69

*Author for Correspondence: Dr. Subhasree Sen Gupta, E. Mail: subha_sree2@rediffmail.com

ASSESSING MACROINVERTEBRATE DIVERSITY IN THE LITTORAL ZONES OFTWO WATERBODIES IN KOLKATA IN RELATION TO SEASONAL VARIATIONS AND

HYDROLOGICAL PARAMETERS

Sangeeta Saha1 and Subhasree Sen Gupta2*

1Department of Zoology, Bethune College, 181, Bidhan Sarani, Kolkata-700006, India.2Department of Zoology, Taki Government College, Taki, North 24 Parganas, West Bengal, India.

Received: August 31, 2016 Revised & Accepted: November 30, 2016

Abstract:The littoral zone is defined as the nearshore lake bottom areas where emerged macrophytes grow. The macroinvertebratespresent in the littoral zone play an essential role in key processes within lake ecosystems. This study was made toassess the macroinvertebrate diversity in the littoral zone of a lake in Dhakuria region of Kolkata. The study revealedmacroinvertebrate population consisting of Mollusca, Arthropoda and Annelida. The results showed greater speciesdiversity in Monsoon with declining trend through post-monsoon and pre-monsoon in relation with receding watertable, dissolved oxygen, depletion in nutrient level and loss of macrophyte cover. Macroinvertebrates are highlyadaptable to a broad range of ecological conditions hence only strong environmental gradients can have a structuringeffect on their communities.

Key words: Macroinvertebrates, littoral zone, hydrological regime, seasonal change, diversity indices

INTRODUCTIONBenthic invertebrates are the most diverse

and abundant organisms in freshwater aquaticsystems and play an essential role in food chaindynamics, productivity, nutrient cycling anddecomposition within lake ecosystems (Reice &Wohlenberg, 1993). Macroinvertebrates form animportant link between primary producers, detritaldeposits and higher trophic levels in aquatic foodwebs (Brinkhurst, 1974; Stoffels et al., 2005).Hence, macroinvertebrate assemblage maypotentially indicate any environmental changes inlakes including eutrophication (Carvalho et al.,2002).

The study of benthic invertebrates in lakesis traditionally segregated by depth zone: littoral, sub-littoral and profundal, of which the littoral zone wasfound to be affected most strongly byhydromorphological alterations of aquatic bodies. The

choice of macroinvertebrates in this study, can beexplained as, (i) they are found to be useful biologicalindicators of change in the aquatic systems, havevarying sensitivities to changes in water quality(ii) some have life span of up to a year and greaterand hence can be monitored easily, (iii) they arerelatively sedentary and hence, can easily becollected and identified. This endeavour was madeto assess the macroinvertebrate diversity in thelittoral zone of two lakes in Dhakuria region ofKolkata with an aim to characterize whetherseasonal changes have any impact on them. Therole of various hydrological factors on shapingmacroinvertebrate community structure was alsoinvestigated.

MATERIALS AND METHODS

Study site selection: This study was made at twolakes at Dhakuria, Kolkata keeping in mind the

Research Article NBU J. Anim. Sc. 10: 21–30 (2016)ISSN 0975-1424

70

Sangeeta Saha and Subhasree Sen Gupta

presence of rich diversity of macrofauna in spite ofpronounced anthropogenic stress (Fig. 1).

Site 1: (Latitude: 22° 30' 04.60'' North; Longitude:88° 22'34.79'' East) received considerable amountsof wastes and domestic sewage. It is also a usedfor fishing with small scale fishery industries. It hasa depth nearly about 6 feet and total surface areaof the aquatic body is about 4000 sq m (Fig. 1).

Site 2: (Latitude: 22° 30'05.18'' North; Longitude:88° 22'44.28'' East) the water body was mainly usedfor dumping of garbage by the local people. It has adepth of approximately 5 feet and has a total areaof 2500 sq m (Fig. 1).

Sampling: Sampling was carried out at earlymorning thrice every month for the two sites fromJune, 2013 to May, 2014. The sampling time wasdivided into Monsoon (June-September), post-monsoon (October-January), pre-monsoon

(February-May). Macroinvertebrates werecollected from the littoral zone of lakes byencroaching either beneath the macrophytes or therocks, snags and woody debris within muddysediment in a non-destructive manner as far aspracticable and their relative abundance (%) wascalculated. The representative specimens werepreserved in a 70% alcohol solution in 250 ml plasticcontainers for identification upto lowest taxonomiclevel possible following Subbarao (1989), Gooderhamand Tsyrlin (2002) and Gerber and Gabriel (2002a,b). Water samples were collected from sub surfacein premeasured clean stopper glass bottles as perstandard procedure. Temperature and pH of watersample were measured.

