Short Communication Zooplankton Composition in Dahanu Creek-West Coast of India Kadam S.S.1 and Tiwari L.R.2 1N.B. Mehta Science college, Bordi, Tal., Dahanu, Dist., Thane, MS, INDIA 2Maharshi Dayanand College Parel, Mumbai MS, INDIA Available online at: www.isca.in (Received 31th January 2012, revised 6th March 2012, accepted 24th March 2012) Abstract The distribution and faunistic composition of zooplankton was studied during November 2008 and October 2009 from Dahanu creek- west coast of India. Geographical location of Dahanu is 190 58' N and 720 44'E .Total 21 group of zooplankton were observed during the study period. Maximum species diversity was observed at station 1 (in open sea) and minimum at station 5 (in creek). Zooplankton biomass varied from 65.40 to 120.80 ml .100 m-3 (average 80.94 ml. 100 m-3) in the outer creek and 12.50 to 64.30 ml.100 m-3 ( average 29.62 ml. 100 m-3) in the inner creek area . Zooplankton biomass was highest in October at all stations however low biomass was recorded in July when the salinity decreased considerably. The dry weight of zooplankton ranged from 3.965 to 11.830 gr.100 m-3 (average 7.496 gr.100 m-3) in outer creek and 1.280 to 5.932 gr.100 m-3 (average 3.005 gr.100 m-3) in inner creek area .The dry wet of zooplankton was maximum in October at all the stations and was minimum in July. Copepods, decapod larvae, egg mass, fish eggs, fish larvae, polychaete larvae, hydrozoans, tintinnids and chethognaths formed dominant groups of total zooplankton population. Key wards: Dahanu creek, zooplankton biomass, composition. Introduction Zooplankton is the myriads of floating and drifting animals with limited or no power of locomotion. It includes protozoan, jelly fishes, chaetognaths, worms, small crustaceans, egg and larvae of benthos and nekton. Majority of them feed on phytoplankton and facilitate the conservation of plant material into the animal tissue and in turn constitute the basic food for higher animals .Their occurrence and distribution influence pelagic fishery potentials (Zooplankton identification manual of National Institute of Oceanography - Goa). The zooplanktons are more varied as compared to phytoplankton their variability in any aquatic ecosystem is influenced majority by patchiness, diurnal vertical migration and season1. Zooplankton forms an important link in the marine food chain as secondary producers. They play an important role in the conservation of energy from primary to secondary level2. Zooplankton is an important component of the pelagic community since it includes the major consumers of primary production. It plays an active role in the modification and remineralization of the particulate organic matter in the water column 3. This paper briefly describes the zooplankton distribution of the Dahanu creek along the west coast of India and elaborates the decapods and copepod species composition. Material and Methods Zooplankton was sampled from November 2008 to October 2009 in Dahanu creek (190 58' N and 720 44'E).Total five stations were selected for collection of zooplankton, three stations were in the open sea and two stations were in the creek. These stations covered an area of 20 km long and the depth varied from 5 to 26.5 meters (figure 1). The study period lasted for 15 months. During this period, total 65 samples were collected for qualitative and quantitative evaluation of zooplankton. Zooplankton samples were collected by using H.T. net mesh size 0.3 µm and the collected zooplankton samples were kept in 500 ml wide mouth plastic bottles having 4%formalin.The wet weight of the zooplankton was determined after washing the zooplankton with distilled water and thereafter filtering through filter paper. The dry weight of zooplankton was determined by drying the filtered samples in a hot air oven at 700C till constant weight. The results were calculated as mg m-3 of sea water. Zooplankton volume was measured by displacement method, in this method zooplankton were filtered and blotted with filter paper and mass was transferred to measuring cylinder having known volume of 4% formalin prepared in sea water. The rise in level of sea water in measuring cylinder was recorded. The difference between final and initial reading gave volume of zooplankton. The results were expressed as ml m-3. Zooplankton analysis was done using standard methods 4 and 5. For identification of