Biocides in Relation to Water Pollution. Part 2: Bioassay Studies of Few Biocides to a Fresh Water Fish,Channa gachua.

The present paper deals with the determination of LT_m values of zolone, rogor, sumithion and abate for Channa gachua by conducting static bioassay experiments. The TL_m values for zolone came out to be 0.08275 mg/l, 0.08225 mg/l, 0.0815 mg/l and 0.0810 mg/l; for rogor 5.155 mg/l; 4.955 mg/l, 4.65 mg/l and 4.475 mg/l; for sumithion 12.60 mg/l, 12.50 mg/l, 12.30 mg/l and 12.20 mg/l and for abate 217.25 mg/l, 225.575 mg/l, 221.575 mg/l and 217.25 mg/l for 24, 48, 72 and 96 hours, respectively. Relative susceptibility indicates that this fish is not susceptible to zolone and less to rogor, sumithion and abate, respectively. Present studies also show that increased temperature and pH increase the toxicity of all the biocides, but increased hardness of water decreases the toxicity of biocide solutions. The safe concentrations for zolone, rogor, sumithion and abate came out to be 0.02437 mg/l, 1.3733 mg/l, 3.6907 mg/l and 66.678 mg/l, respectively.     

Studies on the Toxicity of a few Pesticides on Colisa fasciatus and Notopterus notopterus with Reference to Histopathology and Histochemistry. Part 1: Bioassay Studies

An attempt has been made to study the toxicity of two commonly used pesticides aldrin (organochlorine) and ethyl-parathion (organophosphorus) to the fish Colisa fasciatus (Anabantidae) and Notopterus notopterus (Notopteridae). During bioassay studies, the behaviour of the fishes was recorded. The aldrin concentration used lies between 0.021 mg/1 and 0.042 mg/1 for C. fasciatus and 0.00056 mg/1 and 0.00135 mg/1 for N. notopterus. The ethyl-parathion concentration used lies between 1.8 mg/1 and 3.7 mg/1 for C. fasciatus and 0.49 mg/1 and 1.00 mg/1 for N. notopterus.

• – The effect of lethal aqueous concentrations of pesticides on the Fishes prior to death are usually manifested by excitation, erratic swimming ability, difficulty in respiration, increasing in ventilation rate, jerky movements of body and fin fast, up- and downward movements, convulsions, loss of equilibrium, loss of the original colour of the body skin and the excess secretion of mucus by the gills and the body wall.
• – the TL_m values for 24, 48 and 96 hours of exposition are determined for both species of fish and both pesticides at the following variables:

• ? three levels of temperature,
• ? three levels of dissolved oxygen,
• ? three levels of pH,
• ? three fish sizes.

• – statistical analysis of variance shows, that all variables have a significant effect on the TL_m values of both pesticides for both fish species;
• – Aldrin (chlorinated hydrocarbon) is more toxic than ethylparathion (organophosphate) at all variables;
• – Colisa fasciatus is the more resistant species than Notopterus notopterus.
• – the relationship between the total number of the fishes N₀, survival numbers N and time t can be expressed by a mathematical formula as:
• – the harmless concentration to C. fasciatus ranged from 0.0049 mg/1 to 0.0161 for aldrin, 0.54 mg/1 to 0.99 mg/1 for ethyl-parathion and to N. notopterus from 0.00012 mg/1 to 0.00045 mg/1 for aldrin, 0.10 mg/1 to 0.21 mg/1 for ethyl-parathion;
• – the aldrin should be diluted at least 4000 times and ethyl-parathion 320 times of its actual concentration.

     

Evaluation of the Relative Resistance of Twelve Species of Fish in Toxicity Bioassays with Electroplating Waste

The present paper deals with the evaluation of the relative resistance of 12 species of fish in static toxicity bioassay tests of electroplating waste. The electroplating waste is highly toxic as it contains several toxic metals like copper, nickel, cadmium, zinc, lead and chromium alongwith cyanides, acids and alkalies. On the basis of TL₅₀, the fish Clarias batrachus ist the most resistant fish and Labeo rohita the most sensitive. The relative resistance of the fish is in the decreasing order: Clarias batrachus, Saccobranchus fossilis, Ophiocephalus gachua, Ophiocephalus punctatus, Puntius stigma, Puntius sophore, Mystus vittatus, Cyprinus carpio, Colisa fasciatus, Notopterus notopterus, Cirrhina mrigala and Labeo rohita.     

