scholarly journals Impacts of Hurricane Disturbance on Water Quality across the Aquatic Continuum of a Blackwater River to Estuary Complex

2020 ◽  
Vol 8 (6) ◽  
pp. 412
Author(s):  
Tracey Schafer ◽  
Nicholas Ward ◽  
Paul Julian ◽  
K. Ramesh Reddy ◽  
Todd Z. Osborne
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Saline Water ◽  
System Response ◽  
Blackwater River ◽  
Fluorescent Dissolved Organic Matter ◽  
Hurricane Disturbance ◽  
Wind Velocities

Hurricanes cause landscape-scale disturbances that affect biogeochemical cycling and water quality in coastal ecosystems. During Hurricane Irma’s passage through northern Florida, water movements driven by wind velocities up to 105 km h−1 caused a salinity peak in an estuary/blackwater river complex. Water quality was monitored across the 15 km site to detect the magnitude and duration of disturbance. Saline water intruded 15 km inland into a freshwater portion of the river that peaked at a salinity of 2 psu. Due to the volume of precipitation from the hurricane, significant runoff of freshwater and dissolved organic matter (DOM) caused a decrease in salinity, dissolved oxygen (DO), and Chlorophyll-a concentrations while increasing turbidity and fluorescent dissolved organic matter (fDOM). The disturbance caused rapid changes observed by in-situ water quality monitors over a 3-week period, but some effects persisted for longer periods as shown by 3-month weekly water sampling. This disturbance caused shifts in DOM loading, altered salinity dynamics, and reshaped landscapes due to wind and wave surge both in upland marsh and downstream estuary. Hurricane disturbance temporarily and abruptly alters the aquatic continuum, and observations of system response can help us understand the mechanisms associated with ecosystem resilience and recovery.

scholarly journals Characteristics of Chromophoric and Fluorescent Dissolved Organic Matter in the Nordic Seas

2018 ◽  
Author(s):  
Anna Makarewicz ◽  
Piotr Kowalczuk ◽  
Sławomir Sagan ◽  
Mats A. Granskog ◽  
Alexey K. Pavlov ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Chlorophyll A ◽  
Saline Water ◽  
Atlantic Water ◽  
Nordic Seas ◽  
Ice Melt ◽  
Fluorescent Dissolved Organic Matter ◽  
West Spitsbergen

Abstract. Optical properties of Chromophoric (CDOM) and Fluorescent Dissolved Organic Matter (FDOM) were characterized in the Nordic Seas including the West Spitsbergen Shelf during June–July of 2013, 2014 and 2015. The CDOM absorption coefficient at 350 nm, aCDOM(350) showed significant interannual variation. In 2013, the highest average aCDOM(350) values (aCDOM = 0.30 ± 0.12 m−1) were observed due to the influence of cold and low–saline water from the Sørkapp Current in the southern part of West Spitsbergen Shelf. In 2014, aCDOM(350) values were significantly lower than in 2013 (av. aCDOM(350) = 0.14 ± 0.06 m−1), which was associated with the dominance of warm and saline Atlantic Water (AW) in the region, while in 2015 intermediate CDOM absorption (av. aCDOM(350) = 0.19 ± 0.05 m−1) was observed. In situ measurement of three FDOM components revealed that protein–like FDOM dominated and concentration of marine and terrestrial humic–like DOM were very low and its distribution were generally vertically homogenous in the upper ocean (0–100 m). Fluorescence of terrestrial and marine humic–like FDOM decreased in surface waters (0–15 m) near the sea–ice edge by dilution of oceanic waters by sea–ice melt water. The vertical distribution of protein–like FDOM was characterized by a prominent sub–surface maximum that matched the subsurface chlorophyll a maximum and was observed all across the study area. The highest protein–like FDOM fluorescence was observed in the Norwegian Sea in the core of warm AW. There was a significant relationship between the protein–like fluorescence and chlorophyll a fluorescence (R2 = 0.65, p 

scholarly journals Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shigemitsu ◽  
T. Yokokawa ◽  
H. Uchida ◽  
S. Kawagucci ◽  
A. Murata
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Dissolved Organic Matter ◽  
Oxygen Utilization ◽  
Fluorescent Dissolved Organic Matter ◽  
Vertical Distributions ◽  
The Difference ◽  
The Relationship ◽  
Apparent Oxygen Utilization

