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City sewage fish ponds in Hungary and India
Aquaculture,
Elsevier
54 (1986)
Science
129-134
Publishers
CITY SEWAGE
FISH PONDS
J. OLAH’ , N. SHARANG12
129
B.V., Amsterdam
- Printed
IN HUNGARY
in The Netherlands
AND INDIA
and N.C. DATTA3
’ Fisheriea
Research Institute, H-5540 Szarvas (Hungary) 2 Freshwater Aquaculture Research and Training Centre, Kausalyagang, Bhubaneswar, Orissa 751’002 (India) ) Fishery and Ecology Unit, Department of Zoology, University of Calcutta, 35 B.C. Road, Calcutta 70019 (India)
(Acceptecl
4 October
1985)
ABSTRACT Ollh, J., Sharangi, N. and Datta, N.C., India. Aquaculture, 54: 129-134.
1986.
City sewage
fish ponds
in Hungary
and
The management parameters and culture techniques followed in the production of fish in domestic sewage oxidation ponds in Hungary and in sewage-fed ponds in Calcutta (India) are compared, along with the physico-chemical parameters, and nutrient status in the context of biological productivity. The environment supporting healthy growth of fish was more stable in Hungarian oxidation ponds due to the daily introduction of sewage. The die1 oxygen concentration ranged between 4 and 19 mg dm-’ in the Hungarian fish ponds and 3.2 and 16.4 mg dmm3 in the Indian ponds. The highest total Of the natural fish food resources, ammonia was 0.9 and 3.6 mg dm-“, respectively. zooplankton reached the same maxima (around 11000 dm-‘) but chironomids and oligochael.es were more abundant in Indian ponds with maxima of 22 000 and 35 000 m-‘. A considerably higher fish production was realized in the tropical zone (21.3 kg ha-’ day-‘) than in the temperate zone (12.0 kg ha-’ day-‘) with production efficiency - in terms of percent primary production converted to fiih - of 2.7 and 1.5-5.2 respectively. The results from both sets of ponds are presented, viz. choice of species, stocking structure .and density, manipulation, period of rearing, and possibilities of implementing the technique in tropical and temperate urbanised areas with high sewage production.
INTRODIJCTION
The utilization of sewage oxidation ponds for aquaculture, with organic recycling, benefits both resource conservation and waste water disposal. Aquaculture utilising city sewage is not very common in the world, but has gained in importance in recent years. A comparative account of ecosystem analysis and technologies developed recently in Hungary (at the Fisheries Research Institute, Szarvas) and in India (near Calcutta) is given here with due presentation of data on the physico-chemical environment, nutrient status, and natural fish food resources, along with management parameters and culture techniques.
0044-8486/86/$03.50
o 1986 Elsevier
Science
Publishers
B.V.
130 MANAGEMENT
PRACTICES
In Hungary six experimental fish ponds with a surface area of 1.6 ha were used. They were situated in the town of Szemes (near Lake Balaton) which has a significant summer peak of sewage production. Without an alternative winter sewage disposal in the temperate zone, the short growing season limits the use of sewage fish ponds to cities with a high summer peak of domestic sewage production. The optimum daily amount of sewage introduction, in terms of fish growth and water purification, was determined in a separate experiment with sewage loadings of 50, 100, 150, 200 and 250 m3 ha-’ day-‘. It was found that 150 m3 ha-’ day-’ resulted in the most effective purification and acceptable fish growth. Raw sewage, after sedimentation, is pumped through tubing and finally released into the pond via sprinklers which are distributed over the ponds at the rate of 5 sprinklers per ha (Table 1). In India, ponds are located on the outskirts of the city of Calcutta. The water area is 5.7 ha and the mean depth is 0.7 m. Two narrow simple sluices are used as inlet and outlet. The sluices are operated manually. The ponds are drained every year during March-April. The raw sewage of the metropolis of Calcutta was allowed to flow into the ponds after preliminary screening of floating matter. After 12 days, the water was disturbed by repeated netting and manual agitation with split bamboos for oxidation, mixing and quick recovery of the water quality. Generally the ponds were ready to receive the stock of fish seed 25 days after sewage introduction. Later on, TABLE
