Despite common fish poisoning, puffer fish is still considered as a delicacy in Japan and China. ... more Despite common fish poisoning, puffer fish is still considered as a delicacy in Japan and China. Most of the poisoning cases occur after consuming marine puffer fish species. The principle toxin exists in puffer fish is known as tetradotoxin (TTX). In freshwater puffer fish species, paralytic shellfish toxins (PSTs) have also been detected besides the TTX. Studies have shown that the highest toxin content was found in the skin, followed by gonad, muscle, liver and intestine.
The use of nematodes Panagrellus redivivus, dry diet and brine shrimp Artemia salina as feed for ... more The use of nematodes Panagrellus redivivus, dry diet and brine shrimp Artemia salina as feed for african catfish...
ABSTRACT Water Quality” is used to define the physical and chemical characteristics by which one ... more ABSTRACT Water Quality” is used to define the physical and chemical characteristics by which one evaluates the acceptability of water. The high cost of treated water makes most people in the rural communities to resort to readily availab water sources which are normally of low quality exposing them to waterborne diseases. Present research work deals with the applicability of the coagulation-flocculation process using Moringa oleifera seeds as natural absorbent and environmentally friendly antimicrobial agent for purification of Nagavali river water for drinking purpose. In present study various doses of Moringa oleifera seed powder like 50, 100 and 150 mg/l were taken and checked for the efficiency dose on raw river water. After treatment of water samples with Moringa oleifera seed powder were analyzed for different physicochemical parameters like pH, turbidity, total dissolved solids (TDS), electrical conductivity, hardness, alkalinity and chlorides. All parameters were reduced with increased dose of Moringa oleifera seed powder except alkalinity and pH. Application of this low cost Moringa oleifera seeds is recommended for eco-friendly, nontoxic, simplified water treatment where rural and peri-urban people living in extreme poverty are presently drinking highly turbid and microbiologically contaminated water.
Spatial and temporal variations of heavy metal contamination in sediments of a small mangrove sta... more Spatial and temporal variations of heavy metal contamination in sediments of a small mangrove stand in Hong Kong were examined by laying two transects perpendicular across the shore. Surface sediment samples were taken along the two transects running landward to seaward at intervals of 5 or 10 m during December 1989, and March, July and September 1990. Total concentrations of
The water quality of a eutrophic tropical reservoir was studied over a 5-year period (2000–2004),... more The water quality of a eutrophic tropical reservoir was studied over a 5-year period (2000–2004), with quarterly sampling (Jan, Apr, Jul, and Oct) carried out at 3 sampling stations with one station in each of 3 zones (fluvial, transitional, and lacustrine). During the wet season, large amounts of phosphorus were introduced into the reservoir by the increased inflow of the
Shrimp farming is an important source of revenue for Sarawak. Shrimp farms are usually located at... more Shrimp farming is an important source of revenue for Sarawak. Shrimp farms are usually located at the estuary utilizing brackish water for the growth of shrimps. Due to the excess fE~ed and feces accumulation over the culture period, pond water had to be drained and the pond bottom cleaned during harvesting before the next cycle of culture could begin. It is important to study the quality of the pond water during discharge so that the effluent can be properly managed and nutrient recovered. This study was conducted in a commercial shrimp farm whereby water quality of the effluent was monitored in the outflow drain during harvesting. Results show that turbidity increased from 51 to 92 NTU during draining. Dissolved oxygen was below the minimum recommended for aquatic organism (S mg/L). Mean total ammonia-nitrogen exceeded 1 mg/L and ortho-phosphorus was 0.06 mg/L. The final portion of the effluent water was the highest in turbidity, nitrate-N, ammonia-nitrogen and ortho-phosphorus. I...
NH3-N is an important parameter considered for water quality monitoring. High NH3-N contents in t... more NH3-N is an important parameter considered for water quality monitoring. High NH3-N contents in the river system may lead into euthrophication. Tidal flushing in the river determines the assimilation capacity of the river system affected by the tide. Therefore. the objective of this study was to monitor the tidal effect on the NH3-N dilution in the Batang Salak. The study conducted along Batang Salak comprised eight stations during nebb tide. The first round of sampling started at 0900 hr during low tide with the highest NH3-N concentration found at station 8. NH3-N ranged from 0.47 mg/L - 2.86 mg/L. The 0900 hr trip corresponded with the decrease in tide level that brought the upstream farm discharge water of Loba Kara channel into Loba Bodoh where station 8 is located. NH3-N recorded among station during 0900 hr trip was significantly different. Second round started at 1200 hr during low tide with station 6 showing the highest NH3-N concentration. NH3-N ranged from 1.17 mg/L - 3.0...
