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Evaluation of trace metals in seawater, sediments, and bivalves of Nellore, southeast coast of India, by using multivariate and ecological tool Full text
2019
Jha, Dilip Kumar | Ratnam, Krupa | Rajaguru, S. | Dharani, G. | Devi, M Prashanthi | Kirubagaran, R.
Urbanization in recent years has driven us to investigate metal contamination on Nellore coast by collecting seawater, sediment, and bivalve samples monthly at five stations from 2015 to 2017. Non-metric multidimensional scaling and cluster analysis indicated that open sea (OS) samples were markedly different from the samples collected at other stations. Strong factor loadings of Al (0.76), Mn (0.79), and Cd (0.78) showed variability in seawater, while those for Fe (0.76), Ni (0.77), Zn (0.85), and Pb (0.81) showed variability in sediment. The mean values of Fe (346 ppm) and Mn (21 ppm) were high in bivalves compared to the mean values of other metals. A higher contamination factor was observed for Cd at Buckingham Canal, while the lowest was observed for sediment in OS. The order of trace metals in sediments according to risk index was Cd > Pb > Cu > Cr > Zn. The results obtained are essential to establish a reference for better comparison of tropical environments.
Show more [+] Less [-]Live fast, die young: Behavioural and physiological impacts of light pollution on a marine fish during larval recruitment Full text
2019
O'Connor, J.J. | Fobert, E.K. | Besson, M. | Jacob, H. | Lecchini, D.
Artificial light at night (ALAN) is a recently acknowledged form of anthropogenic pollution of growing concern to the biology and ecology of exposed organisms. Though ALAN can have detrimental effects on physiology and behaviour, we have little understanding of how marine organisms in coastal areas may be impacted. Here, we investigated the effects of ALAN exposure on coral reef fish larvae during the critical recruitment stage, encompassing settlement, metamorphosis, and post-settlement survival. We found that larvae avoided illuminated settlement habitats, however those living under ALAN conditions for 10 days post-settlement experienced changes in swimming behaviour and higher susceptibility to nocturnal predation. Although ALAN-exposed fish grew faster and heavier than control fish, they also experienced significantly higher mortality rates by the end of the experimental period. This is the first study on the ecological impacts of ALAN during the early life history of marine fish.
Show more [+] Less [-]Dinoflagellate resting cysts from surface sediments of the Adriatic Ports: Distribution and potential spreading patterns Full text
2019
Di Poi, Elena | Kraus, Romina | Cabrini, Marina | Finotto, Stefania | Flander-Putrle, Vesna | Grego, Mateja | Kužat, Nataša | Ninčević Gladan, Živana | Pezzolesi, Laura | Riccardi, Elena | Bernardi Aubry, Fabrizio | Bastianini, Mauro
The ability of microalgae to preserve viable in coastal sediments as resting forms provides a reservoir of biodiversity and a useful tool to determine species spreadings. This study represents the first port baseline survey on dinoflagellate cysts, investigated in nine Adriatic ports during a cross border project. 40 dinoflagellate taxa were detected. The assemblages resulted in all ports dominated by Lingulodinium polyedra and Alexandrium minutum/affine/tamutum group. General separation to the western and eastern side of the Adriatic regarding cysts assemblage composition, partially abundance, was observed. Six taxa were detected as non-indigenous species for the Adriatic. Two taxa are included in the list of harmful aquatic organisms, indicating the potential threat of ballast waters in the Adriatic. Potential spreading of taxa by general circulation and ballast waters, intra- and extra-Adriatic was investigated. The entering in to force of the ballast waters management regulations should enhance prospects to minimize future harmful impacts.