Estimation of hydrological parameters:Hydrological parameters (dissolved oxygen, watertemperature, pH, total alkalinity, total hardness,inorganic phosphate, nitrite nitrogen and dissolvedsilicate were recorded following standard procedureof APHA, 2005.

Assessment of faunal diversity: In order to assessmacroinvertebrate diversity in the study site inassociation with seasonal variation followingdiversity indices were used.1. Shannon-Weaver diversity index (H’) (Shannon

& Weaver, 1949)2. Species evenness or equitability (J) (Pielou,

1969)3. Dominance index (D) (Berger & Parker, 1970)4. Species richness (Margalef, 1958)5. Rank abundance curve

Correlating hydrological parameters withspecies diversity: Canonical CorrespondenceAnalysis (CCA) (ter Braak, 1988; McGarigal et al.,2000) was carried out using CANOCO (ver. 4.5)software to elucidate the possible relationshipsbetween biological assemblages of species and theenvironmental variables.

Fig. 1. Map showing location of study site at Dhakuria,Kolkata.

71

Diversity of macroinvertebrates in lake littoral region

RESULTSThe macroinvertebrate assemblage at

littoral zone of both the study sites showedabundance of arthropods like, millipedes, centipedes,Camponotus sp., mosquito larvae, Water measurer,Dermapteran beetles, caterpillar and crustaceanlarvae; Molluscs, like, Lymnea sp., Bellamya sp.,Segmentina sp. and Thiara sp. and annelid, likeleeches (Table 1). There were representations of14 different type of specimens in Site 1 whereas 11in Site 2 at the maximum in monsoon.Macrinvertebrate diversity decreased in post-monsoon and pre-monsoon in both the sites inaccordance with receding water column. As a result,

the Shanon–Weaver diversity index depicted adecreasing trend in post- and pre-monsoon seasonsfor both the ponds (Fig. 2) signifying existence ofmore diverse faunal assemblage in monsoon whenthe water column was highest. Pielous evennessindex (Fig. 3) was found to be higher in Site 2 whichindicated that species were more evenly distributedhere in comparison with Site1. Significant correlationwas found in between the diversity index anddominance index as well as species richness anddominance index in both the sites (Table 2). Therank abundance curve (Fig. 3) depicted steepgradient at the study sites.

Table 1: List of macroinvertebrate fauna found at the study sites.

M = Monsoon, PoM = Post-Monsoon, PrM = Pre-Monsoon, + = Present, - = Absent

72

Fig. 2. Temporal variation in macroinvertebrate diversity indices at study sites.

Sangeeta Saha and Subhasree Sen Gupta

73

Fig. 3. Seasonal variation in macroinvertebrate rank abundance curve with number of samples in X-axis and abundance value in Y-axis for the study sites.

Hydrological parameters revealed sharpdifference between the aquatic bodies withreference to dissolved oxygen level, alkalinity,hardness and nutrient content (Fig. 4). The dissolvedoxygen level was found to be higher in Site 1(5.645±0.329) in monsoon than that of Site 2(4.3±0.38) when the faunal abundance were foundto be maximum. Similar trend were shown byhardness data at Site 1 (328.67±1.89) than site 2(210.6±1.89) in monsoon. However, the hardnessvalue depicted opposite trend in pre and post-monsoon seasons. The alkalinity and nitrite contentis higher in Site 2 in all the seasons. The watercolumn in the study site was found to vary withseasonal cycles. The water bodies under studydepicted higher nutrient content in water in monsooncompared with post and pre-monsoon seasons.

