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Resultados 2821-2830 de 6,558
Initial beach litter survey in a conservation unit (Santa Isabel Biological Reserve, Sergipe) from northeast Brazil Texto completo
2020
Santos, Ana Alice | Nobre, Fernanda Silva de Melo | Ribeiro, Fabianne | Nilin, Jeamylle
This study aimed to evaluate the presence and distribution of litter on four beaches in a conservation unit in northeast Brazil (Santa Isabel Biological Reserve; SIBR), and at the tourist beach of Pirambu (PB). Samplings occurred during low tide in March 2018 and May 2018. We observed that PB contained a higher number of litter items (March = 12.5 ± 1.2 items m⁻¹; May = 6.1 ± 2.1 items m⁻¹) when compared to SIBR beaches with a general average of 1.7 ± 0.8 items·m⁻¹ (March) and 2.1 ± 1.1 items·m⁻¹ (May). Plastics were the most quantified items (~ 80% in PB and ~ 90% in SIBR). SIBR beaches were considered moderately clean. Despite access restriction on the SIBR beaches, the considerable amount of litter found in those beaches (mainly near the villages) calls attention to the importance of waste management improvements in Sergipe cities.
Mostrar más [+] Menos [-]Marine plastic debris in Central Chile: Characterization and abundance of macroplastics and burden of persistent organic pollutants (POPs) Texto completo
2020
Gomez, Victoria | Pozo, Karla | Nuñez, Dariela | Přibylová, Petra | Audy, Ondřej | Baini, Matteo | Fossi, Maria Cristina | Klánová, Jana
In this study, we characterized plastic debris (PD) found on beaches from Concepción Bay in central Chile during spring 2017 and summer 2018. The identification of polymers was carried out using FT-IR. Persistent organic pollutants (POPs) were extracted with hexane using an ultrasonic bath and further quantified through GC–MS. The highest abundance of PD was obtained during the summer (4.1 ± 3.7 items/m²), with the most common size range between 2.5 and 10 cm (42%) and the most frequent shape were plastic fragments (44%). FT-IR analysis showed that polypropylene was the most recurrent plastic polymer found. The ∑10PBDEs ranged from 2.1 to 1300 ng/g in spring 2017 and 392 to 3177 ng/g in summer 2018. ∑7PCBs ranged from 0.9 to 93 ng/g during the spring 2017 and 0.3 to 4.5 ng/g for summer 2018. This study is the first with information on POPs occurrence in the plastic debris of central Chile.
Mostrar más [+] Menos [-]Polycyclic aromatic hydrocarbons (PAHs) in marine organisms from two fishing grounds, South Yellow Sea, China: Bioaccumulation and human health risk assessment Texto completo
2020
Zhang, Chuchu | Li, Yali | Wang, Chenglong | Feng, Ziyue | Hao, Zhe | Yu, Wenwen | Wang, Teng | Zou, Xinqing
Sediment and marine organism samples collected from Haizhou Bay and Lusi fishing ground in South Yellow Sea, China were analysed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 PAHs in marine organisms ranged from 127.43 to 350.53 ng/g dry weight (dw, Haizhou Bay fishing ground) and from 86.37 to 213.02 ng/g dw (Lusi fishing ground). The dominant compounds were 2- and 3-ring PAHs in marine organism tissues. The main PAH sources were found to be coal combustion. Specific habitat, feeding habit, trophic level and environmental differences may affect the PAH levels in marine organisms in our study area. The biota–sediment accumulation factor (BSAF) decreased with increasing PAH log Kₒw and BSAF values might differ in response to various environmental conditions and species. The excess cancer risk from PAH-contaminated seafood consumption was slightly higher than the guideline value (10⁻⁶), but much lower than the priority risk level (10⁻⁴).
Mostrar más [+] Menos [-]Degradation of bio-based and biodegradable plastics in a salt marsh habitat: Another potential source of microplastics in coastal waters Texto completo
2020
Weinstein, John E. | Dekle, Jack L. | Leads, Rachel R. | Hunter, Rebecca A.
Degradation of bio-based (polylactic acid [PLA] cups, Mater-Bi® [MB] bags) and biodegradable plastics (biodegradable extruded polystyrene [bioPS] plates, biodegradable high density polyethylene [bioHDPE] bags) were compared to conventional plastics (recycled polyethylene terephthalate [rPET] cups, HDPE bags, extruded PS plates) in a salt marsh over a 32-week period. Following 4 weeks, biofilm developed on all plastics, resulting in an increased weight and concomitant decrease in UV transmission for most plastics. All plastics produced microplastic particles beginning at 4 weeks, with single-use bags producing the most microplastics over the 32-week period. At 32 weeks, SEM revealed microcracks and delamination for all plastics except PLA and MB, the latter of which degraded through embrittlement. IR spectral analysis indicated degradation for all plastics except PLA. Results suggest that degradation rates of bio-based and biodegradable plastics vary widely, with MB bags and bioPS plates demonstrating the greatest degradation, while PLA cups demonstrated the least degradation.
