scholarly journals Crust Biometry of Hydrolithon Boreale (Rhodophyta: Hydrolithaceae) on Leave of Posidonia Oceanica Along a Mediterranean Coast Fed by Siliciclastic-Carbonate

2021 ◽  
Author(s):  
Erhan Mutlu ◽  
Doğukan Karaca ◽  
Güler Sıla Duman ◽  
Ahmet Şahin ◽  
Yaşar Özvarol ◽  
...  
Keyword(s):  
Trace Elements ◽  
Environmental Parameters ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Total Suspended Matter ◽  
The West ◽  
Area Index ◽  
Carbonate Deposition ◽  
Soft Bottoms ◽  
Reduced Density

Abstract A study was conducted to estimate biometry of an epiphytic micro-calcareous red algae, Hydrolithon boreale found on leaves of a Mediterranean meadow, Posidonia oceanica along the entire Turkish coast of the Mediterranean Sea in time (winter and summer 2019) and space (regions, and bottom type and depth). Percent occurrence of the epiphyte was lower in winter (25%), particularly found in a small bay in the west than summer (44%), entirely along the coast. The epiphyte grew up to 5 mm in diameter, 0.35 mm in thickness of the crust size, and was populated up to 1006 ind/m2 in summer owing to the increased utilization of the carbonate by the epiphyte with the increased water temperature. The size was contrasted to the density (abundance and biomass) in space. The biometry was significantly dependent on the siliciclastic-carbonate deposition as inferred from SiO2 of the water in relation the leaf area index (LAI) of P. oceanica. Therefore, this deposition induced specimens growing in size, followed by the reduced density in relation to N-based nutrient of the water. Further major environmental parameters which negatively affected the biometry were pH and total suspended matter of the water, analogous to the turbidity. Of the trace elements, Ni was negatively correlated with the biometry whereas the LAI was however positively correlated with all the anthropogenic-sourced trace elements (V, Cu, Zn, As, Cd, and Pb) in the leaves. Of the bottom types, the calcite rock had higher density than the other soft bottoms in contrast to the size of the epiphyte.

Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

2014 ◽  
Vol 8 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Emmanuel Wafo ◽  
Véronique Risoul ◽  
Thérèse Schembri ◽  
Véronique Lagadec ◽  
Frank Dhermain ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Marine Pollution ◽  
Element Distribution ◽  
Mediterranean Coast ◽  
Trace Element Distribution ◽  
Slight Reduction ◽  
Stenella Coeruleoalba ◽  
Contamination Levels

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

scholarly journals Posidonia oceanica as a Source of Chromophoric Dissolved Organic Matter for the Oligotrophic NW Mediterranean Coast

2020 ◽  
Vol 8 (11) ◽  
pp. 911
Author(s):  
Francesca Iuculano ◽  
Carlos M. Duarte ◽  
Jaime Otero ◽  
Xosé Antón Álvarez-Salgado ◽  
Susana Agustí
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Rocky Shore ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Balearic Islands ◽  
Chromophoric Dissolved Organic Matter ◽  
Absorption Increase ◽  
Seagrass Meadows ◽  
Nw Mediterranean

Posidonia oceanica is a well-recognized source of dissolved organic matter (DOM) derived from exudation and leaching of seagrass leaves, but little is known about its impact on the chromophoric fraction of DOM (CDOM). In this study, we monitored for two years the optical properties of CDOM in two contrasting sites in the Mallorca Coast (Balearic Islands). One site was a rocky shore free of seagrass meadows, and the second site was characterized by the accumulation of non-living seagrass material in the form of banquettes. On average, the integrated color over the 250–600 nm range was almost 6-fold higher in the beach compared with the rocky shore. Furthermore, the shapes of the CDOM spectra in the two sites were also different. A short incubation experiment suggested that the spectral differences were due to leaching from P. oceanica leaf decomposition. Furthermore, occasionally the spectra of P. oceanica was distorted by a marked absorption increase at wavelength < 265 nm, presumably related to the release of hydrogen sulfide (HS−) associated with the anaerobic decomposition of seagrass leaves within the banquettes. Our results provide the first evidence that P. oceanica is a source of CDOM to the surrounding waters.

scholarly journals Seasonal and Spatial Patterns of Ecotoxicological Indices of Trace Elements in Superficial Sediments of the Marchica Lagoon Following Restoration Actions during the Last Decade

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 51
Author(s):  
Bouchra Oujidi ◽  
Mohammed El Bouch ◽  
Mounia Tahri ◽  
Mostafa Layachi ◽  
Soilam Boutoumit ◽  
...  
Keyword(s):  
Trace Elements ◽  
Integrated Management ◽  
Risk Index ◽  
Sediment Quality ◽  
Contamination Factor ◽  
Management Plan ◽  
Mediterranean Coast ◽  
Pollution Indices ◽  
Ecological Value ◽  
Wet Season

