خيارات البحث
النتائج 2621 - 2630 من 7,979
Trophic transfer of microbeads to jellyfish and the importance of aging microbeads for microplastic experiments
2021
Sucharitakul, Phuping | Pitt, Kylie A. | Welsh, David T.
Concepts in microplastics studies are not well established due to the emerging nature of microplastic research, especially in jellyfish. We conducted experiments to test whether ephyrae would ingest more microbeads via trophic transfer than direct ingestion and whether medusae would ingest more aged microbeads than virgin microbeads. We exposed ephyrae of Aurelia coerulea to two treatments, aged microbeads and Artemia nauplii that had ingested microbeads. We found that the ephyrae ingested 35 times more microbeads via trophic transfer than by direct ingestion. In the second experiment, medusae of A. coerulea were exposed to virgin microbeads and microbeads in seawater under a 12/12 light/dark cycle or constant darkness. Ingestion rates of microbeads from the light incubation were greater than those from the dark incubation or virgin microbeads, suggesting the likely presence of photosynthetic organisms in biofilms from the light incubation increased the palatability of the microbeads and promoted their ingestion.
اظهر المزيد [+] اقل [-]Identifying hotspots of non-indigenous species' high impact in the Maltese islands (Central Mediterranean Sea)
2021
Bartolo, Angela G. | Tsiamis, Konstantinos | Küpper, Frithjof C.
Several invasive non-indigenous species (NIS) cause ecological and socio-economic impacts. A good understanding of the impacts of invasive NIS in Mediterranean habitats is important for managing and prioritising measures in the marine environment. We applied a conservative additive model to sum up the Cumulative IMPacts of invasive Alien (CIMPAL) species of 19 invasive marine NIS on 13 habitats in Maltese waters. This analysis identified three hotspot areas of NIS' high impact and five top-priority together with four high-priority invasive NIS for management. By using CIMPAL, it was also possible to differentiate between areas within the same Marine Protected Area. CIMPAL is thus recommended as a good tool for managers and policy makers for prioritising measures as well as funds. Finally, recommendations are made with respect to future steps that are needed for the CIMPAL applicability, aiming to a more appropriate decision-making on prioritisation of hotspot areas and invasive marine NIS.
اظهر المزيد [+] اقل [-]Climate change impacts on pollutants mobilization and interactive effects of climate change and pollutants on toxicity and bioaccumulation of pollutants in estuarine and marine biota and linkage to seafood security
2021
Kibria, Golam | Nugegoda, Dayanthi | Rose, Gavin | Haroon, A.K Yousuf
This article provides an overview of the impacts of climate change stressors (temperature, ocean acidification, sea-level rise, and hypoxia) on estuarine and marine biota (algae, crustaceans, molluscs, corals, and fish). It also assessed possible/likely interactive impacts (combined impacts of climate change stressors and pollutants) on pollutants mobilization, pollutants toxicity (effects on growth, reproduction, mortality) and pollutants bioaccumulation in estuarine and marine biota. An increase in temperature and extreme events may enhance the release, degradation, transportation, and mobilization of both hydrophobic and hydrophilic pollutants in the estuarine and marine environments. Based on the available pollutants' toxicity trend data and information it reveals that the toxicity of several high-risk pollutants may increase with increasing levels of climate change stressors. It is likely that the interactive effects of climate change and pollutants may enhance the bioaccumulation of pollutants in seafood organisms. There is a paucity of literature relating to realistic interactive effects of climate change and pollutants. Therefore, future research should be directed towards the combined effects of climate change stressors and pollutants on estuarine and marine bota. A sustainable solution for pollution control caused by both greenhouse gas emissions (that cause climate change) and chemical pollutants would be required to safeguard the estuarine and marine biota.
اظهر المزيد [+] اقل [-]Human health and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in sediment of Woji creek in the Niger Delta region of Nigeria
2021
Ihunwo, Owhonda Chikeru | Ibezim-Ezeani, Millicent Uzoamaka | DelValls, Tomás Angel
Human health risk was determined by assessing risk due to dermal contact with the sediment and Benzo [a] pyrene -equivalent concentrations (BaP-TEQ- carcinogenic equivalents and BaP-MEQ- mutagenic equivalents). Ecological risk of PAHs in the sediment was determined by comparing PAHs concentrations to effect range low (ERL) and effect range median (ERM); to estimate the risk associated with the combined effects of PAHs, mean ERM quotient (mERMq) was calculated. Results revealed that hazard index (HI) due to dermal contact of the sediment for adults are 596 and 73.84 for children. Similarly, cancer risk for adults was all >10⁻¹ and was within 10⁻³ ≤ 10⁻¹ for children, for every compound; the sum of cancer risk for adults and children were 8.26 and 1.022 respectively.
