scholarly journals ­Blue mussel (Mytilus spp.) cultivation in mesohaline eutrophied inner coastal waters: mitigation potential, threats and cost effectiveness

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11247
Author(s):  
Lukas Ritzenhofen ◽  
Anna-Lucia Buer ◽  
Greta Gyraite ◽  
Sven Dahlke ◽  
Annemarie Klemmstein ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Nutrient Removal ◽  
Coastal Waters ◽  
Secchi Depth ◽  
Waste Water Treatment Plant ◽  
Nutrient Inputs ◽  
Mitigation Potential ◽  
Mussel Farms ◽  
Mussel Cultivation

The EU-water framework directive (WFD) focuses on nutrient reductions to return coastal waters to the good ecological status. As of today, many coastal waters have reached a steady state of insufficient water quality due to continuous external nutrient inputs and internal loadings. This study focuses first on the current environmental status of mesohaline inner coastal waters to illustrate their needs of internal measures to reach demanded nutrient reductions and secondly, if mussel cultivation can be a suitable strategy to improve water quality. Therefore, nitrogen, phosphorus, chlorophyll a, and Secchi depth of nine mesohaline inner coastal waters in north east Germany were analyzed from 1990 to 2018. Two pilot mussel farms were used to evaluate their effectiveness as a mitigation measure and to estimate potential environmental risks, including the interactions with pathogenic vibrio bacteria. Further, estimated production and mitigation potential were used to assess economic profitability based on the sale of small sized mussels for animal feed and a compensation for nutrient mitigation. The compensation costs were derived from nutrient removal costs of a waste water treatment plant (WWTP). Results show that currently all nine water bodies do not reach the nutrient thresholds demanded by the WFD. However, coastal waters differ in nutrient pollution, indicating that some can reach the desired threshold values if internal measures are applied. The mitigation potential of mussel cultivation depends on the amount of biomass that is cultivated and harvested. However, since mussel growth is closely coupled to the salinity level, mussel cultivation in low saline environments leads to lower biomass production and inevitably to larger cultivation areas. If 50% of the case study area Greifswald Bay was covered with mussel farms the resulting nitrogen reduction would increase Secchi depth by 7.8 cm. However, high chlorophyll a values can hamper clearance rates (<20 mg m−3 = 0.43 l h−1 dry weight g−1) and therefore the mitigation potential. Also, the risk of mussel stock loss due to high summer water temperatures might affect the mitigation potential. The pilot farms had no significant effect on the total organic content of sediments beneath. However, increased values of Vibrio spp. in bio deposits within the pilot farm (1.43 106 ± 1.10 106CFU 100 ml−1 (reference site: 1.04 106 ± 1.45 106 CFU 100 ml−1) were measured with sediment traps. Hence, mussel farms might act as a sink for Vibrio spp. in systems with already high vibrio concentrations. However, more research is required to investigate the risks of Vibrio occurrence coupled to mussel farming. The economic model showed that mussel cultivation in environments below 12 PSU cannot be economic at current market prices for small size mussels and compensations based on nutrient removal cost of WWTPs.

Periphyton collectors as a tool to measure environmental performance of ocean outlets

2003 ◽  
Vol 47 (7-8) ◽  
pp. 125-131 ◽  
Author(s):  
S. Lemmens
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Environmental Quality ◽  
Coastal Waters ◽  
Quality Criteria ◽  
Carbonate Content ◽  
Total Biomass ◽  
Effective Measure ◽  
North East ◽  
The North