zooplankton published research paper were followed6-12. Results and Discussion Dahanu creek is fully rich with zooplankton community because about 20 to 30 tones marine fishes captured by local fishermen per year (Fish production report 2006-08). The important landings are Bombay duck, pomfrets, sienids, elasmobranchs, lobsters and prawns etc. Biotic features of Dahanu creek were influenced by the tides and monsoon. Total 21 groups of zooplankton were observed during the study period includingcopepods, decapods, eggmass, fisheggs, fishlarvae, polychaetelarvae, hydrozoans, tintinnids, chethognaths, pyrosomids, isopods, amphipods, mysids, meduceae, foraminiferans, gastropods, siphnophors, ctenophors, lucifer, cladoceras, bivalves, hydrozoans, ostracods, euphausids and echinoderms (table 1). Copepods, decapods, tintinnids, chaetognaths, fish eggs and fish larvae were observed at all the stations. Amphipods and euphausids were observed only at station 1. In addition to this echinoderms and ostracods were observed at station 3. The minimum number of group (13) during the study period was observed at station 5 where as maximum group (19) at station 1.Zooplankton biomass was highest in October at all stations however low biomass was recorded in July when the salinity decreased considerably. Copepods usually maximum in number except July at station 1 and 3 when decapod larvae occurred in higher numbers. Zooplankton biomass ranged from 65.40 to 120.80 ml .100 m-3 (average 80.94 ml. 100 m-3) in the outer creek and 12.50 to 64.30 ml.100 m-3 ( average 29.62 ml. 100 m-3) in the inner creek area (Table 2). The dry weight of zooplankton ranged from 3.965gr.100 m-3 to 11.830 gr.100 m-3 (average 6.92 gr.100 m-3) in outer creek and 1.280 to 5.932 gr.100 m-3(average). The dry wet of zooplankton was maximum in October at all the stations and was minimum in July (table 3). The minimum fresh weights, dry weight, volume of zooplankton were observed in July at station 5 that was in the creek. This was probably due to presence of suspended solids in sea water. The high productivity in terms of fresh weight, dry weight and volume of zooplankton was observed at station 1 in October. Total population of zooplankton in the outer creek area was varied from 475350 to 1182160 (no.100-3) and inner creek was 125760 to 678640 (no.100-3) table-3. Copepods was more abundant in all zooplankton community both in open sea and creek, copepod species including Eucalanus sp., Paracalanus sp.,Euchaeta sp., Centropages sp., Lucicutia sp., Pontella sp., Pleuromamma sp. were present in zooplankton collection. The second largest group in zooplankton community was decapod larvae including Zoea and Brachvura. Most marine animal-phyla from poriferans to chordates are represented in the plankton, many species are holoplanktonic i.e. they live permanently in the pelagic habitat. The study of marine zooplankton ecology demands considerable efforts from scientific and technological standpoint13. Table -1 Monthly variation in zooplankton total population (no.100-3) and dominant groups at 5 different stations of Dahanu creek west coast of India MonthsOuter creekInner creek Dominant groupsStation 1Station 2Station 3Station 4Station 5Nov.08690430766780475350125760622870Cope,deca,chaet, Tin,poly,hydro, F and LDec.08908200795130985340324850140580Cope,deca,chaet, Tin,poly,hydro,F and LJan.09983270690840923420177440126780Cope,deca,chaet, Tin,poly,hydro,F & LFeb.098054301084320634280178650252240Cope,deca,chaet, Tin,poly,hydro,F & LMar.09774520927230698050126930678640Cope,deca,chaet, Tin,poly,hydro,F & LApr.09704360838270892650325450387460Cope,deca,chaet, Tin,poly,hydro,F & LMay 09698420523470865090568780496510Cope,deca,chaet, Tin,poly,hydro,F & LJune 091034280949830732090318750237640Cope,deca,chaet, Tin,poly,hydro,F & LJuly 09684220498060423170304520166430Deca,cope,chaet,poly,tin,F&LAug.09824560597640889660854200316590Cope,deca,chaet, Tin,poly,hydro,F & LSep.09657120876350598760597620154360Cope,deca,chaet, Tin,poly,hydro,F & LOct.0911821601036570889750342180453270Cope,deca,chaet, Tin,poly,hydro,F & LCope = Copepods,Deca = Decapods, Chaet = chaetognaths, Tin = tintinnids, Hydro = Hydrozoans, Poly = Polychaet larvae , F & L = Fish eggs/larvae. Table - 2 Monthly variation in zooplankton biomass (ml.100-3) at 5 different stations of Dahanu creek west coast of India Outer creekInner creekMonthsStation 1Station 