Show more [+] Less [-]Land use-induced change in trophic state of Shenzhen Bay (South China) over the past half-century Full text
2019
Yan, Hongyu | He, Xiufang | Lei, Yuanda | Wang, Yasu | Su, Hong | Jiang, Shijun
Mangroves connect terrestrial and marine ecosystems and are sensitive to environmental change, and the sediments within faithfully record long-term changes in the aquatic environment and supplement the generally short monitoring archives. Here we present a sediment-core record of TN, TP, TOC, and C/N ratios from the Futian mangrove wetland, Shenzhen Bay (South China), and compare with our remote sensing-derived land use change and the nearby seawater monitoring records. Our reconstructed record extends the history of tropic state change back to the Year 1958, supplementing the monitoring activity initiated in 1987. More importantly, the results reveal two distinct periods. The pre-1983 period (Year 1958–1982) is characterized by increased nutrient due to agricultural activities, while the post-1983 period (Year 1983–2014) is marked by reduced TP but relatively stable TN values, during which the simultaneous increase in construction lands and C/N ratios suggests enhanced soil erosion due to the rapid urbanization of Shenzhen City.
Show more [+] Less [-]Zooplankton dynamics in a highly eutrophic microtidal estuary Full text
2019
Rose, Thomas H. | Tweedley, James R. | Warwick, Richard M. | Potter, I. C.
Mesozooplankton was sampled seasonally in a large microtidal estuary (Peel-Harvey) suffering from massive macroalgal growths and cyanobacterial blooms. Comparisons with other estuaries indicate that eutrophication led to copepod abundance declining and macroalgal-associated species increasing. Mesozooplankton species are almost exclusively autochthonous, i.e. spend entire life cycle within the estuary. Meroplanktonic species are virtually absent because main benthic macroinvertebrate species undergo direct benthic rather than planktotrophic development. There are also few abundant holoplanktonic species. Most species are tychoplanktonic, i.e. benthic and transported into plankton through physical disturbance of sediment. Species number, concentration and Simpson's Index are greater during night than day. Annual cyclical changes in species composition are related closely to changes in salinity. At the most degraded site, nematode concentrations were high and the species number and concentration changed markedly during extreme eutrophication, when oxygen concentrations were low, disrupting annual cyclical changes in species composition.
Show more [+] Less [-]Hydrocarbon molecular markers in the Holocene bottom sediments of the Barents Sea as indicators of natural and anthropogenic impacts Full text
2019
Morgunova, Inna P. | Petrova, Vera I. | Litvinenko, Ivan V. | Kursheva, Anna V. | Batova, Galina I. | Renaud, Paul E. | Granovitch, Andrei I.
The recent intensification of energy resource exploration and human activities in the Barents Sea (BS) requires a more thorough assessment of the natural and anthropogenic impact of hydrocarbons on the environment. We analyzed a wide set of sensitive indicators, including hydrocarbon molecular markers and organic matter (OM) maturity parameters in the Holocene sediments from three regions of the BS: the Kola-Kanin Monocline (KKM), the Svalbard shelf, and the Shtokman gas-condensate field (GCF). An increase in pyrogenic polycyclic aromatic hydrocarbons toward the core surface traces the intensification of anthropogenic contamination in the KKM region during last century. An input of highly mature OM from the eroded coal rocks of Barentsburg were confirmed by comparison of biomarker distribution in sediments and coals. An increase in biogenic hopanes and hopenes content down-core, and a crude-oil stage of OM maturity in surface sediments of the Shtokman GCF attests to hydrocarbons migration from subsurface strata.
Show more [+] Less [-]Detecting the occurrence of indigenous and non-indigenous megafauna through fishermen knowledge: A complementary tool to coastal and port surveys Full text
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.
Show more [+] Less [-]Historical records of trace metals in core sediments from Jiangsu coastal area, China Full text
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.
Show more [+] Less [-]Morpho-functional effects of heat stress on the gills of Antarctic T. bernacchii and C. hamatus Full text
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.
Show more [+] Less [-]A 3D numerical model to Track Marine Plastic Debris (TrackMPD): Sensitivity of microplastic trajectories and fates to particle dynamical properties and physical processes Full text
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.
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