scholarly journals Seasonal variation in viral-induced mortality of bacterioplankton in the water column of a large mesotrophic lake (Lake Biwa, Japan)

2010 ◽  
Vol 58 ◽  
pp. 249-259 ◽  
Author(s):  
AS Pradeep Ram ◽  
Y Nishimura ◽  
Y Tomaru ◽  
K Nagasaki ◽  
T Nagata
Keyword(s):  
Seasonal Variation ◽  
Water Column ◽  
Lake Biwa ◽  
Mesotrophic Lake

scholarly journals Seasonal variation of glycollate-utilizing bacteria in the water column of lake Biwa.

1975 ◽  
Vol 41 (11) ◽  
pp. 1129-1134 ◽  
Author(s):  
Nobuhiko TANAKA ◽  
Masami NAKANISHI ◽  
Hajime KADOTA
Keyword(s):  
Seasonal Variation ◽  
Water Column ◽  
Lake Biwa

Seasonal variation of water-column light utilization efficiency for primary production in Saroma-ko Lagoon

2021 ◽  
pp. 1-9
Author(s):  
Akihiro Shiomoto ◽  
Yushi Kamuro
Keyword(s):  
Seasonal Variation ◽  
Primary Production ◽  
Water Column ◽  
Fresh Water ◽  
Utilization Efficiency ◽  
Commercial Activity ◽  
The Sustainable Development ◽  
Light Utilization Efficiency ◽  
Light Utilization ◽  
Sunlight Intensity

Abstract In Saroma-ko Lagoon, where scallop aquaculture is a thriving commercial activity, monitoring primary production is essential for determining the amount of scallops that can be farmed. Using the primary production data obtained so far, we calculated Ψ, an index of water-column light utilization efficiency, and clarified its seasonal variation. Ψ tended to be lower in the spring bloom season (February–April), and higher in the late autumn to winter (October–December). Low chlorophyll-normalized production, an index of growth rate, resulted in lower values, while low daily irradiance resulted in higher values. The values of Ψ from our study had a range of 0.05–1.42 gC gChl-a−1 mol photons−1 m2 (N = 56). These values were within the previously reported range of 0.07–1.92 (gC gChl-a−1 mol photons−1 m2) for seawater and fresh water worldwide. Therefore, it is likely that Ψ varies from 0.05–2 gC gChl-a−1 mol photons−1 m2, being affected by conditions of phytoplankton growth and sunlight intensity, regardless of whether samples are collected from seawater or fresh water. Using the median Ψ value of 0.45 gC gChl-a−1 mol photons−1 m2 obtained in this study, primary production was 0.3–3.5 times the actual production at Saroma-ko Lagoon. Using this method, primary production can be easily and constantly monitored, facilitating the sustainable development of scallop aquaculture.

scholarly journals Biogeochemical processes and buffering capacity concurrently affect acidification in a seasonally hypoxic coastal marine basin

2015 ◽  
Vol 12 (5) ◽  
pp. 1561-1583 ◽  
Author(s):  
M. Hagens ◽  
C. P. Slomp ◽  
F. J. R. Meysman ◽  
D. Seitaj ◽  
J. Harlay ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Primary Production ◽  
Water Column ◽  
Bottom Water ◽  
Substantial Reduction ◽  
Buffering Capacity ◽  
Total Alkalinity ◽  
Acid Base ◽  
Data Set ◽  
Ph Fluctuations