Effect of a Sublethal Concentration of Zinc Sulphate on the Growth Rate of Fingerlings of Channa punctatus (Bloch), a Freshwater Murrel

Fingerlings of Channa punctatus are exposed to 12 mg/l zinc sulphate for 31 d at daily feeding. From the 19th day a significant decrease of growth (increase of weight) by 7 … 8 % as compared with the untreated control fishes was found. After exposure for 30 d the RNA- and protein-contents of the muscles are lower by 10 and 13 %, respectively.     

Effect of Zinc,Copper and Mercury on Channa marulius (HAMILTON)

Static bioassay acute toxicity tests of Zinc, Copper and Mercury were conducted to determine the median lethal concentrations (LC₅₀s) of a freshwater teleost Channa marulius (HAM .) The 96 h LC₅₀ and 95% confidence limits for Zn²⁺ were 25.61 (24.13 … 27.12) mg/l; 0.90 (0.80 … 1.038) mg/l; for Cu²⁺ and 0.314 (0.257 … 0.371) mg/l for Hg²⁺. However, these values decreased at 240 h of exposure and were: 21.09 (18.29 … 24.60) mg Zn²⁺/l; 0.66 (0.568 … 0.841) mg Cu²⁺/l; and 0.131 (0.103 … 0.158) mg Hg²⁺/l. The relative potency ratio of Zn/Hg, Zn/Cu and Cu/Hg suggests that fish were most sensitive to Hg, followed by Cu and Zn ions. The acute toxicities of mixtures of Zn²⁺?Cu²⁺; Zn²⁺?Hg²⁺, Cu²⁺?Hg²⁺ and Zn²⁺?Cu²⁺?Hg²⁺ up to 48 h of exposure were also investigated. The additive index and ranges for Zn²⁺?Cu²⁺ were ?0.241 (-0.577 … 0.054); 0.056 (-0.269 … 0.475) for Zn-Hg; 0.285 (-0.043 … 0.718) for Cu-Hg; and -0.542 (-1.215 … 0.005) for Zn-Cu-Hg. All the mixtures tested showed a greater than additive toxicity because index ranges overlapped zero.     

Acute toxicity of cadmium to Channa punctatus (BLOCH)

Effects of acute cadmium poisoning on survival, its residual values and histopathology in certain organs of a freshwater airbreathing fish, Channa punctatus (BLOCH ) were investigated. The threshold concentration, MATC and LC₅₀ values obtained from 96 h static bioassay, revealed that Channa is more susceptible to cadmium ions at higher temperature. The atomic absorption spectrophotometric determination of cadmium residues differed significantly in organs of specimens having survived and died after 96 h of exposure. The gill accumulate the highest amount of cadmium, the liver accumulated a slightly smaller amount than the gill, while the kidney accumulated the least. The histopathological lesions subjected to sublethal (5.2 mg/l Cd) and lethal (8.4 mg/l Cd) concentrations of cadmium were: detachment and rupture of lamellar epithelium, collapse of pillar cells and hypertrophy in mucus producing gland cells in the gill; vacuolization and coagulative necrosis in hepatic cells of the liver; and expansion, necrosis and accumulation of cellular debris in renal tubules of the kidney. The probable causes for death of fish due to cadmium ions have been discussed.     

Acute Toxicity of Sodium Nitrite on Channa punctatus (BLOCH) and Mystus (Mystus) vittatus (BLOCH)

This paper deals with the toxicity of sodium nitrite to freshwater fishes, Channa punctatus (BL.) and Mystus (M). vittatus (Bl.) as to determine the acute toxicity. The LC 50 values were obtained by using a static bioassay method for a period of 24, 48, 72 and 96 hour intervals. The LC 50 values of sodium nitrite for C. punctatus were 375, 325, 250 and 200 ppm and for M. (M). vittatus 164, 140, 90 and 64 ppm, respectively. A profuse mucus secretion was evident at higher concentrations as compared to lower ones. The probable causes of mortality of the fishes are also discussed.     

