Birds of the man-made ecosystems: the plantations

One-hectare plots were sampled for bird species diversity in the Uttara Kannada district. These plots represented well-preserved evergreen/semievergreen forests, secondary/moist deciduous forests showing different levels of degradation by man and plantations of teak, eucalypts and betelnut. It was found that the betelnut plantation and the evergreen/semievergreen forests had the least bird species diversity ofH′ = 2.58 and 2.61 respectively. The eucalypt and teak plantations hadH′ = 2.69 and 2-92 respectively. In the secondary/moist deciduous forests it ranged from 2.80–3.39. Despite the apparent increase in diversity in the man-modified vegetation types, it was found that there was a gradual displacement of the bird species composition from what was typical to the evergreen forests to those of more urban and scrubby habitats in these man-modified vegetation types. This was particularly so in the eucalypt plantation

Spatial Analysis and Characterisation of Lentic Ecosystems: A Case Study of Varthur Lake, Bangalore

Lentic ecosystems vital functions such as recycling of nutrients, purification of water, recharge of groundwater,augmenting and maintenance of stream flow and habitat provision for a wide variety of flora and fauna along with their recreation values necessitates their sustainable management through appropriate conservation mechanisms. Failure to restore these ecosystems will result in extinction of species or ecosystem types and cause permanent ecological damage. In Bangalore, lentic ecosystems (for example lakes) have played a prominent role serving the needs of agriculture and drinking water. But the burgeoning population accompanied by unplanned developmental activities has led to the drastic reduction in their numbers (from 262 in 1976 to 81). The existing water bodies are contaminated by residential, agricultural, commercial and industrial wastes/effluents. In order to restore the ecosystem, assessment of the level of contamination is crucial. This paper focuses on characterisation and restoration aspects of Varthur lake based on hydrological, morphometric, physical-chemical and socio-economic investigations for a period of six months covering post monsoon seasons. The results of the water quality analysis show that the lake is eutrophic with high concentrations of phosphorous and organic matter. The morphometric analysis indicates that the lake is shallow in relation to its surface area. Socio-economic analyses show dependence of local residents for irrigation, fodder, etc. These analyses highlight the need and urgency to restore the physical, chemical and biological integrity through viable restoration and sustainable watershed management strategies, which include pollution abatement, catchment treatment, desilting of the lake and educating all stakeholders on the conservation and restoration of lake ecosystems.

Aquatic Ecosystems: Conservation, Restoration and Management

Aquatic Ecosystems perform numerous valuable environmental functions. They recycle nutrients, purify water, recharge ground water, augment and maintain stream flow, and provide habitat for a wide variety of flora and fauna and recreation for people. A rapid population increase accompanied by unplanned developmental works has led to the pollution of surface waters due to residential, agricultural, commercial and industrial wastes/effluents and decline in the number of water bodies. Increased demands for drainage of wetlands have been accommodated by channelisation, resulting in further loss of stream habitat, which has led to aquatic organisms becoming extinct or imperiled in increasing numbers and to the impairment of many beneficial uses of water, including drinking, swimming and fishing. Various anthropogenic activities have altered the physical, chemical and biological processes within aquatic ecosystems. An integrated and accelerated effort toward environmental restoration and preservation is needed to stop further degradation of these fragile ecosystems. Failure to restore these ecosystems will result in sharply increased environmental costs later, in the extinction of species or ecosystem types, and in permanent ecological damage.

Impact of heavy metals on bacterial communities from mangrove soils of the Mahanadi Delta (India)

