Diel, seasonal and man-induced changes in copepod assemblages and diversity, with special emphasis on hyperbenthic calanoid species, in a Mediterranean meromictic system (Lake Faro)

2013 ◽  
Vol 64 (10) ◽  
pp. 951 ◽  
Author(s):  
G. Zagami ◽  
C. Brugnano
Keyword(s):  
Late Summer ◽  
Distribution Patterns ◽  
Plankton Community ◽  
Mediterranean Ecosystem ◽  
Ecological Group ◽  
Night Time ◽  
Remarkable Change ◽  
Abundance Pattern ◽  
Coastal Marine ◽  
Induced Changes

The present study focuses on variations in day and night copepod community structure in a meromictic Mediterranean ecosystem (Lake Faro). Because of the high salinity in the lake, this environment is defined as a coastal-marine rather than true-lagoon ecosystem. Copepod abundances showed wide oscillations, with marked spatial and seasonal heterogeneity. The copepod assemblage was dominated by coastal and estuarine species Paracartia latisetosa and Acartia margalefi, in late summer–autumn and spring, respectively. A remarkable change in species composition was the occurrence of the alien species Oithona brevicornis, never having been reported in this environment before. O. brevicornis is progressively replacing the congener species O. nana. The discovery of the hyperbenthic calanoid species ‘ecological group’ contributes to increased functional diversity of this ecosystem, despite their relatively low abundances. All six hyperbenthic calanoid species occurred in the plankton community only at night, with spatial distribution patterns being related to substrate more than water physico-chemical parameters. Among all hyperbenthic calanoid species, Pseudocyclops xiphophorus was the only one able to inhabit the whole lake because of its daytime habitat (fouling material, attached to submerged ropes and mooring posts, widely distributed all around the lake). In this habitat, the temporal abundance pattern resembled the night-time one in plankton community.

Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)

2011 ◽  
Vol 89 (9) ◽  
pp. 796-807 ◽  
Author(s):  
S. Tang ◽  
A.G. Lewis ◽  
M. Sackville ◽  
L. Nendick ◽  
C. DiBacco ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Pink Salmon ◽  
Distribution Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Night Time ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Louse ◽  
Seawater Acclimation

We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.

scholarly journals Processing of biomass burning aerosol in the Eastern Mediterranean during summertime

2013 ◽  
Vol 13 (10) ◽  
pp. 25969-25999 ◽  
Author(s):  
A. Bougiatioti ◽  
I. Stavroulas ◽  
E. Kostenidou ◽  
P. Zarmpas ◽  
C. Theodosi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Biomass Burning ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Organic Aerosol ◽  
High Temporal Resolution ◽  
Night Time ◽  
Air Masses ◽  
Aerosol Mass ◽  
Atmospheric Processing

Abstract. The aerosol chemical composition in air masses affected by wildfires from the Greek islands of Chios, Euboea and Andros, the Dalmatian Coast and Sicily, during late summer of 2012 was characterized at the remote background site of Finokalia, Crete. Air masses were transported several hundreds of kilometers, arriving at the measurement station after approximately half a day of transport, mostly during night-time. The chemical composition of the particulate matter was studied by different high temporal resolution instruments, including an Aerosol Chemical Speciation Monitor (ACSM) and a seven-wavelength aethalometer. Despite the large distance from emission and long atmospheric processing, a clear biomass burning organic aerosol (BBOA) profile containing characteristic markers is derived from BC measurements and Positive Matrix Factorization (PMF) analysis of the ACSM mass spectra. The ratio of fresh to aged BBOA decreases with increasing atmospheric processing time and BBOA components appear to be converted to oxygenated organic aerosol (OOA). Given that the smoke was mainly transported overnight, it appears that the processing can take place in the dark. These results show that a significant fraction of the BBOA loses its characteristic AMS signature and is transformed to OOA in less than a day. This implies that biomass burning can contribute almost half of the organic aerosol mass in the area during summertime.

scholarly journals Extreme Levels of Ocean Acidification Restructure the Plankton Community and Biogeochemistry of a Temperate Coastal Ecosystem: A Mesocosm Study