Brown and Root has participated in extensive investigations of the effects of the discharges from Perth's Ocean Outlets, as part of the Perth Long-Term Ocean Outlet Monitoring (PLOOM) Programme (1995 to 2001). The major environmental concern with these discharges is the potential for nutrients in the wastewater to stimulate excess primary production in the sea. PLOOM, and its predecessor, the Perth Coastal Waters Study, have been instrumental in developing parameters for the measurement of the performance of Perth's ocean outlets. These parameters are currently being integrated in the development of Environmental Quality Criteria (EQC) for the Perth region. EQC play an important role in the management framework by providing the quantitative benchmarks for measuring success in achieving the environmental quality objectives. PLOOM has monitored a range of environmental parameters in the Perth Metropolitan area, including water quality, nutrient levels, water circulation and plume dilution, levels of metals and pesticides present in the marine environment, and the environmental health of benthic communities, in particular of temperate reef systems. During the PLOOM studies, a valuable tool was being developed to monitor outlet performance. Artificial reef structures (“periphyton collectors”) were placed in the plume trajectory. Here, periphyton is defined as: the microalgae (diatoms and microscopic filamentous forms), algal propagules, bacteria, microfauna and particulate material that are found in a mucous-like layer commonly coating seagrass leaves, and that initially colonise artificial surfaces. The advantage of periphyton collectors is that these largely remove the effects of natural variability, can be placed at any depth and distance from a potential nutrient source, provide an easy, cost effective measure of environmental impact, integrated over an extended period (one month), and produce tangible results which can be interpreted by the wider community, as well as legislative authorities and by outlet managers. In addition, outlet performance can be measured by means of these tools, and tested against accepted environmental criteria. Between 1995-2001, periphyton collectors, consisting of 15 × 15 cm PVC plates attached to moorings at fixed depths (2, 4 and 8 m), were deployed for one month during spring, summer and autumn, at increasing distance from the source (250 and 500 m distance to the north, east, west, and south, and at 1,000, 2,000, 4,000 m to the north and south only). After retrieval, the collectors were analysed for total biomass (g AFDW m−2), calcium carbonate content (% AFDW) and chlorophyll levels (chlorophyll a m−2). The results confirmed the predictions made by hydrodynamic modelling (e.g. Zic and Gondinoudis, 2002) and are in accordance with measured nutrient and chlorophyll a levels around the outlets, and demonstrated that the zone of influence was strongly determined by the prevailing currents (to the north), and largely restricted to surface layers (2-4 m depth). Both biomass and chlorophyll content proved reliable parameters, which have the potential to be used as Environmental Quality Criteria (EQC's) for the management of Perth's coastal waters. These EQC's were developed in collaboration with legislative authorities, as part of draft criteria, in accordance with national guidelines: ANZECC/ARMCANZ (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

scholarly journals Water quality in Lake Xochimilco, Mexico: zooplankton indicators and Vibrio cholerae

2015 ◽  
Author(s):  
Sarma Nandini ◽  
Pedro Ramirez García ◽  
S.S.S. Sarma
Keyword(s):  
Water Quality ◽  
Vibrio Cholerae ◽  
Chlorophyll A ◽  
Local Population ◽  
Secchi Depth ◽  
Treatment Plant ◽  
Nitrogen And Phosphorus ◽  
Physico Chemical ◽  
Eutrophic Water ◽  
Depth Water

<p>Lake Xochimilco is a eutrophic water body in Mexico City used by the local population for aquaculture and agriculture. Water level is maintained with inputs of partially treated waste water from the Cerro de la Estrella treatment plant. In this study we analysed the water quality at two sites of Lake Xochimilco, Lake Xaltocan and the Santa Cruz Canal using various indicators such as zooplankton diversity, saprobic indices, bacterial concentrations and physico-chemical variables. Eighty litres of water was filtered from Lake Xochimilco from each site, once a month from March to October of 2012, and the rotifers, cladocerans and copepods were enumerated and identified. Physico-chemical parameters such as temperature, pH, Secchi depth, water depth, nitrogen and phosphorus and chlorophyll a concentrations, and bacterial densities were measured. During the study we recorded 33 species of rotifers, the most abundant being <em>Brachionus angularis</em>, <em>B. calyciflorus</em> and <em>B. havanaensis</em>.  Among the microcrustaceans the most abundant were the cladoceran <em>Moina micrura</em> and the copepods <em>Acanthocyclops americanus</em> and <em>Arctodiaptomus dorsalis</em>. The species diversity was around 2 bits/ind. and the saprobic index between 1.5-2.0, indicating that both sites were β meso-saprobic.  At both sites nitrogen was &lt;1 mg/L and phosphorus ranged between 2.5-7.8 mg/L. Chlorophyll a concentrations were between 66-136 µg/L. The toxigenic (<em>Vibrio cholerae </em>No-O1/No-O139) and the non-toxigenic (<em>Vibrio cholerae </em>No-O135) strains of the bacterium were recorded, closely associated with littoral rotifers and cladocerans particularly <em>Brachionus quadridentatus</em> and  <em>Alona</em> sp. All variables indicate that these sites in Lake Xochimilco are eutrophic and highly contaminated and that the water quality needs to be improved.<strong></strong></p>

scholarly journals DISSOLVED SILICATE IN COASTAL WATER OF SOUTH SULAWESI

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Muhammad Lukman ◽  
Andriani Nasir ◽  
Khairul Amri ◽  
Rahmadi Tambaru ◽  
Muhammad Hatta ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Coastal Water ◽  
Coastal Waters ◽  
Dry Season ◽  
Limiting Factor ◽  
Western Coast ◽  
Wet Season ◽  
South Sulawesi ◽  
Dissolved Silicate

