scholarly journals Seasonal Changes in Microbial Dissolved Organic Sulfur Transformations in Coastal Waters

2020 ◽  
Vol 8 (3) ◽  
pp. 337
Author(s):  
Joanna L Dixon ◽  
Frances E Hopkins ◽  
John A Stephens ◽  
Hendrik Schäfer

The marine trace gas dimethylsulfide (DMS) is the single most important biogenic source of atmospheric sulfur, accounting for up to 80% of global biogenic sulfur emissions. Approximately 300 million tons of DMS are produced annually, but the majority is degraded by microbes in seawater. The DMS precursor dimethylsulfoniopropionate (DMSP) and oxidation product dimethylsulphoxide (DMSO) are also important organic sulfur reservoirs. However, the marine sinks of dissolved DMSO remain unknown. We used a novel combination of stable and radiotracers to determine seasonal changes in multiple dissolved organic sulfur transformation rates to ascertain whether microbial uptake of dissolved DMSO was a significant loss pathway. Surface concentrations of DMS ranged from 0.5 to 17.0 nM with biological consumption rates between 2.4 and 40.8 nM·d−1. DMS produced from the reduction of DMSO was not a significant process. Surface concentrations of total DMSO ranged from 2.3 to 102 nM with biological consumption of dissolved DMSO between 2.9 and 111 nM·d−1. Comparisons between 14C2-DMSO assimilation and dissimilation rates suggest that the majority of dissolved DMSO was respired (>94%). Radiotracer microbial consumption rates suggest that dissimilation of dissolved DMSO to CO2 can be a significant loss pathway in coastal waters, illustrating the significance of bacteria in controlling organic sulfur seawater concentrations.

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2271
Author(s):  
Pretom Saha ◽  
Nepu Saha ◽  
Shanta Mazumder ◽  
M. Toufiq Reza

Co-hydrothermal carbonization (Co-HTC) is an emerging technology for processing multiple waste streams together to improve their fuel properties in the solid product, known as hydrochar, compared to the hydrothermal carbonization (HTC) of those individual streams. Sulfur is considered one of the most toxic contaminants in solid fuel and the combustion of this sulfur results in the emission of SOx. It was reported in the literature that, besides the fuel properties, Co-HTC reduced the total sulfur content in the hydrochar phase significantly. However, the transformation of different forms of sulfur has not yet been studied. Therefore, this study investigated the transformation of different forms of sulfur under the Co-HTC treatment. In the study, the Co-HTC of food waste (FW) and two types of coal wastes (middle bottom (CW1) and 4 top (CW2)) were conducted at 180 °C, 230 °C and 280 °C for 30 min. Different forms of sulfur were measured by using elemental analysis (total sulfur), and a wet chemical method (sulfate sulfur and pyritic sulfur). The organic sulfur was measured by the difference method. The results showed that a maximum of 49% and 65% decrease in total sulfur was achieved for CW1FW and CW2FW, respectively, at 230 °C. Similar to the total sulfur, the organic sulfur was also decreased about 85% and 75% for CW1FW and CW2FW, respectively. Based on these results, a sulfur transformation mechanism under Co-HTC treatment was proposed.


1989 ◽  
Vol 16 (2) ◽  
pp. 141 ◽  
Author(s):  
P Bayliss ◽  
WJ Freeland

Aerial surveys of coastal waters (27 216 km2) in the western Gulf of Carpentaria during the dry season of 1984 and wet season of 1985 indicated no major seasonal changes in distribution and relative abundance of dugongs. Minimum population size in the dry season was estimated as 16 816 � 2946 (standard error), with a relative density of 0.62 k 0.11 km-2, and that for the wet season 16 846 + 3257, with a relative density of 0.62 � 0.12 km-2. The estimates exclude 5% of observations which could have been either dugongs or Irrawaddy dolphins, and were corrected for submerged dugongs and those missed on the surface. Dugongs were unevenly distributed over the study area, and neither mean group size nor proportion of calves varied between seasons. Dugong abundance was correlated with area of available seagrass. The catch rate of dugongs by Aboriginal people off Numbulwar decreased six-fold between the 1960s and 1985 (60 to 10 p.a.), possibly due to excessive hunting.


Zootaxa ◽  
2008 ◽  
Vol 1807 (1) ◽  
pp. 47
Author(s):  
QINGXI HAN ◽  
XINZHENG LI

Based on the material collected mainly by the National Comprehensive Oceanography Survey (1959) and the ChinaVietnam Comprehensive Oceanographic Survey to Beibu Gulf (Gulf of Tonkin) (1959–1960, 1962) from coastal waters of the mainland of China, four Pontocaris species, P. hilarula (De Man, 1918), P. major Chan, 1996, P. pennata Bate, 1888 and P. sibogae (De Man, 1918), are reported in the present paper, of which the former two are reported for the first time from Chinese waters. The seasonal changes of the population of the most common species, P. pennata, are discussed.


1974 ◽  
Vol 52 (11) ◽  
pp. 1311-1315 ◽  
Author(s):  
J. Harling ◽  
R. M. F. S. Sadleir

The frequency distribution of over 600 stomach weights of deer mice showed considerable variation and was highly skewed. Because of the difficulty of defining a "full" stomach, it was not possible to use the weights of stomachs sampled to estimate consumption rates. There were no significant seasonal changes in mean stomach weights over a 3-year study and no relationship between stomach weights and sexual condition was found.