This study aimed to assess soil nutrient status and heavy metal content and their impact on the predominant soil bacterial communities of mangroves of the Mahanadi Delta. Mangrove soil of the Mahanadi Delta is slightly acidic and the levels of soil nutrients such as carbon, nitrogen, phosphorous and potash vary with season and site. The seasonal average concentrations (g/g) of various heavy metals were in the range: 14810-63370 (Fe), 2.8-32.6 (Cu), 13.4-55.7 (Ni), 1.8-7.9 (Cd), 16.6-54.7 (Pb), 24.4-132.5 (Zn) and 13.3-48.2 (Co). Among the different heavy metals analysed, Co, Cu and Cd were above their permissible limits, as prescribed by Indian Standards (Co=17g/g, Cu=30 g/g, Cd=3-6 g/g), indicating pollution in the mangrove soil. A viable plate count revealed the presence of different groups of bacteria in the mangrove soil, i.e. heterotrophs, free-living N-2 fixers, nitrifyers, denitrifyers, phosphate solubilisers, cellulose degraders and sulfur oxidisers. Principal component analysis performed using multivariate statistical methods showed a positive relationship between soil nutrients and microbial load. Whereas metal content such as Cu, Co and Ni showed a negative impact on some of the studied soil bacteria.

Mercury exposure Aasessment in fish and humans from Sundarban Mangrove Wetland of India

Present study had documented total mercury levels in six commonly consumed fish species, and performed across-sectional study on local residents to gauge their intake of fish (via dietary survey) and mercury exposure (via hair biomarker analyses). Mean total mercury content in edible composites of locally-caught fishes (topse, hilsa, mackerel, topse, sardinella, khoira) was low and ranged from 0.01 to 0.11 mu g g(-1) mercury, dry weight. In a cross-sectional study of 58 area residents, the mercury content in hair ranged from 0.25 to 1.23 mu g g(-1), with a mean of 0.65 +/- 0.23 mu g g(-1), Flair mercury level was not influenced by gender, age, or occupation. Mean number of meals consumed per week was 3.1 +/- 1.1, and all participants consumed at least one fish meal per week. When related to fish consumption, a significant positive association was found between number of fish meals consumed per week and hair mercury levels.

Perceptions of priority issues in the conservation of biodiversity and ecosystems in India

We report on the results of a country-wide survey of people's perceptions of issues relating to the conservation of biodiversity and ecosystems in India. Our survey, mainly conducted online, yielded 572 respondents, mostly among educated, urban and sub-urban citizens interested in ecological and environmental issues. 3160 ``raw'' questions generated by the survey were iteratively processed by a group of ecologists, environmental and conservation scientists to produce the primary result of this study: a summarized list of 152 priority questions for the conservation of India's biodiversity and ecosystems, which range across 17 broad thematic classes. Of these, three thematic classes-''Policy and Governance'', ``Biodiversity and Endangered Species'' and ``Protection and Conservation''-accounted for the largest number of questions. A comparative analysis of the results of this study with those from similar studies in other regions brought out interesting regional differences in the thematic classes of questions that were emphasized and suggest that local context plays a large role in determining emergent themes. We believe that the ready list of priority issues generated by this study can be a useful guiding framework for conservation practitioners, researchers, citizens, policy makers and funders to focus their resources and efforts in India's conservation research, action and funding landscape. (C) 2015 Elsevier Ltd. All rights reserved.

Factors affecting distribution of fish within a tidally drained mangrove forest in the Andaman and Nicobar Islands, India

Mangrove forests in meso-tidal areas are completely drained during low tides, forming only temporary habitats for fish. We hypothesised that in such temporary habitats, where stranding risks are high, distance from tidal creeks that provided access to inundated areas during receding tides would be the primary determinant of fish distribution. Factors such as depth, root density and shade were hypothesised to have secondary effects. We tested these hypotheses in a tidally drained mangrove patch in the Andaman Islands, India. Using stake nets, we measured fish abundance and species richness relative to distance from creeks, root density/m(2), shade, water depth and size (total length) of fish. We also predicted that larger fish (including potential predators) would be closer to creeks, as they faced a greater chance of mortality if stranded. Thus we conducted tethering trials to examine if predation would be greater close to the creeks. Generalised linear mixed effects models showed that fish abundance was negatively influenced by increasing creek distance interacting with fish size and positively influenced by depth. Quantile regression analysis showed that species richness was limited by increasing creek distance. Proportion of predation was greatest close to the creeks (0-25 m) and declined with increasing distance. Abundance was also low very close to the creeks, suggesting that close to the creeks predation pressure may be an important determinant of fish abundance. The overall pattern however indicates that access to permanently inundated areas, may be an important determinant of fish distribution in tidally drained mangrove forests.