Spiveyoddershede0344

This study proposes a pro-active approach for evaluations of methylmercury (MeHg), total mercury (THg), arsenic (As), cadmium (Cd) and lead (Pb) in situ bioaccumulation in fish (Atherinella brasiliensis) muscles, using specimens from the external sector of Guanabara Bay as a study case. This approach included an hierarchical sequence analysis of the pollutants concentrations and their comparison to safety criteria; correlations between specimens concentrations vs length (as a proxy of exposure time); projections of concentrations in key lengths (sexual maturation, asymptotic, length limits for fishing and median of fish population) through polynomial regressions, dose-response analysis (Probit), decreasing curves and incorporation rates (using only three length intervals). The incorporation rates were ascending for MeHg and THg (continued bioaccumulation) and descending for As, Pb and Cd (possible biological dilution). The projections were satisfactory, evidencing their use for an improvement on the risks monitoring of fishing and fish consumption by humans in coastal environments. To determine an optimal sampling strategy for collecting samples with an expected taxonomic breadth, a 1-year baseline colonization survey was conducted in Chinese coastal waters using glass slides as an artificial substratum for biofilm-dwelling ciliates. A total of 240 slide samples were collected at a depth of 1 m in a four-season cycle. The taxonomic composition and structure of the ciliate communities differed from spring to winter. The colonization dynamics in taxonomic distinctness showed a significant variability among the four seasons. Expectation tests on the pairs of average taxonomic distinctness indices demonstrated a seasonal variability in taxonomic breadth of the ciliates, with high expectation levels in spring and autumn and low levels in the other two seasons. These findings suggest that there was a significant seasonal variability in taxonomic breadth for colonization surveys of biofilm-dwelling ciliates, and that an optimal sampling strategy should be determined for bioassessment in marine ecosystems. This study investigates the frequency of microplastic (MP) ingestion and the relationship between microplastics in the guts of two commercial fish species in Iceland (cod; Gadus morhua and saithe; Pollachius virens) and the weight, length, gut fullness, and condition index (CI) of the fish. MPs were found in 20.5% of the cod (n = 39) and 17.4% of the saithe (n = 46). There was no significant correlation between gut fullness nor CI and findings of MPs, indicating that, especially in large individuals, MPs are not retained to a large extent, and if so, the CI is most likely not affected. Deferoxamine molecular weight A difference was found in fish length between fish containing plastic and fish without plastics. Further studies such as this must be conducted in all water ecosystems if we are to fully understand the impact that MP's are having at the individual, population, species, and ecosystem levels. The aerobic biodegradation of common textiles that shed microfibers during laundering was evaluated under the action of microbes found in the environment, such as lake and seawater, and activated sludge at a low concentration from a wastewater treatment plant (WWTP). Under these conditions, the biodegradation potential was the same in all the experiments Microcrystalline Cellulose (MCC) > Cotton > Rayon > Polyester/Cotton ≫ Polyester. Nevertheless, for cotton and rayon yarns, >70% biodegradation was achieved with activated sludge at low concentration and lake water, whereas in seawater, about 50% degradation was reached. Polyester did not appreciably degrade. The biodegradation results herein indicate potential not absolutes in nature. The bacterial diversity analyses in the different biodegradation inoculums show that there are distinct bacterial communities related to the assimilation and mineralization of complex carbohydrates that were promoted with the cellulosic MCC, cotton, and rayon samples different than the polyester sample. The emergence of a red tide resulting in yellow-brownish discoloration of waters in Porto Cesareo bay (Italy) during July-August 2018 is reported. The species responsible for the bloom was the dinoflagellate Margalefidinium cf. polykrikoides. Cell densities reached 9.1 × 106 cells L-1 during the initial outbreak. A second peak was observed about three weeks later reaching 6.7 × 105 cells L-1. Study of live specimens showed great variation in cell size and shape. Different cyst morphotypes were found in the water samples and in the sediment. For the first time, we followed several stages of the life cycle of M. cf. polykrikoides in natural samples. Fish die-offs in the bay were not observed, however this high-density bloom may have caused consequences on the ecosystem (amount of mucilage on the beach) and in turn, on tourism that is the main activity in the area during the summer season. Due to strong regulation of phthalates, non-phthalate plasticizers (NPPs) have been introduced to the industrial market. In this study, concentrations of 16 phthalates and five NPPs in sediment were measured to investigate the occurrence, potential source, and ecotoxicological implications of these contaminants. Phthalates and NPPs were detected in all sediment samples, indicating ubiquitous contaminants. Di(2-ethylhexyl)phthalate (DEHP) and trioctyl trimellitate (TOTM) were the dominant for phthalates and NPPs, respectively, implying emerging contamination by TOTM. Spatial distribution of these contaminants showed decreasing gradients from inner to outer bays. Clear declining trends in phthalate and NPP concentrations were found in sediment near a wastewater treatment plant outfall, suggesting a potential source of contamination. Approximately 95% of sediment samples exceeded sediment quality guidelines for DEHP suggested by previous studies, implying that benthic organisms are suffering from adverse biological effects. This is the first report on the occurrence of NPPs in the coastal environment. The visual survey is the most common method to quantify and characterize beach litter. However, it is very labor intensive and difficult to carry out on beaches which are remote or difficult to access. We suggest an alternative approach for assessing beach litter using an unmanned aerial vehicle (UAV), or aerial drone, with automated image requisition and processing. Litter of different sizes, colours, and materials were placed randomly on two beaches. Images of beaches with different substrates were obtained by the drone at different operating heights and light conditions and litter on the beaches was identified from the photos by untrained personnel. The quantification of beach litter using the drone was three times faster than that by visual census. This study has demonstrated the potential of using the drone as a cost-effective and an efficient sampling method in routine beach litter monitoring programs.