Author(s):  
P. Laskaridou Nott

Abra alba and Abra tenuis are closely related marine bivalves. They both inhabit similar types of sandy-mud sediments but they prefer different localities. The smaller A. tenuis is found in a few scattered intertidal mudflats, whereas A. alba is more widely distributed and in great abundance in the coastal waters of north-west Europe. The latter can be found at any depth between low-water mark and 80 m (Tebble, 1966; Ansell, 1974) and often forms the dominant species of shallow water benthic communities.The reproductive cycle of the two species has been studied and compared as a part of a wider ecological investigation. There is minimal literature concerning the reproduction of A. tenuis but A. alba has received a lot of attention, because it forms a major source of food for flatfish. However, most of the earlier investigations are confined to the time that spawning occurs with the evidence derived from either the time of the year that larvae appear in the plankton (Lebour, 1938; Jorgensen, 1946; Fosshagen, 1965; Muus, 1973; Rasmusen, 1973), or the time of the year that juveniles first appear in the bottom samples (Orton, 1924; Ford, 1925; Stephen, 1932). The inadequacy of such indirect methods has been discussed by Seed (1969,1975, 1976). Ansell (1974) derived the reproductive cycle of A. alba from seasonal changes in the biochemical composition. In the present investigation, histological techniques have been used, since they are considered to offer the most reliable information about the reproductive cycle (Seed, 1969, 1975, 1976).


2017 ◽  
Vol 12 (2) ◽  
pp. 95-105
Author(s):  
Nadir M. Al-Abri ◽  
Sergey A. Piontko ◽  
Mahnaz Rabbaniha ◽  
Khalid Al-Hashmi ◽  
Tatyana Chesalina

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1806 ◽  
Author(s):  
Feng-Hsin Hsu ◽  
Chih-Chieh Su ◽  
Pei-Ling Wang ◽  
In-Tian Lin

Submarine groundwater discharge (SGD) is evidenced around Taiwan, but the seasonal/temporal changes of SGD have not been fully examined. Here, we report a time-series investigation of SGD into a tide-dominated coastal wetland, the Gaomei Wetland, located to the south of the Da-Chia River’s mouth, western Taiwan, by using environmental tracers (222Rn, 224Raex, 228Ra, δD, and δ18O). Our results showed that regardless of dry and wet seasons, the 222Rn activities in coastal waters were high at low tide but low at high tide. It represents the continuous input of 222Rn-enriched groundwater. However, the 224Raex and 228Ra activities showed seasonal changes with tide conditions. In the dry season, the 224Raex and 228Ra activities in coastal waters were low at low tide but high at high tide; whereas in the wet season, an opposite relation was observed with quite high 224Raex and 228Ra activities in the low-tide waters. Coupled with the lower δD and δ18O values of coastal and pore waters in the dry season, in comparison to those in the wet season, it is suggested that these phenomena probably reflected a seasonal difference in the main SGD component with fresh SGD in the dry season, but saline ones in the wet season. Based on a 222Rn mass balance model, the estimated SGD fluxes into the Gaomei Wetland varied with tidal fluctuations and ranged from 0.2 to 25 cm d−1 and from 0.1 to 47 cm d−1 for the dry and wet seasons, respectively. A slightly high SGD flux occurring during the wet season at spring tide, implied a stronger tidal pumping coupled with a larger hydraulic gradient between land and sea. In this study, we demonstrated that the variation of SGD into the Gaomei Wetland is not only controlled by the seasonal changes of groundwater recharge, but also by the tidal pumping process.


2013 ◽  
Vol 93 (6) ◽  
pp. 1525-1531 ◽  
Author(s):  
S. Satheesh ◽  
S.G. Wesley

The diversity and distribution of polychaete species under the families Nereididae, Syllidae and Eunicidae in sub-tidal fouling assemblage was studied by submerging wood as test substratum. Wooden panels were fitted onto a raft and submerged in Kudankulam coastal waters (south east coast of India) in pre-monsoon, monsoon and post-monsoon seasons from May 2003 to July 2005. Panels (in replicate) were retrieved from the raft at 15-day intervals. A total of 24 polychaete species belonging to the three families were identified from the test panels.Perinereis cultrifera,Platynereis dumerilii,Syllis variegata,Syllis truncata, andEunice australiswere the dominant species observed on the test panels. The abundance of major polychaete group was varied considerably between the panel series submerged in May 2003 (post-monsoon), November 2003 (monsoon) and July 2004 (pre-monsoon). The major difference in the polychaete community structure was the low abundance of both nereidids on pre-monsoon season panels and the eunicids on monsoon and post-monsoon season panels.


1983 ◽  
Vol 40 (8) ◽  
pp. 1258-1263 ◽  
Author(s):  
David J. Carlson ◽  
Lawrence M. Mayer

Seasonal changes in profiles of both UV absorbance and phenolic material versus salinity were observed in some estuarine and coastal waters of the Gulf of Maine. Profiles of riverine UV-absorbent and phenolic materials were seasonally invariant, with slight losses from high molecular weight fractions during estuarine mixing. In estuaries containing significant populations of fucoid macroalgae, exudation by the macroalgae increased levels of these parameters by as much as threefold. These increases showed a strong seasonal pulsing, following water temperature. This pulsing was detectable in seasonal transects of adjacent shelf waters.


Sign in / Sign up

Export Citation Format

Share Document