According to interset correlations of CCA,dissolved oxygen (DO), temperature (Temp),hardness (Hard), dissolved silicate (Sil) and nitrite(Nit) were the most important environmentalvariables acting on the structure of themacroinvertebrate assemblages in both the sites(Fig. 5). In Site 1, there was a main sampleordination gradient in the third ordination quadrantrelated with hardness (interset correlations being-0.5555 and -0.2944 for the the first and secondaxes, respectively) and dissolved oxygen (interset

correlations being - 0.5563 and -0.2939 for the thefirst and second axes, respectively) (Fig. 5).According to these gradients, two different groupsof organisms were distinguished: the first groupconsists of Segmentina sp., Thiara sp. and fewDermapteran beetles showing higher dependenceon dissolved oxygen and hardness. The secondgroup consists of the leeches, Bellamya sp.,centipedes and a few crustaceans displayingimportance of dissolved silicate and watertemperature in Site 1. On the other hand, in Site 2,there was a main sample ordination gradient in thesecond ordination quadrant related with nitrite(interset correlations being 0.8958 and -0.1044 forthe first and second axes, respectively) and dissolvedoxygen (interset correlations being -0.6915 and -0.3911 for the first and second axes, respectively)in third ordination quadrant (Fig. 5). The caterpillars,Water Measurers and Bellamya sp. show significantdependence on dissolved oxygen value whereas theleeches, millipedes and Camponotus sp. showimportance of dissolved nitrite values in water.

DISCUSSIONThe macroinvertebrate assemblage

structure differ significantly in both the sites due todifference in anthropogenic pressure since Site 1was used mainly for fishing, whereas Site 2 wasquite unmanaged and used for dumping garbages.

Diversity of macroinvertebrates in lake littoral region

74

Fig. 4. Variation in hydrological parameters in different seasons.

Sangeeta Saha and Subhasree Sen Gupta

75

Fig. 5. Canonical correspondence analysis biplot showing the species-environment association by first two canonicalaxes throughout the study period at both Sites.Alk=Total alkalinity, DO=Dissolved oxygen, Hrd=Hardness, Nit=Nitrite-Nitrogen, Phos=Inorganic Phosphate,Sil=Dissolved silicate, Temp=Water temperature, Mos=Mosquito laravae, Mill=Millipedes, Cent=Centipedes,Camp=Camponotus sp., Wat=Water measurer, Dermap=Dermapteran beetles, Pump=Pumpkin beetle, Crust=Crustaceanlarvae, Cater=Caterpiller, Bell=Bellamya sp., Lym=Lymnea sp., Seg=Segmentina sp., Thia=Thira sp.

Macrinvertebrate diversity was found to vary withseasonal cycle and water level fluctuations mighthave a strong impact on faunal diversity (Baxter,1977; Hellsten et al., 1996; Hill & Keddy, 1992).The low mobility of organisms under study restrictstheir ability to follow the receding water. This explainsthe reason behind decrease in the faunal abundance,species richness and Shanon-Weaver diversityindices in both the sites in pre-monsoon season whenthe water depth is minimal.

The steep gradient of rank abundance curve(Fig. 4) quite clearly revealed that, most taxa foundin the lake littoral are rare (Brodersen et al., 1998;Irvine et al., 2001; Nijboer & Verdonschot, 2004)and low impacted sites tend to have greater taxarichness and more rare species than impacted ones(Doberstein et al., 2000; Fairchild et al., 2000; Chase& Liebold, 2002). As in this study, Site 2 wasadversely affected by indiscriminate dumping ofgarbage and display lower faunal diversity. For thisreason a number of authors (Lyons et al., 1995;Cao et al., 1998) have argued that rare species are

critically important indicators of ecosystem health.The four molluscan species found in these two sitescould be considered as bioindicators of goodculturable condition as noted in case of East CalcuttaWetlands by Basu et al., 2013. However, amongthese four, Lymnea sp., Thiara sp. and Segmentinasp. are also known to be intermediate hosts fortrematode species (Subba Rao, 1989). Side by side,absence of Tubifex sp. indicated relatively lesspollution in water (Basu et al., 2013).

Higher nutrient content in water at monsooncan be explained on account of receiving largesurface run off in monsoon loaded with nutrientsfrom allochthonus sources. High levels of nutrientsin the form of nitrogen and phosphorus fromwastewater were found to activate excessive algalgrowth (algal blooms) as noted in Site 2. The deathand decay of these algae can produce toxins andstagnant conditions. In such conditions,macroinvertebrate community diversity wasreduced with the exception of increased abundanceof few tolerant species, like millipedes, mosquito

Diversity of macroinvertebrates in lake littoral region

76

larvae and Camponotus sp. This was reflected bythe sharp gradient of rank abundance curve (Fig. 4)in this study. Those macroinvertebrates are able totake advantage (opportunistic) of the alteredconditions and exploit the excess of food supply.The abundance of the species decreased in post-monsoon, probably corresponding to low dissolvedoxygen and high alkalinity of water (Chattopadhyay& Banerjee, 2007).

