Species area plots used to show the cumulative number of differentspecies observed as each new sample is added. The advantage ofplotting this technique is to predict the total number of stations to besampled for getting the maximum number of species in a station. Thepresent study revealed that 12 times sampling during various seasonsis enough to get all the species in the study areas. The dendrogramsderived in the present study showed clustering of stations and gradualchange in species composition from the island mangrove ecosystemtowards riverine mangrove ecosystem. This means that a certain level ofsimilarity prevails in faunal diversity in developing and island mangrovesthan in the riverine mangrove ecosystem. Derived multidimensionalscaling (MDS) ordination reveals the same grouping of stations as inthe cluster analysis. The stress values found in the MDS configurationis low (0.11), indicating good representation of the interrelationshipbetween the macrofauna of each station. Benthic population density (N)is positively correlated with sediment temperature (r=0.940), salinity(r=0.875), Ph (r=0.975), Silt (r=0.548) in station I. In station II, benthicpopulation density is positively correlated with sediment temperature(r=0.983), salinity (r=0.935), pH (r=0.972) and silt (r=0.887). In stationIII, sediment temperature (r=0.890), sediment salinity (r=0.961), pH(r=0.967) and silt (r=0.579) are positively correlated with benthicpopulation at p<0.05 level.ConclusionAmong the three ecosystems, riverine mangrove (station I)ecosystem is more pristine in nature than the developing and islandmangrove ecosystems. Benthic macrofauna species assemblage iscomparatively higher in station I than in stations II and III. Analysis ofdata undertaken with predictable like line Shannon diversity, Simpsonrichness, and recently introduced diversity indices such as taxonomicdiversity index and total phylogenetic index clearly opined that healthynature of the mangrove ecosystem. From the present study, it could beconcluded that the hydrography, nutrients, and sediment texture arethe major factors responsible for fluctuation in benthic macrofaunalassemblages in the study area.
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