Is freshwater quality adequately defined by physico-chemical components? Results from two drought-affected estuaries on the east coast of South Africa

2001 ◽  
Vol 52 (3) ◽  
pp. 267 ◽  
Author(s):  
C. F. Mackay ◽  
D. P. Cyrus
Keyword(s):  
Water Quality ◽  
East Coast ◽  
Chemical Properties ◽  
Benthic Fauna ◽  
Chemical Components ◽  
Physico Chemical ◽  
Marine Influence ◽  
Chemical Conditions ◽  
Biological Component ◽  
Two Populations

From 1992 to 1994 the physico-chemical conditions of two systems on the east coast of southern Africa shifted from estuarine to freshwater as a result of mouth closure during the prevailing drought. Although there was gradual colonization by freshwater benthic invertebrates, both systems were dominated by estuarine benthic infauna. The upper reaches of the Siyaya Estuary were entirely characterized by freshwater taxa (95%) by 1994, whereas Nhlabane Estuary showed a smaller increase in the number of these fauna. Non-metric multidimensional scaling plotted benthic populations as separate groups each year. These groups were not the result of a gradual shift in benthic fauna from an estuarine towards a freshwater bias. Rather, the upper estuarine reaches were dominated by taxa characteristic of freshwater environments, despite similar water quality conditions along all reaches. Three quarters of the zoobenthic communities (expressed as density m–2) were still estuarine in nature. The two populations were comparable to those occurring in nearby freshwater coastal lakes, which have been subject to marine influence in geological history. It was concluded that assessment of the biological component in addition to the physico-chemical properties should be considered when defining water quality in such systems.

scholarly journals Dissolved organic nutrients at the interface of fresh and marine waters: flow regime changes, biogeochemical cascades and picocyanobacterial blooms—the example of Florida Bay, USA

2021 ◽  
Author(s):  
Patricia M. Glibert ◽  
Cynthia A. Heil ◽  
Christopher J. Madden ◽  
Stephen P. Kelly
Keyword(s):  
Water Quality ◽  
Anthropogenic Activities ◽  
Florida Bay ◽  
Climate Conditions ◽  
Regime Changes ◽  
Physico Chemical ◽  
Organic Nutrients ◽  
High Concentrations ◽  
Chemical Conditions ◽  
Favorable Conditions

AbstractThe availability of dissolved inorganic and organic nutrients and their transformations along the fresh to marine continuum are being modified by various natural and anthropogenic activities and climate-related changes. Subtropical central and eastern Florida Bay, located at the southern end of the Florida peninsula, is classically considered to have inorganic nutrient conditions that are in higher-than-Redfield ratio proportions, and high levels of organic and chemically-reduced forms of nitrogen. However, salinity, pH and nutrients, both organic and inorganic, change with changes in freshwater flows to the bay. Here, using a time series of water quality and physico-chemical conditions from 2009 to 2019, the impacts of distinct changes in managed flow, drought, El Niño-related increases in precipitation, and intensive storms and hurricanes are explored with respect to changes in water quality and resulting ecosystem effects, with a focus on understanding why picocyanobacterial blooms formed when they did. Drought produced hyper-salinity conditions that were associated with a seagrass die-off. Years later, increases in precipitation resulting from intensive storms and a hurricane were associated with high loads of organic nutrients, and declines in pH, likely due to high organic acid input and decaying organic matter, collectively leading to physiologically favorable conditions for growth of the picocyanobacterium, Synechococcus spp. These conditions, including very high concentrations of NH4+, were likely inhibiting for seagrass recovery and for growth of competing phytoplankton or their grazers. Given projected future climate conditions, and anticipated cycles of drought and intensive storms, the likelihood of future seagrass die-offs and picocyanobacterial blooms is high.

scholarly journals Groundwater physico-chemical properties and water quality changes in shallow aquifers in arid saline wetlands, Ouargla, Algeria

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Fethi Medjani ◽  
Mohamed Djidel ◽  
Sofiane Labar ◽  
Louiza Bouchagoura ◽  
Chouaib Rezzag Bara
Keyword(s):  
Water Quality ◽  
Chemical Properties ◽  
High Water ◽  
Quality Changes ◽  
Shallow Aquifers ◽  
Shallow Water Table ◽  
Chemical Mechanisms ◽  
Desert Region ◽  
Physico Chemical ◽  
Hypersaline Water

