scholarly journals Influence of sea cucumbers on chromophoric of dissolved organic matter in multitrophic aquaculture tanks

2017 ◽  
Author(s):  
Seyed Mohammad Sadeghi-Nassaj ◽  
Teresa S. Catalá ◽  
Pedro A. Álvarez ◽  
Isabel Reche
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquatic Ecosystems ◽  
Light Transmission ◽  
Optical Parameters ◽  
Absorption Coefficients ◽  
Sea Cucumbers ◽  
Anemonia Sulcata ◽  
High Concentrations

Background. The effluents of the mono-specific aquaculture contain high concentrations of dissolved nutrients and organic matter, which affect negatively water quality of the recipient aquatic ecosystems. A key feature of water quality is its transparency. Chromophoric dissolved organic matter (CDOM) determines most of the light transmission in the ultraviolet and blue bands in the aquatic ecosystems. A sustainable alternative to mono-specific aquaculture is the integrated multitrophic aquaculture that includes species trophically complementary named “extractive” species. Sea cucumbers are recognized as efficient extractive species, with a high potential to improve water quality, due to the consumption of particulate organic matter (POM). However, the effects of sea cucumbers on CDOM are still unknown. Methods. During one year, we biweekly monitored CDOM in two aquaculture tanks with different trophic structure. One of the tanks (-holothurian tank) only contained the primary species, Anemonia sulcata, whereas the other tank (+ holothurian tank) also contained individuals of Holothuria tubulosa and H. forskali. We routinely performed CDOM absorption spectra from 200 nm to 750 nm and determined quantitative (absorption coefficients at 325 nm) and qualitative (spectral slopes and molar absorption coefficients at 325 nm) optical parameters in the inlet waters, in the tanks, and in their corresponding effluents. Results. Absorption coefficients at 325 nm (a325) and spectral slopes from 275 to 295 nm (S275-295) were significantly lower in the effluents of the +holothurian tank (average: 0.33 and 16 μm-1, respectively) than in the effluents of the −holothurian tank (average: 0.69 m-1 and 34 μm-1, respectively), being the former similar to those found in the inlet waters (average: 0.32 m-1 and 22 μm-1, respectively). This reduction in CDOM absorption appears to be mediated by the POM consumption by the holothurians. The reduction of POM concentration in the +holothurian tank may weaken the process of POM disaggregation into dissolved organic matter, which ultimately might have generated CDOM in the –holothurian tank. Discussion. Extractive species such as holothurians improve water transparency through POM consumption, likely because reduces POM disaggregation into CDOM. We suggest that CDOM monitoring in aquaculture facilities, using automatic probes or even remote sensing, could be a useful tool to trace the effectiveness of extractive species at large scales of time and space.

scholarly journals Influence of sea cucumbers on chromophoric of dissolved organic matter in multitrophic aquaculture tanks

2017 ◽  
Author(s):  
Seyed Mohammad Sadeghi-Nassaj ◽  
Teresa S. Catalá ◽  
Pedro A. Álvarez ◽  
Isabel Reche
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquatic Ecosystems ◽  
Light Transmission ◽  
Optical Parameters ◽  
Absorption Coefficients ◽  
Sea Cucumbers ◽  
Anemonia Sulcata ◽  
High Concentrations

Background. The effluents of the mono-specific aquaculture contain high concentrations of dissolved nutrients and organic matter, which affect negatively water quality of the recipient aquatic ecosystems. A key feature of water quality is its transparency. Chromophoric dissolved organic matter (CDOM) determines most of the light transmission in the ultraviolet and blue bands in the aquatic ecosystems. A sustainable alternative to mono-specific aquaculture is the integrated multitrophic aquaculture that includes species trophically complementary named “extractive” species. Sea cucumbers are recognized as efficient extractive species, with a high potential to improve water quality, due to the consumption of particulate organic matter (POM). However, the effects of sea cucumbers on CDOM are still unknown. Methods. During one year, we biweekly monitored CDOM in two aquaculture tanks with different trophic structure. One of the tanks (-holothurian tank) only contained the primary species, Anemonia sulcata, whereas the other tank (+ holothurian tank) also contained individuals of Holothuria tubulosa and H. forskali. We routinely performed CDOM absorption spectra from 200 nm to 750 nm and determined quantitative (absorption coefficients at 325 nm) and qualitative (spectral slopes and molar absorption coefficients at 325 nm) optical parameters in the inlet waters, in the tanks, and in their corresponding effluents. Results. Absorption coefficients at 325 nm (a325) and spectral slopes from 275 to 295 nm (S275-295) were significantly lower in the effluents of the +holothurian tank (average: 0.33 and 16 μm-1, respectively) than in the effluents of the −holothurian tank (average: 0.69 m-1 and 34 μm-1, respectively), being the former similar to those found in the inlet waters (average: 0.32 m-1 and 22 μm-1, respectively). This reduction in CDOM absorption appears to be mediated by the POM consumption by the holothurians. The reduction of POM concentration in the +holothurian tank may weaken the process of POM disaggregation into dissolved organic matter, which ultimately might have generated CDOM in the –holothurian tank. Discussion. Extractive species such as holothurians improve water transparency through POM consumption, likely because reduces POM disaggregation into CDOM. We suggest that CDOM monitoring in aquaculture facilities, using automatic probes or even remote sensing, could be a useful tool to trace the effectiveness of extractive species at large scales of time and space.