Marchica Lagoon, a Ramsar site on the Mediterranean coast of Morocco, is experiencing the impacts of watershed pollution, which includes pollutants from the domestic, agricultural, industrial, and mining sectors. Restoration actions were undertaken around this lagoon during the last decade in order to protect its ecological value and to develop tourist activity. To conserve the biodiversity in the lagoon, it is important to assess the environmental state of this ecosystem. This study aims to evaluate the ecotoxicological state of sediments through the post restoration characterization of the trace elements Pb, Cu, Zn, Cr, Co, and Ba, as well as their correlation to the major elements, grain size, and total organic carbon, sampled during two campaigns (the wet and dry seasons of 2018) across a sampling network of thirteen stations. Multivariate analysis and ecotoxicological risk assessment of the trace elements using the sediment quality guidelines and five pollution indices (geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (CF), pollution-load index (PLI), and mean effect range median quotient (m-ERM-Q)) revealed contamination of the lagoon by Pb, Zn, and Cu, and minimal pollution by Cr, Co, and Ba. The distribution of the biological-risk index reveals that four zones of the lagoon may present a high probability of toxicity, thus constituting potential risk areas for aquatic organisms: during the wet season, the area in the northwestern sandbar border, the southwest eutrophication zone, and the mouth of the stream valley conveying industrial discharges; and during dry season, the northwestern eutrophication zone. Despite the restoration actions achieved around the lagoon, the lead, zinc, and copper concentrations increased, and their variation was significant between group stations. The biodiversity conservation of Marchica Lagoon requires continuous monitoring and assessment, as well as the implementation of an integrated management plan with restoration actions, not only around the lagoon, but also at its watershed level.

scholarly journals Monitoring of marine phanerogams’ habitats and assessment of areas exposed to anchoring in the International Marine Park of Bonifacio (Sardinia Area)

2015 ◽  
Author(s):  
Andrea Cossu ◽  
Mario De Luca ◽  
Yuri Donno
Keyword(s):  
Direct Method ◽  
Structural Characteristics ◽  
Ecological Status ◽  
Posidonia Oceanica ◽  
Monitoring And Control ◽  
Area Index ◽  
Marine Park ◽  
Minimum Requirements ◽  
Marine Areas ◽  
The Impact

The International Marine Park of the Strait of Bonifacio and the National Park of La Maddalena have started a series of investigations in the marine areas under their jurisdiction. Through the European project, GECT (European Group of Territorial Cooperation), studies have been carried out to define the type, the structural characteristics of the Posidonia oceanica seagrass and to evaluate the impact of dropping anchors. The study, carried out by a team of experts from the institutions named above, used shared methodologies in relation to the same type of challenges and problems. The study areas on the Sardinian side were Passo Asinelli pass, Porto della Madonna harbor and Cala Portese cove. For each site two stations were identified, a monitoring and a control one. The type of meadow, its morphological and structural characteristics (matte, rocks, degree of fragmentation, height of matte, etc.) and the possible presence of marks/signs caused by the dropping of anchors were assessed in selected areas. The compactness of the matte, estimated using a penetrometer, the percentage of seabed covered by the plant and density were assessed by direct method by divers. The results for the leaf density show the meadows are in regression; however, there are better conditions in Porto Madonna where the monitoring and control stations show density near to normal values. Particularly low values were measured in Passo Asinelli where, despite prohibitions, the high pressure of tourism generates stress to the plant formation. The leaf standing crop, the leaf area index and measures penetrometric lead to conclusions almost similar indicating best ecological conditions in Porto Madonna, confirming previous results. The indicators used show an ecological status of lesser quality for the sites of both Passo Asinelli and, more visible, of Cala Portese. Porto Madonna, on the other hand, shows values equal to the minimum requirements for a meadow surface.