2Station 3Station 4Station 5Nov.0865.574.0043.0012.536.00Dec. 0852.2080.0092.5024.8026.00Jan.0990.5068.2091.5024.0014.50Feb.0984.00108.0062.0019.0037.20Mar.0978.2090.5074.8014.0064.30Apr.0968.5084.2089.2030.5040.00May 0970.8060.8088.0060.8052.20June 09105.2090.0072.8034.3024.20July 0976.5052.8045.2032.0019.50Aug.0986.2066.5092.5016.0032.80Sep.0967.5088.5067.0020.0016.20Oct.09120.80106.5094.0036.8042.50 Table - 3 Monthly variation in zooplankton dry weight (gr.100-3) at 5 different stations of Dahanu creek west coast of India Outer creekInner creekMonthsStation 1Station 2Station 3Station 4Station 5Nov.086.3607.8564.3421.2803.540Dec. 084.9607.5408.8672.7602.132Jan.098.5635.6289.1082.6521.312Feb.097.9509.8505.7562.4322.920Mar.096.8908.7546.9761.8765.932Apr.096.4207.8538.1233.9123.866May 096.8725.6738.5435.4424.929June 099.9608.9507.5432.9912.902July 097.2404.8653.9652.8622.231Aug.098.2305.6608.9751.9922.950Sep.095.9677.9605.8762.1201.820Oct.0911.83010.5409.5423.4323.923 Conclusion The present investigation suggests that Dahahu creek is fully rich with zooplankton and supported a diverse community. The zooplankton species which occur during the high saline period tolerate wide salinity fluctuations. The present baseline information on the zooplankton is useful for preparing data sheet on fish production report of Dahanu area. The present report on zooplankton provides the baseline information for future ecological assessment and monitoring of the Dahanu coastal area. Acknowledgments The authors are grateful to Dr. John T. Eapen, Scientist-In-Charge of M.E. Eapen Institute of Science and Technology for Community Development (MEEISATCODE), Dahanu for his constant encouragements and guidance. Mr. S.S. Kadam is grateful to University of Mumbai for the financial assistance rendered to him under minor research project scheme. References 1. Reymont, Plankton and productivity in the oceans, II Zooplankton 2nd Edition Pergamon press 824 (1983) 2. Gajbhiye S.N., Comparative study of zooplankton population in polluted and unpolluted regions of Bombay, M.Sc.Thesis, University of Bombay, (1979) 3. Heinner Fabian, Rolf Koppelmann and Horst Weikert, Full depth of zooplankton composition at two deep sites in the western and central Arabian sea, Indian J marine sci. 34 (2), 174-187 (2005) 4. Strikland J.D.J. and Parsons, A., practical handbook of sea water analysis, Fis.Res.Bv.of Canada, Bull. no.167 (1972) 5. Gajbhiye S.N., Krishnakumari L. Govindan K., Abidi S.A.H. and Nair V.R., Studies on selected Biological parameters off Mithapur (Gujarat), J.Indian Fish.Asso., 18, 459-473 (1988) 6. I. Nageswara Rao and R. Ratna Kumari, Biochemical composition of zooplankton from Visakhapatnam harbour waters, east coast of India, Indian J marine sci. 3(2), 125-129 (2002) 7. Goswami S.C. and Padmavati G., Zooplankton production, composition and diversity in the coastal water of Goa, Indian J. marine sci., 25(2), 91-97 (1996) 8. Nair V.R., Gajbhiye S.N., Krishnakumari L. and Desai B.N., Biomass and composition of zooplankton in the near sea shore waters of Thal, Maharashtra, Indian J marine sci., 12, 160-165 (1883) 9. Tiwari LR, Nair V.R., Zooplankton composition in Dharamtar creek adjoining Bombay horbour, Indian J marine sci., 22, 63-69 (1993) 10. Madhupratap M., Free-living copepods of the Arabian sea, Distribution and research prospective, Indian J marine sci., 28, 146-149 (1999) 11. Jiyalal Ram M. and Goswami S.C., Observation of plankton pigments, zooplankton and physico-chemical parameters in surface waters from souththern Indian ocean and Antarctic ocean, Mahasagar, 26(2), 123-131(1993) 12. Santhakumari V., Tiwari L.R. and Vijayalakshmi Nair, Species composition, abundance and distribution of hydromededuceae from Dharamtar estuarine system, adjoining Bombay harbor, Indian J marine sci., 28, 158-162 (1999) 13. Rubens M., Lopes, Marine zooplankton studies in Brazil-A brief evaluation and perspectives, Annals of the Brazilian Academy of Sciences, 79(3), 369-379 (2007) Research Journal of Recent Sciences _____________________________________________________________ ISSN 2277-2502 Vol. 1(5), 62-65, May (2012) Res.J.Recent.Sci. International Science Congress Association 65 Research Journal of Recent Sciences _________________________________________________ ISSN 2277-2502 Vol. 1(5), 62-65, May (2012) Res.J.Recent Sci. International Science Congress Association 62