Mostrar más [+] Menos [-]Leatherback sea turtle (Dermochelys coriacea) hatch success and essential and nonessential metals in eggs and embryos from nests in St. Kitts (2015) Texto completo
2020
Dennis, Michelle M. | Poppenga, Robert | Conan, Anne | Hill, Kristine | Hargrave, Sabine | Maroun, Victoria | Stewart, Kimberly M.
Northwest Atlantic leatherback sea turtles (Dermochelys coriacea) are endangered and low hatch success limits potential for population recovery. We examined essential and nonessential metal concentrations in 43 eggs from nests on St. Kitts to determine if there was a relationship with hatch success. Whole homogenized embryos and undeveloped eggs contained detectable concentrations of arsenic, barium, copper, iron, selenium, vanadium, and zinc, but not beryllium, cadmium, chromium, cobalt, lead, mercury, molybdenum, and thallium. Of detected metals, only vanadium concentrations negatively correlated with hatch success (P = 0.01). Manganese and vanadium were associated with pneumonia occurring in the nest, and arsenic with renal mineralization. This study adds to the knowledge regarding baseline values for environmental contaminants in sea turtles, supporting the trend that leatherback eggs have relatively low concentrations of toxic metals, lacking a strong relationship with hatch success, and normally contain the essential elements copper, iron, selenium, and zinc.
Mostrar más [+] Menos [-]Historical inputs of polycyclic aromatic hydrocarbons in the preserved tropical estuary of the Itapicuru River, Bahia, Brazil Texto completo
2020
Guimarães, Lucas Medeiros | De França, Elvis Joacir | de Arruda, Gilberto Nascimento | Albergaria-Barbosa, Ana Cecília Rizzatti de
The aim of present study was to evaluate temporal changes in the distribution of polycyclic aromatic hydrocarbons (PAHs) in the estuary of the Itapicuru (Brazil). A sediment core was sampled in the study area. Concentrations of the 16 priority PAHs were analyzed using gas chromatography coupled to a mass spectrometry. A gas flow proportional counter was used to estimate the sedimentation rate through the determination of ²¹⁰Pb. Granulometric fractions and total organic carbon (TOC) concentrations were also evaluated. Concentrations of TOC and PAHs ranged from 0.65 to 2.51% and 1.98 to 43.1 ng g⁻¹ (dry weight), respectively. Significant correlations (p < .05) were found between the mud content in the sediment core samples and concentrations of both TOC and PAHs. Higher PAH concentrations occurred after the 1950s. The main sources of PAHs over time were local human activities on the northern coast of the state of Bahia.
Mostrar más [+] Menos [-]Ecosystem-based fisheries management and the precautionary approach in the Indian Ocean regional fisheries management organisations Texto completo
2020
Karim, Saiful | Techera, Erika | Arif, Abdullah Al
The Indian Ocean hosts a wide range of living resources including fish stocks. Marine resources contribute significantly to economies and livelihoods, and seafood is a major source of protein in Indian Ocean nations. Fisheries resources in the Indian Ocean have started showing symptoms of depletion. Several regional fisheries management organisations (RFMOs) have been established for sustainable management of the fisheries resources in the Indian Ocean region. These RFMOs were created at different times with various particular mandates, and in some cases prior to the emergence of contemporary scientific concepts and legal approaches to marine environmental governance. In this article, eight such RFMOs are studied to determine the implementation of ecosystem-based fisheries management (EBFM) and the precautionary approach (PA), which are now widely accepted norms of fisheries management and international law. This article argues that there is a mismatch between the legal and governance frameworks, and the fisheries science and management.
Mostrar más [+] Menos [-]Characteristics of long-term changes in microbial communities from contaminated sediments along the west coast of South Korea: Ecological assessment with eDNA and physicochemical analyses Texto completo
2020
Lee, Aslan Hwanhwi | Lee, Junghyun | Noh, Junsung | Lee, Changkeun | Hong, Seongjin | Kwon, Bong-Oh | Kim, Jae Jin | Khim, Jong Seong
The environmental DNA (eDNA) metabarcoding was applied to assess benthic ecological health in the west coast of South Korea by investigating a long-term microbial community change (2015–17). The ecological interaction among microorganisms, from phylum to family level, and their associations to environmental variables across the five regions were highlighted. As part of the study, the available chemistry and toxicological data in the regions during the monitoring periods were incorporated into an integrated sediment triad assessment. The bacterial communities were dominated by Proteobacteria (34.2%), Bacteroidetes (13.8%), and Firmicutes (10.8%). Proteobacteria and Bacteroidetes dominated consistently across regions and years, while Firmicutes and Cyanobacteria significantly varied by region and years (p < 0.05). The abundance of this phylum declined over time with the increasing abundance of Cyanobacteria, indicating their independent interactions to certain environmental changes. Planctomycetes and Gemmatimonadetes linked to some contaminants (ΣPAHs and Cu), implying indicator taxa. Overall, eDNA-based microbial community analysis combined with exposures of contaminants and responses of microorganisms is a promising strategy for the assessment of benthic ecological health in contaminated sediments from coastal waters.