scholarly journals Sea cucumbers reduce chromophoric dissolved organic matter in aquaculture tanks

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4344 ◽  
Author(s):  
Seyed Mohammad Sadeghi-Nassaj ◽  
Teresa S. Catalá ◽  
Pedro A. Álvarez ◽  
Isabel Reche
Keyword(s):  
Water Quality ◽  
Molecular Weight ◽  
Time Series ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Chromophoric Dissolved Organic Matter ◽  
Low Molecular Weight ◽  
Optical Parameters ◽  
Absorption Coefficients ◽  
Sea Cucumbers

Background Mono-specific aquaculture effluents contain high concentrations of nutrients and organic matter, which affect negatively the water quality of the recipient ecosystems. A fundamental feature of water quality is its transparency. The fraction of dissolved organic matter that absorbs light is named chromophoric dissolved organic matter (CDOM). A sustainable alternative to mono-specific aquaculture is the multitrophic aquaculture that includes species trophically complementary named “extractive” species that uptake the waste byproducts. Sea cucumbers are recognized as efficient extractive species due to the consumption of particulate organic matter (POM). However, the effects of sea cucumbers on CDOM are still unknown. Methods During more than one year, we monitored CDOM in two big-volume tanks with different trophic structure. One of the tanks (−holothurian) only contained around 810 individuals of Anemonia sulcata, whereas the other tank (+holothurian) also included 90 individuals of Holothuria tubulosa and Holothuria forskali. We routinely analyzed CDOM absorption spectra and determined quantitative (absorption coefficients at 325 nm) and qualitative (spectral slopes) optical parameters in the inlet waters, within the tanks, and in their corresponding effluents. To confirm the time-series results, we also performed three experiments. Each experiment consisted of two treatments: +holothurians (+H) and –holothurians (−H). We set up three +H tanks with 80 individuals of A. sulcata and 10 individuals of H. tubulosa in each tank and four –H tanks that contained only 80 individuals of A. sulcata. Results In the time-series, absorption coefficients at 325 nm (a325) and spectral slopes from 275 to 295 nm (S275−295) were significantly lower in the effluent of the +holothurian tank (average: 0.33 m−1 and 16 µm−1, respectively) than in the effluent of the −holothurian tank (average: 0.69 m−1 and 34 µm−1, respectively), the former being similar to those found in the inlet waters (average: 0.32 m−1 and 22 µm−1, respectively). This reduction in the absorption of the dissolved organic matter appears to be mediated by the POM consumption by holothurians. The experiments confirmed the results observed in the time-series. The a325 and S275−295 values were significantly lower in the treatment with holothurians than in the treatment without holothurians indicating a reduction in the concentration of chromophoric organic compounds, particularly of low molecular weight. Discussion Consequently, sea cucumbers appear to improve water transparency in aquaculture tanks. The underlying mechanism of this improvement might be related to the POM consumption by holothurians, which reduces the concentration of CDOM derived from POM disaggregation or to the direct assimilation of dissolved compounds of low molecular weight as chromophoric amino acids.

scholarly journals Optical Properties of Dissolved Organic Matter in Finnish and Estonian Lakes

2003 ◽  
Vol 34 (4) ◽  
pp. 361-386 ◽  
Author(s):  
L. Sipelgas ◽  
H. Arst ◽  
K. Kallio ◽  
A. Erm ◽  
P. Oja ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters ◽  
Mean Value ◽  
Published Data ◽  
Optical Parameters ◽  
Exponential Approximation ◽  
Absorption Coefficients ◽  
Specific Absorption ◽  
The Mean

