The use of photosynthesis inhibitor (DCMU) for in situ metabolic and primary production studies on soft bottom benthos

Hydrobiologia ◽  
1992 ◽  
Vol 246 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Claire Garrigue Jacques Clavier ◽  
Guy Boucher
Keyword(s):  
Primary Production ◽  
Soft Bottom ◽  
Production Studies

In situ assessment of the daily primary production of the temperate symbiotic coral Cladocora caespitosa

2013 ◽  
Vol 58 (4) ◽  
pp. 1409-1418 ◽  
Author(s):  
C. Ferrier-Pagès ◽  
F. Gevaert ◽  
S. Reynaud ◽  
E. Beraud ◽  
D. Menu ◽  
...  
Keyword(s):  
Primary Production ◽  
Cladocora Caespitosa ◽  
In Situ Assessment

The Simulated in situ Measurements of Oceanic Primary Production

1963 ◽  
Vol 14 (2) ◽  
pp. 139 ◽  
Author(s):  
HR Jitts
Keyword(s):  
Primary Production ◽  
In Situ Measurements ◽  
Light Conditions ◽  
Significant Relation ◽  
Blue Glass ◽  
Simultaneous Measurements ◽  
Reflected Light

Simultaneous measurements with two types of incubators were made on replicate samples both in the incubators and in situ in the ocean. Both incubators used sunlight and blue glass filters to simulate light conditions at depths in the ocean. The first gave measurements of column production 1.58 times those in situ. This was due to the fact that at depths greater than 20 m the incubator gave much higher results with no significant relation to those measured in situ. In the second incubator the accuracy of reproduction of oceanic light conditions was improved by reducing reflected light and using a balance-by-depth twin photometer system for determining the depths of sampling. The measurements of column production in the second incubator were 1.03 times the in situ values.

The relation of oceanic primary production to available photosynthetic irradiance

1976 ◽  
Vol 27 (3) ◽  
pp. 441 ◽  
Author(s):  
HR Jitts ◽  
A Morel ◽  
Y Saijo
Keyword(s):  
Primary Production ◽  
Surface Ocean ◽  
Surface Samples ◽  
In Situ Method ◽  
Wide Range ◽  
Total Irradiance ◽  
Highly Correlated ◽  
Bodies Of Water ◽  
High Degree

Primary production was measured at 14 stations covering a wide range of oceanic waters. Measurements were made by both the in situ method (Pi) and the simulated in situ method (Ps) Production v. constant irradiance (P v. I) was also measured. Available photosynthetic irradiance [Eq(350-700) in quanta m-2 s-1] was calculated from continuous records of total irradiance and measurements of the percentage submarine transmission of irradiance were made with a quantum meter. Using the P v. I curves and Eq(350-700), primary production at several depths at each station was calculated (P,). Pc was shown to be a precise estimate of Ps at all depths. Pc was also highly correlated with Pi, but both Pc and Pi overestimated Pi at the surface by 40 %. Some experiments at three stations showed that a 2-mm thickness of clear glass placed over surface samples in the measurement of Ps could increase Ps by about 50%. This suggested that U.V. irradiance in surface ocean waters decreased Pi and could explain the overestimates by Pc and Ps. The results showed the need for precise information of spectrai composition of irradiance in studies of primary production but demonstrated the kalidity of Eq(350-700) as an estimate of available photosynthetic irradiance. They also showed that Pc could estimate Pi with a high degree of precision, and that such a calculative method could provide a useful way of continuously monitoring the primary production of large bodies of water for extended periods.

Geobiology of In Situ Uranium Leaching

2013 ◽  
Vol 825 ◽  
pp. 372-375 ◽  
Author(s):  
Carla Zammit ◽  
Kan Li ◽  
Barbara Etschmann ◽  
Joël Brugger ◽  
Frank Reith
Keyword(s):  
Microbial Communities ◽  
Underground Mining ◽  
Close Association ◽  
Cost Effective ◽  
Open Pit ◽  
Uranium Recovery ◽  
Production Studies ◽  
Site Rehabilitation ◽  
And Function

Driven by the world’s thirst for energy, the demand for uranium is rapidly increasing. Hence, producers of uranium are struggling to keep up with demands and are exploring more cost-effective methods of extraction. Uranium is currently mined via open pit and underground mining as well as with in situ leaching methods, with in situ leaching currently accounting for approximately 45 % of total uranium production. Studies have shown that the presence of uranium in soils strongly affects the composition and function of resident microbial communities. In view of the close association of biological processes and uranium geochemistry, it is surprising how little information is available on the effect of microbial communities on in situ leaching. Hence, this review focuses on the possibility to exploit the properties of such microorganisms and identify opportunities to use natural microbial processes to improve uranium recovery and mine site rehabilitation.

Modelling Primary Production in Water Bodies: A Numerical Approach that Allows Vertical Inhomogeneities

1973 ◽  
Vol 30 (10) ◽  
pp. 1469-1473 ◽  
Author(s):  
Everett J. Fee
Keyword(s):  
Primary Production ◽  
Algal Biomass ◽  
Numerical Approach ◽  
Light Responses ◽  
Phytoplankton Primary Production ◽  
Basic Approach ◽  
Mathematical Solution ◽  
Model Predictions ◽  
Vertical Variations

A new model for computing integral daily phytoplankton primary production is described. The model incorporates vertical variations of algal biomass, complex photosynthesis vs. light responses, nonexponential extinction of light vs. depth, and any distribution of surface light over a day. The basic approach is to combine measured relations for photosynthetic rate vs. light, light vs. depth, and light vs. time in an interpolative scheme rather than attempting to fit equations to the data and using the resulting equations to obtain a mathematical solution. The model is general and should have wide applicability. Model predictions agreed well with in situ measurements of production.

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