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Mahi river near Sarod in Bharuch district (Fig. 1). It. 43 t:N J)JsPOs~o\RJlAII4DIm contains treated industrial effluent from various small and large industrial units.
Poll Res. 24 (1) : 243-246 (2005) Copyright © Enviromedia

CRUSTACEAN COMMUNITY STRUCTURE OF MAHI

RECEIVING INDUSTRIAL EFFLUENT

ADITI NANDA, K.D. VACHHRAJANI* AND P.C. MANKODI

Toxicology Division, Department of Zoology, Faculty of Science, M.S. University of Baroda,

Vadodara 390002, Gujarat, India.

ABSTRACT Mahi river (Mahi Sagar), one of the perennial rivers of Gujarat, flows around 12 km from Baroda. It receives treated and even raw industrial effluent from petroleum, petrochemicals, organo­

chemical, dyes and other chemical industries. Aquatic pollution over the years has adversely affected the biota of Mahi river. Present study reports crustacean community structure in the river. A total of thirty crustacean species were identified from the samples and their seasonal occurrence and distribution was studied. The crustaceans were dominated by copepods and cladocearns. Highest density observed was that of Moina sp. at site 1. Variations were noted in the distribution of crustaceans of different sites, however no significant effect of pollution could be identified.

INTRODUCTION Mahi river is one of the perennial rivers, which flows around 12 km from Baroda city. Most of the industries are situated on the southern bank of the river while a thermal power station is situated on the northern bank at Dhuvaran (Fig. 1.). An effluent channel from the industrial area heads towards the estuarine end of river and discharges the effluent in Mahi river near Sarod in Bharuch district (Fig. 1). It contains treated industrial effluent from various small and large industrial units. During high tide these effluent are taken upstream and thus pollute the entire estuarine region. A small tributary, Mini river flows through the industrial area and meets Mahi river near Sindrot, which is located in the upper estuarine region (Fig. 1). Mini river is usually laden with raw industrial effluent and thus further pollute Mahi river. (Sharma, 1995). The faunal diversity studies of streams and river were greatly neglected in parts of Gujarat, where riverine pollution is extensive (Pilo and Pathak, 1996). Therefore an attempt was made to study zooplankton diversity of few sites of Mahi river.

43

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t:N J)JsPOs~o\RJlAII4DIm

Fig. 1. Showing the route of effluent channel.

MATERIALS AND METHODS Site of study: Three sites were selected from upper estuarine region for the study Site I: Area where Mini river meets Mahi river. Site II : Located around 1.5 km upstream of site 1. Site III : Located further around 1.5 km upstream of site II and was almost beyond the estuarine region (upper tidal influenced zone) and thus having status comparable to freshwater condition. Sampling Procedure: Surface sampling was done

*Corresponding author, e-mail: [email protected]

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using 30-11m plankton net from all three sites every fortnightly. The samples were properly fixed and brought to lab for further studies. The data was pooled for pre mqnsoon and post monsoon seasons for the year 1997-98. Identification of crustaceans was done using standard photographic and descriptive keys (Edmondson, 1963; Mellanby, 1971; Needham and Needham 1962). The data is presented in terms of animal noll of water sample. Berger Parker diversity index, Jaccard's similarity index and Pielous distribution pattern were derived to describe the diversity and distribution pattern of crustaceans at various sites during.different seasons. (Berger and Parker, 1970; Pielou, 1975; Smith, 1995).

composition was dominated by Copepods followed by Cladocerans. Through the Decapods are bottom dwellers in their habit, small sized Macrobrachium were often found in various samples (Tables 1 and 2).

For the study of crustacean density, number of animals were counted in individual concentrated sample and from that the density in terms of nolL was calculated. Some of the species were occasional and were present in low numbers. To avoid any type of statistical misinterpretation their presence was noted but number were not counted. The Table 2. Order wise average density (Noll) of crustances at different sites. Sites

RESULTS

Orders

A total of 28 genera distributed within fives orders of crustacea were observed in different samples. Three common larval forms such as Meglopa, Nauplius and Zoea were also found however their identification was note done. The crustacean

Cladocera Copepoda Decapoda Mysidaceae Ostracoda

II

119.9 134.6 14.5 3.5 9.8

103.3 148.9 48.8 10.0 20.2

III

62.9 83.6 6.3 14.6

Table 1. Taxonomic composition of crustacea. A. Cladocera 1. Alona

2. 3. 4. 5. 6. 7.

8. 9. 10.

Alonella Chydorus Cerriodaphnia Daphnia Macrothrix Moina Podon Scapholebris Simocephalus

B.Copepoda 1. Acartia 2. Allodiaptomus 3. Calanus 4. Centrophagus 5. Corycaeus 6. Diaptomus 7. Eurytemora 8. Euterpina 9. Limnocalanus 10. Mesocyclops 11. Neodiaptomus 12. ParacaJanus 13. Pseudocalanus H-Holoplankton, M-Meroplankton

Type H H H H H H H H H

C. Decapoda

1.

Macrobrachium

Type M

D. Mysidaceae 1.

Larval stage

M

E. Ostracoda 1. Cypris Larva 2. Cyprinus 3. Potamocypris

M M M

H H

H H H H H H H H H H

H

F. other larval stages 1. Nauplius

2. Zoea 3. Megalopa

M M M

CRUSTACEAN COMMUNITY STRUCTURE OF MAHI RIVER findings indicate that sites I and II had comparati­ vely higher number of different genera and also overall higher plankton density as compared to site III. Highest density and diversity of animals were recorded a site II during monsoon (Table 3). Among all the crustaceans the density of Cladoceran genera, Moina, was very high during pre monsoon. It was followed by Copepod genera Calanus and Eurytemora and by Cladoceran general Macrothrix at site II. At site III Eurytemora and Daphnia dominated during the pre monsoon (Table 3). The density of these genera were very less during monsoon, at all the three sites. During post monsoon, Macrothrix were abundant at sites I and II while Megalopa larvae were high in densities at sites and I and III.