Toxicity of polynuclear aromatic hydrocarbons to the polychaete Neanthes arenaceodentata

The toxicity of ten polynuclear aromatic hydrocarbons (PNAs) to Neanthes arenaceodentata was studied in replicate 96 h bioassays with specific hydrocarbons in solution. Relative solubilities for each PNA were derived in short-term equilibration experiments. Disappearance of representative di-, tri, tetra- and pentacyclic-aromatic hydrocarbons from test solutions was also characterized by ultraviolet spectrophotometry. PNA toxicity and residence time in test solutions were directly related to molecular weight (MW), while relative solubility is inversely related to MW. 96 h TL_m values for the diaromatic PNAs naphthalene, 2,6-dimethylnaphthalene, and 2,3,6-trimethylnaphthalene were 3.8, 2.6 and 2.0 ppm, respectively. Phenanthrene, fluorene and 1-methylphenanthrene (triaromatics) exhibited 96 h TL_m values of 0.6, 1.0 and 0.3 ppm, respectively. None of the tetra- and pentacyclic-aromatics (chrysene, 3,4-benzo(a)pyrene, 1,2,5,6-dibenzanthracene) were toxic up to the highest concentration tested (1 ppm), excepting fluoranthene, with a 96 h TL_m of 0.5 ppm. PNA toxicity appears to be related to both solubility and residence time in test solutions.     

The acute toxicity of silver to some freshwater fishes

In the batch experiment with daily exchange of medium the acute toxicity of Ag from AgNO₃ to Channa punctatus, Lebistes reticulatus and Puntius sophore is determined over 12 to 96 h exposure. In general, the sensitivity of species increases in the order mentioned. The LC_{50, 96h} are 18.89 μg/l Ag for Channa punctatus, 7.55 μg/l Ag for Puntius sophore and 6.44 μg/l for Lebistes reticulatus. For 12 and 48 h exposure the values in the same order of species are: 62 and 30, 44 and 14 as well as 57 and 16 μg/l Ag.     

Studies on the Effect of DDT on the Regeneration of Cutaneous Wounds in Mystus (mystus) vittatus Bl. (Bagridae)

The effects of DDT on the regeneration of cutaneous wounds has been studied in Mystus (mystus) vittatus. The fishes were locally collected, they were inflicted incised wounds surgically and kept in 0.01 and 0.15 ppm concentrations of DDT. The regenerating skin at different stages of development ranging from 15 min to 25 d after the injury was studied through microtomy sections. The following toxic effects were studied:

• A small amount of DDT accumulated in the subcutis at the 25 days stage,
• the regeneration of wounds under DDT stress has been slower, delayed or irregular,
• the secretion of fibrinous exudate has been copious,
• epithelization and fibroblastic activities have been slower,
• the higher concentration of 0.15 ppm of DDT produced more toxic effects than the lower concentration of 0.01 ppm,
• the earlier stages of wound healing up to 3 d have been more adversely affected than later stages.

     

Hydrobiological Investigations of the Water Quality of the Water Supply Reservoirs Husinec and Římov

The two eutrophicated reservoirs Husinec (2.6 km³, 35 ha, z_max 18 m, MQ 1.87 m^3/s) and ?ímov (34.5 hm³, 216 ha, z_max 44 m, MQ 4.14 m^3/s) show concentrations of total phosphorus of 10… 50 mg/m³ and chlorophyll contents of 7… 36 mg/m³ in the summer season. For both reservoirs a good correlation exists between the chlorophyll concentration and the density of the phytoplankton (20 · 10³… 13 · 10⁶ ind./l). With average concentrations of 10… 20 mg/m³ chlorophyll a in summer, the water can be treated for producing drinking water only at a higher expenditure. The water quality will be improved by a reduction of the phosphorus load.     

Acute and chronic toxic effects of the carbamate pesticide Sevin on some haematological,biochemical and enzymatic parameters in the fresh water teleost fish Channa punctatus

The effects of exposure to LC₅₀ (10.5 mg/l) for 96 h and to a sublethal concentration (1.05 mg/l) of Sevin for 120 days have been observed on some haematological, biochemical and enzymatic parameters of Channa punctatus. The fish were hyperglycemic and hyperlactemic and the glycogen content of the liver and muscles decreased, but the lactic acid content of two tissues increased. The activity of hexokinase increased in the kidney, intestine, liver and muscles but decreased in the gills and brain. The activity of lactate dehydrogenase decreased in the kidney and intestine, and increased in the liver, muscles, brain and gills. The pyruvate dehydrogenase activity decreased in all the six tissues. Both the exposures produced a decrease in the succinate dehydrogenase activity of the liver. The enzyme activity decreased in the brain, gills and muscles after chronic exposure, whereas the kidney and intestine showed an elevation in enzyme activity.     