AbstractShallow aquifers are vulnerable to natural geogenic processes as well as anthropogenic influences, and this is especially apparent in desert regions. Within arid and hyperarid climates, evaporation is a controlling hydrologic process leads to an important increase in the concentration of dissolved minerals of both surface water and groundwater. In groundwater, this increase is not only dependent on shallow water table depth, but also on the hydraulic properties of sediments present within the unsaturated zone of the aquifer itself. The main objective of this research is to investigate possible mechanisms that might influence water quality changes under seasonal conditions in shallow aquifers situated within the Saharan desert region of Algeria. In this work, we focus on observed changes in hydrogeochemical characteristics, and the possible responsible processes. Under arid conditions, high water mineralization results in hypersaline water or brine solution formation within shallow aquifers. Due to active physico-chemical mechanisms such as Na+/Ca2+ ion exchange, the successive precipitation of calcite, gypsum, mirabilite or blœdite and halite is induced. Biological processes were also observed as prevalent; evidenced by large measured variations in CO2 load concentrations. These processes contributed to an inverse relationship between CO2 and O2 concentrations within the shallow aquifers studied.

Fish Abundance and Physico-chemical Properties of Matingao River and Marbel River, Mount Apo Natural Park, Mindanao, Philippines

2019 ◽  
Vol 23 (2) ◽  
Author(s):  
Victoria Quimpang ◽  
◽  
Maricris Cudal ◽  
Einstine Opiso ◽  
Romeo Tubongbanua, Jr. ◽  
...  
Keyword(s):  
Water Quality ◽  
Freshwater Fish ◽  
Chemical Properties ◽  
Fish Abundance ◽  
Natural Park ◽  
Physico Chemical

freshwater fish, introduced, native, turbidity, water quality

scholarly journals Chemical composition of germinating Tunisian almond (Prunus Amygdalus Mill.) seedlings oil

2021 ◽  
Vol 48 (2) ◽  
Author(s):  
Refka Dhouibi ◽  
◽  
Hanen Oueslati ◽  
Senda Bahri ◽  
Khaled Jabou ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Lipolytic Activity ◽  
Chemical Properties ◽  
Dry Mass ◽  
Chemical Components ◽  
Prunus Amygdalus ◽  
Almond Oil ◽  
Physico Chemical ◽  
Total Fatty Acids

Almonds (Prunus amygdalus) are a rich source of many essential nutrients. However, there is a lack of enough information on almond varieties' biochemical composition, especially at the germination stage. Therefore, this study was conducted to determine the chemical components of the germinating Tunisian almonds. The study included determining the content of oils, proteins, fatty acids, and triglycerides during germination. Results indicated that the oleaginous seeds are rich in oil (55 to 65% of the dry mass) and crude protein (21.825 mg/mL). The dominant polyunsaturated fatty acids are oleic and linoleic acids which represent 64.53% and 24.38%, respectively, while palmitic acid is the most dominant saturated fatty acid with 7.65% of the total fatty acids. Also, the primary molecular types of triglycerides detected by L.C. analysis are triolein (32.3%) and dioleolinolein (24.0%), followed by palmitodiolein (12.5%) and oleodilinolein (12.6%.). The physico-chemical properties study revealed that almond oil remains stable, thus preserving its quality and nutritional value, even during transition from dormancy to germination. On the other hand, we also detected the presence of a lipolytic activity which is maximum on the 3rd day of germination (4.66 mUI). Our results indicate that almond oil plays an important role in human nutrition due to the presence of unsaturated fatty acids, and it is more stable than other oils.

scholarly journals A comparison of the water quality between the mangrove areas Mulyorejo and Wonorejo

2018 ◽  
Vol 177 ◽  
pp. 01014
Author(s):  
Luc Kauhl ◽  
Kayleigh Lambregts ◽  
Suntoyo
Keyword(s):  
Water Quality ◽  
Local Community ◽  
East Coast ◽  
Tree Density ◽  
Biological Parameters ◽  
Chemical Parameters ◽  
Good View ◽  
Physico Chemical ◽  
Biological State

The East Coast of Surabaya consists of large mangrove and fish pond areas. These areas are crucial for the ecosystem and for providing food and shelter for the local community. If the water quality decreases the mangroves will not be able to provide these functions. The water quality of these areas can be measured in two ways: by looking at the physico-chemical parameters or by looking at the biological parameters. Both offer a very good view of what state the area is in. The purpose of this study is to find out what the differences are between the Mulyorejo and the Wonorejo areas to see what differences there are within the East Coast of Surabaya and what could be the main cause of these differences. The data shows that the physico-chemical data does not comply with the limitation factors. The main problem are the nutrients which will have to be lowered to preserve the ecosystem. In terms of the biological state of the mangrove, there are few problems found. It is, however, unclear why the tree density in one of the Wonorejo areas is declining and it should be determined what the reason for this is.