Chapter 5.4b Marie Byrd Land and Ellsworth Land: petrology

2021 ◽  
pp. M55-2019-50 ◽  
Author(s):  
K. S. Panter ◽  
T. I. Wilch ◽  
J. L. Smellie ◽  
P. R. Kyle ◽  
W. C. McIntosh
Keyword(s):  
Trace Elements ◽  
Fractional Crystallization ◽  
High Pressures ◽  
Early Stage ◽  
Thermal Anomaly ◽  
Rift System ◽  
The West ◽  
Full Spectrum ◽  
West Antarctic Ice Sheet ◽  
West Antarctic

AbstractIn Marie Byrd Land and Ellsworth Land 19 large polygenetic volcanoes and numerous smaller centres are exposed above the West Antarctic Ice Sheet along the northern flank of the West Antarctic Rift System. The Cenozoic (36.7 Ma to active) volcanism of the Marie Byrd Land Volcanic Group (MBLVG) encompasses the full spectrum of alkaline series compositions ranging from basalt to intermediate (e.g. mugearite, benmoreite) to phonolite, peralkaline trachyte, rhyolite and rare pantellerite. Differentiation from basalt is described by progressive fractional crystallization; however, to produce silica-oversaturated compositions two mechanisms are proposed: (1) polybaric fractionation with early-stage removal of amphibole at high pressures; and (2) assimilation–fractional crystallization to explain elevated87Sr/86Sriratios. Most basalts are silica-undersaturated and enriched in incompatible trace elements (e.g. La/YbN>10), indicating small degrees of partial melting of a garnet-bearing mantle. Mildly silica-undersaturated and rare silica-saturated basalts, including tholeiites, are less enriched (La/YbN<10), a result of higher degrees of melting. Trace elements and isotopes (Sr, Nd, Pb) reveal a regional gradient explained by mixing between two mantle components, subduction-modified lithosphere and HIMU-like plume (206Pb/204Pb >20) materials. Geophysical studies indicate a deep thermal anomaly beneath central Marie Byrd Land, suggesting a plume influence on volcanism and tectonism.

scholarly journals Variasi Musiman Hubungan Antara Parameter Oceanografi Dengan Hasil Tangkapan Ikan Tongkol Berdasarkan Data Harian Di Selat Bali

2017 ◽  
Vol 4 (1) ◽  
pp. 109 ◽  
Author(s):  
I Gusti Agung Bagus Wisesa Sastra ◽  
I Wayan Gede Astawa Karang ◽  
Abd. Rahman As-syakur ◽  
Yulianto Suteja
Keyword(s):  
Chlorophyll A ◽  
Environmental Parameters ◽  
Pelagic Fish ◽  
Sea Surface ◽  
Fishing Ground ◽  
Temporal Fluctuation ◽  
Simple Correlation ◽  
The West ◽  
Chlorophyll A Concentration ◽  
Fish Catch

Mackerel fish that classified pelagic fish and an export commodity in Indonesia. Distribution of mackerel fish are foundn all Indonesian waters, one of them in the Bali Strait. Distribution of mackerel fish influenced by oceanographic condition such as sea surface temperature (SST) and chlorophyll-a concentration. SST and chlorophyll-a concentrations are environmental parameters that can provide information on fishing ground. The purpose of this research is explained the temporal fluctuation and relationship between SST and chlorophyll-a concentration with mackerel fish had been catch in Bali Strait waters during 2011-2016. Data were analyzed using simple correlation analysis with 95% confidence interval. Temporally, the highest average SST occurred during the transition season I (March-May) and the lowest in the east season (June-August). The highest average chlorophyll-a concentration occurs in the east season and the lowest in the west season (December-February). The highest catch of mackerel fish occurred during transitional season II (September-November) and lowest in west season. The association between SST and chlorophyll-a concentration on mackerel fish catch showed low correlation with significant relationship, whereas concentration between SST and chlorophyll-a concentration strong with significant correlation

scholarly journals Bayesian Sigmoid-Type Time Series Forecasting with Missing Data for Greenhouse Crops

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3246 ◽  
Author(s):  
Alexander Kocian ◽  
Giulia Carmassi ◽  
Fatjon Cela ◽  
Luca Incrocci ◽  
Paolo Milazzo ◽  
...  
Keyword(s):  
Time Series ◽  
Environmental Control ◽  
Measurement Data ◽  
Environmental Parameters ◽  
Integrated Approach ◽  
Crop Growth ◽  
Parameter Estimates ◽  
Sigmoid Function ◽  
Area Index ◽  
Hidden States

This paper follows an integrated approach of Internet of Things based sensing and machine learning for crop growth prediction in agriculture. A Dynamic Bayesian Network (DBN) relates crop growth associated measurement data to environmental control data via hidden states. The measurement data, having (non-linear) sigmoid-type dynamics, are instances of the two classes observed and missing, respectively. Considering that the time series of the logistic sigmoid function is the solution to a reciprocal linear dynamic model, the exact expectation-maximization algorithm can be applied to infer the hidden states and to learn the parameters of the model. At iterative convergence, the parameter estimates are then used to derive a predictor of the measurement data several days ahead. To evaluate the performance of the proposed DBN, we followed three cultivation cycles of micro-tomatoes (MicroTom) in a mini-greenhouse. The environmental parameters were temperature, converted into Growing Degree Days (GDD), and the solar irradiance, both at a daily granularity. The measurement data were Leaf Area Index (LAI) and Evapotranspiration (ET). Although measurement data were only available scarcely, it turned out that high quality measurement data predictions were possible up to three weeks ahead.

