Impact of Tannery Effluent on Wetland Birds of Dindigul District, Tamilnadu, India
Nazeema Mohamed Ali, Nirmala Thivyanathan
Research Centre of Zoology, Jayaraj Annapackiam College for Women, Periyakulam, Tamilnadu, India
To cite this article:
Nazeema Mohamed Ali, Nirmala Thivyanathan. Impact of Tannery Effluent on Wetland Birds of Dindigul District, Tamilnadu, India. Hydrology. Vol. 4, No. 2, 2016, pp. 10-18. doi: 10.11648/j.hyd.20160402.11
Received: February 18, 2016; Accepted: May 14, 2016; Published: May 19, 2016
Abstract: Water and soil is the most important and crucial factor on the global ecosystems and human health. This study focuses on the physico chemical parameters of effluent water and soil serving as an indicator of Tannery effluent tank, in Dindigul District. Bird census made using total bird count from December 2009 to May 2012 to enumerate bird species composition in the Tannery effluent tank. The study area harbored totally 14 species of birds which is grouped under 9 families falls under 7 orders. The maximum abundance of birds species was from the family Ardeidae and Charadridae. The most dominant species in Tannery Effluent tank was Black-winged Stilt and Little Egret. Water bird species seen abundantly were Black-winged Stilt, Little Egret, Grey Duck and Green Shank. The least number of bird species observed was Large Egret, Little Grebe and Median Egret. Electrical conductivity, total dissolved solids and the level of Chloride, Sulphate, Iron, Ammonia, Nitrate, Phosphate, BOD, COD and DO were high in the effluent water. Fluoride and Nitrite was within the standard limit of effluent water. The accumulation of micro nutrient in soil as Manganese, Zinc, Copper and Iron were high during the study. Determining the bird community in Tannery Effluent Tank and to evaluate the impact of Tannery Effluent Tank on the distribution of birds in Dindigul and the results highlights the discharge of highly polluted waste water effluent from tanneries of Dindigul District.
Keywords: Tannery Effluent, Bird Species, Physico Chemical Analysis - Water, Soil, Dindigul
Wetlands are defined as "areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions .
Avian community studies are effective tools for monitoring a pond ecosystem. Wetlands constitute a treasury of economic reserves and provide the right kind of habitats for breeding, nesting, mounting and wintering of local and migratory birds. Such sites also provide fodder and forage for many animals including birds and have aesthetic values as well. The relationship between wetlands and birds is shaped by many factors. These include the availability of depth and quality of water and the availability of food  and shelters and the presence and absence of predators. Water birds play an important role in several spheres of human interest, culturally, socially, scientifically and as a food resource .
Many studies have suggested that the combination of variable topography with suitable water depth provides habitats accessible for diverse water birds [4, 5 and 6] Ponds with gentle sloping sides can also increase topographical variation and attract both short and long legged wading birds .
In addition to the habitat variables, other variables related to the characteristics of sediments (organic matter content and particle size) and water quality such as temperature, Dissolved Oxygen, N, P, K, Mn, Zn, Cu, Fe, and pH can also directly or indirectly affect the use of wetlands by water birds. The organic matter content in water and sediments affects the growth of aquatic plants, and determines invertebrate abundance . Particle size of sediments determines how water and oxygen penetrate sediments and thus affects the presence of microfaunal and avifaunal invertebrates . Kersten et al.,  have demonstrated that the dissolved oxygen in the water affects the foraging of water birds by changing the vertical distribution of prey.
Industrial wastes, agriculture wastewaters, runoffs and atmospheric deposition are major sources of contamination of many surface waters. Runoffs cause sedimentation problems  in receiving streams, rivers and lakes. They can also transport toxic pollutants into catchments  with potential transfer to the food chain. Good quality water resources are of becoming more and more scarcity of conventional water resources, due to water demand increases both for human consumption and for agricultural use, the reuse of saline, brackish, and treated waste water could be a realistic way for reducing water shortage, as it has been demonstrated in many countries in the Mediterranean basin . Effluent differs from fresh water for salinity, pH and concentrations of micro- elements and nutrients. Lakhiwal and Chauhan,  studied the physico-chemical parameters of tannery effluent water and its applicability to irrigation.
Many different types of pollutants, if added to soil and soil are in direct contact with water, the ultimate fate of a pollutant will have its direct impact on the soil and agricultural land. In this back ground, it becomes necessary to study the soil that mostly degraded by tannery effluents .
