Lake 2000 SECTION-2 Biodiversity PAPER-5
________________________________________________ THERMAL SPRINGS OF DAKSHINA KANNADA
________________________________________________ K.R. Chandrashekar1*, K.R. Sridhar**, M. Rajashekhar** and K.M. Kaveriappa* *Department of Applied Botany, **Deparment of Biosciences, Mangalore University, Mangalagangothri 574 199, Karnataka, India; 1Correspondence: E-mail:
[email protected] Chandrashekar, K.R., Sridhar, K.R., Rajashekhar, M. and Kaveriappa, K.M. 2000. Thermal springs of Dakshina Kannada. In: Lake 2000: Restoration of lakes and wetlands. Indian Institute of Science, Bangalore, India: http://wgbis.ces.iisc.ernet.in/energy/water/proceed/proceedings_text/section2/paper5/section2paper5.htm
The two thermal springs, Bendre Thirtha near Puttur and Panekal near Uppinangady of Dakshina Kannada district were visited several times to study the temperature, pH, dissolved oxygen, sulphur content and aquatic hyphomycetes. The aquatic hyphomycetes were studied by the following methods: Leaf litter observation, water filtration and analysis of natural and induced foam. There were 20 species in Bendre Thirtha and 16 in Panekal. Out of these, nine species were common for both the springs. The study of the effect of temperature and sulphide content on sporulation and growth of fungi revealed the adverse effect of temperature on mycoflora. Studies on the actinomycetes of Panekal spring revealed the presence of facultative sulphur oxidising species. The geology and biodiversity of these springs are also discussed. Bendre Thirtha has been developed as a tourist spot by the Karnataka State Tourism Department. Panekal is yet to get publicity. These natural thermal springs form a special ecological niche that should be conserved with utmost care in order to protect the biodiversity. Key words – Thermal springs, Dakshina Kannada, Western Ghats, Aquatic hyphomycetes, Actinomycetes Introduction Oldham, T., a veteran geologist, catalogued the thermal springs of India as early as 1882. He located a thermal spring in a remote and inaccessible part of Puttur taluk in South Kanara district (cf. Radhakrishna, 1971). This spring, referred to as "Bendre Thirtha" by the locals, is located on the south bank of the Badantadka river, which emerges after the confluence of two tributaries, Balakku and Ermati (12° 43' N, 75° 13' S) (Fig. 1). The spring is located on a private areca garden. There are very few trees surrounding the spring viz., Ficus benghalensis L., Mangifera indica L., Artocarpus heterophyllus Lam., Cocos nucifera L. and Areca catechu L. Waring (1965) referred to the existence of this spring in U.S.G.S. Publication "Thermal springs of the United States and other countries of the world". Radhakrishna (1971) was impressed by a beautiful description of this spring in the Kannada novel "Karulina Kare" written by the noted Kannada writer Dr. Shivarama Karanth who had woven a beautiful story around this thermal spring. He carried out preliminary investigations on the geology of this thermal spring. Later, Chandrashekar et al. (1991) Did some investigations on the aquatic hyphomycetes occurring in this spring.
1
Fig. 1. Map showing the location of Bendre Thirha Spring
Fig. 2. Map showing the location of Panekal Spring
2
There is another thermal spring in Dakshina Kannada, located in Panekal, about 22 km from Uppinangady (12°54' N, 75°17.5'S) (Fig. 2). It originates under the crevices of rocks, and forms a small pond, which flows through paddy fields for about 0.5 km before joining river Nethravathi. The surrounding vegetation is sparse and consists of trees such as Artocarpus heterophyllus Lam, Ficus benghalensis L., Mangifera indica L., and Macaranga peltata Muell. Arg. Bambusa arundinacea Willd. Some studies on the aquatic hyphomycetes and actinomycetes of this spring have been carried out (Rajashekhar & Kaveriappa, 1996; Ranjekar, 1990; Ranjekar and Sridhar, 1993). The microbiological studies undertaken so far in these two springs are summarised. Materials and Methods The materials for the study were collected from three sites in each spring namely, the spring proper, the connecting region of the spring and the rivulet and the spot where the spring joins the rivulet. Foam, water samples and submerged leaves were collected from these spots and analysed for the presence of conidia of hyphomycetes by employing the four methods viz., leaf litter analysis, foam analysis, water filtration and foam induction (Chandrashekar et al., 1986). The temperature, pH, dissolved oxygen and sulphide content of water in these sites were also recorded. The procedure given by Chandrashekar et al (1991) was followed to study sporulation. Conidia of some species were cultured on the semi-synthetic media and their growth was measured (Rajashekhar and Kaveriappa, 1996). The actinomycetes were isolated from the spring and their antimicrobial activities were studied (Ranjekar, 1990). Results and Discussion The data on temperature, pH, dissolved oxygen and sulphide content of the two springs at the three sites have been compared (Table 1). In Bendre Thirtha, a total of 20 species of aquatic hyphomycetes belonging to 14 genera was recorded (Table 2). The number of species of hyphomycetes occurring at sites I, II and III were 1, 14 and 20 respectively. A total of 16 species of aquatic hyphomycetes belonging to 13 genera was recorded from Panekal spring. The spring proper (site I) did not show the presence of any hyphomycetes. The number of species collected in September samplings, i.e., immediately after the monsoon, was the highest. Lowest number of species was recorded in the summer samplings. When the mycoflora of the two sulphur springs were compared, there