خيارات البحث
النتائج 1811 - 1820 من 4,938
Detecting the occurrence of indigenous and non-indigenous megafauna through fishermen knowledge: A complementary tool to coastal and port surveys النص الكامل
2019
Azzurro, E. | Bolognini, L. | Dragičević, B. | Drakulović, D. | Dulčić, J. | Fanelli, E. | Grati, F. | Kolitari, J. | Lipej, L. | Magaletti, E. | Marković, O. | Matić-Skoko, S. | Mavrič, B. | Milone, N. | Joksimović, A. | Tomanić, J. | Scarpato, A. | Tutman, P. | Vrdoljak, D. | Zappacosta, F.
Marine bioinvasions and other rapid biodiversity changes require today integrating existing monitoring tools with other complementary detection strategies to provide a more efficient management. Here we explored the efficacy of fishermen observations and traditional port surveys to effectively track the occurrence of both indigenous and non-indigenous megafauna in the Adriatic Sea. This consisted mainly of mobile taxa such as fishes, crustaceans and molluscs. Port surveys using traps and nets within 10 major Adriatic harbours, were compared with the information obtained from 153 interviews with local fishermen. Information gathered by traps and nets varied significantly and generally resulted of limited efficacy in exotic species detection. Interviews allowed tracking the occurrence of new species through time and space, providing complementary knowledge at the low cost. This combined approach improves our capability of being informed on the arrival of species of different origin, providing a more rational, improved basis for environmental management and decision making.
اظهر المزيد [+] اقل [-]Historical records of trace metals in core sediments from Jiangsu coastal area, China النص الكامل
2019
Qiu, Jiandong | Yin, Ping | Liu, Jinqing | Cao, Ke | Li, Meina | Wang, Shuang
The major and trace metal (Cu, Pb, Zn, Cr, Cd, As, Hg, Ni, Li, and Co) concentration profiles along a 60.2-m-long sediment core are investigated to assess their depositional trends and contamination levels in the Jiangsu coastal area, China. All of the metals, except Cd, had similar profiles that exhibited increasing concentrations during the Holocene. Their enrichment factors indicate that the metals were naturally sourced throughout the observed depositional period, with the exception of As, Hg, and Li, which may have also had anthropogenic sources. Their geoaccumulation indices indicate that the sediments were not contaminated by any metals prior to the Holocene, whereas they were contaminated by As, Hg, and Li throughout the Holocene (11–0 ka), and by Pb, Cr, and Zn since 2 ka.
اظهر المزيد [+] اقل [-]Morpho-functional effects of heat stress on the gills of Antarctic T. bernacchii and C. hamatus النص الكامل
2019
Garofalo, Filippo | Santovito, Gianfranco | Amelio, Daniela
The effect of increasing ocean water temperature on morpho-functional traits of Antarctic marine species is under intense attention.In this work, we evaluated the effects of acute heat stress on the gills of the Antarctic haemoglobinless Chionodraco hamatus and the red blooded Trematomus bernacchii in terms of morphology, heat shock response, antioxidant defense and NOS/NO system. We showed in both species that the exposure to high temperature (4 °C) induced structural alterations, such as epithelial lifting and oedema of secondary lamellae. By immunolocalization we also observed that HSP-90, HSP-70, Xantine Oxidase, Heme Oxigenase and NOS are expressed in both species under control conditions. After heat stress the signals increase in C. hamatus being absent/or reduced in T. bernacchii. Our preliminary results suggest a specie-specific morpho-functional response of the gills of the two Antarctic teleosts to heat stress.
اظهر المزيد [+] اقل [-]A 3D numerical model to Track Marine Plastic Debris (TrackMPD): Sensitivity of microplastic trajectories and fates to particle dynamical properties and physical processes النص الكامل
2019
Jalón-Rojas, Isabel | Wang, Xiao Hua | Fredj, Erick
Numerical modelling is a key tool in understanding and determining the sources, trajectories and fates of micro-plastic debris (MPD). In this study, we introduce TrackMPD, a new modelling framework for the 3D transport of marine debris. TrackMPD fills the gaps in previous models by: (1) using a three-dimensional approach; (2) providing compatibility with a variety of ocean models; and (3) including a wide range of physical processes (advection, dispersion, windage, sinking, settling, beaching and re-floating) and MPD behaviours that depend on particle dynamical properties, and the fouling and degradation states. We implement a sensitivity analysis based on 44 scenarios to assess the relative importance of the different processes and behaviours on the MPD trajectories and fates. Results show that the MPD dynamical properties that impact their sinking, in particular plastic density and biofilm thickness and density, have the biggest effect on the MPD transport, followed by turbulent dispersion and washing-off.