Abstract. Coastal areas are impacted by multiple natural and anthropogenic processes and experience stronger pH fluctuations than the open ocean. These variations can weaken or intensify the ocean acidification signal induced by increasing atmospheric pCO2. The development of eutrophication-induced hypoxia intensifies coastal acidification, since the CO2 produced during respiration decreases the buffering capacity in any hypoxic bottom water. To assess the combined ecosystem impacts of acidification and hypoxia, we quantified the seasonal variation in pH and oxygen dynamics in the water column of a seasonally stratified coastal basin (Lake Grevelingen, the Netherlands). Monthly water-column chemistry measurements were complemented with estimates of primary production and respiration using O2 light–dark incubations, in addition to sediment–water fluxes of dissolved inorganic carbon (DIC) and total alkalinity (TA). The resulting data set was used to set up a proton budget on a seasonal scale. Temperature-induced seasonal stratification combined with a high community respiration was responsible for the depletion of oxygen in the bottom water in summer. The surface water showed strong seasonal variation in process rates (primary production, CO2 air–sea exchange), but relatively small seasonal pH fluctuations (0.46 units on the total hydrogen ion scale). In contrast, the bottom water showed less seasonality in biogeochemical rates (respiration, sediment–water exchange), but stronger pH fluctuations (0.60 units). This marked difference in pH dynamics could be attributed to a substantial reduction in the acid–base buffering capacity of the hypoxic bottom water in the summer period. Our results highlight the importance of acid–base buffering in the pH dynamics of coastal systems and illustrate the increasing vulnerability of hypoxic, CO2-rich waters to any acidifying process.

Modeling ammonia removal in aerated facultative lagoons

2005 ◽  
Vol 51 (12) ◽  
pp. 139-142 ◽  
Author(s):  
C.D. Houweling ◽  
L. Kharoune ◽  
A. Escalas ◽  
Y. Comeau
Keyword(s):  
Seasonal Variation ◽  
Activated Sludge ◽  
Water Column ◽  
Bacterial Growth ◽  
Organic Material ◽  
Mechanistic Model ◽  
Ammonia Removal ◽  
Stirred Tank ◽  
Tank Reactor ◽  
Continuously Stirred Tank Reactor

A mechanistic model has been developed to model ammonia removal in aerated facultative lagoons. Flow is modeled through the water column by a continuously stirred tank reactor and exchanges between the sludge layer and the water column are simulated by a solids separator. The biological model is based on an activated sludge model with reactions added for anaerobic bacterial growth and degradation of inert organic material. Results show that the model is able to predict seasonal variation in ammonia removal as well as sludge accumulation in the lagoons.

scholarly journals Distribution and activity of glycollate-utillzing bacteria in the water column in lake biwa.

1975 ◽  
Vol 41 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Nobuhiko TANAKA ◽  
Masami NAKANISHI ◽  
Hajime KADOTA
Keyword(s):  
Water Column ◽  
Lake Biwa

scholarly journals Seasonal Variation of Nutrient Flux Between Sediments and Water Column in the Inner Area of the Ariake Bay

2012 ◽  
Vol 68 (2) ◽  
pp. I_1056-I_1060
Author(s):  
Masumi KORIYAMA ◽  
Keisuke ARAKI ◽  
Yuji ITO ◽  
Toshiya KATANO ◽  
Tetsuhiro ISHITANI
Keyword(s):  
Seasonal Variation ◽  
Water Column ◽  
Nutrient Flux ◽  
Ariake Bay

scholarly journals Protistan grazing and viral lysis losses of bacterial carbon production in a large mesotrophic lake (Lake Biwa)

Limnology ◽  
2014 ◽  
Vol 15 (3) ◽  
pp. 257-270 ◽  
Author(s):  
Hiroyuki Takasu ◽  
Tadao Kunihiro ◽  
Shin-ichi Nakano
Keyword(s):  
Lake Biwa ◽  
Viral Lysis ◽  
Carbon Production ◽  
Mesotrophic Lake ◽  
Protistan Grazing

Seasonal variation of methane in the water column of Arkona and Bornholm Basin, western Baltic Sea

2014 ◽  
Vol 139 ◽  
pp. 332-347 ◽  
Author(s):  
W. Gülzow ◽  
U. Gräwe ◽  
S. Kedzior ◽  
O. Schmale ◽  
G. Rehder
Keyword(s):  
Seasonal Variation ◽  
Baltic Sea ◽  
Water Column ◽  
Bornholm Basin
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