A Critical Survey of Seaweed Diversity of Chilika Lake, India
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Algae Volume 18(1): 1-12, 2003 A Critical Survey of Seaweed Diversity of Chilika Lake, India Debasish Sahoo, Nivedita Sahu and Dinabandhu Sahoo* Marine Biotechnology Laboratory, Department of Botany, University of Delhi, Delhi - 110 007, India A critical survey of seaweed diversity was under taken to different parts of the Chilika lake over a period of three years from 1999 to 2002. Total of 14 species of seaweeds were recorded from different parts of the lake which includes 8 species of Chlorophyceae and 6 species of Rhodophyceae. No members of Phaeophyceae was reported during the present investigation. Our study not only gives a detailed description of all the taxa but also reports occurrence of two new Chlorophyceae members such as Enteromorpha flexuosa subsp. flexuosa and Ulva fasciata. Key Words: Chilik Lake, India, seaweed diversity from some parts of the lake. Out of all these studies only INTRODUCTION Biswas gave a detailed authentic monograph on algal flora. But since Biswas’s study in 1932, the lake had During the last seventy years several studies have undergone several ecological changes due to closing of been undertaken on different aspects of marine algae the lake mouth to the sea thus blocking the entry of from different parts of the Indian coast. The country has saline water to the lake. Besides, large-scale aquacultural a vast coastline of more than 7,000 km, which harbours a activities have gone up in the lake during last several large diversity of marine algal species. So far nearly years. Eutrification has also caused several problems to seven hundred seventy species of marine algae have the lake along with siltation. All these activities over the been reported from different parts of the Indian coast, years have not only changed the ecological characters of which includes 184 species of Chlorophyceae, 166 the lake but also its floristic composition. Thus, the pre- species of Phaeophyceae and 420 species of sent study is an important step to re-evaluate the sea- Rhodophyceae (Sahoo et al. 2001). Although systematic weeds diversity of the lake. studies on marine algal distribution and diversity are known from different coastal provinces of India, not MATERIALS AND METHODS much published information is available about the marine algal flora of Orissa. The state has a coastline of Field trips were undertaken to different parts of the 460 km covering mostly sandy beaches. Sahoo (1989); Chilika lake over a period of three years from 1999 to Sahoo and Vijayraghvan (1986) reported occurrence of 2002. After carefully studying the topography of the lake Centroceras clavulatum, Chaetomorpha antennina and five important sites were selected for collection of eco- Herposiphonia tenella from Gopalpur coast of Orissa. logical data and marine algal samples (Fig. 1). Reports of occurrence of some marine algal species have Hydrobiological data as well as algal samples were col- also been reported from Chilika, a brackish water lake in lected once in every three months during the study peri- Orissa. Biswas (1932) in his monumental work reported od. Some of the algal samples were fixed in the field in nine different species of seaweeds from different parts of 4% formalin and 10% acrolein separately for light micro- the lake. Parija and Parija (1947) studied the succession scopic studies. Fresh materials were brought to the labo- of some algae on a rocky island of the lake. Sahu and ratory at Department of Botany, University of Delhi, Adhikary (1999) reported only six marine algal species Delhi for culture studies and further investigation. In the field, a digital thermometer measured temperature, pH *Corresponding author ([email protected]) was measured by a hand pH meter and salinity was 2 Algae Vol. 18(1), 2003 Stn-I Stn-III Stn-II Stn-V Stn-IV Fig. 1. Chilika Lake. Map of Chilika Lake showing different sectors and place of collection. measured by a salinity meter (Atago-2442-W05, Japan). Table 1. Salinity data of different sites of Chilika Lake (in ppt) Besides these parameters, the nature of substratum, Month Place habitat of plants, locality and abundance of species were also noted. Station I II III IV V January 2.5 9.5 10.0 11 6.2 OBSERVATIONS April 8.1 12.8 10.5 10.5 34.3 July 8.1 12.9 12.2 13.0 7.3 Physico-chemical characteristics of the lake: Chilika October 2.0 9.5 10.5 10.5 11.0 is situated between 19°28’-19°54’N and 85°5’-85°38’ E in the east coast of India. The pear shaped lake receives fresh water from small rivulets, rivers and tributaries in ty is given in Table 1. The minimum temperature of the the northern side whereas it gets saline water from Bay water is 21°C in January and the maximum of 32°C in of Bengal through an opening on the Southern side. May. The lake has an average depth of upto 2 meters Ecologically the lake is divided into four parts namely - and has different types of substratum at different sites Southern, Northern, Central sector and Outer channel varying from muddy to rocky and sandy which favors (Fig. 1). The lake has an area of 740 km2 in summer and the growth of different algae at different places (Table 3). 