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As has been suggested by the absolute density data of various genera (Table 3). Berger Parker index also indicate diversity variations in three study sites during different seasons. Lower values of Berger Parker index suggest co-dominance of several species, which is clearly observed in case of site III during pre monsoon (Table 4). Higher values indicate dominance of one or two species and less density of other species. This is obvious with the findings at site I during pre monsoon and site III during post monsoon seasons. Jaccards similarity index clearly indicated greater similarity of crustacean diversity between site I and II and least similarity among sites I and III (Table 4). Calculation of distribution pattern indicated clumped species distribution or clumped

Table 3. Season wise density of crustanceans at different study site. Pre-monsoon

11

Species 1. 2. 3. 4.

5. 6. 7. 8.

9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.

Alona Alonella Chydorus Cerriodaphnia Daphnia Macrothrix Moina Pod on Cerriodaphnia Simocephalus Cypris Larva Cyprinus Potamocypris Acartia Allodiaptomus Cal anus Centrophage Coryaeus Diaptomus Eurytemora Euterpina Limmocalnus Mesocyclops Neodiptomus Paracalanus Pseudocalanus Larva of Mysidaceae Macrobrachium Megalopa Nauplius Zoea

Monsoon III

Post-monsoon

11

III

10.7

8.9

15.6 15.6

15.6 62.5

33

137.5

15.6

46.8

12.4 3.5 7.1

7.1 5.3 3.5

5.3 7.1 1.7

21.8

11

III

14.2

10.7

10.6 21.4

5.3

8.9 8.9 8.9 23.2

7.1 7.1

12.4 42.8 7.1

30.3 3.5

7.1

8.9 3.5 8.9

5.3

1.7

24.9 8.9

3.5

78

15.62 31.25 78.12 31.25

15.62 31.25

78.12 15.62

15.62 8.2 15.62 6.25 31.25 67.85

15.6

46.87 65.2 15.6 15.6 17.4 15.62

7.1 3.5

8.9 3.5

7.1

3.5 14.2 7.1

35.7

1.7 5.3

1.7

3.5

3.5

16.05 1.7

8.9

10.7 26.7

76.7 1.7

125.0 8.9

7.1

1.7

7.1

1.7 3.5

6.25 62.5 46.87 3.55

7.1

1.7 15.62 6.25 15.62

3.5

15.6

1.7

26.3

14.2 1.7

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community structure (Table 4). The species distribution can be considered highly clumped or aggregated for site II during pre monsoon and for site I during post monsoon. Table 4. Population Indices BPI

JI

DP

Premonsoon I II II

0.228 0.082 0.036

63.8 24.7 19.7

'2.8 11.79 0.69

Monsoon I II III

0.120 0.172 0.122

64.0 47.7 30.0

2.0 1.2 3.6

Postmonsoon I II III

0.246 0.222 0.354

63.6 63.1 34.6

11.96 4.4 3.8

I, II, III: Study Sites, BPI: Barger Parker Index, JI: Jaccard's Index, DP: Distribution Pattern

DISCUSSION Estuaries are generally extensively studied areas with respect to aquatic pollution management (Castel, 1995). In present studies sites I and I fall under the estuarine tidal influenced zones and hence several of the marine species are encountered during high tide sampling. Study site III is largely freshwater region, however presence of few marine species suggest that it is probably the uppermost end of estuarine zone where the freshwater zone ends during the maximum high tide period. A very clear-cut impact of pollutants on the

distribution and diversity of crustaceans was not observed in the present study however, these preliminary observations indicate that Moina, Calanus, Paracalanus and Macrothrix are dominant at Site I which is greatly influenced by pollutant inputs. On the other hand, Alonella, Acartia, Allodiaptomus, Corycaeus, Scapholebris and Simocephalus were dominant at site III that is a freshwater zone. Some of these species were present at site II also but were absent from site 1. REFERENCES Castel, 1995. Long term changes in the population of Eurytemora affinis (Copepod, Calanoidia) in The Girnode eStuary (1978­ 1992). Hydrobiologia 3 I I : 85-10 I. Sharma, A.H., 1995. Environment impoct assessment along the effluent channel from Baroda to Jambusar and at its confluence with Mahi estuary at gulf of Cam bey with reference to heavy metals. Ph.D. Thesis, M.S. University of Baroda. Pilo B. and J. Pathak 1996. Biological Diversity ofGujarat (current knowledge), Gujarat Ecology Commision. Edmondson,WT. 1963. Fresh water Biology (2nd ed). John Wiley and Sons. Inc. USA. Mellanby, H. 1971. Life in Fresh water, Chapman and Hall Ltd. London. Needham, J.G. and P.R. Needham, 1962. A guide to Fresh Water Biology (5th ed.). Holdendy Inc. San Francisco. Berger, W.H. and Parker, F.L. 1970. Diversity of planktonic foraminifera in deep sea sediments. Science. 168 : 1345­ 1347. Smith, R.L. 1995. Ecology and Field Biology (5th ed.), Harpar Collins College Publishers, New York, USA. Pielou, E.C. 1975. Ecology Diversity, Wiley Interscience, New York, USA. Kotangle,J.P. et al. 1994. Diversity of Zooplankton and Benthos at Dahanu, Danda and Savta Creeks in West cost of India. Proceedings ofAcademy of Environment Biology. 3(1) : 1-8.