2021 ◽  
Vol 7 ◽  
Author(s):  
Carsten Spisla ◽  
Jan Taucher ◽  
Lennart T. Bach ◽  
Mathias Haunost ◽  
Tim Boxhammer ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Fish Larvae ◽  
Plankton Community ◽  
Trophic Levels ◽  
Coastal Regions ◽  
Mesozooplankton Community ◽  
Planktonic Food ◽  
Elemental Stoichiometry ◽  
Secondary Consumers ◽  
Induced Changes

The oceans’ uptake of anthropogenic carbon dioxide (CO2) decreases seawater pH and alters the inorganic carbon speciation – summarized in the term ocean acidification (OA). Already today, coastal regions experience episodic pH events during which surface layer pH drops below values projected for the surface ocean at the end of the century. Future OA is expected to further enhance the intensity of these coastal extreme pH events. To evaluate the influence of such episodic OA events in coastal regions, we deployed eight pelagic mesocosms for 53 days in Raunefjord, Norway, and enclosed 56–61 m3 of local seawater containing a natural plankton community under nutrient limited post-bloom conditions. Four mesocosms were enriched with CO2 to simulate extreme pCO2 levels of 1978 – 2069 μatm while the other four served as untreated controls. Here, we present results from multivariate analyses on OA-induced changes in the phyto-, micro-, and mesozooplankton community structure. Pronounced differences in the plankton community emerged early in the experiment, and were amplified by enhanced top-down control throughout the study period. The plankton groups responding most profoundly to high CO2 conditions were cyanobacteria (negative), chlorophyceae (negative), auto- and heterotrophic microzooplankton (negative), and a variety of mesozooplanktonic taxa, including copepoda (mixed), appendicularia (positive), hydrozoa (positive), fish larvae (positive), and gastropoda (negative). The restructuring of the community coincided with significant changes in the concentration and elemental stoichiometry of particulate organic matter. Results imply that extreme CO2 events can lead to a substantial reorganization of the planktonic food web, affecting multiple trophic levels from phytoplankton to primary and secondary consumers.

Bacterioplankton: A Sink for Carbon in a Coastal Marine Plankton Community

Science ◽  
1986 ◽  
Vol 232 (4752) ◽  
pp. 865-867 ◽  
Author(s):  
H. W. DUCKLOW ◽  
D. A. PURDIE ◽  
P. J. LEB. WILLIAMS ◽  
J. M. DAVIES
Keyword(s):  
Plankton Community ◽  
Marine Plankton ◽  
Coastal Marine

scholarly journals The Relative Importance of Niche Process and Neutral Process in the Community Assembly of Subtropical Karst Forest: A Perspective on the Changes of Species Distribution Patterns at Different Scales

2021 ◽  
Author(s):  
Yan He ◽  
Yong Jiang ◽  
Hongling Lin ◽  
Yuanfang Pan ◽  
Shichu Liang ◽  
...  
Keyword(s):  
Community Assembly ◽  
Variation Partitioning ◽  
Species Abundance ◽  
Distribution Patterns ◽  
Relative Importance ◽  
Ecological Processes ◽  
Abundance Pattern ◽  
Karst Forest ◽  
Neutral Processes ◽  
Neutral Process

Abstract Background and aimsThe importance of niche processes and neutral processes to community assembly has been affirmed by most studies, although their relative importance needs to be determined in many systems. Moreover, as the spatial scale changes, the ecological processes that determine the community pattern may differ. We tested these ideas in subtropical karst forest in southwestern China in order to aid efforts of community reconstruction.MethodsTo test the importance of niche-based and neutral mechanisms we compared the fit six models to the observed SAD of the plot at three different sampling scales (10 m × 10 m, 20 m × 20 m, 50 m × 50 m). We also used spatial autocorrelation and distance-based Moran's eigenvector maps (dbMEM) combined with variation partitioning to further determine the relative contribution of the niche process and the neutral process under different sampling scales.ResultsThe neutral theoretical and statistical models fit the observed species abundance distribution curve best at each sampling scale. And variation partitioning showed that although the contribution of spatial structure was lower at larger sampling scales, it was still important, suggesting that neutral processes drive community structure at all sampling scales. In contrast, habitat filtering and interspecies competition may lead to a net weakening of the contribution of the niche process to the species abundance pattern of the community because they act in opposite directions. ConclusionsIn the restoration and reconstruction of local karst forest communities, environmental heterogeneity, inter-species relationships, and geographic spatial differences should all be considered.