Shrimp aquaculture is a lucrative industry worldwide and more so in the tropics where two or thre... more Shrimp aquaculture is a lucrative industry worldwide and more so in the tropics where two or three crops could be produced per year. Malaysia has extensive coastal zones for shrimp aquaculture and this industry will expand further with the creation of Aquaculture Industrial Zone. However, little is known about the extent of impact of this industry in terms of the quality and quantity of pollutants generated. Therefore, the objective of this study was to determine shrimp pond effluent quality and subsequently estimate the pollutants loading. Water samples were taken at the outflow gate every 10 cm drop in the level of the pond water during harvesting and analyzed. Results show that dissolved oxygen was below 4 mg/L when not aerated. Total suspended solids was high (33-173 mg/L) and five-day biochemical oxygen demand (BOD5) ranged from 5.9 to 18.7 mg/L. Chemical oxygen demand (COD) was much higher than BOD5 values. Total soluble phosphorus (TP) were less than 0.07 mg/L and total nitrogen (TN) was 1.2 to 3.7 mg/L. Chlorophyll a (Chl-a) was high, ranging from 61 to 112 µg/L. Using Simpson’s rule, pollutant loadings were computed and the quantities (kg/ha/cycle) from the highest to the lowest were COD>TSS>BOD5>TN>TP>Chl-a. This study shows that shrimp pond effluent needs to be treated to protect the estuarine ecosystems and ensure the sustainability of this industry.
Batang Ai reservoir has been an inland aquaculture site. However, little is known about the water... more Batang Ai reservoir has been an inland aquaculture site. However, little is known about the water quality of the reservoir which is important for aquaculture expansion. Therefore, the objective of this study was to determine the level of dissolved oxygen (DO), biochemical oxygen demand (BOD5) and sulfide in the reservoir. Samplings were conducted at 12 stations and at three different depths. Results show that pH and dissolved oxygen decreased as depth increased. Mean DO at 0.5 m, 14 m and 27 m were 6.4 mg/L, 3.9 mg/L and 2.95 mg/L respectively. BOD5 were 3.9 mg/L, 8.7 mg/L and 8.3 mg/L at 0.5 m, 14 m and 27 m depth respectively. Total sulfide ranged from 0.33 to 32.0 µg/l and the mean at 27 m was significantly higher than 0.5 m depth. Multiple linear regression indicates that BOD5 was the only significant predictor of total sulfide. This study shows that sulfide was much lower than the lethal level and it would only be unhealthy for the caged fish if there were upwelling or mixing where lower DO water with toxic sulfide at and below 14 m depth were to be brought to the culture zone.
Despite common fish poisoning, puffer fish is still considered as a delicacy in Japan and China. ... more Despite common fish poisoning, puffer fish is still considered as a delicacy in Japan and China. Most of the poisoning cases occur after consuming marine puffer fish species. The principle toxin exists in puffer fish is known as tetradotoxin (TTX). In freshwater puffer fish species, paralytic shellfish toxins (PSTs) have also been detected besides the TTX. Studies have shown that the highest toxin content was found in the skin, followed by gonad, muscle, liver and intestine.
The use of nematodes Panagrellus redivivus, dry diet and brine shrimp Artemia salina as feed for ... more The use of nematodes Panagrellus redivivus, dry diet and brine shrimp Artemia salina as feed for african catfish...
ABSTRACT Water Quality” is used to define the physical and chemical characteristics by which one ... more ABSTRACT Water Quality” is used to define the physical and chemical characteristics by which one evaluates the acceptability of water. The high cost of treated water makes most people in the rural communities to resort to readily availab water sources which are normally of low quality exposing them to waterborne diseases. Present research work deals with the applicability of the coagulation-flocculation process using Moringa oleifera seeds as natural absorbent and environmentally friendly antimicrobial agent for purification of Nagavali river water for drinking purpose. In present study various doses of Moringa oleifera seed powder like 50, 100 and 150 mg/l were taken and checked for the efficiency dose on raw river water. After treatment of water samples with Moringa oleifera seed powder were analyzed for different physicochemical parameters like pH, turbidity, total dissolved solids (TDS), electrical conductivity, hardness, alkalinity and chlorides. All parameters were reduced with increased dose of Moringa oleifera seed powder except alkalinity and pH. Application of this low cost Moringa oleifera seeds is recommended for eco-friendly, nontoxic, simplified water treatment where rural and peri-urban people living in extreme poverty are presently drinking highly turbid and microbiologically contaminated water.
