Beyhan dam lake (Elazığ, Türkiye) are available. This study aimed to investigate the presence of MPs in freshwater mussel species found in this water reservoir. The distribution and characterization of MPs were investigated by Fourier transform infrared spectroscopy (FTIR) in zebra mussel (D. polymorpha) samples at four different stations. A significant difference in the MP presence between the 1st and 4th stations was observed (p D. polymorpha as a bioindicator in the aquatic ecosystems’ MP pollution

Interaction of Microplastic Presence and Oxidative Stress in Freshwater Fish: A Regional Scale Research, East Anatolia of T&uuml;rkiye (Erzurum &amp; Erzincan &amp; Bing&ouml;l)

The presence of microplastic (MP) in different fish species taken from stations in Erzurum, Erzincan and Bing&ouml;l was examined. The obtained data were classified and shared with the scientific world as the first record made in this region. In the obtained results, the most dominant color was black (39&ndash;58%) and the most prevalent forms were fragment and fiber. The sizes (0&ndash;50, 50&ndash;100 &micro;m) of microplastics differed according to the region and species. When the number of MPs in the gastrointestinal systems of different fish species in the Bing&ouml;l, Erzurum and Erzincan provinces was evaluated, the most microplastics were found in Squalius squalus (20.7%) and Blicca bjoerkna (18.2%) in Bing&ouml;l province from among six different species. In Erzincan province, four fish species were sampled, and the rates were (29.7%) in Capoeta umbla and (26.6%) in Blicca bjoerkna. The highest abundance in Erzurum province was determined in Cyprinus carpio (53.0%). In the analyses performed on liver tissues, the highest ROS, which is the indicator of oxidative damage, was listed as Bing&ouml;l &gt; Erzincan &gt; Erzurum, while MDA levels were recorded as Bing&ouml;l &gt; Erzurum &gt; Erzincan, from high to low. When the differences between species were examined, the highest SOD and CAT activity was determined in the Mugil cephalus species. Considering the total MP numbers in fish samples, 47 MP was determined in this species. On the other hand, in the Squalius squalus species, where the highest total MP was determined, SOD and CAT activities were found to be low in Bing&ouml;l province. Therewithal, the high levels of ROS and MDA in this species can be said to induce oxidative stress due to the presence of microplastics on the one hand and to reduce antioxidant levels on the other hand. When the findings were evaluated, it was concluded that MPs in freshwater are a potential stressor, and freshwater environments may represent a critical target habitat for future MP removal and remediation strategies

Effect of climate change on hematotoxicity/hepatoxicity oxidative stress, Oncorhynchus mykiss, under controlled conditions.

Described as the 'main ecological factor', temperature, strongly affects the physiological stress responses of fish. In order to evaluate the effects of temperature variations on fish culture and food value chain, the present study was designed as a climate change model. Furthermore, the present study provides a theoretical basis for a better understanding of the mechanisms of the environmentally induced changes. In this direction, we examined the blood physiology and oxidative stress responses induced by temperature variation in the rainbow trout, a temperature-sensitive cold-water fish. The obtained results showed that climate changes promoted the inhibited activities' expressions and the development of potential tissue and hematological defense mechanisms against temperature-induced toxic damage. This study showed that climate change could be a subset of the studies on the stress physiology in aquaculture, which can be developed for new experimental designs and research collaborations. Furthermore, it highlights knowledge gaps to guide future research in this emerging field

EVALUATION OF ADDITION OF WHITE WORM (ENCHYTRAEUS ALBIDUS HENLE, 1837) TO DIETS ON QUALITY OF BROWN TROUT (SALMO TRUTTA FARIO)

This paper evaluated usage possibility of white worm added to brown trout pellets at different percentages. The experiment was designed as 4 groups (Live feed, Pellet, and additions of (0.25 and 0.5%) white worm with 3 replicates. Each tank included 30 fish. After 90 days of feeding proximate analyzes of whole body were made from 16 fish of each group. It was shown that addition of white worm increased meat quality

EVALUATION EFFECTS OF ADDITION OF WHITE WORM (ENCHYTRAEUS ALBIDUS HENLE, 1837) TO DIETS ON GROWTH OF BROWN TROUT FRY (SALMO TRUTTA FARIO L.)

This paper evaluated usage possibility of white worm, Enchytraeus albidus added to brown trout fry pellets at different percentages. The experiment was designed as 4 groups (Live feed, pellet, and additions of (0.25 and 0.5%) white worm with 3 replicates. Each tank included 30 fish. Weigh gains and survival rates of fish were compared and assumptions were made with respect to consumption. It was found that addition of white worm to diets increased weight gain slightly (p>0.05). No differences were observed at survivals of fish (p>0.05). Feed conversion ratio was the higher in Lf group and followed by 0.5, 0.25 % white worm added groups and pellet groups in order. It may be suggested to fish farmers adding White worm at small quantities may provide better survival with not significant changes in total production