Impacts of the aquaculture on the distribution of dissolved organic matter in the coastal Jeju Island, Korea, revealed by absorption and fluorescence spectroscopy

Abstract To demonstrate behavior of dissolved organic matter (DOM) derived from coastal aquaculture, dissolved organic carbon (DOC), total dissolved nitrogen (TDN), chromophoric dissolved organic matter (CDOM), and fluorescent dissolved organic matter (FDOM) were measured around the coastal Jeju Island, Korea. As reported by previous studies, pristine groundwater with extremely depleted DOC (< 30 µM) has been used as culturing water in the coastal aquafarms. However, the concentration of DOC within 1.5 km from the discharge outlet of the aquafarms was approximately two times higher than that in the groundwater. In addition, the concentration of TDN exponentially increased close to the discharge outlet. These distribution patterns indicate the aquafarm is a significant DOM source. Herein, principal component analysis including the absorption coefficient (a350), spectral slope coefficient (S250 − 600), specific UV absorbance (SUVA254), and five fluorescent components were applied to categorize DOM origins. We found two distinct groups: aquaculture activity for TDN with high molecular weights and natural biological activity for DOC enrichment. Our study has also critical implications for the efficient monitoring of anthropogenic organic pollutant from aquafarms using unique optical signals.

Download Full-text

Impact of aquaculture on distribution of dissolved organic matter in coastal Jeju Island, Korea, based on absorption and fluorescence spectroscopy

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15553-3 ◽

2021 ◽

Author(s):

Jeonghyun Kim ◽

Yeseul Kim ◽

Sung Eun Park ◽

Tae-Hoon Kim ◽

Bong-Guk Kim ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Fluorescence Spectroscopy ◽

Dissolved Organic Matter ◽

Coastal Water ◽

Coastal Region ◽

Principal Component ◽

Distribution Patterns ◽

Organic Pollution ◽

Jeju Island

AbstractIn Jeju Island, multiple land-based aquafarms were fully operational along most coastal region. However, the effect of effluent on distribution and behaviours of dissolved organic matter (DOM) in the coastal water are still unknown. To decipher characteristics of organic pollution, we compared physicochemical parameters with spectral optical properties near the coastal aquafarms in Jeju Island. Absorption spectra were measured to calculate the absorption coefficient, spectral slope coefficient, and specific UV absorbance. Fluorescent DOM was analysed using fluorescence spectroscopy coupled with parallel factor analysis. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured using high-temperature catalytic oxidation. The DOC concentration near the discharge outlet was twice higher than that in natural groundwater, and the TDN concentration exponentially increased close to the outlet. These distribution patterns indicate that aquafarms are a significant source of DOM. Herein, principal component analysis was applied to categorise the DOM origins. There were two distinct groups, namely, aquaculture activity for TDN with humic-like and high molecular weights DOM (PC1: 48.1%) and natural biological activity in the coastal water for DOC enrichment and protein-like DOM (PC2: 18.8%). We conclude that the aquafarms significantly discharge organic nitrogen pollutants and provoke in situ production of organic carbon. Furthermore, these findings indicate the potential of optical techniques for the efficient monitoring of anthropogenic organic pollutants from aquafarms worldwide.

Download Full-text

Optical properties of chromophoric and fluorescent dissolved organic matter in the coastal Jeju Island: Impact of the anthropogenic sources

10.5194/egusphere-egu2020-20832 ◽

2020 ◽

Author(s):

Jeonghyun Kim ◽

Yeseul Kim ◽

Tae-Hoon Kim ◽

Sung Eun Park ◽

Dong-Jin Kang ◽

...

Keyword(s):

Organic Matter ◽

Optical Properties ◽

Absorption Coefficient ◽

Coastal Area ◽

Sewage Treatment ◽

Principal Component ◽

Point Sources ◽

Jeju Island ◽

Anthropogenic Sources ◽

Fluorescent Dissolved Organic Matter

The hydrological properties (temperature, salinity, pH, and dissolved oxygen), dissolved organic carbon (DOC) and nitrogen (DON), and optical absorption and fluorescence signals were measured in Jeju Island, Korea, during 2016&#8211;2018, especially in potential point-sources (e.g. coastal aquafarms, a sewage treatment facility, and coastal artesian springs). The water samples were filtered through 0.2 &#956;m polycarbonate syringe filters. The optical analysis was conducted using a spectrophotometer (Aqualog, Horiba, USA). Absorbance spectra were converted into the absorption coefficient, and fluorescence intensities were conducted by the parallel factor analysis (PARAFAC) model. The fluorescent components were compared with previous studies through the web-based OpenFluor database.The absorption coefficient at 350 nm ranged from 0.05 to 7.63 m &#8722;1, and it was up to 150 times higher near the point-sources than in the normal coastal ocean. In addition, a350 was observed to be exponentially increased as the reduced distance from the aquafarm outlet. Similarly, the concentration of DOC was 89 &#177; 29 &#956;M near the point-sources and 78 &#177; 13 &#956;M in the normal coastal area. They were also observed to be high fluorescence near the point-sources. Principal component analysis (PCA) was applied to illustrate the relationship among the five PARAFAC components, DOC, DON, a350, and fluorescence indexes (HIX, BIX, FI, TC ratio, and RI). The PCA results separated allochthonous, terrestrial components from autochthonous, microbial components, as explained 71.3% of the variance in the data. Based on the HIX (1.26 &#8211; 55.70) and BIX (0.52 &#8211; 2.87) values in this study, the organic matter around the coastal Jeju Island seem to be highly affected by the coastal groundwater. Here, we used multiple optical properties of organic matter near the coastal area to identify the key factor contributing its distribution and water qualities and to determine the significant influence of the point-sources.