1
Management
parameters
Parameter
Hungary
India
Pond bed Pond area (ha) Water depth (m) Water movement Water supply Aeration Draining Piscicide (ppm) Liming (kg ha-‘) Sewage
Earthen 1.6 1 Standing River Nil Winter Nil Nil Raw sewage after sedimentation Pumping through tubing and sprinklers Daily during morning 150
Earthen 5.7 0.7 Standing Sewage Manual agitation
Sewage introduction
Introduction
frequency
Sewage quantity
(m3 ha-’
day-‘)
March-April Mohua cake, 250 500 Raw sewage after screening floating Through inlet
matter
3 h daily for I days in every month 130
131
the ponds were fertilised with sewage every month for 7 days for a period of 3 h daily during the morning, and this appeared to supply adequate nutrients without causing much biological imbalance (Table 1). FISH CULTURE
TECHNIQUES
In the Hungarian ponds, after preliminary polyculture trials, a simple two-species culture was chosen, with one efficient filter feeder and one bottom scavenger. The ponds were stocked during April with silver carp (Hypophthulmichthys molitrix) 2500 fingerlings ha-’ and common carp (Cyprinus curpio) 1500 fingerlings ha- l, having an initial weight of 200 g and 190 g respectively (Table 2). The stock was reared up to October without any supplementary feed or any other type of manuring. Fish production was 12 k.g ha-’ day-! In India ponds served simultaneously as sedimentation, oxidation and holding ponds. These ponds were stocked during May and June with fry of catla (Cutlu adz), rohu (Lube0 rohitu), mrigal (Cirrhinus mrigulu), common carp (Cyprinus curpio) and tilapia (Oreochromis mossumbicus) at 35 087 fish ha-’ (Table 2). The stock was reared without any supplementary feeding, inorganic fertiliser or organic manure. Because of the high stocking density, fish were harvested intermittently after 120 days of rearing and harvesting continued up to 300 days. Harvesting was done by partial netting with a drag net and finally draining. As the fishes reared up to 120 days were acceptable for the local market, the stocking rate was higher for repeated harvesting. The production of 21.3 kg fish ha-’ day-’ is considered high. Table Culture
2 techniques
Procedure
Hungary
India
Stocking density (fish ha-‘) Stocking structure weight (g))‘; density (ha-‘) Hy~~ophthalmichthys molitrix Cyprinus carpio Catbz catla Labeo rohita Cirnzinus mrigala Oreochromis mossambicus Stocking time Feeding Inorganic fertilization Growing period (days) Harvesting time Fish production (kg ha-’ day-‘)
4000
35 087
200; 2500 190; 1500 -
20; 4210 30; 7193 22; 5965 26; 12105 22; 5614 May-June Nil Nil 300 October-February 21.3
April Nil Nil 120 October 12
132
POND
ENVIRONMENT
Fish health and production are intimately associated with the pond environment. The temperature, dissolved oxygen, pH and ammonia may have a direct adverse effect on fish condition and growth, determining the upper limit of the nutrient load into the fish ponds. The water temperature and pH varied widely in the Hungarian ponds, whereas in India a higher order of variation was observed in dissolved oxygen and ammonia (Table 3). The ranges of oxygen, pH and ammonia in pond water inidicate that the domestic sewage, while promoting fish growth, exerted a moderate and tolerable environmental stress for the fishes both in India and Hungary. A more stable environment was observed in the Hungarian oxidation ponds where sewage was pumped in daily, after sedimentation, through sprinklers. TABLE
3
Physico-chemical Annual
environment
ranges
Water temperature (c” ) Dissolved oxygen (mg dmm3) PH NH,-N (mg dme3)
NUTRIENT
Hungary
India
8-26 4-19 8.2-9.2 0.1-0.9
22-34 3.2-16.4 7.4-8.8 0.2-3.6