ABSTRACT Dissolved silicate (DSi) in coastal waters plays a crucial role in phytoplankton growth particularly diatom. This study aimed to determine DSi concentration seasonally in waters of the western coast of South Sulawesi in relation to coastal water quality indicator. Water, chlorophyll-a, and diatom samples were collected from the coastal areas of the Tallo-Makassar, Maros, and Pangkep, in April 2013 (transitional season), June 2013 (dry season), and February 2014 (wet season). Factorial analysis of variance was used to identify significant seasonal and temporal variations, and linear regression was used to test the relationship of chlorophyll-a and diatom abundance to DSi concentrations. The results showed that the DSi concentration was higher in the wet season of 35.2-85.2 µM than in the other seasons (transitional season: 10.8-68.4 µM, dry season: 9.59-24.1 µM). The abundance of diatoms during the transitional season reached ~9.7x107 cell/m3 in the Pangkep river, 2.3x107 cell/m3 in the Tallo river, and 1.3 x 107 cell/m3 in the Maros river. Chaetoceros, Nitzschia, and Rhizosolenia dominated the diatom composition. The mean concentration of chlorophyll-a in the Makassar coastal waters was 4.52±4.66 mg/m3, while in the Maros and Pangkep waters of 1.40±1.06, and 2.72±1.94  mg/m3, respectively. There was no strong linear corelation between DSi and diatom abundances, nor chlorophyll-a. These results suggested that DSi become a non-limiting factor for the diatom growth and potentially reduce the water quality via eutrophication and diatom blooms. Keywords: dissolved silicate, diatom, chlorophyll-a, coastal waters, South Sulawesi

scholarly journals DISSOLVED SILICATE IN COASTAL WATER OF SOUTH SULAWESI

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Muhammad Lukman ◽  
Andriani Nasir ◽  
Khairul Amri ◽  
Rahmadi Tambaru ◽  
Muhammad Hatta ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Coastal Water ◽  
Coastal Waters ◽  
Dry Season ◽  
Limiting Factor ◽  
Western Coast ◽  
Wet Season ◽  
South Sulawesi ◽  
Dissolved Silicate

<p><strong><em>ABSTRACT</em></strong></p> <p><em>Dissolved silicate (DSi) in coastal waters plays a crucial role in phytoplankton</em><em> </em><em>growth particularly diatom</em><em>.</em><em> This study aimed to </em><em>determine</em><em> DSi</em><em> </em><em> concentration </em><em>seasonally </em><em>in waters of the western coast of South Sulawesi in relation to coastal water quality</em><em> indicator. Water, c</em><em>hlorophyll-a</em><em>,</em><em> and diatom samples were collected </em><em>from</em><em> the coastal areas of the Tallo-Makassar, Maros, and Pangkep, in April 2013 (transitional season), June 2013 (dry season), and February 2014 (wet season). Factorial analysis of variance was used to identify significant seasonal and temporal variations, and linear regression was used to test the relationship of chlorophyll-a and diatom abundance to DSi concentrations. The results showed that the DSi concentration was higher in the wet season </em><em>of</em><em> 35.2</em><em>-</em><em>85.2 µM than in the other seasons (transitional season: 10.8</em><em>-</em><em>68.4 µM, dry season: 9.59</em><em>-</em><em>24.1 µM). The abundance of diatoms during the transitional season reached ~9.7x10<sup>7</sup> cell/m<sup>3</sup> in the Pangkep river, 2.3x10<sup>7</sup> cell/m<sup>3</sup> in the Tallo river, and 1.3 x 10<sup>7</sup> cell/m<sup>3</sup> in the Maros river. <span style="text-decoration: underline;">Chaetoceros,</span> <span style="text-decoration: underline;">Nitzschia</span>, and <span style="text-decoration: underline;">Rhizosolenia </span>dominated the diatom composition. The mean concentration of chlorophyll-a in the Makassar coastal waters was 4.52±4.66 mg/m<sup>3</sup></em><em>, </em><em>while in the Maros </em><em>and Pangkep </em><em>waters </em><em>of</em><em> 1.40±1.06</em><em>, and </em><em>2.72±1.94  mg/m<sup>3</sup>,</em><em> respectively.</em><em> There was no strong linear corelation between DSi and diatom abundances, nor chlorophyll-a. These results suggest</em><em>ed</em><em> that DSi become a non-limiting factor for the </em><em>diatom </em><em>growth </em><em>and potentially reduce the water quality via</em><em> eutrophication and diatom blooms. </em></p> <p><strong> </strong></p> <strong><em>Keywords: </em></strong><em>dissolved silicate, diatom, chlorophyll-a, coastal waters, South Sulawesi</em>

Correlation of Water Quality Parameters in Tolo Harbour, Hong Kong

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2555-2558 ◽  
Author(s):  
K. W. Chau ◽  
Y. S. Sin
Keyword(s):  
Water Quality ◽  
Hong Kong ◽  
Chlorophyll A ◽  
Secchi Depth ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Phosphorus Concentration ◽  
Control Zone ◽  
Chlorophyll A Concentration ◽  
Tolo Harbour