1,165 km2 in the rainy season. The salinity in the outer The substratum in station-I (Balugaon) is completely channel area remains between 30-34 ppt in most part of muddy with depth upto several meters. It is quite diffi- the year, except the rainy season. In contrast the salinity cult to collect the samples because of deep mud. The sta- varies between 2-20 ppt in northern, southern and cen- tion is also highly polluted due to human activities. tral sectors. In some parts of the lake the salinity reaches Station-II (Kalijai), III (Barkul), IV (Pathara) are almost to 0 ppt during rainy season. So the lake shows a salinity rocky substratum with some muddy and sandy places in gradient from 0-30 ppt from Northern to Southern sector between. The algal vegetation is found all over the sub- including the Outer channel. The detailed data of salini- stratum. The water in these areas are more clear and less Sahoo et al.: Seaweed Diversity of Chilika Lake, India 3 Table 2. Temperature data of different sites of Chilika Lake (°C) Table 3. List of Seaweeds collected from different parts of the Lake Month Place Species Name Place of collection Station I II III IV V 1. Enteromorpha compressa Kalijai, Pathara and January 21.5 22.5 24.0 24.0 23.0 Satpara April 30.0 30.0 32.0 32.0 32.0 2. Enteromorpha flexuosa sub sp. Kalijai Island July 31.0 28.0 29.0 30.0 29.0 flexuosa October 30.0 29.0 32.0 32.0 30.5 3. Enteromorpha intestinalis Throughout the lake. 4. Ulva fasciata Kalijai and Pathara. 5. Ulva lactuca Kalijai and Pathara. polluted. Station-V (Satpara), is predominantly sandy, 6. Chaetomorpha linum All around the lake. however some small rocks and concrete bases are also 7. Cladophora glomerata Balugaon, Kalijai and found. In the low tide these area are suitable for collec- Pathara. 8. Pithophora oedogonia Balugaon, Kalijai, Pathara tions. and Satpara. 9. Gracilaria verrucosa Kalijai, Pathara, Systematic list Honeymoon Island and Out of the 14 species recorded from different parts of Barkul. the lake 8 species belongs to Chlorophyceae and 6 10. Gracilariopsis megaspora Balugaon and Satpara. species belongs to Rhodophyceae. Interestingly two of 11. Grateloupia filicina var. luxurians Kalijai 12. Ceramium diaphanum var. elegans Kalijai, Pathara and the species have not been recorded from the lake earlier. Barkul. 13. Polysiphonia sertularioides Kalijai, Pathara and Chlorophyceae Satpara. 1. Enteromorpha compressa (Linnaeus) Nees 14. Polysiphonia subtilissima Kalijai, Pathara and Harvey 1858a, p. 57, Fig. 2A. Satpara. Habitat: Growing profusely on rocks and free floating Location: The plants are found growing luxuriantly all over the lake. simple or branched; fronds with tubular, cylindrical µ Plants generally gregarious, attached, bright to dark stalk, about 5-7 m long; blade expanding above stalk green, about 5 to 20 cm long and 2-5 mm broad, more or and becoming flexuosa, ending in an obtuse apex, some- less compressed collapsed, below long tapering and times constricted at intervals; cells in surface view polyg- µ characteristically with several branches from the gradu- onal, 11-23 m across, arranged in linear series except in ally contracted stalk like base which are entirely similar upper flexuos part, where they are somewhat irregularly µ to the principal blade, cells minute rounded but more arranged, cells in section rectangular, 19-23 m long, 15- µ commonly polygonal, oblong or subquadrate by mutual 19 m wide, cells uninucleate; chloroplast filling cell, pressure, arranged irregularly cell contents granular with 4-5 pyrenoids. with one nucleus and a parietal chloroplast. Luxuriant growth is found in December and January Luxuriant growth is found in December and January in the lake. Usually found attached to rocks and boul- in the lake. Usually found attached to rocks and boul- ders some times found free floating. Usually found ders, but many a times found free floating due to wave growing with U. fasciata, E. compressa and E. intestinalis. actions. Usually found growing with U. fasciata and E. The plant is found throughout the year. intestinalis. The plant is found throughout the year. 3. Enteromorpha intestinalis (Linnaeus) Nees 2. Enteromorpha flexuosa subsp. flexuosa (Wulf) Harvey 1858a, p. 57, Fig. 2D. J.Agardh Habitat: Growing profusely in rocks and floating Agardh J.G. 1883, p.