scholarly journals The Impacts of Growth and Environmental Parameters on Solar-Induced Chlorophyll Fluorescence at Seasonal and Diurnal Scales

2019 ◽  
Vol 11 (17) ◽  
pp. 2002
Author(s):  
Leizhen Liu ◽  
Wenhui Zhao ◽  
Jianjun Wu ◽  
Shasha Liu ◽  
Yanguo Teng ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Growth Parameters ◽  
Pearson Correlation ◽  
Canopy Structure ◽  
Principal Component ◽  
Environmental Parameters ◽  
Area Index ◽  
Relationship Of ◽  
The Impact

Solar-induced chlorophyll fluorescence (SIF) is considered to be a potential indicator of photosynthesis. However, the impact of growth and environmental parameters on SIF at different time-scales remains unclear, which has greatly restricted the application of SIF in detecting photosynthesis variations. Thus, in this study, the impact of growth and environmental parameters on SIF was thoroughly clarified. Here, continuous time series of canopy SIF (760 nm, F760) over wheat and maize was measured based on an automated spectroscopy system. Meanwhile, field measurements of growth and environmental parameters were also collected using commercial-grade devices. Relationships of these parameters with F760, apparent SIF (F760/solar radiance, AF760), and SIF yield (F760/canopy radiance of 685 nm, Fy760) were analyzed using principal component analysis (PCA) and Pearson correlation to reveal their impacts on SIF. Results showed that F760 at seasonal and diurnal scales were mainly driven by solar radiation (SWR), leaf area index (LAI), chlorophyll content (Chl), mean leaf inclination angle (MTA), and relative water content (RWC). Other environmental parameters, including air temperature (Ta), relative humidity (Rh), vapor pressure deficit (VPD), and soil moisture (SM), contribute less to the variation of seasonal or diurnal F760. AF760 and Fy760 are likely to be less dependent on Ta, Rh, and VPD due to the removal of the impact from SWR, but an enhanced relationship of AF760 (and Fy760) with SM was observed, particularly under water stress. Compared with F760, wheat AF760 was better correlated to LAI and RWC as expected, while maize AF760 did not show an enhanced relationship with all growth parameters, probably due to its complicated canopy structure. The relationship of wheat Fy760 with canopy structure parameters was further reduced, except for maize measurements. Furthermore, SM-induced water stress and phenological stages should be taken into consideration when we interpret the seasonal and diurnal patterns of SIF since they were closely related to photosynthesis and plant growth (e.g., LAI in our study). To our knowledge, this is the first exploration of the impacts of growth and environmental parameters on SIF based on continuous ground measurements, not only at a seasonal scale but also at a diurnal scale. Our results could provide deep insight into the variation of SIF signals and also promote the further application of SIF in the health assessments of terrestrial ecosystems.

Evaluation of the Extent of Contaminated Sediments in the West Branch of the Grand Calumet River, Indiana-Illinois, USA

1993 ◽  
Vol 28 (8-9) ◽  
pp. 53-58 ◽  
Author(s):  
R. A. Cahill ◽  
M. T. Unger
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Sediment Cores ◽  
River Sediments ◽  
Organic Carbon Content ◽  
Sedimentation Rates ◽  
The West ◽  
Surface Samples ◽  
Rate Information ◽  
The Mean

The extent of contamination in river sediments is often not rigorously evaluated. In many cases, only surface sediment samples are taken. In other cases, entire sediment cores are composited for analysis, an approach that limits the ability to identify discrete zones of contamination. In addition, few studies include information on the rate of sedimentation. Composited sediment cores, subsamples of cores made at discrete intervals, and surface samples were obtained from locations in the West Branch of the Grand Calumet River. The organic carbon content and concentrations of up to 26 major, minor, and trace elements were determined. Sedimentation rates at the ten locations were estimated using 137Cs. The mean concentrations of metals in the surface samples were considerably higher than concentrations in samples obtained by the two coring approaches. Only by analyzing discrete subsamples was it possible to plot the concentrations by depth and location. This approach was used to demonstrate that high levels of organic carbon and trace elements are confined between river miles 5 and 7.5. Sedimentation rate information combined with chemical analyses of the same cores indicate that contamination of this part of the river began in the 1930s.

Sign in / Sign up

Export Citation Format

Share Document