اظهر المزيد [+] اقل [-]Strategy of port baseline surveys (PBS) in the Adriatic Sea النص الكامل
2019
Kraus, Romina | Ninčević-Gladan, Živana | Auriemma, Rocco | Bastianini, Mauro | Bolognini, Luca | Cabrini, Marina | Cara, Magdalena | Čalić, Marijeta | Campanelli, Alessandra | Cvitković, Ivan | Despalatović, Marija | Dragičević, Branko | Drakulović, Dragana | Dulčić, Jakov | Flander-Putrle, Vesna | Grati, Fabio | Grego, Mateja | Grilli, Federica | Jaklin, Andrej | Janeković, Ivica | Kolitari, Jerina | Lipej, Lovrenc | Magaletti, Erika | Marini, Mauro | Matić-Skoko, Sanja | Mavrič, Borut | Mikuš, Josip | Mozetič, Patricija | Orlando Bonaca, Martina | Petović, Slavica | Precali, Robert | Supić, Nastjenjka | Trabucco, Benedetta | Travizi, Ana | Žuljević, Ante
Port baseline surveys (PBS) provide species inventories in and around ports, with a focus on non-indigenous species that may have been introduced by vessels, primarily via ballast water. PBS are an essential tool to support effective management strategies for non-indigenous as well as native harmful aquatic organisms and pathogens (HAOP). This paper describes the methodology of PBS that were conducted in 12 Adriatic ports. The PBS employed existing protocols that were adapted to meet the characteristics of the Adriatic sites. Their results are reported in several papers included in this special issue, each of which is devoted to a specific community. An overview of existing surveys protocols – which provide valuable support to decision-making and to design effective monitoring of non-indigenous species – is also supplied.
اظهر المزيد [+] اقل [-]Preliminary study and first evidence of presence of microplastics and colorants in green mussel, Perna viridis (Linnaeus, 1758), from southeast coast of India النص الكامل
2019
S.A., Naidu
Pollution by microplastics (MPs) is currently a global problem in the coastal and marine environment. Transfer of MPs from land to sea and their inclusion in the food web has a significant adverse effect on the marine life and human health. The present study was carried out at the fishing harbour of Chennai, southeast coast of India. The possible MPs were isolated from the soft tissues of the commercially important bivalve Perna viridis and examined by microscopic and DXR Raman spectroscopic methods. The MPs were identified as to be polystyrene polymers in the soft tissues. This investigation revealed that size and color are the major factors affecting the bioavailability of MPs to bivalves in the study area. The presence of colorants in organisms revealed an anthropogenic origin through the use of a wide array of applications. Hence, coastal zones are a hotspot for pollution by MPs, and filter feeding bivalves are at the highest risk. Therefore, further studies are required to understand the accumulation rates and residence time of MPs across the food webs.
اظهر المزيد [+] اقل [-]Using solitary ascidians to assess microplastic and phthalate plasticizers pollution among marine biota: A case study of the Eastern Mediterranean and Red Sea النص الكامل
2019
Vered, Gal | Kaplan, Aviv | Avisar, Dror | Shenkar, Noa
The interaction of microplastic (MP) with marine organisms is crucial for understanding the significant effect that MP and its additives may have on marine environments. However, knowledge regarding the magnitude of these pollutants in the Eastern Mediterranean Sea and the tropical Red Sea is still scarce. Here we examined the levels of phthalate acid esters (PAEs) and MP in Herdmania momus and Microcosmus exasperatus sampled along the Mediterranean and Red Sea coasts of Israel. High levels of dibutyl phthalate (DBP) and bis (2‑ethylhexyl) phthalate (DEHP) were found in ascidians at the majority of sampling sites, and MP particles were found in ascidians at all sites. As efficient filter-feeders and being widely-distributed, invasive ascidians present fundamental opportunities for the environmental monitoring of microplastic and its additives worldwide. The high levels of pollutants revealed emphasize the need for further research into the magnitude and effects of MP and PAEs in these regions.