Download Full-text

Investigating variations of fluorescent dissolved organic matter in wastewater treatment using synchronous fluorescence spectroscopy combined with principal component analysis and two-dimensional correlation

Environmental Technology ◽

10.1080/09593330.2017.1357759 ◽

2017 ◽

Vol 39 (19) ◽

pp. 2495-2502 ◽

Cited By ~ 7

Author(s):

Hongwei Pan ◽

Huibin Yu ◽

Yanan Wang ◽

Ruixia Liu ◽

Hongjun Lei

Keyword(s):

Principal Component Analysis ◽

Organic Matter ◽

Wastewater Treatment ◽

Fluorescence Spectroscopy ◽

Dissolved Organic Matter ◽

Principal Component ◽

Synchronous Fluorescence ◽

Two Dimensional ◽

Synchronous Fluorescence Spectroscopy ◽

Fluorescent Dissolved Organic Matter

Download Full-text

Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

10.5194/bg-2017-209 ◽

2017 ◽

Author(s):

Emil Kristensen ◽

Mikkel Madsen-Østerbye ◽

Philippe Massicotte ◽

Ole Pedersen ◽

Stiig Markager ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Groundwater Recharge ◽

Groundwater Discharge ◽

Time Frame ◽

Dissolved Phosphorus ◽

Sources Of Pollution ◽

Total Dissolved Nitrogen ◽

Fluorescent Dissolved Organic Matter ◽

Degradation Rates

Abstract. Groundwater borne contaminants such as e.g., nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides impact the biological quality of lakes. The sources of pollution can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from groundwater wells installed every 50 m within 5–45 m from the shore and were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), 𝛿18O isotopes and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). Based on tracer concentrations and degradation rates, the maximum WRT was estimated to 2 years. Isolation of groundwater recharge areas were based on 𝛿18O measurements and sites with high a degree of recharge was isolated using PARAFAC component C4. Groundwater discharge sites and the fractions of water delivered from the sites were isolated with the Community Assembly via Trait Selection model (CATS) for WRTs between 0.25 and 2 years. The identified recharge sites corresponded to areas adjacent to drainage channels and a cluster analysis of component C4 further identified five sites which showed a tendency of high groundwater recharge rates. Isolated groundwater discharge sites were located in the eastern part of the lake and a single site in the southern part. Observations from the eastern part of the lake revealed an impermeable clay layer that promotes discharge during short precipitation events, which would be difficult to identify using traditional hydrological methods. High tracer concentrations in the southern part in relation to lake concentrations showed that only a smaller fraction of water could originate from this area, thereby confirming the model results. The methodology used can be applied to smaller lakes yielding results within a short time frame with information related to the WRT of the lake.

Download Full-text

The dynamics of fluorescent dissolved organic matter in the Paranaguá estuarine system, Southern Brazil

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592011000400002 ◽

2011 ◽

Vol 59 (4) ◽

pp. 311-326 ◽

Cited By ~ 4

Author(s):

Paloma Kachel Gusso-Choueri ◽

Rodrigo Brasil Choueri ◽

Ana Teresa Lombardi ◽

Eunice C Machado

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Fluorescence Emission ◽

Principal Component ◽

Estuarine System ◽

Southern Brazil ◽

Fluorescent Dissolved Organic Matter ◽

Tidal Condition ◽

Dom Characterization ◽

Different Sources

The aim of this study was to investigate the dynamics of the fluorescent dissolved organic matter (FDOM) in Paranaguá Estuarine System (PES) as to infer about the contribution of allochthonous FDOM to the estuarine waters in relation to tidal condition and seasons. Fluorescence spectroscopy was used for such purpose and DOM characterization through fluorescence emission was performed using excitation wavelengths of λex 350 nm and λex 450 nm, the two main fluorescence groups known to be present in natural DOM. Relations between emission wavelength (λem) and environmental variables, and the relevance of these variables to the different tides and seasons were identified by principal component analysis. The results showed that the first class of fluorophores (λex 350 nm) changed from the river (freshwater) towards the estuary, whilst the second class (λex 450 nm) has a more conservative nature and does not change as significantly as the first. Allochthonous DOM contribution to the estuarine system is intensified during the rainy season, especially in spring tides, whereas in the dry season the ratio of autochthonous DOM to total DOM in PES waters increased. We concluded that the variation of maximum λem of the first class of fluorophores (λex 350 nm) is mainly related to allochthonous contribution, whilst the maximum of emission for the second class of fluorophores (λex 450 nm) is dependent on the contribution of the different sources of organic matter (freshwater and marine water DOM contribution).

Download Full-text