were nine species common to both the springs. In both the springs, samples nearer to the spring contained fewer species of fungi than the samples taken away from the spring. As there was not much variation in the pH and dissolved oxygen between the sites of both the springs, the effect of these factors on the occurrence of species of aquatic hyphomycetes was discounted. However, temperature and sulphide content of both springs varied significantly between the three sites, indicating the possibility of their interference with the occurrence of hyphomycetes. The percent inhibition of growth of the five species of hyphomycetes, which were cultured using sulphur spring water decreased with increased dilution of water. Maximum inhibition of growth was in undiluted spring water. The data on the effect of spring water at different temperatures on sporulation of hyphomycetes indicated that maximum number of species sporulated in a temperature range of 20-30°C. The overall record of fungi was less on the leaves incubated in spring water than in stream water. Field and Webster (1985) observed a tolerance limit of 5 mg-1 of sulphide for the growth of aquatic hyphomycetes. In these two studies, the sulphide content of the spring water recorded was not more than 4.2 mg-1. Therefore, it was concluded that the sulphide concentration of the springs was not influencing the occurrence of aquatic hyphomycetes in the two springs but higher temperature had an adverse effect on the mycoflora. The investigations on the actinomycetes of Panekal spring revealed a poor total count in the water samples compared to the samples of sediment and leaf litter. In some cultures, there was a wide and clear zone around the colonies indicating their ability to oxidise elemental sulphur. The number of colonies of such sulphur-oxidising actinomycetes was higher in the spring sediment than in the 3
TABLE 1: TEMPERATURE, PH, DISSOLVED OXYGEN AND SULPHIDE CONTENT OF TWO THERMAL SPRINGS Site I
Site II
Site III
Bendre Thirtha Temperature (°C)
36.5
35.5
26.5
pH
5.9
6.1
7.3
Dissolved oxygen (mgl-1)
3.2
3.8
8.2
Sulphide (mgl-1)
3.1
1.2
0.1
Panekal Temperature (°C)
38.5
30.0
34.2
pH
8.9 to 9.2
Dissolved oxygen (mgl-1)
3.1 to 4.0
Sulphide (mgl-1)
4.0
4.3
3.8
river sediment. Ranjekar and Sridhar (1993) have reported the anti microbial activities of a few isolates of streptomycetes of this spring and suggested further scope for screening the thermal spring actinomycetes for antimicrobial properties. Radhakrishna (1971) suggested a test drill hole to a depth of 70 m at the site to know more about the subsurface geology and the reason behind the thermal character of the spring water. But for this report, there is no other information on geology of this area. Therefore, it merits a detailed study. Oldham (1882) was of the opinion that there may be more hot springs in the comparatively flat ground of the Konkan region, which stretched from Surat to South Kerala. Therefore, a thorough survey of this area should be undertaken. Conclusions Bendre Thirtha spring has been developed as a tourist spot by the Karnataka State Tourism Department. A permanent laterite wall has been constructed around the spring. This has affected the normal flow of water from the spring. Of late, it has been reported in some newspapers that the tourism department is not likely to maintain this as a tourist spot for long as there are not many visitors. Panekal sulphur spring is yet to be considered as a tourist spot. Since, these thermal springs have a special ecological niche, care and attention should be given to conserve them and protect the biodiversity. References Chandrashekar, K.R., Sridhar K.R. and Kaveriappa, K.M., 1986. Aquatic hyphomycetes of the river Kempu Hole in the Western Ghats Forests of Karnataka, Indian phytopath. 39: 368372. Chandrashekar, K.R., Sridhar, K.R. and Kaveriappa, K.M., 1991. Aquatic hyphomycetes of a sulphur spring. Hydrobiologia 218: 151-156. Field, J.I. and J. Webster., 1985. Effect of sulphide on survival of aero-aquatic and aquatic hyphomycetes. Trans. Br. Mycol. Soc. 85: 193-199. Oldham, T., 1882. Thermal springs of India, Geol. Surv. Ind. Mem., 19: 2. Radhakrishna, B.P., 1971. On a little known thermal spring from near Puttur, Mysore State, India. J. Geol Soc. Ind. 10: 88-94. 4
TABLE 2: AQUATIC HYPHOMYCETES RECORDED FROM BENDRE THIRTHA AND PANEKAL SULPHUR SPRINGS Bendre Thirtha
Panekal spring
Common to both the springs
Alatospora acuminata
+
-
-
Anguillospora longissima
+
+
+
Anguillospora sp.
+
-
-
Beltrania rhombica
+
+
+
Camposporium antennuatum
-
+
-
Camposporium pellucidum
+
-
-
Flabellospora multiradiata
-
+
-
Flabellospora verticillata
+
+
+
Flagellospora curvula
+
-
-
Flagellospora penicillioides
+
-
-
Helicomyces sp.
-
+
-
Helicosporium sp.
+
+
+
Isthmotricladia laeensis
-
+
-
Lunulospora curvula
+
+
+
Lunulospora cymbiformis
+
-
-
Phalangispora constricta
+
+
+
Speiropsis hyalospora
-
+
-
Speiropsis pedatospora
+
+
+
Tetraploa aristata
+
-
-
Tetraploa sp.
+
-
-
Tricladium brunnium
+
-
-
Triscelophorus accuminatus
+
+
+
Triscelophorus monosporus
+
+
+
Triscelophorus sp.
+
-
-
Vermispora sp.
-
+
-
Wiesneriomyces laurinus
+
+
+
Total
20
16
9
5
Rajashekhar, M., and Kaveriappa, K.M., 1996. Studies on the aquatic hyphomycetes of a sulphur spring in the Western Ghats, India, Microbial Ecology 32: 73-80. Ranjekar, M. and Sridhar K.R., 1993. Preliminary studies on antimicrobial activity of thermal spring streptomycetes. J. Microbial Biotechnol. 8: 62-67. Ranjekar, M., 1990. Observations of Actinomycetes of Thermal springs. M.Phil. Dissertation, Mangalore University 63. Waring, T., 1965. Thermal springs of the United States and other countries of the world. U.S. Geol. Surv. Paper # 492.
6