STATUS
The productivity of any aquatic ecosystem is governed by its nutrient status. In sewage-fed fish ponds a large amount of nutrients, both organic and inorganic, enters the sediment and water; in addition to their direct availability the nutrients enhance the productivity of the water bodies. The organic carbon, available phosphate and nitrate and ammonia in the water and sediments of both sets of ponds was sufficient to supply the production processes (Table 4). In India higher values of nutrients were recorded after TABLE Nutrient Annual
4 status ranges
Organic carbon in water (mg dmm3) Organic carbon in sediment (mg g-l) Phosphate in water (mg dm-“) Phosphate in sediment (mg g-‘) Nitrate in water (mg dm“) Nitrate in sediment (mg g-‘) Ammonia in water (mg dm-‘)
Hungary
India
9-23 10-20 O-2+.5 0.2-0.4 0.1-0.5 0.1-0.6 0.1-0.9
5.5-28 14-20 0.37-4.27 0.1-0.26 0.09+0.41 0.43-0.47 0.2-3.6
133
the entry of sewage, followed by a gradual reduction with an increased production of autochthonous organic matter. In Hungary the nutrient status was more balanced due to the daily introduction of sewage, except for an autumnal increase in inorganic nutrients caused by decreasing light intensity limiting the photosynthetic uptake of these nutrients. BIOLOG
[CAL PRODUCTION
A rich production of natural fish food organisms occurred in all ponds. The phytoplankton biomass fluctuated between 3.7 and 14.6 mg dme3 with dominance of Oscillatoriu, Spirulina, diatoms, Chlorella, and Ankistrodesmus species in the tropics. In the temperate zone the chlorophyll content was maintained on a rather high level of lOW200 pg dmm3. Photosynthetic production of organic matter fluctuated to a greater extent in Indian ponds than in Hungarian ponds (Table 5). The total zooplankton population ranged from 2390 to 10 460 in India and from 100 to 10 000 dmW3 in Hungary, indicating the availability of rich natural food resources for the fishes. Rotifers, copepods and cladocera dominated in both temperate and tropical ponds. The abundant zoobenthos was dominated by insect larvae and oligochaetes in temperate as well as tropical ponds, with almost the same species compostion. The population density of the animals was very high in the tropics :br both groups. The generation period of the insect larvae appeared to vary from 40 to 80 days and from 15 to 40 days in the temperate and tropical ponds, respectively. TABLE
5
Natural
fish food resources
Food
Hungary 100-150 /.lg drnm3 as chlorophyll
Phytoplankton
Zooplank ton (number dm-‘) Rotatoria Cladoeera Copepoda Zoobentl OS (number m-‘) Chiror, onus plumosus Chiron omus filitarsis Limnodrilus hoffmeisteri Branchium sowerbyi Primary production (g C m-l day-‘) Fish production (kg ha-’ day-’ ) Fish production efficiencya aPrimary production organic carbon)
India
per
fish
production
3.7-14.6 mg dm-” biomass
1000-10000 100-1000 10-100
-
2100-8500 160-210 130-1750 -
100-9000
100-22500 200-32340 up to 3170 2.6-16 21.3 2.7
100-5000
up to 1000 2-6.4 12 1.5-5.2 multiplied
as
by
100
(calculated
on
basis of
134
The rich supply of food organisms was maintained by primary production and by the organic content of the sewage. The primary production was higher in the tropical ponds, reaching the value of 16.1 g C m-’ day-’ which is the theoretical upper limit of primary production in standing waters. Fish production was also higher in the tropical ponds. The production efficiency of this fish rearing ecosystem (i.e., the percent of primary production transferred to fish flesh) was almost identical in the tropical and temperate ponds. The high primary productivity and the rich allochthonous organic supply lead to rich zooplankton and zoobenthos production and ultimately to high fish production. However, the simple biculture of a filter feeding and a benthic-feeding species in Hungarian ponds appears to be the more practical. The stocking of the Indian ponds was oriented towards the culture of commercially important species.
