Fish Fauna Diversity and Conservation Status of Pulicat Lagoon in Tamil Nadu
- 1. Department of Zoology, University of Madras, India
Abstract
Fish fauna is considered as a good indicator of water quality. The aim of this study was to assess the influence of environmental factors on the fish distribution and conservation status in Pulicat Lagoon. Bimonthly surveys were conducted from September 2013 to August 2015 in which 83 fish species were recovered, belonging to 14 orders and 50 families. The dominant order was Perciformes which were represented by 44 species. Various physico-chemical parameters and nutrients were found to be suitable for growth of plankton and stocking of fish species. Hence, the present study there are only few fish species were near threatened and endangered of in the Pulicat therefore serious conservation action and renovation is required to prevent the loss of biodiversity.
Citation
Govindan S, Ravichandran R (2016) Fish Fauna Diversity and Conservation Status of Pulicat Lagoon in Tamil Nadu. Ann Aquac Res 3(2): 1018.
Keywords
• Pulicat lagoon
• Physico- chemical properties
• Biodiversity
INTRODUCTION
Fishes are an important vertebrate group of the animal world and contribute overwhelmingly to global biodiversity. Fishes are used as a food source and contain many vital vitamins and fatty acids. The study of fish and their stability is important because fish populations very significantly from year to year. They play an important role, as they are not only useful for food and recreation, but also act as a tool for biological control by feeding upon the planktonic population and aquatic vegetation [1]. Worldwide 27,977 valid species of fishes under 62 orders, 515 families and 1,494 genera [2]. Indian species represent about 8.9 % of the known fish species in the world. Venkatraman [3] estimated 4,000 species of fish belonging to 969 genera, 254 families and 40 orders in the Indian region. The coastal region is a place of hectic human activity owing to urbanization and industrialization resulting in human interference of rapid development. In recent years, the coastal ecosystems have become highly disturbed and very much threatened and attributed to problems like pollution, siltation, erosion, flooding, salt water intrusion and storm surges [4]. Pulicat Lagoon, which is located in the North Chennai coastal region, is a typical brackish water ecosystem of great importance with regard to its biodiversity and aesthetic value. Due to its morphological and brackish water characteristics, it is the most suitable breeding and nursing ground habitat for fishes in the North Chennai coastal region. It runs parallel to the coast of the Bay of Bengal, being separated from it by an extensive sand-strip called the Sriharikota Island, on which the Sriharikota High Altitude Range (SHAR) of the Indian Space Research Organization (ISRO) is located [5]. Water is the natural habitat of fishes and other aquatic animals, it is therefore of great importance to study water quality while studying fish production especially when done in an artificial setting [6]. In particular, fish populations are highly dependent upon the variations of physicochemical characteristics of their aquatic habitat which supports their biological functions [7]. The present study was conducted to determine the physico-chemical parameters of water, icthyofaunal diversity and conservation status of Pulicat Lagoon.
MATERIALS AND METHODS
Study area
The fishes were collected from the Pulicat Lagoon during the period of Sept 2013 - Aug 2015 from the following locations Barmouth (S1), Kunankuppam (S2), Light house kuppm (S3) Sattankuppam (S4) and Jameelabad (S5).
Collection and analysis
The water quality parameters like temperature, pH, dissolved oxygen etc., must be watched commonly, individually or synergistically to keep the aquatic habitat positive for existence of fish. Water samples were collected early in the morning in sterilized sampling bottles and physico-chemical parameters like pH, (Figure 1), temperatures were analysed at site. Dissolved oxygen (DO), phosphate were analyzed in accordance with American Public Health Association [8].
Fish samples were collected from different stations during the study period from September 2013 to August 2015 with the help of local fishermen using different types of nets namely gill nets, cast nets and dragnets [9]. Fish specimen were collected and preserved in 10% formaldehyde solution. Fishes were keyed and identified using Day [10-11].