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.

scholarly journals Spectral characterization of dissolved organic matter along trophic gradients: Potential indicators of eutrophication of plateau lakes in Southwest China

2021 ◽  
Author(s):  
Yuying Guan ◽  
Ruiming Han ◽  
Nannan Jia ◽  
Da Huo ◽  
Gongliang Yu
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Optical Properties ◽  
Dissolved Organic Matter ◽  
Trophic State ◽  
Intensity Increase ◽  
Optical Parameters ◽  
Trophic State Index ◽  
Main Role ◽  
Neural Network Prediction

Abstract Dissolved organic matter (DOM) acts as a chemical intermediary between terrestrial and lacustrine ecosystems and significantly affects the structure and function of lakes. The optical characteristics of DOM have been widely used to estimate the water quality. However, little is known about its absorption and fluorescence under different trophic states. Especially, comparative research is needed among gradient eutrophic level of plateau lakes when considering their special characteristics. A total of 119 water samples were collected in the Erhai watershed from November 2018 to July 2019 to investigate the optical properties of DOM depending on the trophic state using ultraviolet–visible spectroscopy and parallel factor analysis of the excitation–emission matrix. The water quality conditions in the Erhai watershed were classified using the trophic state index (TSI; 31 < TSI < 67). The DOM is largely autochthonous and includes tyrosine-like protein (C1), tryptophan-like protein (C2), and humic-like compounds (C3). Except for an apparent trend of decreasing slope ratio (SR) (p < 0.01), both absorption coefficient at 254 nm and fluorescence intensity increase with the rising trophic state (p < 0.01). In this study, new models (R2aCDOM(254) = 0.762; R2 Fn(355) = 0.705, p < 0.01) basing on significant correlations between the TSI and aCDOM(254) and Fn(355) were established to predict the trophic state. The results of this study demonstrate that the effects of nutrients and environmental factors (pH and water temperature) on DOM vary depending on the trophic state and that the pH plays the main role in DOM production. Our analyses highlight the importance of DOM in aquatic ecosystems and the correlation between TSI and the optical properties of DOM. Our research unmasks the strong linkage between optical parameters of DOM and freshwater quality by applying neural network prediction.

scholarly journals Biological factors of water quality in a mesotrophic ecosystem

Fisheries ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 16-19
Author(s):  
Anatoliy Sadchikov ◽  
Sergei Ostroumov
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquatic Environment ◽  
Aquatic Ecosystems ◽  
Biological Factors ◽  
Physiological Processes ◽  
Negative Effect

Dissolved organic matter (DOM) is one of the important parameters of water quality in aquatic ecosystems. In the experiments, phyto- and bacterioplankton actively consumed 14C-labeled chlorella hydrolyzate. Removal (by filtration) of cyanobacteria from the aquatic environment leads to an increase in the rate of DOM consumption by bacteria. This indicates the possibility of a negative effect of cyanobacterial metabolites on the physiological processes of bacterioplankton.

scholarly journals Heavy-metal pollution alters dissolved organic matter released by bloom-forming Microcystis aeruginosa

RSC Advances ◽  
2017 ◽  
Vol 7 (30) ◽  
pp. 18421-18427 ◽  
Author(s):  
Haiming Wu ◽  
Li Lin ◽  
Guangzhu Shen ◽  
Ming Li
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Microcystis Aeruginosa ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Aquatic Ecosystems ◽  
Eutrophic Lakes

The risk of heavy metals to aquatic ecosystems was paid much attention in recent years, however, the knowledge on effects of heavy metals on dissolved organic matter (DOM) released byMicrocystiswas quite poor, especially in eutrophic lakes.

Facilitated Heterogeneous Photodegradation of Dissolved Organic Matter by Particulate Iron

2004 ◽  
Vol 1 (3) ◽  
pp. 197 ◽  
Author(s):  
Julia A. Howitt ◽  
Darren S. Baldwin ◽  
Gavin N. Rees ◽  
Barry T. Hart
Keyword(s):  
Organic Matter ◽  
Iron Oxide ◽  
Dissolved Organic Matter ◽  
Iron Oxides ◽  
Aquatic Ecosystems ◽  
Photochemical Reactions ◽  
Freshwater Systems ◽  
Particulate Iron ◽  
Presence And Absence ◽  
Australian Freshwater