In this paper, long-term biweekly measurements on the various water quality parameters in Tolo Harbour from year 1982 to 1990, subsequent to the declaration of the area as water control zone, were analyzed and correlated. Correlations have been demonstrated between surface chlorophyll-a concentration with secchi depth and with total nitrogen concentration (TN) in the three sub-zones of Tolo Harbour in Hong Kong with different water quality objectives. The correlation between chlorophyll-a concentration and total phosphorus concentration (TP) is less significant which can be explained by the TN/TP ratio. The correlations are useful for water management, planning and effective pollution control on the land-locked estuary.

scholarly journals Hyper-spectral Remote Sensing of Water Quality Parameters in Lakes: A Case Study of Hyderabad City, Telangana State, India

2017 ◽  
Vol 8 (2) ◽  
pp. 5
Author(s):  
V. Hema Sailaja ◽  
P. Suman Babu ◽  
M. Anji Reddy
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Chlorophyll A ◽  
Secchi Depth ◽  
Quality Parameters ◽  
Water Quality Modeling ◽  
Hyperspectral Data ◽  
Water Quality Parameters ◽  
Model Versus

This paper is a research work intended to present a comprehensive water quality modeling for predicting three water quality parameters (Chlorophyll (a), Turbidity and Secchi Depth) in typical Inland lake environments (Hussain sagar and Umda sagar) using Hyperspectral Remote sensing technique. They are estimated through regression models by combining the field Spectro-radiometer reflectance values with concurrent in situ ground data (Analytical) collected in the study area and correlated and validated with the available Hyperspectral data (Hyperion).  A total of 180 in situ water sample and 900 spectral signatures were analysed during campaigns from 2010 to 2014 study period. The mean values of Chlorophyll-a varied between 6.983mgL<sup>-1</sup> and 24.858mgL<sup>-1</sup>, Turbidity varied between 16.583mgL<sup>-1</sup> and 48.867mgL<sup>-1</sup> and Secchi depth varied between 0.104mgL<sup>-1</sup> and 0.375mgL<sup>-1</sup> over the study period considering the two lakes during pre and post monsoon seasons. The band ratios of the reflected spectra at R670/R710, R710/R740 and R710/R550 are used for the development of the mathematical model of chlorophyll-a, Turbidity and Secchi depth respectively. The trained sets of the pixels extracted from the hyperspectral data for pure spectra are processed for preparing the water quality distribution maps. When subjected to multi-variant statistical tests of significance, the models have yielded satisfactory R<sup>2</sup> values. The model versus in situ analysis results demonstrated R<sup>2</sup>= 0.81% for Chlorophyll-a, R<sup>2</sup>= 0.81%  for Turbidity and R<sup>2</sup>= 0.78% for Secchi depth correlation and that of model versus satellite data exhibited R<sup>2</sup>= 0.60% for Chlorophyll-a, R<sup>2</sup>= 0.66% for Turbidity and R<sup>2</sup>= 0.65 %  for Secchi depth mean efficiency.

scholarly journals Retrieval of Chlorophyll-a Concentrations in the Coastal Waters of the Beibu Gulf in Guangxi Using a Gradient-Boosting Decision Tree Model

2021 ◽  
Vol 11 (17) ◽  
pp. 7855
Author(s):  
Huanmei Yao ◽  
Yi Huang ◽  
Yiming Wei ◽  
Weiping Zhong ◽  
Ke Wen
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Spatial Distribution ◽  
Decision Tree ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Gradient Boosting ◽  
Beibu Gulf ◽  
Landsat 8 ◽  
Chl A

Remote sensing for the monitoring of chlorophyll-a (Chl-a) is essential to compensate for the shortcomings of traditional water quality monitoring, strengthen red tide disaster monitoring and early warnings, and reduce marine environmental risks. In this study, a machine learning approach called the Gradient-Boosting Decision Tree (GBDT) was employed to develop an algorithm for estimating the Chl-a concentrations of the coastal waters of the Beibu Gulf in Guangxi, using Landsat 8 OLI image data as the image source in combination with field measurements of Chl-a concentrations. The GBDT model with B4, B3 + B4, B3, B1 − B4, B2 + B4, B1 + B4, and B2 − B4 as input features exhibited higher accuracy (MAE = 0.998 μg/L, MAPE = 19.413%, and RMSE = 1.626 μg/L) compared with different physics models, providing a new method for remote sensing inversion of water quality parameters. The GBDT model was used to study the spatial distribution and temporal variation of Chl-a concentrations in the coastal sea surface of the Beibu Gulf of Guangxi from 2013 to 2020. The results showed a spatial distribution with high concentrations in nearshore waters and low concentrations in offshore waters. The Chl-a concentration exhibited seasonal changes (concentration in summer > autumn > spring ≈ winter).

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