Diurnal light utilization efficiency of phytoplankton is decreased by elevated CO2 concentration: a mesocosm experiment

2016 ◽  
Vol 188 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Tao Xing ◽  
Yaping Wu ◽  
Jiancheng Ding ◽  
Kunshan Gao
Keyword(s):  
Mesocosm Experiment ◽  
Utilization Efficiency ◽  
Light Utilization Efficiency ◽  
Light Utilization

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.

Light utilization efficiency in photosynthetic microbial mats

2011 ◽  
Vol 14 (4) ◽  
pp. 982-992 ◽  
Author(s):  
Mohammad A. A. Al-Najjar ◽  
Dirk de Beer ◽  
Michael Kühl ◽  
Lubos Polerecky
Keyword(s):  
Microbial Mats ◽  
Utilization Efficiency ◽  
Light Utilization Efficiency ◽  
Light Utilization

Light utilization efficiency of phytoplankton in the Western Subarctic Gyre of the North Pacific during summer

2014 ◽  
Vol 70 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Yuichi Nosaka ◽  
Tomonori Isada ◽  
Isao Kudo ◽  
Hiroaki Saito ◽  
Hiroshi Hattori ◽  
...  
Keyword(s):  
North Pacific ◽  
Utilization Efficiency ◽  
The North ◽  
Light Utilization Efficiency ◽  
Western Subarctic Gyre ◽  
Light Utilization ◽  
The North Pacific

Studies on a nudibranch that contains zooxanthellae. I. Photosynthesis, respiration and the translocation of newly fixed carbon by zooxanthellae in Pteraeolidia ianthina

1986 ◽  
Vol 228 (1253) ◽  
pp. 493-509 ◽  
Keyword(s):  
Respiratory Rate ◽  
Photosynthetic Capacity ◽  
Utilization Efficiency ◽  
Fixed Carbon ◽  
Compensation Irradiance ◽  
Light Utilization Efficiency ◽  
Eastern Australia ◽  
Light Utilization ◽  
Exponential Decrease

Zooxanthellae of the genus Symbiodinium are present in the tissues of the aeolid nudibranch Pteraeolidia ianthina . Individuals with widely differing densities of zooxanthellae are found living off the mid-central coast of eastern Australia. Nudibranchs with low densities of zooxanthellae (0.02-0.5 x 10 6 cells mg -1 protein) are common in winter populations, whereas those with comparatively higher densities (1–3 x 10 6 cells mg -1 protein) are the most common form at other times of the year. Zooxanthellae at all densities in the host exhibit the capacity for photosynthesis, and they grow while resident in the host. The mitotic indices of the zooxanthellae were found to vary as a function of the population density of the algae in the host and were highest in those animals with the lowest densities of zooxanthellae. Oxygen flux was measured as a function of irradiance. Maximum photosynthetic capacity ( P max ), light utilization efficiency ( α ) and compensation irradiance ( I c ) varied between animals, although most of the variation was attributable to differences in the density of zooxanthellae between animals. P max and α were positively correlated with density ( r 2 = 0.82 and 0.88 respectively); I c exhibited an exponential decrease with the density of zooxanthellae in the host ( r 2 > 0.81). I c for animals with 1–2 x 10 6 cells mg-1 protein had values of I c between 30 and 50 μE m -2 s -1 (1 μE = 6 x 10 17 photons), similar to values of I c measured for shade-adapted corals in other studies. Between 25 and 50% of the total photosynthetic products synthesized over 1 h were shown to move from the alga to the animal in that hour. The total respiratory rate of the association was positively correlated with the density of zooxanthellae ( r 2 = 0.94). This relation was used to estimate the respiratory rate of a zooxanthella in vivo . Estimates were, however, unreasonably high; this result suggests that zooxanthellae may directly influence the respiratory rate of the host, possibly by increasing the supply of respiratory substrates.

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