Environmental Context. Iron oxides, as suspended minerals or as a colloidal phase, are common in Australian freshwater systems. Freshwater systems are also loaded with carbon-based substances, ‘dissolved organic matter’, but not all is biologically available as food to freshwater organisms. However, photochemical interactions between these iron oxides and dissolved organic matter provide a mechanism for biologically resistant carbon to re-enter the food web. Suspended iron oxides thus need to be considered in carbon cycles in aquatic ecosystems. Abstract. The photochemical degradation of dissolved organic matter (DOM) derived from the leaves of River Red Gum (Eucalyptus camaldulensis) was examined, with a particular focus on the photochemical generation of CO2, consumption of O2, and the effect of particulate iron minerals on these photochemical reactions. Solutions of leaf leachate were irradiated with ultraviolet and visible light in the presence and absence of amorphous iron oxides. Addition of fresh iron oxide was found to increase the rate of photodegradation of the organic matter by up to an order of magnitude compared to the reactions without added iron oxide. The ratio of CO2 produced to O2 consumed was ~1:1 in both the presence and absence of iron oxyhydroxide. The reactivity of the iron oxides was dependent on the preparation method and decreased with increased storage time. These results suggest that photochemical reactions on particle surfaces should be considered when examining carbon transformation in aquatic ecosystems, especially at sites with potential for the production of iron oxyhydroxides.

USE OF DISSOLVED ORGANIC MATTER BY MICROORGANISMS: FORMATION OF WATER QUALITY IN A POND OF A HIGH TROPHIC LEVEL

Fisheries ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 25-29
Author(s):  
Anatoliy Sadchikov ◽  
Sergey Ostroumov
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Trophic Level ◽  
Aquatic Ecosystem ◽  
High Trophic Level ◽  
Bacterioplankton Community ◽  
Algae And Bacteria

The role of algae and bacteria in the consumption and mineralization of dissolved organic matter (DOM) in a highly trophic aquatic ecosystem was studied. The phytoplankton and bacterioplankton community consumed 60% of added DOM in August and 56% of DOM in September. Of the uptaken DOM, a significant amount of organic carbon was mineralized. In August 42.7% and in September 29% of organic carbon (of the consumed organic matter) were used for respiration.

scholarly journals Structural Characterization of Dissolved Organic Matter in Permafrost Peatland Lakes

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3059
Author(s):  
Diogo Folhas ◽  
Armando C. Duarte ◽  
Martin Pilote ◽  
Warwick F. Vincent ◽  
Pedro Freitas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Complex Mixture ◽  
Resonance Spectroscopy ◽  
Hudson Bay ◽  
Microbial Decomposition ◽  
Thermokarst Lakes ◽  
Geochemical Properties ◽  
High Concentrations ◽  
Analytical Approaches

Thermokarst lakes result from the thawing of ice-rich permafrost and are widespread across northern landscapes. These waters are strong emitters of methane, especially in permafrost peatland regions, where they are stained black by high concentrations of dissolved organic matter (DOM). In the present study, we aimed to structurally characterize the DOM from a set of peatland thermokarst lakes that are known to be intense sites of microbial decomposition and methane emission. Samples were collected at different depths from three thermokarst lakes in the Sasapimakwananisikw (SAS) River valley near the eastern Hudson Bay community of Kuujjuarapik–Whapmagoostui (Nunavik, Canada). Samples were analyzed by spectrofluorometry, Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and elemental analysis. Fluorescence analyses indicated considerable amounts of autochthonous DOM in the surface waters of one of SAS 1A, indicating a strong bioavailability of labile DOM, and consequently a greater methanogenic potential. The three lakes differed in their chemical composition and diversity, suggesting various DOM transformations phenomena. The usefulness of complementary analytical approaches to characterize the complex mixture of DOM in permafrost peatland waters cannot be overlooked, representing a first step towards greater comprehension of the organic geochemical properties of these permafrost-derived systems.

scholarly journals Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer

2015 ◽  
Vol 12 (23) ◽  
pp. 6999-7011 ◽  
Author(s):  
P. Glaz ◽  
J.-P. Gagné ◽  
P. Archambault ◽  
P. Sirois ◽  
C. Nozais
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Forest Harvesting ◽  
Spectroscopic Techniques ◽  
Clear Cutting ◽  
Fluorescence Measurements ◽  
Fluorescence Characteristics ◽  
Boreal Shield ◽  
Shield Lakes

Abstract. Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L−1 compared to 12.5 mgC L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.

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