Tanning is a major polluter worldwide and tannery wastewater, in particular, is a potential environmental pollutant . Water pollution by tannery wastes in Tamil Nadu is very severe and there is large number of tanneries in the state and the wastewater from the industry has caused considerable damage to water sources, affecting drinking water supply and irrigation. Dindigul district is one of the important tanning centres in Tamil Nadu with 60 registered tanning industries. Due to lack of integration of environmental considerations in the development of this region, the fast growth of the tanning industry in this belt has resulted in a drastic change in the environment. The tanneries which do not have effluent treatment plants discharge the untreated effluents laden with salts and other pollutants like chromium, lead etc. in large amounts indiscriminately in to the open lands, pits, channels, tanks and in low-lying areas. Lagooning of tannery wastes, or spreading on land for evaporation, together with the solid wastes has led to the contamination of ground water, which is the only source for drinking water and irrigation.
Thus the present investigation was designed to analyze the Physico chemical parameters of tannery effluent water and soil and to enumerate the bird’s species composition in tannery effluent tank, Dindigul district.
The bird census was taken from December 2009 to April 2010. The method of total count was employed to survey the bird population . In this method, the blocks were identified and the bird in the blocks were counted using a (7x50) pentax binocular and identified using physical features with the help of field guild [18, 19]. Birds were recorded during the study period. The census was made thrice a month.
The vegetation of the area was studied by identifying the plants. Specimens may be collected when they are in flower or fruit and preserved for identification with the help of books or some botanists for later reference.
Aquatic plants and succulents may be stored in liquid medium of either 5% formaldehyde or 70% alcohol. Dried herbarium specimen is to be stuck onto the herbarium sheet using gum / glue and thicker specimen may be tied to the sheet by a thread. Label is to be affixed on to the sheet by recording name of plant, details of the flower, habitat and plant associations, collection number and collector’s name.
Birds Population and Distribution
Birds of the wetland may be identified upto species and counted separately. The total counts being made by walking along the trail stopping at specific points and combing a particular area viewing through a binocular pentax 20x50 PCF. Care should be taken to avoid overlap. Birds flying from area to the other should also be noted in order to minimize error while compiling the data. Such count may be conducted thrice a month and recorded for analysis.
Analysis of water and soil samples
The water was collected once in a study period and the soil samples were collected once in a month immediately after the bird census in order to facilitate comparison of bird count with water and soil characteristics. Techniques used to measure the different variables are using standard methods as follows.
Water quality analysis such as temperature, pH, acidity, alkalinity, and chloride were analyzed by volumetric means, the macro and micro elements were analyzed in laboratory as per the standard methods (APHA, 2005). Overall results were subjected to statistical analysis of mean and standard deviation.
Species Richness and Abundance
Characterization of a community in a simple way is to count the various species recoded is expressed as species richness. Species abundance was measured by number of water birds species recorded from the habitat during census . The total number of birds recorded divided by number of counts conducted is expressed as the average number of birds and it is considered as the abundance of birds.
The Richness of bird species was calculated using the margalef  index.
R1 = (S – 1) / Ln (n)
S = The total number of species
N = The number of individuals.
Species diversity was calculated using the Shannon – Weaver index (Shannon Weaver .
H1 = - Σ Pi × Ln (Pi)
Pi = The proportion of individuals found in the 1th species.
Ln = Log normal
A number of indices have been used to quantify evenness.
Component of diversity
E1 = H1 / Ln (S)
H1 = Diversity
Ln = Log normal
S = Number of Species
The commonness of each bird species in habitat was found out by calculating
Commonness index, which is the average sighting frequency of a species in one.
The relative dominance of each bird species in the habitat was determined by calculating dominance index using the following formula
Relative dominance = n1 × 100 / N
N1 = Number of individual in 1th species
N = Means the total number of individual of all species.
Seen during the study period.
3. Result and Discussion
A study was conducted from December 2009 - May 2012 to enumerate the bird species composition in the tannery effluent tank. A total of 14 species represented, 7 orders of 9 families were observed. The results showed that the most dominant bird species were Black-winged Stilt followed by Little Egret, Grey Duck and Greenshank. The rarest bird species were Pond Heron, Little Cormorant, Spotted Redshank, Common Sandpiper, Red-rumped Swallow, Painted Stork and Grey Patridge.
The number of species was high in January and December. The least number of bird species was observed during the month of April and March (Figure 1). Bird abundance was high in February and low in April. High abundance in February was due to the high water inflow and incoming of migratory bird (Figure 2). The same result was reported by Vijayan  and Meena .
The number of species was high in December and low in March during 2010-2011 (Figure 3). The maximum species richness was observed in December and the minimum species richness was observed in January, February and March (Figure 4).