Elsevier
54 (1986)
Science
129-134
Publishers
CITY SEWAGE
FISH PONDS
J. OLAH’ , N. SHARANG12
129
B.V., Amsterdam
- Printed
IN HUNGARY
in The Netherlands
AND INDIA
and N.C. DATTA3
’ Fisheriea
Research Institute, H-5540 Szarvas (Hungary) 2 Freshwater Aquaculture Research and Training Centre, Kausalyagang, Bhubaneswar, Orissa 751’002 (India) ) Fishery and Ecology Unit, Department of Zoology, University of Calcutta, 35 B.C. Road, Calcutta 70019 (India)
(Acceptecl
4 October
1985)
ABSTRACT Ollh, J., Sharangi, N. and Datta, N.C., India. Aquaculture, 54: 129-134.
1986.
City sewage
fish ponds
in Hungary
and
The management parameters and culture techniques followed in the production of fish in domestic sewage oxidation ponds in Hungary and in sewage-fed ponds in Calcutta (India) are compared, along with the physico-chemical parameters, and nutrient status in the context of biological productivity. The environment supporting healthy growth of fish was more stable in Hungarian oxidation ponds due to the daily introduction of sewage. The die1 oxygen concentration ranged between 4 and 19 mg dm-’ in the Hungarian fish ponds and 3.2 and 16.4 mg dmm3 in the Indian ponds. The highest total Of the natural fish food resources, ammonia was 0.9 and 3.6 mg dm-“, respectively. zooplankton reached the same maxima (around 11000 dm-‘) but chironomids and oligochael.es were more abundant in Indian ponds with maxima of 22 000 and 35 000 m-‘. A considerably higher fish production was realized in the tropical zone (21.3 kg ha-’ day-‘) than in the temperate zone (12.0 kg ha-’ day-‘) with production efficiency - in terms of percent primary production converted to fiih - of 2.7 and 1.5-5.2 respectively. The results from both sets of ponds are presented, viz. choice of species, stocking structure .and density, manipulation, period of rearing, and possibilities of implementing the technique in tropical and temperate urbanised areas with high sewage production.
INTRODIJCTION
The utilization of sewage oxidation ponds for aquaculture, with organic recycling, benefits both resource conservation and waste water disposal. Aquaculture utilising city sewage is not very common in the world, but has gained in importance in recent years. A comparative account of ecosystem analysis and technologies developed recently in Hungary (at the Fisheries Research Institute, Szarvas) and in India (near Calcutta) is given here with due presentation of data on the physico-chemical environment, nutrient status, and natural fish food resources, along with management parameters and culture techniques.
0044-8486/86/$03.50
o 1986 Elsevier
Science
Publishers
B.V.
130 MANAGEMENT
PRACTICES
In Hungary six experimental fish ponds with a surface area of 1.6 ha were used. They were situated in the town of Szemes (near Lake Balaton) which has a significant summer peak of sewage production. Without an alternative winter sewage disposal in the temperate zone, the short growing season limits the use of sewage fish ponds to cities with a high summer peak of domestic sewage production. The optimum daily amount of sewage introduction, in terms of fish growth and water purification, was determined in a separate experiment with sewage loadings of 50, 100, 150, 200 and 250 m3 ha-’ day-‘. It was found that 150 m3 ha-’ day-’ resulted in the most effective purification and acceptable fish growth. Raw sewage, after sedimentation, is pumped through tubing and finally released into the pond via sprinklers which are distributed over the ponds at the rate of 5 sprinklers per ha (Table 1). In India, ponds are located on the outskirts of the city of Calcutta. The water area is 5.7 ha and the mean depth is 0.7 m. Two narrow simple sluices are used as inlet and outlet. The sluices are operated manually. The ponds are drained every year during March-April. The raw sewage of the metropolis of Calcutta was allowed to flow into the ponds after preliminary screening of floating matter. After 12 days, the water was disturbed by repeated netting and manual agitation with split bamboos for oxidation, mixing and quick recovery of the water quality. Generally the ponds were ready to receive the stock of fish seed 25 days after sewage introduction. Later on, TABLE
