scholarly journals Distribution of carbon and nitrogen as indictors of environmental significance in coastal sediments of Weizhou Island, Beibu Gulf

2020 ◽  
Author(s):  
Zhiyi Tang ◽  
Chao Cao ◽  
Kunxian Tang ◽  
Hongshuai Qi ◽  
Yuanmin Sun ◽  
...  
Keyword(s):  
Intertidal Zone ◽  
Coastal Sediments ◽  
Upstream Region ◽  
Beibu Gulf ◽  
Northern Coast ◽  
Environmental Significance ◽  
Tidal Zone ◽  
Ams Radiocarbon Dating ◽  
Carbon And Nitrogen ◽  
Oxygen Isotopic

Carbon and nitrogen contents and their isotopic components and AMS radiocarbon dating ages were measured for 57 coastal sediments from Weizhou Island to analyze the distribution of total inorganic carbon (TIC) and its carbon and oxygen isotopic components (δ13Ccarb and δ18Ocarb), total organic carbon (TOC) and total nitrogen (TN) contents and their stable isotopic components (δ13CTOC and δ15NTN) and environmental significance. The results showed that the oldest age of coastal sediments on Weizhou Island was 2750 cal. a BP, and the average TIC contents of A1, A2, B1, C1, and D1 in the intertidal zone were all greater than 5%, where δ13Ccarb and δ18Ocarb were enriched, while the TIC contents in A3, C2, and D2 of the supra-tidal zone were low, where δ13Ccarb and δ18Ocarb were depleted. Moreover, TIC decreased sharply from the estuary to upstream region in the C1-C2 section. The average C/N ratio was 7.02, and δ13CTOC and δ15NTN were between -14.96‰~-27.26‰ and -14.38‰~4.12‰, respectively. These measurements indicated that the TIC in coastal sediments mainly came from seawater. A1, A2, and B1 in the northern intertidal zone exhibited organic terrestrial signals because of C3 and C4 plant inputs, which proved that the important source of the northern coast of Weizhou Island came from the island. The lacustrine facies deposits were mainly distributed in the upper reaches of the river, the northern coastline was rapidly advancing toward the sea, and part of the southwestern coastal sediments rapidly accumulated to the shore under the influence of a storm surge. The relative sea level of the Weizhou Island area has continuously declined at a rate of approximately 2.07 mm/a, using beach rock as a marker, since the Holocene.

scholarly journals Distribution of Carbon and Nitrogen as Indictors of Environmental Significance in Coastal Sediments of Weizhou Island, Beibu Gulf

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3285
Author(s):  
Zhiyi Tang ◽  
Chao Cao ◽  
Kunxian Tang ◽  
Hongshuai Qi ◽  
Yuanmin Sun ◽  
...  
Keyword(s):  
Intertidal Zone ◽  
Coastal Sediments ◽  
Upstream Region ◽  
C3 Plants ◽  
Beibu Gulf ◽  
Northern Coast ◽  
Environmental Significance ◽  
Tidal Zone ◽  
Carbon And Nitrogen ◽  
Oxygen Isotopic

Carbon and nitrogen contents and their isotopic components, and AMS (Accelerator Mass Spectrometry) radiocarbon dating ages, were measured for 57 coastal sediments from Weizhou Island to analyze the distribution of total inorganic carbon (TIC) and its carbon and oxygen isotopic components (δ13Ccarb and δ18Ocarb), total organic carbon (TOC) and total nitrogen (TN) contents and their stable isotopic components (δ13CTOC and δ15NTN), and their environmental significance. The results showed that the oldest age of coastal sediments on Weizhou Island was 2750 cal. a BP (before present), and the average TIC contents of cores A1, A2, B1, C1, and D1 in the intertidal zone were all greater than 5%, where δ13Ccarb and δ18Ocarb were enriched, whereas the TIC contents in cores A3, C2, and D2 of the supra-tidal zone were low, where δ13Ccarb and δ18Ocarb were depleted. Moreover, TIC decreased sharply, 4.95% on average, to close to zero from the estuary to the upstream region in the C1-C2 section. The average C/N ratio was 7.02, and δ13CTOC and δ15NTN were between −14.96‰ and −27.26‰ and −14.38‰ and 4.12‰, respectively. These measurements indicate that the TIC in coastal sediments mainly came from seawater. Cores A1, A2, and B1 in the northern intertidal zone exhibited organic terrestrial signals because of C3 and C4 plant inputs, which indicates that the important source on the northern coast of Weizhou Island came from island land but followed the decrease in C3 plants. The lacustrine facies deposits were mainly distributed in the upper reaches of the river, the northern coastline was advancing toward the sea, and part of the southwestern coastal sediments rapidly accumulated on the shore under the influence of a storm surge. The relative sea level of the Weizhou Island area has continuously declined at a rate of approximately 2.07 mm/a, using beach rock as a marker, since the Holocene.

Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

Isotope Paleobiology of the Vertebrates: Ecology, Physiology, and Diagenesis

1998 ◽  
Vol 4 ◽  
pp. 101-137
Author(s):  
Reese E. Barrick
Keyword(s):  
Stable Isotopes ◽  
Tooth Enamel ◽  
Temperature Changes ◽  
Carbon And Nitrogen ◽  
Oxygen Oxygen ◽  
Dinosaur Extinction ◽  
Isotopic Analyses ◽  
Isotopic Studies ◽  
Oxygen Isotopic ◽  
Isotopic Variations

Isotopic studies of vertebrate material have a short history, while isotopic analyses of invertebrates originated in the 1940's. Interestingly, the driving force behind Harold Urey's desire to derive a carbonate paleotemperature scale in the 1940's and 1950's was the hope that it would solve the mystery of dinosaur extinction by demonstrating temperature changes at the K/T boundary. The most useful and commonly investigated stable isotopes for paleobiologic studies of vertebrates are carbon, nitrogen and oxygen. Oxygen is available from the inorganic bone or tooth apatite phase. Carbon is most often derived from tooth enamel carbonate or organic collagen, and nitrogen is derived from collagen. Each of these stable isotopes provides information on different aspects of an animal's biology and when combined, provide powerful analyses for ecological and evolutionary reconstructions. In the 1970's, much work was done describing the carbon and nitrogen variations in plants. This period was followed in the late 1970's and early 1980's by research on these isotopic variables in mammals (e.g., DeNiro and Epstein, 1978, 1981; Vogel, 1978; Van der Merwe, N.J., 1982). The utility of these isotopes for dietary recognition led to their extensive investigation in archeological studies. Not until the mid to late 1980's and 1990's have these isotopes been utilized in both the inorganic component of teeth and bones as well as the organic component of bones in Pleistocene and older paleobiologic studies. The 1980's also saw the emergence of research on the oxygen isotopic variations in mammals. However, the focus of isotopic studies on vertebrates was not for paleobiologic purposes, but rather, for attempts to derive paleohydrologic or paleoclimatic information from them (e.g., Longinelli, 1984; Luz et al., 1984).

Scleractinian corals (Cnidaria: Anthozoa) from reef ecosystems on the Alagoas coast, Brazil

2010 ◽  
Vol 91 (3) ◽  
pp. 659-668 ◽  
Author(s):  
Monica Dorigo Correia
Keyword(s):  
Intertidal Zone ◽  
Coral Species ◽  
Scleractinian Corals ◽  
Northern Coast ◽  
Southern Coast ◽  
Quaternary Period ◽  
North East ◽  
Distribution And Ecology ◽  
Siderastrea Stellata ◽  
Reef Platform

The distribution and ecology of scleractinian corals on reef ecosystems along the coast of the State of Alagoas, north-east Brazil, were characterized. The scleractinians comprised 13 species in nine families, with five endemic corals, on the Alagoas coast. All of these species were found on reef ecosystems of two distinct geological origins. Coral reefs are predominant on the northern and central coast with banks near the beach line and distributed along the coast line, with many platform surfaces emerging during low tide. Sandstone reefs are more common along the south coast of Maceió city and the southern coast of Alagoas. These reefs were formed by old sand banks solidified through sedimentation starting from chemical reactions with calcium carbonate or iron oxide from the Quaternary period, and are generally in rows parallel to the coastline and near the outlets of rivers and estuaries. A few species including Favia gravida and Siderastrea stellata were found in the intertidal zone on top of the reef platform of both types of reefs. The other scleractinian species were observed on the reef borders where there were some inlets and channels. A larger number of coral species occur on the northern coast where the seawater is clearer throughout the year.