Local movements of Greylag Geese Anser anser in South Sweden during the non-breeding season

Ornis Svecica ◽  
2017 ◽  
Vol 27 (1) ◽  
Author(s):  
Leif Nilsson ◽  
Hakon Kampe-Persson
Keyword(s):  
Late Summer ◽  
Distribution Patterns ◽  
Western Coast ◽  
Anser Anser ◽  
Breeding Sites ◽  
Feeding Sites ◽  
South West ◽  
South Sweden ◽  
The Difference ◽  
Greylag Geese

During 1984–2009, Greylag Geese Anser anser were neck-banded at two lakes six kilometres apart in south-west Scania, southernmost Sweden: 2,308 at lake Yddingen and 633 at Klosterviken (part of lake Börringe). Through 2013 we recorded 51,132 and 29,937 resightings, respectively. We analyse the distribution patterns within Scania during the post-breeding months July–March. In spite of the short distance between the breeding sites, marked differences in the local distributions were found. In late summer and early autumn, Greylags from Klosterviken stayed longer inland close to the breeding lake than geese from Yddingen, the availability of good inland feeding sites close to Klosterviken explained the difference. In late autumn, when many resightings were made along the western coast, it seemed that the distance from the breeding lake explained some of the differences, geese from Yddingen dominated in the northern part, whereas geese from Klosterviken were found further south. There was also a time difference in that the birds from Yddingen moved to the coast earlier than those from Klosterviken.

scholarly journals Effect of Magnesium Supplementation on the Distribution Patterns of Zinc, Copper, and Magnesium in Rabbits Exposed to Prolonged Cadmium Intoxication

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Zorica Bulat ◽  
Danijela Đukić-Ćosić ◽  
Biljana Antonijević ◽  
Petar Bulat ◽  
Dragana Vujanović ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Beneficial Effect ◽  
Aqueous Solutions ◽  
Distribution Patterns ◽  
Atomic Absorption Spectrophotometry ◽  
Magnesium Supplementation ◽  
Beneficial Effects ◽  
Absorption Spectrophotometry ◽  
Induced Changes ◽  
Cd Exposure

The present study is designed to investigate whether magnesium (Mg) supplementation may prevent Cd-induced alterations in zinc (Zn), copper (Cu), and magnesium (Mg) status in rabbits. For this purpose, the concentrations of Zn, Cu, and Mg were estimated in blood, urine, and organs (brain, heart, lungs, liver, kidney, spleen, pancreas, skeletal muscle, and bone) of rabbits given Cd (10 mg/kg b.w.) and rabbits cotreated with Mg (40 mg/kg b.w.) orally, as aqueous solutions of Cd chloride and Mg acetate every day for 4 weeks. Samples were mineralized with conc. HNO3and HClO4(4:1) and metals concentrations were determined by atomic absorption spectrophotometry (AAS). Magnesium supplementation succeeded to overcome Cd-induced disbalance of investigated bioelements. Beneficial effects of Mg were observed on Zn levels in blood and urine, on Cu levels in urine, and on Mg levels in blood. Magnesium pretreatment also managed to counteract or reduce all Cd-induced changes in levels of Cu and Mg in organs, while it did not exert this effect on Zn levels. These findings suggest that enhanced dietary Mg intake during Cd exposure can have at least partly beneficial effect on Cd-induced alterations in homeostasis of zinc, copper, and magnesium.

scholarly journals Linking Microbial Functioning and Trophic Pathways to Ecological Status in a Coastal Mediterranean Ecosystem

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1325
Author(s):  
Franco Decembrini ◽  
Carmela Caroppo ◽  
Gabriella Caruso ◽  
Alessandro Bergamasco
Keyword(s):  
Coastal Waters ◽  
Sea Water ◽  
Ecological Status ◽  
Mediterranean Ecosystem ◽  
The North ◽  
Coastal Marine ◽  
Prokaryotic Abundance ◽  
Trophic Pathways ◽  
Terrestrial Inputs ◽  
Heterotrophic Production

