Coccolithophores in surface sediments of the Arabian Sea in relation to environmental gradients in surface waters

2002 ◽  
Vol 186 (3-4) ◽  
pp. 505-526 ◽  
Author(s):  
Harald Andruleit ◽  
Ulf Rogalla
Keyword(s):  
Surface Waters ◽  
Arabian Sea ◽  
Surface Sediments ◽  
Environmental Gradients

Assessment of the Effect of Increasing Temperature On the Ecology and Assemblage Structure of Modern Planktic Foraminifers in the Caribbean and Surrounding Seas

2018 ◽  
Vol 48 (3) ◽  
pp. 251-272 ◽  
Author(s):  
Anna Jentzen ◽  
Joachim Schönfeld ◽  
Ralf Schiebel
Keyword(s):  
Surface Waters ◽  
Surface Sediments ◽  
Seawater Temperature ◽  
Chlorophyll Concentration ◽  
Caribbean Sea ◽  
Trophic Conditions ◽  
Near Surface ◽  
The Caribbean ◽  
Standing Stocks ◽  
The 1960S

Abstract Habitat patterns of subtropical and tropical planktic foraminifers in the Caribbean Sea were obtained from plankton samples collected in spring 2009 and 2013. The spatial distribution in surface waters (3.5 m water depth) and depth habitat patterns (surface to 400 m) of 33 species were compared with prevailing water-mass conditions (temperature, salinity, and chlorophyll-a concentration) and planktic foraminiferal test assemblages in surface sediments. Distribution patterns indicate a significant relationship with seawater temperature and trophic conditions. A reduction in standing stocks was observed close to the Orinoco River plume and in the Gulf of Paria, associated with high turbidity and concomitant low surface-water salinity. In contrast, a transient mesoscale patch of high chlorophyll concentration in the eastern Caribbean Sea was associated with higher standing stocks in near surface waters, including high abundances of Globigerinita glutinata and Neogloboquadrina dutertrei. Globorotalia truncatulinoides mainly lives close to the seasonal pycnocline and can be linked to winter conditions indicated by lower sea-surface temperatures (SSTs) of ∼20°C. Globigerinoides sacculifer and Globoturborotalita rubescens were associated with oligotrophic conditions in the pelagic Caribbean Sea during early spring and showed a synodic lunar reproduction cycle. The live assemblages in the water column from 2009 and 2013 were similar to those reported in earlier studies from the 1960s and 1990s and to assemblages of tests in the surface sediments. Minor differences in faunal proportions were attributed to seasonal variability and environmental differences at the local scale. An exception was the low relative abundance of Globigerinoides ruber in the Caribbean Sea in 2009 compared to surface sediment samples and plankton net samples collected in the 1960s and 1990s. Decreasing abundance of Gs. ruber white in the Caribbean Sea may be associated with increasing SSTs over past decades and changes in nutrient flux and primary production.

scholarly journals Microplastics and anthropogenic fibre concentrations in lakes reflect surrounding land use

PLoS Biology ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. e3001389
Author(s):  
Andrew J. Tanentzap ◽  
Samuel Cottingham ◽  
Jérémy Fonvielle ◽  
Isobel Riley ◽  
Lucy M. Walker ◽  
...  
Keyword(s):  
Land Use ◽  
Wastewater Treatment ◽  
Surface Waters ◽  
Water Retention ◽  
Forest Cover ◽  
Field Survey ◽  
Environmental Gradients ◽  
Waste Production ◽  
Future Work ◽  
Local Hydrology

Pollution from microplastics and anthropogenic fibres threatens lakes, but we know little about what factors predict its accumulation. Lakes may be especially contaminated because of long water retention times and proximity to pollution sources. Here, we surveyed anthropogenic microparticles, i.e., microplastics and anthropogenic fibres, in surface waters of 67 European lakes spanning 30° of latitude and large environmental gradients. By collating data from >2,100 published net tows, we found that microparticle concentrations in our field survey were higher than previously reported in lakes and comparable to rivers and oceans. We then related microparticle concentrations in our field survey to surrounding land use, water chemistry, and plastic emissions to sites estimated from local hydrology, population density, and waste production. Microparticle concentrations in European lakes quadrupled as both estimated mismanaged waste inputs and wastewater treatment loads increased in catchments. Concentrations decreased by 2 and 5 times over the range of surrounding forest cover and potential in-lake biodegradation, respectively. As anthropogenic debris continues to pollute the environment, our data will help contextualise future work, and our models can inform control and remediation efforts.

scholarly journals STUDY OF SOME ENVIRONMENTAL IMPLICATIONS DUE TO THE DISPOSAL OF ASHES FROM THE SÃO JERÔNIMO POWER STATION - RS