اظهر المزيد [+] اقل [-]Trace elements in microplastics in Cartagena: A hotspot for plastic pollution at the Caribbean النص الكامل
2019
Acosta-Coley, Isabel | Mendez-Cuadro, Dario | Rodriguez-Cavallo, Erika | Rosa, Jesús de la | Olivero-Verbel, Jesus
Microplastics are new pollutants considered a source of concern for the oceans worldwide. This research reports the concentrations of trace metals on microplastics collected on beaches from Cartagena, an industrialized city in the Caribbean. Mercury (Hg) was quantified using a Hg analyzer and forty-seven trace elements were assessed by ICP/MS. Most abundant microplastics in beaches were those with the lower degree of surface degradation features (SDF), categorized as white-new polyethylene pellets, followed by secondary microplastics (SM). Greater Hg levels were found in SM, white-degraded (WDP) and black pellets. Trace elements concentrations were linked to the degree of SDF registered in examined pellets, with larger concentrations in WDP. Compared to white-new pellets, Ba, Cr, Rb, Sr, Ce, Zr, Ni, Pb were the most accumulated elements in WDP, as their surface enhance the sorption processes. Microplastic pollution represents a toxicological hazard because its ability to accumulate and transport toxic elements.
اظهر المزيد [+] اقل [-]Occurrence, seasonal variation and risk evaluation of selected endocrine disrupting compounds and their transformation products in Jiulong river and estuary, China النص الكامل
2019
Ashfaq, Muhammad | Sun, Qian | Ma, Cong | Rashid, Azhar | Li, Yan | Mulla, Sikandar I. | Yu, Chang-Ping
In the present study, 13 endocrine disrupting compounds (EDCs) and their transformation products (TPs) were monitored in Jiulong River and its estuary, China in different seasons. The analytes included antimicrobials [triclosan (TCS) and triclocarbon (TCC)]; estrogens [estrone (E1), estradiol (E2), estriol (E3) and ethinylestradiol (EE2)]; alkylphenol ethoxylates [4-n-nonylphenol (NP) and 4-n-octylphenol (OP)] and the TPs [methyl triclosan (MeTCS), carbanilide (NCC), dichlorocarbanilide, 4-hydroxy estrone (4-OH E1) and 4-hydroxy estradiol (4-OH E2)]. A significant seasonal variation was observed for most EDCs. Approximately, 79% of the total E2 residues were detected in the normal season in comparison with the wet season to indicate recalcitrant behavior of E2 during the normal season. Risk assessment revealed that E2 was most potent among the EDCs to cause highest risk to both vertebrate and invertebrate aquatic species, whereas, E1, EE2, MeTCS and TCS also showed relatively high risk for some surface water aquatic species.
اظهر المزيد [+] اقل [-]Description of buoyant fibers adhering to Argonauta nouryi (Cephalopoda: Argonautidae) collected from the stomach contents of three top predators in the Mexican South Pacific النص الكامل
2019
del Carmen Alejo-Plata, María | Herrera-Galindo, Eduardo | Cruz-González, Diana Guadalupe
Argonauta nouryi Lorois, 1852 is an octopod that inhabits the holopelagic zone, the objective of this study was to describe the occurrence of buoyant fibers adhering to the body and mantle cavity of A. nouryi females found in the stomach contents from Euthynnus lineatus (skipjack), Coryphaena hippurus (dolphinfish), and Istiophorus platypterus (sailfish). Stomach contents from 224 individuals were examined. All female evaluated presented fibers adhering to the mantle cavity; 92.6% of the fibers measured 0.25 to 5 mm in length and hyaline was the dominant color (72%). The amount of fibers in the fish stomach contents with A. nouryi was significantly greater than in stomachs without; this suggests that the fibers might be introduced via A. nouryi. Findings of this work could be related to the discharge of solid materials in the water column.
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