1
Management
parameters
Parameter
Hungary
India
Pond bed Pond area (ha) Water depth (m) Water movement Water supply Aeration Draining Piscicide (ppm) Liming (kg ha-‘) Sewage
Earthen 1.6 1 Standing River Nil Winter Nil Nil Raw sewage after sedimentation Pumping through tubing and sprinklers Daily during morning 150
Earthen 5.7 0.7 Standing Sewage Manual agitation
Sewage introduction
Introduction
frequency
Sewage quantity
(m3 ha-’
day-‘)
March-April Mohua cake, 250 500 Raw sewage after screening floating Through inlet
matter
3 h daily for I days in every month 130
131
the ponds were fertilised with sewage every month for 7 days for a period of 3 h daily during the morning, and this appeared to supply adequate nutrients without causing much biological imbalance (Table 1). FISH CULTURE
TECHNIQUES
In the Hungarian ponds, after preliminary polyculture trials, a simple two-species culture was chosen, with one efficient filter feeder and one bottom scavenger. The ponds were stocked during April with silver carp (Hypophthulmichthys molitrix) 2500 fingerlings ha-’ and common carp (Cyprinus curpio) 1500 fingerlings ha- l, having an initial weight of 200 g and 190 g respectively (Table 2). The stock was reared up to October without any supplementary feed or any other type of manuring. Fish production was 12 k.g ha-’ day-! In India ponds served simultaneously as sedimentation, oxidation and holding ponds. These ponds were stocked during May and June with fry of catla (Cutlu adz), rohu (Lube0 rohitu), mrigal (Cirrhinus mrigulu), common carp (Cyprinus curpio) and tilapia (Oreochromis mossumbicus) at 35 087 fish ha-’ (Table 2). The stock was reared without any supplementary feeding, inorganic fertiliser or organic manure. Because of the high stocking density, fish were harvested intermittently after 120 days of rearing and harvesting continued up to 300 days. Harvesting was done by partial netting with a drag net and finally draining. As the fishes reared up to 120 days were acceptable for the local market, the stocking rate was higher for repeated harvesting. The production of 21.3 kg fish ha-’ day-’ is considered high. Table Culture
2 techniques
Procedure
Hungary
India
Stocking density (fish ha-‘) Stocking structure weight (g))‘; density (ha-‘) Hy~~ophthalmichthys molitrix Cyprinus carpio Catbz catla Labeo rohita Cirnzinus mrigala Oreochromis mossambicus Stocking time Feeding Inorganic fertilization Growing period (days) Harvesting time Fish production (kg ha-’ day-‘)
4000
35 087
200; 2500 190; 1500 -
20; 4210 30; 7193 22; 5965 26; 12105 22; 5614 May-June Nil Nil 300 October-February 21.3
April Nil Nil 120 October 12
132
POND
ENVIRONMENT
Fish health and production are intimately associated with the pond environment. The temperature, dissolved oxygen, pH and ammonia may have a direct adverse effect on fish condition and growth, determining the upper limit of the nutrient load into the fish ponds. The water temperature and pH varied widely in the Hungarian ponds, whereas in India a higher order of variation was observed in dissolved oxygen and ammonia (Table 3). The ranges of oxygen, pH and ammonia in pond water inidicate that the domestic sewage, while promoting fish growth, exerted a moderate and tolerable environmental stress for the fishes both in India and Hungary. A more stable environment was observed in the Hungarian oxidation ponds where sewage was pumped in daily, after sedimentation, through sprinklers. TABLE
3
Physico-chemical Annual
environment
ranges
Water temperature (c” ) Dissolved oxygen (mg dmm3) PH NH,-N (mg dme3)
NUTRIENT
Hungary
India
8-26 4-19 8.2-9.2 0.1-0.9
22-34 3.2-16.4 7.4-8.8 0.2-3.6
STATUS
