Heterotrophic activity of bacterioplankton along the gradients of the chlorophyll a concentration and water temperature in marine and limnetic ecosystems

2017 ◽  
Vol 44 (3) ◽  
pp. 315-321
Author(s):  
V. V. Boulion
Keyword(s):  
Water Temperature ◽  
Chlorophyll A ◽  
Heterotrophic Activity ◽  
Chlorophyll A Concentration

Bacterial population dynamics, production, and heterotrophic activity in a recently formed reservoir

1999 ◽  
Vol 45 (9) ◽  
pp. 747-753 ◽  
Author(s):  
Louis B Jugnia ◽  
Rémy D Tadonléké ◽  
T Sime-Ngando ◽  
J Devaux ◽  
C Andrivon
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Biomass Production ◽  
Resource Availability ◽  
Bacterial Production ◽  
Standing Stock ◽  
Bacterial Biomass ◽  
Heterotrophic Activity ◽  
Chlorophyll A Concentration ◽  
Biological Variables

Seasonal and spatial fluctuations in abundance, biomass production, and potential heterotrophic activity (i.e., 14C-glucose uptake) of bacterioplankton assemblages in a 1-year-old reservoir (the Sep Reservoir, Puy-de-Dôme, France) were examined concurrently with water temperature, phytoplankton chlorophyll a concentration, and primary production (PP). Based on the values observed for these biological variables, the Sep Reservoir was considered to have evolved to an oligo-mesotrophic state. Spatiotemporal variations of bacterial variables were a consequence of the seasonal evolution of the reservoir coupled with the resource availability. Multivariate regression analyses suggest that about 14 and 26% of the variance in bacterial standing stock and activity may be explained by the physical environment (i.e., temperature) and a resource availability index (chlorophyll a concentration or primary production), respectively. A carbon budget indicated that 4-126% (mean = 20%) of the ambient PP may be channeled through the microbial loop via bacterial biomass production. Heterotrophic bacterial production in the Sep Reservoir may therefore, on occasion, represent a significant source of carbon for higher order consumers.Key words: reservoirs, plankton, bacteria, heterotrophic uptake, primary and bacterial production.

scholarly journals Temporal coherence among tropical coastal lagoons: a search for patterns and mechanisms

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 803-814 ◽  
Author(s):  
A. Caliman ◽  
LS. Carneiro ◽  
JM. Santangelo ◽  
RD. Guariento ◽  
APF. Pires ◽  
...  
Keyword(s):  
Water Temperature ◽  
Chlorophyll A ◽  
Coastal Lagoons ◽  
Temporal Coherence ◽  
Structure And Function ◽  
Tropical Ecosystems ◽  
Water Colour ◽  
Chlorophyll A Concentration ◽  
Biological Variables ◽  
And Function

Temporal coherence (i.e., the degree of synchronicity of a given variable among ecological units within a predefined space) has been shown for several limnological features among temperate lakes, allowing predictions about the structure and function of ecosystems. However, there is little evidence of temporal coherence among tropical aquatic systems, where the climatic variability among seasons is less pronounced. Here, we used data from long-term monitoring of physical, chemical and biological variables to test the degree of temporal coherence among 18 tropical coastal lagoons. The water temperature and chlorophyll-a concentration had the highest and lowest temporal coherence among the lagoons, respectively, whereas the salinity and water colour had intermediate temporal coherence. The regional climactic factors were the main factors responsible for the coherence patterns in the water temperature and water colour, whereas the landscape position and morphometric characteristics explained much of the variation of the salinity and water colour among the lagoons. These results indicate that both local (lagoon morphometry) and regional (precipitation, air temperature) factors regulate the physical and chemical conditions of coastal lagoons by adjusting the terrestrial and marine subsidies at a landscape-scale. On the other hand, the chlorophyll-a concentration appears to be primarily regulated by specific local conditions resulting in a weak temporal coherence among the ecosystems. We concluded that temporal coherence in tropical ecosystems is possible, at least for some environmental features, and should be evaluated for other tropical ecosystems. Our results also reinforce that aquatic ecosystems should be studied more broadly to accomplish a full understanding of their structure and function.

scholarly journals Adding nitrate and phosphate separately or together in the Central Indian Ocean: a nutrient enrichment experiment

2009 ◽  
Vol 6 (3) ◽  
pp. 2649-2666 ◽  
Author(s):  
S. Tang ◽  
L. Jiang ◽  
Z. J. Wu
Keyword(s):  
Growth Rate ◽  
Indian Ocean ◽  
Water Temperature ◽  
Chlorophyll A ◽  
Nutrient Enrichment ◽  
Phytoplankton Bloom ◽  
Phytoplankton Growth ◽  
Chlorophyll A Concentration ◽  
Central Indian Ocean ◽  
Phytoplankton Growth Rate