1997 ◽  
Vol 5 (5) ◽  
pp. 7-19
Author(s):  
Haidi D. Fiedler ◽  
Manuel Carneiro ◽  
Elba C. Teixeira
Keyword(s):  
Surface Waters ◽  
Surface Sediments ◽  
River Sediments ◽  
Cumulative Effect ◽  
Environmental Standards ◽  
Power Station ◽  
Short Term ◽  
Environmental Implications ◽  
Ph Values ◽  
Brazilian Legislation

The residues (ash agglomerates from combustion) generated at the São Jerônimo Power Station (UTSJ) were characterized with the main objective of evaluating, in pre-established conditions, the release of Cd, Co, Cu, Pb, Ni, Zn, Mn, Al, and Fe to the environment. Results revealed that, at different pH values, Fe, Zn, Mn, and Al were present in higher contents. In surface waters, for all sites analyzed, Fe and Al surpass the environmental standards imposed by Brazilian Legislation for class II surface waters. Surface sediments at the sites studied are basically composed by ashes from UTSJ, and a cumulative effect of deposition of the metals on the river sediments was verified. The experimental results are strongly indicative of an imperative need for a change in criteria in relation to the final disposal of residues from UTSJ. Otherwise, there is a high risk that the environmental impact in the short term will irreversibly damage the environment.

scholarly journals Short-term fate of phytodetritus in sediments across the Arabian Sea Oxygen Minimum Zone

2008 ◽  
Vol 5 (1) ◽  
pp. 43-53 ◽  
Author(s):  
J. H. Andersson ◽  
C. Woulds ◽  
M. Schwartz ◽  
G. L. Cowie ◽  
L. A. Levin ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Inorganic Carbon ◽  
Surface Sediments ◽  
Dissolved Inorganic Carbon ◽  
Oxygen Minimum Zone ◽  
Short Term ◽  
Minimum Zone ◽  
Algal Material ◽  
Oxygen Minimum

Abstract. The short-term fate of phytodetritus was investigated across the Pakistan margin of the Arabian Sea at water depths ranging from 140 to 1850 m, encompassing the oxygen minimum zone (~100–1100 m). Phytodetritus sedimentation events were simulated by adding ~44 mmol 13C-labelled algal material per m2 to surface sediments in retrieved cores. Cores were incubated in the dark, at in situ temperature and oxygen concentrations. Overlying waters were sampled periodically, and cores were recovered and sampled (for organisms and sediments) after durations of two and five days. The labelled carbon was subsequently traced into bacterial lipids, foraminiferan and macrofaunal biomass, and dissolved organic and inorganic pools. The majority of the label (20 to 100%) was in most cases left unprocessed in the sediment at the surface. The largest pool of processed carbon was found to be respiration (0 to 25% of added carbon), recovered as dissolved inorganic carbon. Both temperature and oxygen were found to influence the rate of respiration. Macrofaunal influence was most pronounced at the lower part of the oxygen minimum zone where it contributed 11% to the processing of phytodetritus.

scholarly journals Marine Reservoir Correction for the Cocos (Keeling) Islands, Indian Ocean

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 603-610 ◽  
Author(s):  
Quan Hua ◽  
Colin D Woodroffe ◽  
Mike Barbetti ◽  
Scott G Smithers ◽  
Ugo Zoppi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Indian Ocean ◽  
Red Sea ◽  
Surface Waters ◽  
Accelerator Mass Spectrometry ◽  
Arabian Sea ◽  
Indonesian Throughflow ◽  
Gulf Of Aden ◽  
The Indian Ocean ◽  
Reservoir Age

Known-age corals from the Cocos (Keeling) Islands, Indian Ocean, have been analyzed by accelerator mass spectrometry (AMS) for radiocarbon to determine marine reservoir age corrections. The ΔR value for the Cocos (Keeling) Islands is 66 ± 12 yr based on the analyses undertaken for this study. When our AMS and previously published dates for Cocos are averaged, they yield a ΔR of 64 ± 15 yr. This is a significant revision of an earlier estimate of the ΔR value for the Cocos (Keeling) Islands of 186 ± 66 yr (Toggweiler et al. 1991). The (revised) lower ΔR for the Cocos (Keeling) Islands is consistent with GEOSECS 14C data for the Indian Ocean, and previously published bomb 14C data for the Red Sea, Gulf of Aden, and Cocos Islands. The revised ΔR is also close to values for the eastern Indian Ocean and adjacent seas. These suggest surface waters that reach the Cocos Islands might be partly derived from the far western Pacific, via the Indonesian throughflow, and might not be influenced by the southeast flow from the Arabian Sea.

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