SESSION-3: Aquatic Biodiversity
PAPER-7: Algal Resources of Chilika Lagoon, India
Jnanendra Rath and Adhikary S. P.

Abstract:

Algal flora of Chilika Lake has been studied several times during this century. Most of these works were repetitive in nature. None of the authors has studied the algae of the lagoon in every season covering the entire catchment area in a particular year. We for the first time surveyed the lake for algal forms in several collection trips in each season from July 1999 to December 2001 in order to prepare the authentic algal distribution map of the lake.

Totally one hundred numbers of algal forms were recorded belonging to four species. of Rhodophyta, twenty two species of Chlorophyta, eleven species of cyanophyta, fifty-eight species of Bacilariophyta and five species of Dinoflagellates. Fifty-seven species were found to be new record to the algal flora of Chilika lake. A clear distribution pattern of the algal forms in response to the fluctuating salinity of the lake in different sector was observed. In the outer channel sector and central sector where salinity was >20 ppt the common species were the marine diatoms Chaetoceros species , Asterionellopsis glacialis, Odentella mobiliensis etc. In the northern sector where a fresh water environment is maintained mostly Spirogyra species , Chara species , Nitella species , Pediastrum species , Chaetomorpha linum etc. are the common algal forms occur in the lake throughout all the seasons.

UV-absorbing mycosporine amino acid like substances (MAAs) was detected in Gracilaria verrucosa, Ceramium elegans and Lyngbya aesturii showing prominent absorption at 335 nm. The occurrence of high concentration of MAAs in these algae of Chilika lake exposed to high levels of solar radiation has been proposed to provide protection as a UV-absorbing sunscreen. Higher yield of agar with 165 to 180 g/cm 2 gel strength was obtained from Gracilaria verrucosa grown at 6.2 to 8 ppt. Salinity of Chilika was observed suggesting its potential commercial exploitation.