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NUTRIENT ENRICHMENT AND PROLIFERATION
OF INVASIVE MACROPHYTES IN URBAN LAKES
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T.V. Ramachandraa,b,c,*, K S Asulabhaa, Aamir Amin Lonea
aEnergy and Wetlands Research Group, Centre for Ecological Sciences,Indian Institute of Science, Bangalore – 560 012, Karnataka, India
bCentre for Sustainable Technologies (astra)
cCentre for infrastructure, sustainable Transportation and Urban Planning
Indian Institute of Science, Bangalore
*Corresponding author:cestvr@ces.iisc.ernet.in, energy@ces.iisc.ernet.in.
Citation : T.V. Ramachandra, K.S. Asulabha and Aamir Amin Lone, 2014. Nutrient Enrichment and Proliferation of Invasive Macrophytes in Urban Lakes, J Biodiversity, 5(1,2): 33-44
Materials and Methods
Study area
Bangalore city, Karnataka, India is located between 12°39´ - 13°18´N and 77°22´ - 77°52´ E. Bangalore (Fig. 1) city with a large number of lakes, ponds and marshy wetlands, which maintains ground water table and pleasant climate. Bangalore has no natural lakes but large numbers of manmade lakes that were built for various hydrological purposes and to meet the needs of drinking water and irrigation. Land use dynamics show 584% growth in built-up area during the last four decades with the decline of vegetation by 66% and water bodies by 74%. Analyses of the temporal data reveals an increase in urban built up area of 342.83% (during 1973 to 1992), 129.56% (during 1992 to 1999), 106.7% (1999 to 2002), 114.51% (2002 to 2006) and 126.19% from 2006 to 2010 (Ramachandra and Kumar 2008; Ramachandra et al. 2012) due to rapid and unplanned urbanization and expansion. Now, many of the existing lakes are reduced to cesspools due to direct discharge of industrial effluents, sewage and unregulated dumping of solid wastes (Ramachandra et al. 2003). Fig. 2 depicts lakes chosen for the study in Bellandur catchment. Table 1 lists lake wise number of sampling sites and spatial extent of monitored wetlands.
Figure 1: Study area Bangalore, Karnataka, India.
Figure 2 : Spatial distribution of lakes
Lake ID |
Name |
Location (Lat./Long.) |
Area (ha) |
No. of Sampling sites |
1 |
Lalbagh |
12°94´/77°58´ |
14.27 |
3 |
2 |
Sankey |
13°008´/77°57´ |
15.00 |
3 |
3 |
Yediyur |
12°97´/77°57´ |
4.28 |
2 |
4 |
Begur |
12°87´/77°63´ |
79.24 |
2 |
5 |
Doddakalsandra |
12°88´/77°56´ |
6.23 |
2 |
6 |
Kothnur |
12°87´/77°57´ |
5.38 |
2 |
7 |
Chunchunghatta |
12°88´/77°57´ |
7.69 |
1 |
8 |
SubbrayanKere |
12°86´/77°58´ |
5.00 |
1 |
9 |
Hulimavu |
12°87´/77°60´ |
51.41 |
1 |
10 |
Arekere |
12°88´/77°60´ |
10.57 |
1 |
11 |
Madivala |
12°90´/77°61´ |
100.60 |
1 |
12 |
Kodagisingasandra |
12°87´/77°64´ |
3.04 |
1 |
Table 1: Urban wetlands with spatial extent and location.
Analysis of various physico- chemical parameters
Water samples were collected in disinfected plastic polyethylene bottles from identified locations in lakes (Table 1, Fig. 2) between 7:30 a.m. and 2:00 p.m.. Water samples were preserved in the laboratory at 4°C for further analysis. At respective sampling locations, parameters such as temperature, dissolved oxygen, total dissolved solids, electrical conductivity and pH were measured. While, chloride, alkalinity, total hardness, calcium hardness, magnesium hardness, sodium, potassium, nitrate and phosphate were quantified at laboratory as per the standard protocol (Trivedy and Goel 1986; APHA 2005) listed in Table 2.
Parameters |
Method used |
Inland waters tolerance limit |
References |
Te |
Mercury thermometer |
40 |
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EC |
Digital meter |
- |
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TDS |
Digital meter |
500mg/L (BIS,1998) |
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pH |
Digital meter |
6.5–8.5 BIS (IS: 10500, 1992) |
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DO |
Digital meter |
3 |
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Cl |
Titrimetric method |
1000 |
APHA 2005 |
Al |
Titrimetric method |
500 mg/L(BIS,1998) |
APHA 2005 |
Ha |
Titrimetric method |
600 mg/L (BIS 1998) |
APHA 2005 |
Ca |
Titrimetric method |
200 mg/L (BIS 1998) |
APHA 2005 |
Mg |
Titrimetric method |
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APHA 2005 |
NO |
Spectrophotometric method |
45 mg/L |
Brown and Bellinger 1978 |
PO |
Spectrophotometric method |
0.3 mg/L |
Edwards et al. 1965 |
Na |
Flame photometric method |
200 mg/l |
APHA 2005 |
K |
Flame photometric method |
10 mg/l (BIS 1998) |
APHA 2005 |
COD |
Dichromate method |
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APHA 2005 |
Table 2: Methods used for water quality analysis.
Te-Water Temperature (°C), EC-Electrical Conductivity (μS/cm), TDS-Total Dissolved Solids, DO-Dissolved Oxygen (mg/l), COD-Chemical Oxygen Demand (mg/l), Al-Total Alkalinity (mg/l), Cl-Chloride (mg/l), Na-Sodium (mg/l), K-Potassium (mg/l), Ha-Total Hardness (mg/l), Ca-Calcium Hardness (mg/l), Mg-Magnesium Hardness (mg/l), NO-Nitrate, PO-Phosphate (mg/l).
Data analyses
Multivariate statistical analysis of the water quality variables was done through Principal Component Analysis (PCA) and Cluster Analysis (CA).
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