Mostrar más [+] Menos [-]Red-legged cormorant uses plastic as nest material in an artificial breeding colony of Atacama Desert coast Texto completo
2020
Garcia-Cegarra, Ana M. | Ramírez, Roberto | Orrego, Rodrigo
Plastic debris affects the survival of numerous marine species such as seabirds. Several studies have report ingestion and entanglement of seabird species in plastic debris but just few describe plastic presence in nests. Here we report the first evidence of a novel artificial nesting colony of red-legged cormorant (Phalacrocorax gaimardi) using plastic as nesting material in two major seaport structures in Northern Chile. We sampled 18 abandoned nests and determined that overall nests contained plastic: industrial polypropylene bulk bags (35%), plastic bags (33%) and fishing gear (10%). Plastic types differ among seaports, ENAEX (National Company of Explosives) seaport located near the main city contained plastic bags as predominant material while GNL (Liquid Natural Gas Company) seaport located near the industrial area contained bulkbag fibers. Further research should analyze debris in beaches nearby the nesting colony in order to assess whether red-legged cormorants have any plastic preference or if they use the most available in the nature.
Mostrar más [+] Menos [-]Variability of dinoflagellates and their associated toxins in relation with environmental drivers in Ambon Bay, eastern Indonesia Texto completo
2020
Likumahua, Sem | de Boer, M Karin | Krock, Bernd | Hehakaya, Salomy | Imu, La | Müller, Annegret | Max, Thomas | Buma, Anita G.J.
Variability of dinoflagellates and their associated toxins in relation with environmental drivers in Ambon Bay, eastern Indonesia Texto completo
2020
Likumahua, Sem | de Boer, M Karin | Krock, Bernd | Hehakaya, Salomy | Imu, La | Müller, Annegret | Max, Thomas | Buma, Anita G.J.
The aim of the present work was to unravel which environmental drivers govern the dynamics of toxic dinoflagellate abundance as well as their associated paralytic shellfish toxins (PSTs), diarrhetic shellfish toxins (DSTs) and pectenotoxin-2 (PTX2) in Ambon Bay, Eastern Indonesia. Weather, biological and physicochemical parameters were investigated weekly over a 7-month period. Both PSTs and PTX2 were detected at low levels, yet they persisted throughout the research. Meanwhile, DSTs were absent. A strong correlation was found between total particulate PST and Gymnodinium catenatum cell abundance, implying that this species was the main producer of this toxin. PTX2 was positively correlated with Dinophysis miles cell abundance. Vertical mixing, tidal elevation and irradiance attenuation were the main environmental factors that regulated both toxins and cell abundances, while nutrients showed only weak correlations. The present study indicates that dinoflagellate toxins form a potential environmental, economic and health risk in this Eastern Indonesian bay.
Mostrar más [+] Menos [-]Variability of dinoflagellates and their associated toxins in relation with environmental drivers in Ambon Bay, eastern Indonesia Texto completo
2020
Likumahua, Sem | de Boer, M. Karin | Krock, Bernd | Hehakaya, Salomy | Imu, La | Müller, Annegret | Max, Thomas | Buma, Anita G. J.
The aim of the present work was to unravel which environmental drivers govern the dynamics of toxic dinoflagellate abundance as well as their associated paralytic shellfish toxins (PSTs), diarrhetic shellfish toxins (DSTs) and pectenotoxin-2 (PTX2) in Ambon Bay, Eastern Indonesia. Weather, biological and physicochemical parameters were investigated weekly over a 7-month period. Both PSTs and PTX2 were detected at low levels, yet they persisted throughout the research. Meanwhile, DSTs were absent. A strong correlation was found between total particulate PST and Gymnodinium catenatum cell abundance, implying that this species was the main producer of this toxin. PTX2 was positively correlated with Dinophysis miles cell abundance. Vertical mixing, tidal elevation and irradiance attenuation were the main environmental factors that regulated both toxins and cell abundances, while nutrients showed only weak correlations. The present study indicates that dinoflagellate toxins form a potential environmental, economic and health risk in this Eastern Indonesian bay.
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