AbstractMicrobial community structure in the hadal water is reported to be different from that in the upper abyssal water. However, the mechanism governing the difference has not been fully understood. In this study, we investigate the vertical distributions of humic-like fluorescent dissolved organic matter (FDOMH), chemoautotrophic production, apparent oxygen utilization (AOU), and N* in the Izu-Ogasawara Trench. In the upper abyssal waters (< 6000 m), FDOMH has a significantly positive correlation with AOU; FDOMH deviates from the relationship and increases with depth without involving the increment of AOU in the hadal waters. This suggests that FDOMH is transferred from the sediments to the hadal waters through pore water, while the FDOMH is produced in situ in the upper abyssal waters. Chemoautotrophic production and N* increases and decreases with depth in the hadal waters, respectively. This corroborates the effluxes of dissolved substances, including dissolved organic matter and electron donors from sediments, which fuels the heterotrophic/chemoautotrophic microbial communities in the hadal waters. A simple box model analysis reveals that the funnel-like trench topography facilitates the increase in dissolved substances with depth in the hadal waters, which might contribute to the unique microbiological community structure in these waters.

scholarly journals Multi-Parameter Compensation Method for Accurate In Situ Fluorescent Dissolved Organic Matter Monitoring and Properties Characterization

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1146 ◽  
Author(s):  
Guilherme de Oliveira ◽  
Edoardo Bertone ◽  
Rodney Stewart ◽  
John Awad ◽  
Aleicia Holland ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Dissolved Organic Matter ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Quality Monitoring ◽  
Suspended Particles ◽  
Site Specific ◽  
Fluorescent Dissolved Organic Matter

The recent deployment of fluorescent dissolved organic matter (fDOM) probes in dam catchments and drinking water treatment plants (DWTP) for water quality monitoring purposes has resulted in the production of a large amount of data that requires scientific evaluation. This study introduces a comprehensive, transferable methodological framework for scientists and water professionals to model fluorescence site-specific quenching on fDOM probe readings caused by temperature, suspended particles, and the inner filter effect (IFE) and applies it to an Australian subtropical reservoir. The findings revealed that quenching due to turbidity and IFE effects were best predicted by threshold autoregressive models. Raw fDOM probe measurements were validated as being more reliable if they were systematically compensated using the proposed procedure. The developed fDOM compensation procedure must consider the instrument features (i.e., wavelength broadband and responsiveness) and site-specific conditions (i.e., DOM characteristics and suspended particles). A finding of particular interest was that the compensated normalized fDOM readings had a high correlation with the low (<500 Da) molecular weight fraction of the DOM, which is more recalcitrant to removal by coagulation. As a consequence, there is potential to use compensated fDOM probe readings to provide real-time, in situ information on DOM properties in freshwater systems, which will enable water treatment plant operators to optimize the coagulation process.

Production and degradation of fluorescent dissolved organic matter derived from bacteria

2017 ◽  
Vol 74 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Ken Arai ◽  
Shigeki Wada ◽  
Koichi Shimotori ◽  
Yuko Omori ◽  
Takeo Hama
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Fluorescent Dissolved Organic Matter

scholarly journals Functional and Structural Responses of Hyporheic Biofilms to Varying Sources of Dissolved Organic Matter

2014 ◽  
Vol 80 (19) ◽  
pp. 6004-6012 ◽  
Author(s):  
Karoline Wagner ◽  
Mia M. Bengtsson ◽  
Katharina Besemer ◽  
Anna Sieczko ◽  
Nancy R. Burns ◽  
...  
Keyword(s):  
Organic Matter ◽  
16S Rrna ◽  
Dissolved Organic Matter ◽  
Community Composition ◽  
Hyporheic Zone ◽  
Priority Effects ◽  
Stream Ecosystems ◽  
Rrna Gene ◽  
Structural Responses

ABSTRACTHeadwater streams are tightly connected with the terrestrial milieu from which they receive deliveries of organic matter, often through the hyporheic zone, the transition between groundwater and streamwater. Dissolved organic matter (DOM) from terrestrial sources (that is, allochthonous) enters the hyporheic zone, where it may mix with DOM fromin situproduction (that is, autochthonous) and where most of the microbial activity takes place. Allochthonous DOM is typically considered resistant to microbial metabolism compared to autochthonous DOM. The composition and functioning of microbial biofilm communities in the hyporheic zone may therefore be controlled by the relative availability of allochthonous and autochthonous DOM, which can have implications for organic matter processing in stream ecosystems. Experimenting with hyporheic biofilms exposed to model allochthonous and autochthonous DOM and using 454 pyrosequencing of the 16S rRNA (targeting the “active” community composition) and of the 16S rRNA gene (targeting the “bulk” community composition), we found that allochthonous DOM may drive shifts in community composition whereas autochthonous DOM seems to affect community composition only transiently. Our results suggest that priority effects based on resource-driven stochasticity shape the community composition in the hyporheic zone. Furthermore, measurements of extracellular enzymatic activities suggest that the additions of allochthonous and autochthonous DOM had no clear effect on the function of the hyporheic biofilms, indicative of functional redundancy. Our findings unravel possible microbial mechanisms that underlie the buffering capacity of the hyporheic zone and that may confer stability to stream ecosystems.

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