اظهر المزيد [+] اقل [-]Microplastic contamination of sandy beaches of national parks, protected and recreational areas in southern parts of the Baltic Sea
2021
Esiukova, E. | Lobchuk, O. | Haseler, M. | Chubarenko, I.
The distribution of small (0.5–2 mm, S-MPs) and large (2–5 mm, L-MPs) microplastics and mesoplastic particles in 51 samples of surface beach sands at 7 locations along the southern shore of the Baltic Sea was investigated. MPs particles (3267 in total) were found at all the sites and in all the beach zones. The bulk mean MPs (0.5–5 mm) contamination is 68 ± 117 (median 33) items/kg DW (n = 51). The results were confirmed by μ-Raman spectroscopy analysis. National park areas did not differ substantially from other beaches. Expanded polystyrene fragments accounted for about 38% of the total collected particles. Fibres were the predominant type of MPs (55%). The highest contamination was found within the current wrack line (60.1 ± 36.6 items/kg DW of S-MPs). A consistent picture for S-MPs was observed at the beach face, where the mean values in different locations varied between 21.0 and 58.1 items/kg DW, with a bulk mean of 30.4 ± 13.7 items/kg DW.
اظهر المزيد [+] اقل [-]Resilience of the zooplankton community in the northeast Gulf of Mexico during and after the Deepwater Horizon oil spill
2021
Daly, Kendra L. | Remsen, Andrew | Outram, Dawn M. | Broadbent, Heather | Kramer, Kurt | Dubickas, Kate
We evaluated the resilience of the zooplankton community to the Deepwater Horizon oil spill in the northeast Gulf of Mexico, by assessing abundance, biomass, spatial distribution, species composition, and diversity indices during spring, summer, and winter, May 2010 to August 2014. SEAMAP samples collected between spring and summer 2005–2009 were analyzed as a baseline. Our results did not indicate that there was a long-term impact from the oil spill, but did demonstrate that environmental variability and riverine processes strongly governed zooplankton community dynamics. Zooplankton abundances during the oil spill (spring 2010) were not significantly different from abundances during spring 2011 and 2012. Summer 2010 abundances were the highest observed for the 2005 to 2014 period, due to high river discharge, high chlorophyll, and aggregation in eddies. High densities of the dinoflagellate, Noctiluca, during the oil spill, and the copepod, Centropages velificatus, and larvaceans in all years, suggest that these taxa warrant further investigation. Ecosystem connectivity (zooplankton transport by currents into the oil spill region), high fecundity, relatively short generation times, and refugia in deeper depths are key factors in zooplankton resilience to major perturbations. This study serves as a baseline for assessment of future impacts to this system.
اظهر المزيد [+] اقل [-]Emerging contaminants (Rh, Pd, and Pt) in surface sediments from a Brazilian subtropical estuary influenced by anthropogenic activities
2021
Berbel, Gláucia Bueno Benedetti | Hortellani, Marcos Antonio | Sarkis, Jorge Eduardo de Souza | Chiozzini, Vitor Gonsalez | Fávaro, Deborah Inês Teixeira | Sutti, Bruno Otero | Sakazaki, Nixon Claudio | Braga, Elisabete de Santis
The concentrations of Platinum (Pt), Rhodium (Rh) and Palladium (Pd) were evaluated from a highly impacted estuary in Brazil influenced by industrial pole, highway traffic and sewage outfall. The Santos-São Vicente region presents important economic activities derived from a largest harbor of Latin America and an industrial pole surrounded by intensive highway traffic. Values of Rh varied from 0.08 to 1.7 ng g⁻¹ with highest values at stations impacted by domestic waste. Pt ranged from 0.15 to 40.3 ng g⁻¹ with highest concentrations located close to the ferryboat traffic. Pd levels varied from 1.05 to 22.0 ng g⁻¹ with values >5 ng g⁻¹ in 50% of the stations. The spatial distribution of PGEs was not always directly associated with muddy sediments, because high PGE levels found even in sandy sediments. Pollution indexes, including anthropogenic factor (AF), geoaccumulation index (Igₑₒ), Enrichment factor (EF), and Pollution Load Index (PLI) were used for evaluating contaminant potential. Based on EF, Igeo, and PLI, 50% of samples of the sediments from Santos-São Vicente Estuarine System (SSV) were classified with significant to strong PGE contamination. All stations on the Santos Channel (SC), São Vicente Channel (SVC) and Bertioga Channel (BC) had AF higher than 80% in at least one of PGE elements, as showed in station 2A, which presented AF <50% for Rh and Pd and 86% for Pt. Despite high anthropogenic enrichment, no correlations among PGE elements were observed in surface sediments. Only two stations presented Pd/Pt, Pt/Rh, and Pd/Rh typical ratios of auto catalyst (st. 14 and Piaçaguera) both located in the vicinity of highways. This could be due to the PGE deposition process in road dust, soil, and water as well as the biogeochemical cycling of PGEs involving organic metallic and inorganic complexes formed in the estuarine and seawaters.