The maximum species richness was observed in December, January, February and March (Figure 5), because of the availability of prey categories as in the study of Nilsson . The species richness was very low in April and May, and this is because of low water level . The number of bird species was high in December followed by January and February. The least number of bird species was observed during the month of April and May. Bird abundance was high in December followed by January and February. The abundance was very low in April and May (Figure 6) due to the high inflow of effluent water and migrant bird species. The same result was reported by Nazeema and Nirmala .
The Bird species diversity was high in December with high evenness or equitability recorded in December and the minimum in April (Figure 7 & 8). This showed that the species there equally distributed in December than in January. Diversity was low in April with lowest equitability Nirmala and Nazeema, .
Diversity indices are dependent on two factors, species richness and evenness. In tannery effluent tank, the diversity of wetland bird species was high in December and low in February and March (Figure 9). Evenness was high in December and low in January.
The bird species diversity was high in December with high evenness or equitability and the minimum during May (Figure 10 & 11). This showed that this species is equally distributed in December than January.
3.1. Avifauna of Tannery Effluent Tank
Tannery effluent tank holds fourteen number of species during 2009 to 2012. The order Ciconiiformes followed by Charadriiformes hold high number of bird species and Ardeidae was the family share more number of bird species in Tannery effluent tank (Table 1). Pelecaniformes, Anseriformes, Passeriformes, Galliformes, Podicipediformes shared only one species in this area.
|Order||Family||Common Name of the Birds Species||Scientific Name|
|Pelecaniformes||Phalacrocoracidae||Little Cormorant||Phalacrocorax niger|
|Ciconiiformes||Ciconiidae||Painted Stork||Mycteria leucocephala|
|Ardeidae||Little Egret||Egretta garzatta|
|Pond Heron||Ardeola garyii|
|Median Egret||Egretta Intermedia|
|Large Egret||Casminodius Albus|
|Charadriiformes||Recurvirostridae||Black-winged Stilt||Himantopus himantopus|
|Scolopacidae||Spotted Redshank||Tringa erythropus|
|Green Shank||Tringa nebularia|
|Charadridae||Common Sandpiper||Tringa Hypoleucos|
|Galliformes||Phasianidae||Grey Patridge||Francolinus pondicerianus|
|Podicipediformes||Podicipedidae||Little Grebe||Tachybaptus Ruficolis|
3.2. Common Species in the Tannery Effluent Tank
The Black-winged Stilt was the most common species followed by Little Egret and Grey duck of Tannery Effluent Tank. The least common species were Median Egret followed by Grey Patridge and Pond Heron (Table 2) which has the commonness index below 10.
|S. No||Birds Name||Commonness Index During 2009-2012|
3.3. Dominant Bird Species in the Tannery Effluent Tank During the Study Period 2009-2012
The most dominant species in the Tannery effluent tank were Black-winged Stilt followed by the Little Egret and Grey duck. The least dominant bird species were Spotted red shank, Pond Heron and Grey Patridge. (Table 3) which has less than 10 as their dominant index.
|S. No.||Birds Name||Dominance Index During 2009-2012|
|10||Red- rumped Swallow||2.23|
3.4. Physico Chemical Analysis of Water in Tannery Effluent Tank
From the results, the colour of the water sample from tannery effluent was brownish during 2009 and later it was black in color during 2012 (Table 4). The colour is the first contaminant that has to be recognized in waste waters which affects the aesthetics, water transparency and gas solubility of water bodies . Wastewater that is light brown in colour is less than 6 hours old, if the colour is dark grey or black, the wastewater is typically septic, having undergone extensive bacterial decomposition under anaerobic conditions. The blackening of wastewater is often due to the formation of various sulphides, particularly, ferrous sulphide .
Although the turbidity in 2012 was lower than that recorded in 2009, both are exceedingly high from the acceptable limit (Table 4). The electrical conductivity (EC) of the water sample was 15,000 mg/l during 2009 and the value exceeded to 23300 mg/l during 2012. The Increase of EC value indicated the presence of higher concentration of ions. Kaushik  reported that EC of Anantpur samples being too high when compared to Sansarpur samples. Sivakumar et al.,  observed lower electrical conductivity in Dindigul effluent sample than in Ambur district.
Total dissolved solids in the effluent water sample were higher than the acceptable limit (Table 4). Large fluctuations in total solids (i.e., 8000 to 76, 500 mg/l) of tannery effluent water was reported by [33; 34; 35; 36 and 37]. The total dissolved solids may increase salinity of the water and thus may render it unfit for irrigation and drinking purposes. Consumption of water with high concentrations of total dissolved solids has been reported to cause disorders of alimentary canal, respiratory system, nervous system, coronary systems, besides causing miscarriage and cancer .