RESULT AND DISCUSSION
Eighty three species, 14 orders and 50 families were found during our survey. The Perciformes were dominant with 44 species, followed by Tetraodontiformes with 9 species, Pleuronectiformes with 7 species, Clupeiformes, Siluriformes Mugiliformes with 3 species each, Beloniformes with 5 species, Anguilliformes and Scorpaeniformes with 2 species each, Carcharhiniformes, Gonorynchiformes, Myliobatiformes, Torpediniformes and Syngnathiformes 1 species each (Figure 2) (Table 1). Regarding their conservation status 22 species were least concern, 2 species were data deficient, one species for vulnerable (Epinephelus lanceolatus), Endangered (Thunnus thynnus), Near Threatened (Gymnura poecilura) and 57 species were not assessed (IUCN-Version 2015) (Table 1).
Perciformes were the dominant order that were recovered from our surveys, a trend that is similar across various independent studies. Nath and Patra [12] reported 25 Perciformes species from Hooghly river of West Bengal India. Abu Hanif [13] investigated 35 Perciformes species from Southern coastal waters of Bangladesh and 27 Perciformes species of Nizampatnam coastal Andhra Pradesh [14]. Thirteen species were recorded from Cuddalore, located at the southeast coast of India by Asta Lakshmi [15]. Similarly, in the present study, 44 species were the dominant order (Table 1).
Temperature is an important factor for the growth of biodiversity and influences the biological, biochemical, chemical characteristics of aquatic systems [16]. In the present study, temperature minimum as 24.6°C and maximum was 32.2°C at study area (Figure 3). It varied as expected with seasonal climates and showed a great variation season wise. According to Food and Agriculture Organization (FAO) report [17], the increase of temperature directly or indirectly impacts species distribution and the seasonality of production in fishes. Temperature is commonly considered the most important single ecological factor in the coastal and estuarine ecosystem which can influence the distribution of marine organisms [18].
pH was recorded slightly alkaline in Pulicat Lagoon were lowest 7.6 and highest 9 (Figure 4). According to the report of Northeastern Regional Aquaculture Centre (NRAC) by Fluctuations in pH values during different seasons of the year is attributed to factors like removal of carbondioxide by photosynthesis through bicarbonate poverty, dilution of sea water by fresh water influx, reduce of temperature and decomposition of organic matter as suggested by Zingde et al., [19]. In the present investigation pH an attention indicates the alkaline nature of water in the study area. Dissolve oxygen observed were minimum 0.6 mg/l and maximum 4.9 mg/l (Figure 5). Solubility of oxygen in water is inversely proportional to temperature [20]. The low dissolved oxygen concentration observed during summer may be attributed to the higher salinity of the water, higher temperature and less inflow of freshwater coupled with biological processes such as consumption of available oxygen by the organisms for respiration and active decomposition of organic matter during summer. It is well known that the temperature affect the dissolution of oxygen [21].
Additional the bulk of weathering of rocks and soluble alkali metal phosphates in the upstream area are approved into the estuaries [22]. The addition of super phosphates applied in the agricultural fields as fertilizers and alkyl phosphates used in households as detergents can be other sources of inorganic phosphate throughout the monsoon season [23]. The variation may also be due to the processes like adsorption and desorption of phosphates and buffering action of sediment under varying environmental conditions [24]. In the present study, the phosphate lowest was 3.29 mg/ml during at summer and highest 5.44 was observed in monsoon (Figure 6).
CONCLUSION
Pulicat Lagoon indicated that an altered environment supported less biological communities while less anxious sites were characterized by a diverse fish faunal diversity. We found 83 species of 14 various orders; Perciformes represents the order maximum species recorded in study area. The water quality was also affected by pollutants which act on elements existing in water such as DO or produces substances such as phosphates, other elements and therefore affects the fish fauna indirectly. It is significant to take effective strategies for the maintenance of fish fauna of Pulicat lagoon in order to protract biodiversity and the balance of this aquatic ecosystem.
ACKNOWLEDGEMENT
The authors are thankful to DST (SERB), for providing financial assistance Ref: No SR/SO/AS-12/2012.
REFERENCES
2. Nelson JS. Fishes of the World. Forth Edition, John Wiley and Sons, Inc. 2006; 1-601.
3. Venkatraman K. Proceedings of Taal 2007P: the 12th World Lake Conference. 2008; 392-400.
18. Kinne O. Physiology of estuarine organisms with special reference to salinity and temperature: general Teske and Wooldridge: Affinities of estuarine macroinvertebrates to salinity and sediment type 191 aspects. In: Estuaries, (ed.) G.H. Lauff. 1967; 525-540.
