¹Energy and Wetlands Research Group, ²Centre for Ecological Sciences, ³Indian Institute of Science, Bangalore – 560012, India.
*Corresponding author: cestvr@ces.iisc.ernet.in

Citation: Ramachandra T V, Alakananda B and Supriya G, 2015. Efficacy of current restoration approaches - Bangalore wetlands, ENVIS Technical Report 73, CES, Indian Institute of Science, Bangalore 560012

5.1. Water quality investigations

Eleven wetlands were monitored during February to  April 2009. Three replicates of water samples were collected from inlets, outlets and other sites (such as centre, depending on the accessibility) to observe the effect of sewage and effluents as well as to understand the quality variations at the regional scale. Onsite variables like pH, electric conductivity (EC), salinity (SAL), total dissolved solids (TDS), water temperature (WT) (Extech pH/conductivity EC500) and dissolved oxygen (DO) were measured. The samples were stored at 40C in laboratory and analyzed for nitrates (N), inorganic phosphates/or phosphorous (P), total hardness (TH), calcium hardness (CaH), magnesium hardness (MgH), chlorides (CHL), alkalinity (ALK), chemical oxygen demand (COD) and biological oxygen demand (BOD) following standard protocols (Trivedy and Goel, 1986 and APHA, 1998).

5.2. Documentation of flora

5.2.1. Diatoms

Diatom sampling was done following Taylor et al., 2005, covering available habitats such as plants (epiphytic diatoms), stones (epilithic diatoms) and sediments (episammic diatoms). The stem and root portion of submerged plants were collected in a polythene cover and crushed. The sample was then transferred into a sample bottle. Epilithic diatoms were collected from 5-8 stones in a tray and brushed using a toothbrush. The upper 0.5 cm layer of soil was collected as episammic diatom sample. Diatom frustules were cleaned from the organic material using hot HNO3 and HCl method. The cleaned samples were then used to prepared slides with the help of Pleurax as mounting agent and observed under Olympus light microscope at 1000X. Taxa were identified mainly according to Krammer and Lange-Bertalot (1991-1997) and Lange-Bertalot (2001).

 

5.3. Documentation of fauna

5.3.1. Mollusks:

Mollusks in the littoral zone were collected by employing 2 methods viz., quadrat method where, aquatic vegetation and other objects were collected in an area of 25 × 25 cm and transferred to a container and filtered through 0.5 mm sieve by thorough washing and time constrained method which includes mollusks were sampled by search and handpick along the shore littoral zone for five minutes. These samples were kept in separate glass/plastic bottles and preserved with 70% alcohol. Collected samples were examined under a stereo zoom microscope (10X) and identified using standard taxonomic literatures (Ramakrishna and Dey, 2007 and Subba Rao, 1989).

5.3.2. Aquatic insects

Aquatic insects were sampled using a D-net sampler holding against water current and dragged along the shore of the wetlands up to a distance of 1m (Subramanian and Sivaramakrishnan, 2007) followed by preserving in 70% ethanol. Collected samples were examined under a stereo zoom microscope (10X) and identified using standard taxonomic literatures (Fraser, 1933-36, Morse et al. 1994 and Subramanian and Sivaramakrishnan, 2007).

Butterflies were observed from 11 wetlands of Bangalore between February and April 2009. Survey was conducted only once in the surrounding area of the wetlands. Butterflies were observed for half an hour in the morning between 8 am and 9 am. The species were identified in the field following Kunte (2000). The characters of species, which could not be identified in the field, were noted down and identified in the laboratory.

Bird survey was conducted as a time survey method wherein one hour observations (including calls) were done in the morning between 6 am and 8 am using binoculars. Common birds were identified in the field while the characters of rare birds, were recorded and identified using field guide of Salim Ali (1996) and Grimith et al. (1999).