Impairments Induced by Sublethal Doses of Sevin and Thiodan on the Brain of a Freshwater Teleost Channa striatus BL. (Channidae)

Prolonged exposure to two pesticides Sevin and Thiodan for 30 days produced impairments in the brain of Channa striatus on the following ways:

• – Separation and damage to meninges of cerebral hemispheres
• – severe damage to all the five layers of the optic textum
• – severe damage to torus longitudinalis
• – partial damage to the molecular and grannular layers of the corpus cerebelli.
• – no effect on diencephalon and myelencephalon.

     

Toxicity of Phenol,Pentachlorophenol and Sodium Pentachlorophenolate to a Freshwater Teleost Lebistes reticulatus (Peters)

Lebistes reticulatus (Peters) was exposed to various concentrations of phenol, pentachlorophenol and sodium pentachlorophenolate to determine their toxicity, lethal concentrations and slope functions by a static bioassay procedure. Simultaneous controls were also run. The 94h LC₅₀ values were 47.5mg/l (42.04 … 53.68) for phenol, 0.77 mg/l (0.616 … 0.963) for sodium pentachlorophenate and 0.97 mg/l (0.866 … 1.086) for pentachlorophenol. On this basis, the rank order is sodium pentachlorophenolate-pentachlorophenol-phenol. During the treatment, fish showed an abnormal swimming reflex, excessive mucus secretion, haemorrhage near lips, abdomen and basis of fins and loss of equilibrium followed by death.     

Survivality and Impaired Growth in Arsenic Treated Fingerlings of Channa punctatus,a Fresh Water Murrel

The LC₅₀-values of As³⁺-compounds for Channa punctatus are determined for a 48-h exposure to 19.4 (18.02… 21.3) mg/1 and for a 96-h exposure to 14.3 (13.06… 16.80) mg/1. At a long-time exposure to 7.0 mg/1 As³⁺, during the first seven days there does not occur any change of growth, then the growth in length and the increase in weight decreased by 6.6 and 11.7%, respectively, till the 31st day. At the same time, the RNA content of the muscle decreased by 11.5% to 966.7 μg/g fresh weight and the protein content decreased by 12.5 % to 95.39 mg/g fresh weight.     

Zur Rolle der Stickstoffixation im Stoffhaushalt eines geschichteten Sees

In the dimict lake Arend (5.1 km², 146 hm³, 49.5 m z_max), nitrogen is production-limiting with concentrations below the detection limit during the production period. Phytoplankton achieves biomasses of up to 18 mg/l fresh matter, essential contributions being made by Aphanizomenon with 2 mg/l and Anabaena with up to 10 mg/l. Nitrogen fixation was measured by the ethine reduction technique (acetylene reduction) during periods of the occurrence of heterocystforming Cyanophyceae and achieved peak values up to 6.59 μg N² · h^?1 · l^?1 or 14.87 m^?2 · h^?1 g N₂ · m^?2 · h^?1. The rates of fixation show a safe correlation with the biomass of heterocyst-containing Cyanophyceae (r = 0.88), their development beginning at values below the N : P-ratio of 2.66.     

A note on the stress-dilatancy relation for simulated fault gouge

Theoretical constraints on the stress-dilation relation for a deforming Coulomb material requirev ifC=0 andv sin^-1( _m / _m ) always, wherev is the dilation angle, is the friction angle,C is cohesion, _m is the maximum shear stress, and _m is the mean effective stress. Recent laboratory measurements of friction and dilatancy of simulated fault gouge show that small amplitude shear-load cycling causes compaction and consolidation. Comparison of the data with theory indicates that such load cycling produces: (1) increased coefficient of friction (or friction angle), (2) increased cohesion, and (3) increased dilatancy rate (or dilation angle). Under certain conditions of load cycling without significant plastic shear strain accumulation ( ^p <0.005) we find thatv exceeds both and, in contrast to theory, sin^-1( _m / _m ). This result is interpreted in terms of enhanced cohesion and overconsolidation, which lead to residual stresses within the gouge. An analogy is drawn between these special loading conditions and those extant on natural faults. In particular, our results imply that jostling and minor stress variations associated with microearthquakes may produce strengthening of fault gouge and changes in the fault zone's stress-dilatancy relation. Hence, compaction associated with microseismicity may lead to subsequent dilation of fault gouge, even for faults with large displacement rates and large net offsets (e.g., San Andreas). In regions where such dilation persists over sufficient displacements (on the order of the critical slip distance for seismic faulting) it may tend to inhibit unstable slip.     