The productivity of any aquatic ecosystem is governed by its nutrient status. In sewage-fed fish ponds a large amount of nutrients, both organic and inorganic, enters the sediment and water; in addition to their direct availability the nutrients enhance the productivity of the water bodies. The organic carbon, available phosphate and nitrate and ammonia in the water and sediments of both sets of ponds was sufficient to supply the production processes (Table 4). In India higher values of nutrients were recorded after TABLE Nutrient Annual
4 status ranges
Organic carbon in water (mg dmm3) Organic carbon in sediment (mg g-l) Phosphate in water (mg dm-“) Phosphate in sediment (mg g-‘) Nitrate in water (mg dm“) Nitrate in sediment (mg g-‘) Ammonia in water (mg dm-‘)
Hungary
India
9-23 10-20 O-2+.5 0.2-0.4 0.1-0.5 0.1-0.6 0.1-0.9
5.5-28 14-20 0.37-4.27 0.1-0.26 0.09+0.41 0.43-0.47 0.2-3.6
133
the entry of sewage, followed by a gradual reduction with an increased production of autochthonous organic matter. In Hungary the nutrient status was more balanced due to the daily introduction of sewage, except for an autumnal increase in inorganic nutrients caused by decreasing light intensity limiting the photosynthetic uptake of these nutrients. BIOLOG
[CAL PRODUCTION
A rich production of natural fish food organisms occurred in all ponds. The phytoplankton biomass fluctuated between 3.7 and 14.6 mg dme3 with dominance of Oscillatoriu, Spirulina, diatoms, Chlorella, and Ankistrodesmus species in the tropics. In the temperate zone the chlorophyll content was maintained on a rather high level of lOW200 pg dmm3. Photosynthetic production of organic matter fluctuated to a greater extent in Indian ponds than in Hungarian ponds (Table 5). The total zooplankton population ranged from 2390 to 10 460 in India and from 100 to 10 000 dmW3 in Hungary, indicating the availability of rich natural food resources for the fishes. Rotifers, copepods and cladocera dominated in both temperate and tropical ponds. The abundant zoobenthos was dominated by insect larvae and oligochaetes in temperate as well as tropical ponds, with almost the same species compostion. The population density of the animals was very high in the tropics :br both groups. The generation period of the insect larvae appeared to vary from 40 to 80 days and from 15 to 40 days in the temperate and tropical ponds, respectively. TABLE
5
Natural
fish food resources
Food
Hungary 100-150 /.lg drnm3 as chlorophyll
Phytoplankton
Zooplank ton (number dm-‘) Rotatoria Cladoeera Copepoda Zoobentl OS (number m-‘) Chiror, onus plumosus Chiron omus filitarsis Limnodrilus hoffmeisteri Branchium sowerbyi Primary production (g C m-l day-‘) Fish production (kg ha-’ day-’ ) Fish production efficiencya aPrimary production organic carbon)
India
per
fish
production
3.7-14.6 mg dm-” biomass
1000-10000 100-1000 10-100
-
2100-8500 160-210 130-1750 -
100-9000
100-22500 200-32340 up to 3170 2.6-16 21.3 2.7
100-5000
up to 1000 2-6.4 12 1.5-5.2 multiplied
as
by
100
(calculated
on
basis of
134
The rich supply of food organisms was maintained by primary production and by the organic content of the sewage. The primary production was higher in the tropical ponds, reaching the value of 16.1 g C m-’ day-’ which is the theoretical upper limit of primary production in standing waters. Fish production was also higher in the tropical ponds. The production efficiency of this fish rearing ecosystem (i.e., the percent of primary production transferred to fish flesh) was almost identical in the tropical and temperate ponds. The high primary productivity and the rich allochthonous organic supply lead to rich zooplankton and zoobenthos production and ultimately to high fish production. However, the simple biculture of a filter feeding and a benthic-feeding species in Hungarian ponds appears to be the more practical. The stocking of the Indian ponds was oriented towards the culture of commercially important species.