Different multivariate statistical analysis such as, cluster analysis, principal component analysis, and multidimensional scale plot were employed to evaluate the trophic status of water quality for four monitoring stations. The present study was carried out to determine the physicochemical parameters of water and sediment characteristics of ), sulfide (1.98-40.43 mg/L), sediment texture sand (39.54-87.31%), silt (9.89-32.97%), clay (3.06-31.20%), and organic matter (0.94-4.64%). pH, temperature, salinity, sand, silt, clay, and organic matter indicated a correlation at P<0.01. CA grouped the four seasons in to four groups (pre-monsoon, monsoon, postmonsoon, summer) and the sampling sites in to three groups. PCA identified the spatial and temporal characteristics of trophic stations and showed that the water quality was worse in stations 3 and 4 in the Pondicherry mangroves.

Haematological parameters are often used to assess the health status and as stress indicators in fishes. In this present study, the haematological parameters such as red blood cell count (RBC), white blood cell count (WBC), haematocrit (HCT), haemoglobin (HB), mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration, RBC/WBC ratio, erythrocyte sedimentation rate (ESR) and biochemical such as serum glucose (GLU), protein (PRO), cholesterol and urea (UR) of seven teleost fish species were determined. Statistical analysis confirmed that differences in haematological parameters between all the species were (P<0.01) significant. The result revealed that RBC, RBC/WBC ratio, HCT, HB, ESR, PRO, GLU and UR was significantly correlated at P<0.05 level. RBC/ WBC level was more due to the decrease in WBC during the study. These differences can be attributed to the physiological acclimatisation of the fish to their living conditions and feeding regime, which influences the energy metabolism and consequently, the health of the fish.

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Background Macrophytes (fresh water plants) comprise a diverse group of the flora which play important roles in the maintenance of trophic food chains and biogeochemical processes, but are deleterious when present in excess. However, due to various anthropogenic activities, there is accumulation of nutrients in aquatic ecosystems resulting in massive macrophytic growth. These weeds do not possess any economic value and remain laid on lake shores after harvesting and become a source of odor problem, thus posing a challenge to the lake management authorities regarding their proper disposal. However, vermicomposting turns these macrophytes into materials useful in horticulture/agriculture for restoration of soil fertility, in addition to providing a solution to the nuisance of harvested weeds. Results The study was conducted to investigate the effect of different rates (2, 4 and 6 t/ha) of macrophyte-based vermicompost on germination, growth and yield of Solanum melongena under field conditions. The data revealed that different rates of vermicompost produced varied and significant effect (P \ 0.05) as compared to the control on germination, growth and yield parameters with maximum value recorded at 6 t/ha, followed by 4 t/ha and the least at 2 t/ha. The dose of 6 t/ha significantly (P \ 0.05) increased germination (22.56 ± 2.5 %), number of fruits per plant (3.55 ± 0.07) mean fruit weight (73 ± 5.0 g), yield per plant (1.48 ± 0.05 kg) and marketable fruits (28.66 ± 3.0 %) when compared with the control. The study suggests that macrophyte-based vermicompost as a potential source of plant nutrients for sustainable crop production. Conclusion Macrophyte-based vermicompost is an efficient quality yielder and economy enhancer for sustainable agriculture especially for the communities having vegetable gardens around lakes will benefit by using macrophyte vermicompost, a balanced and low-cost organic fertilizer.

BackgroundSpecies distribution, abundance and diversity of mangrove benthic macroinvertebrate fauna and the relationships to environmental conditions are important parts of understanding the structure and function of mangrove ecosystems. In this study seasonal variation in the distribution of macrobenthos and related environmental parameters were explored at four mangrove stations along the Pondicherry coast of India, from September 2008 to July 2010. Multivariate statistical analyses, including cluster analysis, principal component analysis and non-multidimensional scales plot were employed to help define trophic status, water quality and benthic characteristic at the four monitoring stations.ResultsAmong the 528 samples collected over 168 ha of mangrove forest 76 species of benthic macroinvertebrate fauna were identified. Macrofauna were mainly composed of deposit feeders, dominated numerically by molluscs and crustaceans. Statistical analyses yielded the following descriptors of benthic macroinvertebrate fauna species distribution: densities between 140–1113 ind. m-2, dominance 0.17-0.50, diversity 1.80-2.83 bits ind-1, richness 0.47-0.74 and evenness 0.45-0.72, equitability 0.38-0.77, berger parker 0.31-0.77 and fisher alpha 2.46-5.70. Increases of species diversity and abundance were recorded during the post monsoon season at station 1 and the lowest diversity was recorded at station 2 during the monsoon season. The pollution indicator organisms Cassidula nucleus, Melampus ceylonicus, Sphaerassiminea minuta were found only at the two most polluted regions, i.e. stations 3 and 4. Benthic macroinvertebrate fauna abundances were inversely related to salinity at the four stations, Based on Bray-Curtis similarity through hierarchical clustering implemented in PAST, it was possible to define three distinct benthic assemblages at the stations.ConclusionsFrom a different multivariate statistical analysis of the different environmental parameters regarding species diversity and abundance of benthic macroinvertebrate fauna, it was found that benthic communities are highly affected by all the environmental parameters governing the distribution and diversity variation of the macrofaunal community in Pondicherry mangroves. Salinity, dissolved oxygen levels, organic matter content, sulphide concentration were the most significant parameters.