Studies on the Acute Toxicity of Zinc to a Freshwater Teleost: Channa punctatus (Bloch)

Static bioassay tests were carried out on Channa punctatus Bloch in the laboratory after renewal of concentrations every 24 h. The LC₅₀ values and 95 per cent confidence limits were 45.21 (39.62 … 51.11) ppm at 12 h and 29.8 (27.49 … 31.95) ppm of Zn at 96 h of exposure. The actual dissolution values of zinc were also determined in test solutions using an atomic absorption spectrophotometer. Behavioural changes were the higher rate of opercular movements, surfacing, loss of equilibrium and haemorrhage near mouth and caudal fin. The LT₅₀ values indicate that survival was increased with decreasing Zn concentration. The histopathological changes observed due to Zn toxicity in the gills have been discussed in relation to fish mortality.     

Studies on the Pollution of the Kalinadi by Industrial Wastes Near Mansurpur Part 1: Hydrometric and Physico-Chemical Characteristics of the Wastes and River Water

Stream pollution by industrial wastes is posing a problem in Uttar Pradesh. In the present investigations an attempt has been made to study the ecological features of a section of the Kalinadi so as to find out the cumulative or detrimental effect of pollution on fish and fisheries by the effluent discharge of sugar factory and distillery wastes near Mansurpur (District Muzaffarnagar), U. P. This paper is part I of the project. The liquid wastes produced by the sugar factory vary from 66 × 10⁶ to 88 × 10⁶ litres/day excluding condenser water and contain variable quantities of cane fibres, cellulose, lime, waxes, fermented sugar juice, mollasses, and some quantities of sulphate, phosphate, and nitrogen, the oxygen being nil with high values of B. O. D. and C. O. D. The liquid waste from the distillery is called spent wash. The spent wash (62 × 10⁴ litres/day) is highly coloured and acidic (pH 4.3 … 2.9). The B. O. D. and C. O. D. values were very high in the order of 28,526 mg/1 … 45,146 mg/1 and 52,516 mg/1 to 66,862 mg/1. Thus total waste of about 17.3 × 10⁶ litres with no oxygen and high B. O. D. (9,600 mg/1 … 10,116 mg/1) is let off into the Kalinadi. Hydrometric observations on the Kalinadi show that the pollutional hazard is appreciable during the low flow period of the river. The wastes affect the river in a number of ways:

• - The deposition of cellulose fibres, organic and inorganic matter affects the substratum adversely. The blackish brown colour of the wastes affects the light penetration by limiting the growth of phytoplankton.
• - There appears to be no potential danger to the river from the electrolyte pollution as the specific conductivity lies below limiting values.
• - Changes in pH in river water due to the acidic nature of the wastes do not affect directly the fauna and flora, but the acidic condition becomes lethal in the presence of low oxygen and high temperature values.
• - The high load of organic matter present in the wastes draws heavily on the oxygen budget of the river and adversely changes the water and bottom quality of the river for a stretch of 10 km, which adversely affects the environmental condition of both fish and fish food.
• - The presence of sulphuric acid in distillery waste and hydrogen sulphide in river water is toxic to fish and fish food.
• - The decomposition of organic matter in an anaerobic condition and in another favourable environment, as with a low redox potential, the presence of sufficient organic matter and a constant supply of sulphur-reducing bacteria, produces more hydrogen sulphide which may be detrimental or sublethal in the presence of a low oxygen saturation and high temperature.
• - The oxygen level increases at each succeeding station through reaeration and dilution with the lowering of B. O. D. and C. O. D. The oxygen-sag curve is like a typical spoon with handle-shape.

     

“Man and the Biosphere”-Studies on Sikkim Himalayas. Part 1: Acute Toxicity of Copper and Zinc to Common Carp Cyprinus carpio (Linn.) in Soft Water

In the daily exchange of the medium with only 7.1 mg/l Ca²⁺ and 0.7 mg/l Mg²⁺ during the batch experiment the LC_50,96h for Cyprinus carpio is 0.063 mg/l Cu²⁺ and 3.12 mg/l Zn²⁺ at water temperatures of 11 to 14°C. Significant differences in mortality as referred to the LC_50,12h occur for copper only after 72 h of exposure and for zinc after 48 h of exposure. The values of LC_50,96h are clearly lower for both metals in the investigations described than most data given in literature for different fish species.