Les Pierres de Mémoire: The Life History of Two Statue-Menhirs from Guernsey, Channel Islands

2015 ◽  
Author(s):  
Heather Sebire
Keyword(s):  
Tidal Range ◽  
Channel Islands ◽  
Western Coast ◽  
Northern Coast ◽  
Tidal Zone ◽  
North West ◽  
The North ◽  
Female Figures ◽  
History Of ◽  
Maternal Presence

Many prehistoric monuments survive in the landscape and are revered by later generations but there is a special category of artefacts and monuments that reflect images of ourselves, sometimes with just faces and sometimes as life-size human figures. On Guernsey, in the Channel Islands, just off the north-west coast of France, two statuemenhirs or standing stones survive that appear to represent female figures, although the form of the stones themselves may have masculine traits also. Guernsey is the most westerly of the Channel Islands and so it is particularly surprising that these exceptional human representations should be found there (Kinnes 1995). The menhirs have witnessed a long history and have been refigured in modern times possibly in an attempt to Christianize them. One has even been given the local nickname of the ‘Grand Mere’, implying a benign maternal presence. Guernsey is one of a group of small islands that lie strategically placed in the western Channel off the northern coast of France, collectively known as the Channel Islands. The islands of Alderney, Sark, Herm, Lihou and Jethou are part of its Bailiwick, but the largest island of Jersey is independent. Guernsey is positioned some 50 kilometres off the western coast of the Cotentin peninsula of Normandy in France and 120 kilometres from mainland Britain. The Bay of Saint Malo, in which Guernsey and the other Channel Islands are situated, has a very large tidal range due to its position and currents. As a result of this, the inter-tidal zone is extensive. Guernsey is 7.5 kilometres at its widest point and 14 kilometres long, with an area of about 63 square kilometres. This area increases at low tide by some 11 square kilometres. As the great French novelist Victor Hugo famously said, . . . The Channel Islands are fragments of France that fell into the sea and were gathered up by England [ ... ] Of the four islands, Sark, the smallest, is the most beautiful; Jersey, the largest, is the prettiest; Guernsey, wild and charming shares their characteristics. (Hugo 1839, v) . . .

Comparison of flooding-tolerance in four mangrove species in a diurnal tidal zone in the Beibu Gulf

2007 ◽  
Vol 74 (1-2) ◽  
pp. 254-262 ◽  
Author(s):  
Binyuan He ◽  
Tinghe Lai ◽  
Hangqing Fan ◽  
Wenqing Wang ◽  
Hailei Zheng
Keyword(s):  
Beibu Gulf ◽  
Flooding Tolerance ◽  
Mangrove Species ◽  
Tidal Zone

Dolichopodidae (Diptera) from Papua New Guinea. X. Description of the new species of the marine genus Cymatopus Kertesz*

1993 ◽  
Vol 7 (6) ◽  
pp. 1575
Author(s):  
P Grootaert ◽  
HJG Meuffels
Keyword(s):  
New Species ◽  
Thin Layer ◽  
Papua New Guinea ◽  
Intertidal Zone ◽  
New Guinea ◽  
Monophyletic Group ◽  
Northern Coast ◽  
Southern Coast ◽  
Biological Station ◽  
The Western Pacific

Four species of the marine genus Cymatopus are reported from the coasts of Papua New Guinea. Two species, C. calcaratoides, sp. nov. (northern coast), and C. motuporensis, sp. nov. (southern coast), and the female of C. leopoldi Meuffels & Grootaert are described. Together with C. calcaratus and C. malayensis, they form a distinct monophyletic group in the western Pacific. The larvae and pupae of Cymatopus live in the thin layer of algae and debris on the rocks in the eulittoral zone. The adult flies feed at low tide on the larvae of chironomids and ceratopogonids in the intertidal zone. *Contribution No. 257 of the Leopold I11 Biological Station on Laing Island.

Occurrence and distribution of perfluoroalkyl substances in surface riverine and coastal sediments from the Beibu Gulf, south China

2020 ◽  
Vol 150 ◽  
pp. 110706 ◽  
Author(s):  
Chang-Gui Pan ◽  
Ying-Hui Wang ◽  
Ke-Fu Yu ◽  
Wei Zhang ◽  
Jun Zhang ◽  
...  
Keyword(s):  
South China ◽  
Coastal Sediments ◽  
Perfluoroalkyl Substances ◽  
Beibu Gulf
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