Clear seasonal changes in communitystructure can be observed, which are primarily dueto the life cycles of aquatic insects, but may beinfluenced by seasonal changes in habitat conditions,too. As most univoltine insects emerge in summer,these are hardly present in pre-monsoon samplesof benthic invertebrates, and the early larval stagespresent in autumnal samples can often not bedetermined taxonomically as in this study. Thefindings of the study have shown that differences inrichness and abundance of macroinvertebrates in

the study sites were influenced a combination offactors like, seasonal change, altered hydrologicalregime and anthropogenic stress. Macro-invertebrates are highly adaptable to a broad rangeof ecological conditions and hence only strongenvironmental gradients can have a structuringeffect on their communities (Lounaci et al., 2000;Chakona et al., 2009; Nhiwatiwa, 2009). Therefore,the knowledge of the relationships betweenmacroinvertebrates and their environment is ofcrucial importance in the understanding of thefunctioning of ecosystems.

ACKNOWLEDGEMENTSThe authors are thankful to the Principal

and Head of the Department, Department ofZoology, Bethune College, Kolkata for the facilitiesprovided. The authors are also thankful to Dr.Lakshmi Kanta Ghosh for his support in identifyingthe specimen.

APHA. 2005. Standard methods for the examination ofwater and wastewater. American Public HealthAssociation, Washington DC, 21, 1-390.

Basu, A., Sengupta, S., Dutta, S., Saha, A., Ghosh, P. &Roy, S. 2013. Studies on macrobenthic organisms inrelation to water parameters in East Calcutta Wetlands. JEnv. Biol. 34: 733 - 737.

Baxter, R. M. 1977. Environmental effects of dams andimpoundments. Annu. Rev. Ecol. Syst. 8: 255-283.

Berger, W. H. & Parker, F. L. 1970. Diversity ofplanktonic foramnifera in deep sea sediments. Science168: 1345-1347.

Brinkhurst, R. O. 1974. The benthos of lakes. McMillanPress Ltd. London. Pp 190.

Brodersen, K. P., Dall, P. C. & Lindegaard, C. 1998. Thefauna in the upper stony littoral of Danish Lakes:Macroinvertebrates as trophic indicators. FreshwaterBiol., 39: 577-592.

REFERENCES

Cao, Y., Williams, D. D. & Williams, N. E. 1998. Howimportant are rare species in aquatic community ecologyand bioassessment? Limnol. Oceanogr. 43(7): 1403-1409.

Carvalho, A. L., Werneck-de-carvalho, P. & Calil, E. R.2002. Description of the larvae of two species ofDasythemis Karsch, with a key to the genera ofLibellulidae occurring in the states of Rio de Janeiro andSão Paulo, Brazil (Anisoptera). Odonatologica 31(1): 23-33.

Chakona, A., Phiri, C., Chinamaringa, T. & Muller, N.2009. Changes in biota along a dry-land river innorthwestern Zimbabwe: declines and improvements inriver health related to land use. Aquat. Ecol. 43: 1095–1106.

Chase, J. M. & Leibold, M. A. 2002. Spatial scale dictatesthe productivity–biodiversity relationship. Nature 416:427–430.

Chattopadhyay, C. & Banerjee, T. C. 2007. Temporalchanges in environmental characteristics and diversity

Sangeeta Saha and Subhasree Sen Gupta

77

of net-phytoplankton in a freshwater lake. Turk. J. Bot.37: 280-287.

Doberstein, C. P., Karr, J. R. & Conquest, L. L. 2000.The effect of fixed-count subsampling on macro-invertebrate biomonitoring in small streams. FreshwaterBiol. 44: 355-371.

Fairchild, G. W., Faulds, A. M. & Matta, J. F. 2000. Beetleassemblages in ponds: effects of habitat and site age.Freshwater Biol. 44: 523-534.

Gerber, A. & Gabriel, M. J. M. 2002a. AquaticInvertebrates of South African Rivers, Field Guide (1st

edn.). Institute for Water Quality Studies, Department ofWater Affairs and Forestry (DWAF). Pretoria. pp 150.