scholarly journals Physico-chemical properties of Dhepa River in Dinajpur District of Bangladesh

2015 ◽  
Vol 6 (1) ◽  
pp. 59-67
Author(s):  
K Rakiba ◽  
Z Ferdoushi
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Ph Value ◽  
Sampling Site ◽  
Chemical Properties ◽  
Quality Parameters ◽  
P Concentration ◽  
Physical Chemical ◽  
Physico Chemical ◽  
Buffer Condition

Among different water quality parameters dissolved oxygen, transparency, pH, PO4-P and depth varied significantly among the sampling sites. The pH value in the present investigation remained a buffer condition (6.50- 7.90). Dissolved oxygen was ranges from 3.80 to 11.60 mg/l throughout the study periods. PO4-P concentration was observed highest (0.30 mg/l) in sampling site 2. On the basis of physical, chemical aspects sampling site 3 and sampling site 5 (situated in gosaipur and chandandoho) found in better condition in terms of limnological aspects. However, it could be concluded that Dhepa River will play important role in riverine fisheries and for further fisheries management.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22041 J. Environ. Sci. & Natural Resources, 6(1): 59-67 2013

scholarly journals Assessment of Groundwater Quality of Ilorin Metropolis using Water Quality Index Approach

1970 ◽  
Vol 12 (1) ◽  
pp. 18-21
Author(s):  
JA Olatunji ◽  
OA Odediran ◽  
RI Obaro ◽  
PI Olasehinde
Keyword(s):  
Water Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Chemical Properties ◽  
Total Hardness ◽  
Physico Chemical ◽  
Index Approach ◽  
Two Samples ◽  
Total Dissolved Solid

Groundwater as a source of potable water is becoming more important in Nigeria. Therefore, the need to ascertain the continuing potability of the sources cannot be over emphasised. This study is aimed at assessing the quality of selected groundwater samples from Ilorin metropolis, Nigeria, using the water quality index (WQI) method. Twenty two water samples were collected, 10 samples from boreholes and 12 samples from hand dug wells. All these were analysed for their physico – chemical properties. The parameters used for calculating the water quality index include the following: pH, total hardness, total dissolved solid, calcium, fluoride, iron, potassium, sulphate, nitrate and carbonate. The water quality index for the twenty two samples ranged from 0.66 to 756.02 with an average of 80.77. Two of the samples exceeded 100, which is the upper limit for safe drinking water. The high values of WQI from the sampling locations are observed to be due to higher values of iron and fluoride. This study reveals that the investigated groundwaters are mostly potable and can be consumed without treatment. Nonetheless, the sources identified to be unsafe should be treated before consumption.KEYWORDS: groundwater, water quality index, potability, physico - chemical, parameter

scholarly journals Water Quality of Major Ponds of Comilla Town

1970 ◽  
Vol 45 (1) ◽  
pp. 57-62
Author(s):  
SZKM Shamsad ◽  
Md Didar-Ul-Alam ◽  
ASM Shamsuddoha ◽  
Mohammad Naushad Alam
Keyword(s):  
Water Quality ◽  
Community Health ◽  
Key Words ◽  
Water Samples ◽  
Chemical Constituents ◽  
Chemical Properties ◽  
Organic Wastes ◽  
Dry Period ◽  
Physico Chemical

Some important physico-chemical properties of water of major ponds of Comilla Town were studied to evaluate the water quality. Eight water samples were collected during the dry period (March 2005) from eight major ponds of Comilla Town (Ranir dighi, Mandir dighi, Nanuar dighi, Fauzdari dighi, Modina dighi, Dargabari dighi, Darma Sagar and Thakurpara). The result revealed that all the chemical constituents, except a few, are beyond the recommended limit for different uses. Higher value of pH (at Dargabari dighi, Darma Sagar dighi), OM (at Thakurpara dighi, Fauzdari dighi and Modina dighi), NH4+ concentration (at Ranir dighi, Mandir Dighi, Fauzdari dighi, Modina dighi and Dargabari dighi), and lower value of DO (at Fauzdari dighi and Modina dighi) may due to continuous disposal of kitchen wastes, organic wastes, sewage running and fall of twigs as well as extensive used for bathing, washing cloths and utensils etc. All indicate eutrophication and affect community health and hygiene and also create aesthetic problem in the locality. Key words: Ponds; Comilla District; Water quality Eutrophication DOI: 10.3329/bjsir.v45i1.5184 Bangladesh J. Sci. Ind. Res. 45(1), 57-62, 2010

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