Eutrophication and Chlorophyll-a in a Severely Polluted Coastal Water of Jeddah, Red Sea.

2010 ◽  
Vol 21 (2) ◽  
pp. 15-29 ◽  
Author(s):  
S. Al-Harbi ◽  
H. Khomayis
Keyword(s):  
Chlorophyll A ◽  
Red Sea ◽  
Coastal Water

scholarly journals Factors Regulating the Relationship Between Total and Size-Fractionated Chlorophyll-a in Coastal Waters of the Red Sea

2019 ◽  
Vol 10 ◽  
Author(s):  
Robert J. W. Brewin ◽  
Xosé Anxelu G. Morán ◽  
Dionysios E. Raitsos ◽  
John A. Gittings ◽  
Maria Ll. Calleja ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Red Sea ◽  
Coastal Waters ◽  
The Relationship

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 Environmental properties of the southern Gulf of Aqaba, Red Sea, Egypt

2012 ◽  
Vol 13 (2) ◽  
pp. 179 ◽  
Author(s):  
M.M. DORGHAM ◽  
M.M. EL-SHERBINY ◽  
M.H. HANAFI
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Chlorophyll A ◽  
Red Sea ◽  
Environmental Parameters ◽  
Gulf Of Aqaba ◽  
High Concentration ◽  
Environmental Properties ◽  
Epipelagic Zone ◽  
Deep Layers

Environmental properties (temperature, dissolved oxygen, nutrients and chlorophyll a) of the epipelagic zone off SharmEl-Sheikh, Red Sea, Egypt were studied seasonally throughout a year from March 1995 to March 1996. Water samples werecollected from five water depths (0, 25, 50, 75 & 100 m). The studied parameters exhibited clear seasonal variability along the water column. The vertical distribution of water temperature showed thermal homogeneity during most seasons, and thermal stratification in summer. Dissolved oxygen attained slightly high concentrations (5.3-7.8 mg l-1) in the whole water column, with slight seasonal variation. The concentrations of nutrients reflected dominant oligotrophic conditions in the epipelagic zone and occasional mesotrophic status at some depths. Phosphate fluctuated between 0-0.7 μM, ammonium (0-2.27 μM), nitrite (0-0.72 μM), nitrate (0-1.49 μM) and silicate (0-6.48 M). Phytoplankton biomass was generally low in the epipelagic zone throughout the study, whereas chlorophyll a was less than 0.5 μg l-1, except relatively high concentration (0.7-1.12 μg l-1) in deep layers in spring. In comparison with previous studies on the Gulf of Aqaba all environmental parameters during present study showed pronouncedlydifferent values.

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>

scholarly journals Satellite Estimation of Chlorophyll-a Using Moderate Resolution Imaging Spectroradiometer (MODIS) Sensor in Shallow Coastal Water Bodies: Validation and Improvement

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1621
Author(s):  
Mohd Manzar Abbas ◽  
Assefa M. Melesse ◽  
Leonard J. Scinto ◽  
Jennifer S. Rehage
Keyword(s):  
Remote Sensing ◽  
Chesapeake Bay ◽  
Chlorophyll A ◽  
Coastal Water ◽  
Ocean Color ◽  
Ecological Status ◽  
Deep Ocean ◽  
Water Bodies ◽  
Band Ratio ◽  
Chl A

The size and distribution of Phytoplankton populations are indicators of the ecological status of a water body. The chlorophyll-a (Chl-a) concentration is estimated as a proxy for the distribution of phytoplankton biomass. Remote sensing is the only practical method for the synoptic assessment of Chl-a at large spatial and temporal scales. Long-term records of ocean color data from the MODIS Aqua Sensor have proven inadequate to assess Chl-a due to the lack of a robust ocean color algorithm. Chl-a estimation in shallow and coastal water bodies has been a challenge and existing operational algorithms are only suitable for deeper water bodies. In this study, the Ocean Color 3M (OC3M) derived Chl-a concentrations were compared with observed data to assess the performance of the OC3M algorithm. Subsequently, a regression analysis between in situ Chl-a and remote sensing reflectance was performed to obtain a green-red band algorithm for coastal (case 2) water. The OC3M algorithm yielded an accurate estimate of Chl-a for deep ocean (case 1) water (RMSE = 0.007, r2 = 0.518, p < 0.001), but failed to perform well in the coastal (case 2) water of Chesapeake Bay (RMSE = 23.217, r2 = 0.009, p = 0.356). The algorithm developed in this study predicted Chl-a more accurately in Chesapeake Bay (RMSE = 4.924, r2 = 0.444, p < 0.001) than the OC3M algorithm. The study indicates a maximum band ratio formulation using green and red bands could improve the satellite estimation of Chl-a in coastal waters.

scholarly journals MODIS Derived Sea Surface Salinity, Temperature, and Chlorophyll-a Data for Potential Fish Zone Mapping: West Red Sea Coastal Areas, Saudi Arabia

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2069 ◽  
Author(s):  
Saleh Daqamseh ◽  
A’kif Al-Fugara ◽  
Biswajeet Pradhan ◽  
Anas Al-Oraiqat ◽  
Maan Habib
Keyword(s):  
Linear Regression ◽  
Chlorophyll A ◽  
Red Sea ◽  
High Potential ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Chl A ◽  
Modis Data ◽  
The Impact

In this study, a multi-linear regression model for potential fishing zone (PFZ) mapping along the Saudi Arabian Red Sea coasts of Yanbu’ al Bahr and Jeddah was developed, using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data derived parameters, such as sea surface salinity (SSS), sea surface temperature (SST), and chlorophyll-a (Chl-a). MODIS data was also used to validate the model. The model expanded on previous models by taking seasonal variances in PFZs into account, examining the impact of the summer, winter, monsoon, and inter-monsoon season on the selected oceanographic parameters in order to gain a deeper understanding of fish aggregation patterns. MODIS images were used to effectively extract SSS, SST, and Chl-a data for PFZ mapping. MODIS data were then used to perform multiple linear regression analysis in order to generate SSS, SST, and Chl-a estimates, with the estimates validated against in-situ data obtained from field visits completed at the time of the satellite passes. The proposed model demonstrates high potential for use in the Red Sea region, with a high level of congruence found between mapped PFZ areas and fish catch data (R2 = 0.91). Based on the results of this research, it is suggested that the proposed PFZ model is used to support fisheries in determining high potential fishing zones, allowing large areas of the Red Sea to be utilized over a short period. The proposed PFZ model can contribute significantly to the understanding of seasonal fishing activity and support the efficient, effective, and responsible use of resources within the fishing industry.

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