Coastal marine ecosystems host complex microbial communities whose composition and metabolism are influenced by continental inputs and mesoscale properties of seawater masses. The identifying traits of the phytoplankton and bacteria such as biomass, size, shape and their metabolism related to organic matter production and degradation, recognized as indicators of the functioning of an ecosystem, were observed in the Gulf of Manfredonia (South Adriatic Sea, Italy) in late spring. This Gulf area is characterized by terrestrial inputs and mesoscale circulation influence such as coastal waters flowing southward from the North Adriatic and offshore waters interested by the Ionian Sea. Water samples were grouped in clusters (Coastal, Intermediate, Offshore and Deep Systems) according to the water column properties. Phytoplankton community biomass and composition, autotrophic and total prokaryotic abundances and microbial metabolism such as enzyme activity rates and prokaryotic heterotrophic production were analyzed to elucidate the trophic pathways with the objective to infer on the ecosystem status. As expected, size-fractionated phytoplankton biomass and production showed greater concentration in coastal waters with prevalence of the largest fractions (micro- and nano-) supported by the diatoms. Conversely, lower biomass and production were measured in all off-shore waters, mainly sustained by smallest fractions (nano-sized phytoflagellates and picophytoplankton). Total and autotrophic prokaryotic abundance decreased from coastal to offshore stations, inversely with respect to cell volume. Prokaryotic heterotrophic production was just below 50% compared to that of phytoplankton in all waters, evidencing an active biomass synthesis. High alkaline phosphatase and leucine aminopeptidase in coastal and offshore waters suggested the quick regeneration of Phosphorus and protein decomposition, respectively. Different levels of phytoplankton-bacteria association might provide a tool to define the ecological status of the studied system in the observed period; an approach to ecosystem assessment exportable to other coastal systems is proposed.

scholarly journals Pandemic Induced Changes in Economic Activity around African Protected Areas Captured through Night-Time Light Data

2021 ◽  
Vol 13 (2) ◽  
pp. 314
Author(s):  
Anupam Anand ◽  
Do-Hyung Kim
Keyword(s):  
Protected Areas ◽  
Economic Activity ◽  
Protected Area ◽  
Economic Activities ◽  
Night Time ◽  
Key Sectors ◽  
Travel Restrictions ◽  
Proxy Measure ◽  
Spatially Explicit Data ◽  
Induced Changes

The importance of tourism for development is widely recognized. Travel restrictions imposed to contain the spread of COVID-19 have brought tourism to a halt. Tourism is one of the key sectors driving change in Africa and is based exclusively on natural assets, with wildlife being the main attraction. Economic activities, therefore, are clustered around conservation and protected areas. We used night-time light data as a proxy measure for economic activity to assess change due to the pandemic. Our analysis shows that overall, 75 percent of the 8427 protected areas saw a decrease in light intensity in varying degrees in all countries and across IUCN protected area categories, including in popular protected area destinations, indicating a reduction in tourism-related economic activities. As countries discuss COVID-19 recovery, the methods using spatially explicit data illustrated in this paper can assess the extent of change, inform decision-making, and prioritize recovery efforts.

scholarly journals The role of volatile organic compounds in the polluted urban atmosphere of Bristol, England

2003 ◽  
Vol 3 (4) ◽  
pp. 1165-1176 ◽  
Author(s):  
A. C. Rivett ◽  
D. Martin ◽  
D. J. Gray ◽  
C. S. Price ◽  
G. Nickless ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Late Summer ◽  
Early Spring ◽  
Urban Atmosphere ◽  
Electron Capture Detection ◽  
Night Time ◽  
Urban Background ◽  
Flame Ionisation ◽  
Selection Of

Abstract. The results of a field campaign carried out from early spring through to the late summer of 2000, in Bristol, England, are presented. Continuous measurements of over 40 hydrocarbons have been made at an urban background site, located at Bristol University, for approximately nine months using a Gas Chromatography - Flame Ionisation Detection (GC-FID) system and for a selection of halocarbons for approximately one month using a Gas Chromatography - Electron Capture Detection (GC-ECD) system. In this paper we present the time-series of the nine halocarbons and selected hydrocarbons. Daytime and night-time hydroxyl radical concentrations have been estimated based on the diurnal variations of a selection of the measured hydrocarbons. The average summer daytime concentration of OH was found to be 2.5x106 molecules cm-3 and the night-time concentration to be in the range 104 to 105 molecules cm-3. In addition, the role played by certain VOCs in the formation of ozone is assessed using the POCP (Photochemical Ozone Creation Potential) concept.

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