Rapid light curves: A powerful tool to assess photosynthetic activity

Ralph, Peter J.; Gademann, Rolf

doi:10.1016/j.aquabot.2005.02.006

Cited by 919 publications

(726 citation statements)

References 14 publications

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“…These results were coincident with Coles and Jones (2000), in which, the above three parameters could be also influenced by temperature (Coles and Jones, 2000;Reynolds, 2006). Furthermore, the α, rETR max and I k under high light condition were usually considered to be higher than that under low light condition (Ralph and Gademann, 2005;Perkins et al, 2006;. In our study, the three parameters increased with increase of shading ratio though there were no significant differences.…”

Section: Photosynthesis Efficiencysupporting

confidence: 83%

Influence of sunlight on the proliferation of cyanobacterial blooms and its potential applications in Lake Taihu, China

Zhou

Chen

Shan

et al. 2014

Journal of Environmental Sciences

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Section: Photosynthesis Efficiencysupporting

confidence: 83%

Influence of sunlight on the proliferation of cyanobacterial blooms and its potential applications in Lake Taihu, China

Zhou

Chen

Shan

et al. 2014

Journal of Environmental Sciences

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“…A portable PAM fluorometer (AquaPen-C 100, Photon Systems Instruments, Czech Republic) with blue measuring light (centered at 455 nm) was used to measure the response of the quantum yield of photosynthetic electron transport in PSII to increasing irradiance (Ralph and Gademann 2005). Before measurement, an unfiltered water sample was dark-adapted for about 1 h to ensure that all reaction centers were in an ''open'' state.…”

Section: Pam Measurementsmentioning

confidence: 99%

The Absorption of Light in Lakes: Negative Impact of Dissolved Organic Carbon on Primary Productivity

2014

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Colored dissolved organic matter (CDOM) absorbs a substantial fraction of photosynthetically active radiation (PAR) in boreal lakes. However, few studies have systematically estimated how this light absorption influences pelagic primary productivity. In this study, 75 boreal lakes spanning wide and orthogonal gradients in dissolved organic carbon (DOC) and total phosphorus (TP) were sampled during a synoptic survey. We measured absorption spectra of phytoplankton pigments, CDOM, and non-algal particles to quantify the vertical fate of photons in the PAR region. Area-specific rates of gross primary productivity (PP A ) were estimated using a bio-optical approach based on phytoplankton in vivo light absorption and the light-dependent quantum yield of photochemistry in PSII measured by a PAM fluorometer. Subsequently, we calculated the effects of CDOM, DOC, and TP concentration on PP A . CDOM absorbed the largest fraction of PAR in the majority of lakes (mean 56.3%, range 36.9-76.2%), phytoplankton pigments captured a comparatively minor fraction (mean 6.6%, range 2.2-28.2%). PP A estimates spanned from 45 to 993 mg C m -2 day -1 (median 286 mg C m -2 day -1 ). We found contrasting effects of CDOM (negative) and TP (positive) on PP A . The use of DOC or CDOM as predictors gave very similar results and the negative effect of these variables on PP A can probably be attributed to shading. A future scenario of increased DOC, which is highly correlated with CDOM in these lakes, might impose negative effects on areal primary productivity in boreal lakes.

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“…For example, the maximum quantum yield (F v /F m ) decreases with increasing exposure (duration and quantity) to sediment (Philipp and Fabricius 2003) and exposure to agricultural chemicals ; Table 2), but appears not be influenced (for cultured symbionts) by exposure to elevated levels of dissolved inorganic nutrients (Rodriguez-Roman and Iglesias-Prieto 2005). Exposing the symbionts to a series of irradiances in short (10 s)-incremental steps producing a rapid light curve can also provide detailed information on photo-acclimatory responses of corals to changes in water quality (Ralph and Gademann 2005). Quantitative parameters derived from rapid light curves include maximum photosynthetic rate (PS max ), minimum saturating irradiance (E k ) and light utilisation coefficients (a) of the initial rise of the curve.…”

Section: Symbiont Photophysiologymentioning

confidence: 99%

Bioindicators of changes in water quality on coral reefs: review and recommendations for monitoring programmes

2009

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Effective environmental management requires monitoring programmes that provide specific links between changes in environmental conditions and ecosystem health. This article reviews the suitability of a range of bioindicators for use in monitoring programmes that link changes in water quality to changes in the condition of coral-reef ecosystems. From the literature, 21 candidate bioindicators were identified, whose responses to changes in water quality varied spatially and temporally; responses ranged from rapid (hours) changes within individual corals to long-term (years) changes in community composition. From this list, the most suitable bioindicators were identified by determining whether responses were (i) specific, (ii) monotonic, (iii) variable, (iv) practical and (v) ecologically relevant to management goals. For long-term monitoring programmes that aim to quantify the effects of chronic changes in water quality, 11 bioindicators were selected: symbiont photophysiology, colony brightness, tissue thickness and surface rugosity of massive corals, skeletal elemental and isotopic composition, abundance of macro-bioeroders, micro-and meiobenthic organisms such as foraminifera, coral recruitment, macroalgal cover, taxonomic richness of corals and the maximal depth of coralreef development. For short-term monitoring programmes, or environmental impact assessments that aim to quantify the effects of acute changes in water quality, a subset of seven of these bioindicators were selected, including partial mortality. Their choice will depend on the specific objectives and the timeframe available for each monitoring programme. An assessment framework is presented to assist in the selection of bioindicators to quantify the effects of changing water quality on coral-reef ecosystems.

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Rapid light curves: A powerful tool to assess photosynthetic activity

Cited by 919 publications

References 14 publications

Influence of sunlight on the proliferation of cyanobacterial blooms and its potential applications in Lake Taihu, China

Influence of sunlight on the proliferation of cyanobacterial blooms and its potential applications in Lake Taihu, China

The Absorption of Light in Lakes: Negative Impact of Dissolved Organic Carbon on Primary Productivity

Bioindicators of changes in water quality on coral reefs: review and recommendations for monitoring programmes

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