The PH was found 7.6 during 2009 and 7.9 during 2012 within the acceptable limit in the Dindigul tannery effluent tank (Table 4). It is Alkaline. It is the capacity of waste waters to neutralize acids, and is undesirable . The discharge of waste water in to water bodies may cause a drop or increase their PH. Alkalinity of tannery effluent water was 800 mg/l during 2009 (Table 4). Simillar observations were made by Sakthivel and Sampath  in Dindigul.
Total hardness remains the same (2500 mg/l) during the study. High amount of calcium was observed in 2009 (Table 4) where as the magnesium was high in 2012. Vasanthy and Sangeetha  reported higher values of total hardness and magnesium in tannery effluent at Trichy. The presence of Calcium, Magnesium in excess makes water unfit for irrigation since its application increase problems of soil salinity .
|Physical Examination||Acceptable Limit (mg/l)||Exceeding Limit (mg/l)||Dindigul Tannery Water (mg/l) in 2009||Dindigul Tannery Water (mg/l) in 2012|
|Electrical Conductivity Micro mho/cm||-||-||15, 000||23300|
|Total Dissolved Solids mg/l||500||2000||10,500||22500|
|Alkalinity as CaCO3||-||-||800||1600|
|PH||7.0 – 8.5||6.5 – 9.2||7.6||7.9|
|Calcium as Ca||75||200||600||440|
|Magnesium as Mg||30||150||240||260|
|Iron as Fe||0.1||1.0||1.0||10|
|Manganese as Mn||0.05||0.5||0.1||0|
|Ammonia as NH3||-||-||10||60|
|Nitrate as NO3||100||100||30||57|
|Nitrite as NO2||-||-||0.5||2|
|Fluoride as F||1||1.5||0.4||1.2|
|Biological Oxygen Demand||-||-||500||70|
|Chloride as Cl||200||1000||4750||8500|
|Sulphate as SO4||200||400||400||900|
|Phosphate as PO4||-||-||0.5||25|
|Tidys Test (4hours) as O2||-||-||4||25.0|
|Chemical Oxygen Demand||-||-||1400||150|
The level of Chloride, Sulphate and Phosphate was much higher in 2012 than in 2009 (Table 4). Excess outflow of the toxic effluent will make the water body unfit for plants and other living organisms .
The level of Iron, Ammonia, Nitrate, Fluoride and Nitrite in the effluent was high in 2012 where as it was low in 2009. Fluoride and Nitrite was within the standard exceeding limit of effluent water (Table 4).
Dissolved oxygen (DO), was found high (10 mg/l) during 2012 and it was low in 2010. This is in par with the observation made by Nanda Kumar et al., . The high Biological Oxygen Demand levels are indications of high pollution. The BOD value was high in 2012 than in 2010. The high BOD and low oxygen content of tannery waste water will affect survival of gill breathing animals of the receiving water body .
The values of COD from tannery effluent water was high in 1400 mg/l and 150 mg/l it was low in 2012 (Table 4). High COD levels indicate toxic state of the waste water along with presence of biologically resistant organic substances , Sivakumar et al.,  reported high level of COD which was higher than the standard prescribed limit of Central Pollution Control Board (1995).
3.5. Soil Analysis
High PH was observed in 2010 and it was low in 2011 (Figure 12). The electrical conductivity was high during 2009 followed by 2010 and it was low in 2011. The concentration of Nitrogen was higher in 2009 and lower in 2010. The Phosphorous was high in 2011 and low in 2009. The Potassium value was high during 2009 and it was comparatively low in 2010 and 2011 (Figure 13).
The accumulation of micro nutrient as Manganese, Zinc, Copper and Iron were high during 2009 followed by 2011 and 2010 (Figure 14).
Therefore the resultant tannery effluent is found to be highly concentrated with heavy metals. When these tannery effluents percolate the sediments gets contaminated. Beg and Ali  reported that the highly polluted sediments are adversely affected the ecological functioning of rivers due to heavy mobilization from urban areas into biosphere. The present finding indicates that the soil irrigated with tannery effluent and industrial wastewater contained high levels of metallic pollutants. It is evident from these studies that the test sample from tannery tank responded to the long term application of industrial waste water by an resistance to several undesirable agents and maintained physiological traits.
The Physico – Chemical Parameters of tannery effluent water and soil were high throughout the study period. Thus from the above studies the analysis of tannery effluent water was highly polluted. This is because of the industries discharging the waste water without proper treatment and this in turn affect the organism in and around Dindigul District. The results of the present investigation point out the need to implement common objectives, compatible policies and programmes for improvement in the industrial waste water treatment methods.
Authors express sincere thanks to the Research centre of Zoology, and special thanks to Supervisor of this project, Principal, Jayaraj Annapackiam College for Women, Periyakulam.