Spatial and temporal variations of heavy metal contamination in sediments of a small mangrove sta... more Spatial and temporal variations of heavy metal contamination in sediments of a small mangrove stand in Hong Kong were examined by laying two transects perpendicular across the shore. Surface sediment samples were taken along the two transects running landward to seaward at intervals of 5 or 10 m during December 1989, and March, July and September 1990. Total concentrations of
The water quality of a eutrophic tropical reservoir was studied over a 5-year period (2000–2004),... more The water quality of a eutrophic tropical reservoir was studied over a 5-year period (2000–2004), with quarterly sampling (Jan, Apr, Jul, and Oct) carried out at 3 sampling stations with one station in each of 3 zones (fluvial, transitional, and lacustrine). During the wet season, large amounts of phosphorus were introduced into the reservoir by the increased inflow of the
Shrimp farming is an important source of revenue for Sarawak. Shrimp farms are usually located at... more Shrimp farming is an important source of revenue for Sarawak. Shrimp farms are usually located at the estuary utilizing brackish water for the growth of shrimps. Due to the excess fE~ed and feces accumulation over the culture period, pond water had to be drained and the pond bottom cleaned during harvesting before the next cycle of culture could begin. It is important to study the quality of the pond water during discharge so that the effluent can be properly managed and nutrient recovered. This study was conducted in a commercial shrimp farm whereby water quality of the effluent was monitored in the outflow drain during harvesting. Results show that turbidity increased from 51 to 92 NTU during draining. Dissolved oxygen was below the minimum recommended for aquatic organism (S mg/L). Mean total ammonia-nitrogen exceeded 1 mg/L and ortho-phosphorus was 0.06 mg/L. The final portion of the effluent water was the highest in turbidity, nitrate-N, ammonia-nitrogen and ortho-phosphorus. I...
NH3-N is an important parameter considered for water quality monitoring. High NH3-N contents in t... more NH3-N is an important parameter considered for water quality monitoring. High NH3-N contents in the river system may lead into euthrophication. Tidal flushing in the river determines the assimilation capacity of the river system affected by the tide. Therefore. the objective of this study was to monitor the tidal effect on the NH3-N dilution in the Batang Salak. The study conducted along Batang Salak comprised eight stations during nebb tide. The first round of sampling started at 0900 hr during low tide with the highest NH3-N concentration found at station 8. NH3-N ranged from 0.47 mg/L - 2.86 mg/L. The 0900 hr trip corresponded with the decrease in tide level that brought the upstream farm discharge water of Loba Kara channel into Loba Bodoh where station 8 is located. NH3-N recorded among station during 0900 hr trip was significantly different. Second round started at 1200 hr during low tide with station 6 showing the highest NH3-N concentration. NH3-N ranged from 1.17 mg/L - 3.0...
Shrimp aquaculture is a lucrative industry worldwide and more so in the tropics where two or thre... more Shrimp aquaculture is a lucrative industry worldwide and more so in the tropics where two or three crops could be produced per year. Malaysia has extensive coastal zones for shrimp aquaculture and this industry will expand further with the creation of Aquaculture Industrial Zone. However, little is known about the extent of impact of this industry in terms of the quality and quantity of pollutants generated. Therefore, the objective of this study was to determine shrimp pond effluent quality and subsequently estimate the pollutants loading. Water samples were taken at the outflow gate every 10 cm drop in the level of the pond water during harvesting and analyzed. Results show that dissolved oxygen was below 4 mg/L when not aerated. Total suspended solids was high (33-173 mg/L) and five-day biochemical oxygen demand (BOD5) ranged from 5.9 to 18.7 mg/L. Chemical oxygen demand (COD) was much higher than BOD5 values. Total soluble phosphorus (TP) were less than 0.07 mg/L and total nitrogen (TN) was 1.2 to 3.7 mg/L. Chlorophyll a (Chl-a) was high, ranging from 61 to 112 µg/L. Using Simpson’s rule, pollutant loadings were computed and the quantities (kg/ha/cycle) from the highest to the lowest were COD>TSS>BOD5>TN>TP>Chl-a. This study shows that shrimp pond effluent needs to be treated to protect the estuarine ecosystems and ensure the sustainability of this industry.
Batang Ai reservoir has been an inland aquaculture site. However, little is known about the water... more Batang Ai reservoir has been an inland aquaculture site. However, little is known about the water quality of the reservoir which is important for aquaculture expansion. Therefore, the objective of this study was to determine the level of dissolved oxygen (DO), biochemical oxygen demand (BOD5) and sulfide in the reservoir. Samplings were conducted at 12 stations and at three different depths. Results show that pH and dissolved oxygen decreased as depth increased. Mean DO at 0.5 m, 14 m and 27 m were 6.4 mg/L, 3.9 mg/L and 2.95 mg/L respectively. BOD5 were 3.9 mg/L, 8.7 mg/L and 8.3 mg/L at 0.5 m, 14 m and 27 m depth respectively. Total sulfide ranged from 0.33 to 32.0 µg/l and the mean at 27 m was significantly higher than 0.5 m depth. Multiple linear regression indicates that BOD5 was the only significant predictor of total sulfide. This study shows that sulfide was much lower than the lethal level and it would only be unhealthy for the caged fish if there were upwelling or mixing where lower DO water with toxic sulfide at and below 14 m depth were to be brought to the culture zone.
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