اظهر المزيد [+] اقل [-]Effects of Prorocentrum donghaiense bloom on zooplankton functional groups in the coastal waters of the East China Sea
2021
Zhang, Zhihao | Zhuang, Yunyun | Chen, Hongju | Lu, Songhui | Li, Yixuan | Ge, Ruping | Chen, Chang | Liu, Guangxing
Blooms of the non-toxic dinoflagellate Prorocentrum donghaiense are common in the East China Sea; however, the in situ impacts of these blooms on zooplankton community functions have not yet been conducted in this area. Using functional trait-based methods, we found that P. donghaiense bloom significantly changed the zooplankton community structure and functions in the coastal water of the East China Sea. Zooplankton species richness and biodiversity increased after the bloom. Based on body length, feeding type, trophic group and reproductive mode, we categorized zooplankton into four functional groups and characterized their dynamics. Before and after the bloom, the zooplankton community was dominated by herbivorous- and free-spawner- lineages represented by copepods and tunicates, while during the bloom, the zooplankton community was dominated by carnivorous- and egg-brooding- lineages represented by small jellyfish, chaetognaths and copepods.
اظهر المزيد [+] اقل [-]Characterization of microplastics in the water and sediment of Baram River estuary, Borneo Island
2021
Choong, Wei Sheng | Hadibarata, Tony | Yuniarto, Adhi | Tang, Kuok Ho Daniel | Abdullah, Faizuan | Syafrudin, Muhammad | Al Farraj, Dunia A. | Al-Mohaimeed, Amal M.
The Baram River is one of the largest rivers in Sarawak, where many large industries, such as plywood, sawmills, shipyards, interisland ports, and other wood-based industries are located along the river. Microplastic contamination has become a widespread and growing concern worldwide because of the small sizes of microplastics and their presence in seafood such as fish, squid, scallop, crabs, shrimp, and mussels. In this study, microplastics were found in all sampling stations. Out of the 4017 microplastics found in the water and sediment, microplastics fragment accounted for 67.8% of total microplastics, followed by fiber, film, pellet, and foam. Five microplastic polymer types were detected by ATR-FTIR, including polyethylene (PE), polyester (PET) fibers, silicon polymer, nitrile, and polystyrene (PS). The most common microplastics size range in Baram River was 0.3–1 mm, with blue as the highly abundant color.
اظهر المزيد [+] اقل [-]Microfiber abundance associated with coral tissue varies geographically on the Belize Mesoamerican Barrier Reef System
2021
Oldenburg, Kirsi S. | Urban-Rich, Juanita | Castillo, Karl D. | Baumann, Justin H.
Ocean plastic pollution is a global problem that causes ecosystem degradation. Crucial knowledge gaps exist concerning patterns in microfiber abundance across regions and ecosystems, as well as the role of these pollutants within the environment. Here, we quantified the abundance of microfibers in coral samples collected from the Belize Mesoamerican Barrier Reef System (MBRS) using a polarized light microscope and identified a subsample of these to the polymer level using an Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy microscope. Microfibers were found in all coral samples with rayon being identified as the most common microfiber, comprising 85% of quantified pollutants. We found a greater average abundance of microfibers in coral samples from the Sapodilla Cayes (296 ± SE 89) than in samples from the Drowned Cayes (75 ± SE 14), indicating spatial variation in microfiber abundance within coral tissue along the MBRS. These results demonstrate that corals on the Belize MBRS interact with microfibers and that microfiber abundance on reefs varies spatially due to point sources of pollution and local oceanography. As rayon from clothing typically enters the ocean through wastewater effluent, alterations to waste water infrastructure may prove useful in decreasing rayon pollution in coastal waters.
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