Gerber, A. & Gabriel, M. J. M. 2002b. AquaticInvertebrates of South African Rivers, Illustrations,Version 2. Institute for Water Quality Studies, Departmentof Water Affairs and Forestry (DWAF). Pretoria. pp 12.

Gooderham, J. & Tsyrlin, E. 2002. The Waterbug Book.A Guide to the Freshwater Macroinvertebrates ofTemperate Australia. CSIRO Publishing, Victoria.

Hellsten, S., Marttunen, M., Palomäki, R., Riihimäki, J.& Alasaarela, E. 1996. Towards an ecologically-basedregulation practice in Finnish hydroelectric lakes. Regul.River. 12: 535-545.

Hill, N. M. & Keddy, P. A. 1992. Prediction of rarities fromhabitat variables: Coastal plain plants on Nova Scotianlakeshores. Ecol. 73: 1852-1859.

Irvine, K., Allott, N., De Eyto, E., Free, G., White, J.,Caroni, R., Kennelly, C., Keaney, J., Lennon, C., Kemp,A., Barry, E., Day, S., Mills, P., O’ Ríain, G., Quirke, B.,Twomey, H. & Sweeney, P. 2001. Ecological Assessmentof Irish Lakes: The development of a new methodologysuited to the needs of the EU Directive for SurfaceWaters. Environmental Protection Agency, Ireland, pp.501.

Lounaci A., Brosse S., Thomas A. & Lek S. 2000.Abundance, diversity and community structure ofmacroinvertebrates in an Algerian stream: The Sébaouwadi. Ann. Limnol. 36: 123–133.

Lyons, J., Navarro-Perz, S., Cochran, P. A., Samtana, C.E. & Guzman-Arroyo, M. 1995. Index of biotic integritybased on fish assemblages for the conservation ofstreams and rivers in west central Mexico. Conserv. Biol.9: 569-584.

Margalef, R. 1958. Information theory in ecology. Gen.Syst. 3: 36-71.

McGarigal, K., Cushman, S. & Stafford, S. 2000.Multivariate statistics for wildlife and ecology research.Springer Verlag, New York.

Nhiwatiwa, T. 2009. The ecology of temporary pools inthe south-eastern lowland of Zimbabwe, Ph.D. Thesis,Katholieke Universiteit Leuven.

Nijboer, R. C. & Verdonschot, P. F. M. 2004. Rate andcommon macroinvertebrates: definition of distributionclasses and their boundaries. Arch. Hydrobiol. 161: 45-64.

Pielou, E. C. 1969. An Introduction to MathematicalEcology. Wiley, New York.

Quasin, S., Ganguly, K., Roy, S. & Nath, A. 2009. Diversityof macrobenthic fauna of two freshwater piscicultureponds of West Bengal. Environ. Ecol. 27: 1017-1021.

Reice, S. R., & Wohlenberg, M. 1993. Monitoringfreshwater benthic macroinvertebrates and benthicprocesses: measures for assessment of ecosystem health.In Freshwater biomonitoring and benthicmacroinvertebrates, eds. D. M. Rosenberg & V. H. Resh,pp. 287–305. Chapman and Hall, New York.

Shannon, C.E. & Weaver, W. 1949. A MathematicalModel of Communication. University of Illinois Press,Urbana.

Stoffels, R. J., Clarke, K. R. & Closs, G. P. 2005. Spatialscale and benthic community organization in the littoralzones of large oligotrophic lakes: potential for cross-scaleinter-actions. Freshwater Biol. 50: 1131-1145.

Subba Rao, N. Y. 1989. Handbook: Freshwater Molluscsof India, Zoological Survey of India, Calcutta, pp 289.

Ter Braak, C. J. F. 1998. CANOCO – a FORTRANprogram for canonical community ordination by partial,de-trended, canonical correspondence analysis, principalcomponentsanalysis and redundancy analysis (version2.1). The Agricultural Mathematics Group, Netherlands,Waseningen, Report LWA, pp 88-102.

Ter Braak, C. J. F. & Verdonschot, P. F. M. 1988.Canonical correspondence analysis and relatedmultivariate methods in aquatic ecology. Aquat. Sci. 57:255-289.

Diversity of macroinvertebrates in lake littoral region