Abstract. Nutrient enrichment experiments were carried out in the Central Indian Ocean during the Chinese First Around-the world Research Cruise, adding nitrate, phosphate, or a mixture of both of them to surface seawater. The concentration of nitrate, nitrite, ammonia, and phosphate were analyzed spectrophotometrically, the chlorophyll-a concentration with fluorescence analysis, and the temperature variation during the experiment recorded. Addition of nitrate resulted in rapid growth of phytoplankton concomitant with depletion of nitrate in the water samples. No apparent variation occurred in chlorophyll-a concentration when phosphate was added. Combining nitrate and phosphate proved to be best to promote phytoplankton bloom, and nitrate was depleted prior to phosphate. After nitrate was consumed, a substantial amount of phytoplankton survived on the supplied phosphate. No correlation was found between the nitrate to phosphate ratio and chlorophyll-a or phytoplankton growth rate. We also found no correlation between water temperature and chlorophyll-a or phytoplankton growth rate. We conclude that neither nitrate to phosphate ratio nor water temperature control the growth of phytoplankton.

scholarly journals The Variation on Sediment Reworking with Influencing Factors by a Sand Bubbler Crab, Scopimera globosa, in Intertidal Sediments of the Anmyeon Island, Korea

2021 ◽  
Vol 13 (10) ◽  
pp. 5703
Author(s):  
Jaehwan Seo ◽  
Bon Joo Koo
Keyword(s):  
Chlorophyll A ◽  
Influencing Factors ◽  
Surface Sediment ◽  
Intertidal Sediments ◽  
Daily Production ◽  
Chlorophyll A Concentration ◽  
Sediment Reworking ◽  
Pellet Production ◽  
Crab Density ◽  
Annual Sediment

Though biological and ecological characteristics of Scopimera globosa have been intensively investigated, little has been understood on bioturbation, especially sediment reworking. This study was designed to evaluate variation on sediment reworking of S. globosa based on feeding pellet production (FP) and burrowing pellet production (BP) with influencing factors and estimating the chlorophyll content reduction within the surface sediment by its feeding. The FP and BP largely fluctuated according to chlorophyll a concentration and crab density, but both were not influenced by temperature. The FP was enhanced by chlorophyll a concentration, whereas both FP and BP were restricted by crab density. The daily individual production was highest in spring, followed by fall and summer, with values of 25.61, 20.70 and 3.90 g ind.−1 d−1, respectively, while the total daily production was highest in fall, followed by summer and spring 2150, 1660 and 660 g m−2 d−1, respectively. The daily sediment reworking based on the FP and BP of Scopimera was highest in fall, followed by summer and spring, with values of 1.91, 1.70 and 0.77 mm d-1 and the annual sediment reworking rate of this species was calculated 40 cm year−1 based on its density in this study area. The chlorophyll a reduction ratio was estimated from 11 to 24% in one day by its feeding. These results imply that the sediment reworking of S. globosa is regulated by food abundance and its density, and Scopimera is an important bioturbator, greatly influencing biogeochemical changes in the intertidal sediments.

scholarly journals Retrieval and Evaluation of Chlorophyll-a Concentration in Reservoirs with Main Water Supply Function in Beijing, China, Based on Landsat Satellite Images

2021 ◽  
Vol 18 (9) ◽  
pp. 4419
Author(s):  
Yuequn Lai ◽  
Jing Zhang ◽  
Yongyu Song ◽  
Zhaoning Gong
Keyword(s):  
Remote Sensing ◽  
Water Supply ◽  
Chlorophyll A ◽  
Phosphorus Concentration ◽  
Landsat 8 ◽  
Supply Function ◽  
Estimation Model ◽  
Nitrogen And Phosphorus ◽  
Chlorophyll A Concentration ◽  
Guanting Reservoir

Remote sensing retrieval is an important technology for studying water eutrophication. In this study, Guanting Reservoir with the main water supply function of Beijing was selected as the research object. Based on the measured data in 2016, 2017, and 2019, and Landsat-8 remote sensing images, the concentration and distribution of chlorophyll-a in the Guanting Reservoir were inversed. We analyzed the changes in chlorophyll-a concentration of the reservoir in Beijing and the reasons and effects. Although the concentration of chlorophyll-a in the Guanting Reservoir decreased gradually, it may still increase. The amount and stability of water storage, chlorophyll-a concentration of the supply water, and nitrogen and phosphorus concentration change are important factors affecting the chlorophyll-a concentration of the reservoir. We also found a strong correlation between the pixel values of adjacent reservoirs in the same image, so the chlorophyll-a estimation model can be applied to each other.

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