Assessment of ecosystem health of a micro-level Ramsar coastal zone in the Vembanad Lake, Kerala, India.

Health of an ecosystem is very much important as we depend on its goods and services for our existence. Because of this, we need to continuously monitor its health for human benefit and for identifying areas for improvement of our natural systems. The present study tries to assess the condition of a coastal ecosystem within the Vembanad Lake, Kerala, India, using key water quality parameters at micro-level. Principal component analysis identified the minimum required water quality dataset for further analysis and was scored using linear scoring functions. The weighted additive method was used to integrate the individual scores to arrive at a final score representing the ecosystem health. Spline interpolation was applied to develop the ecosystem health map of the study area. Using this method, 35.8% area of the aquatic ecosystem studied was characterized as good, 32.2% as moderate, 26.2% as fair and 5.8% as poor. The assessment results can help the policymakers/managers to make appropriate decisions for the better management of the coastal ecosystems studied. Moreover, this methodology can be replicated for the assessment of coastal regions with similar ecosystem characteristics.

Water and sediment quality parameters of the restored mangrove ecosystem of Gurupura River and natural mangrove ecosystem of Shambhavi River in Dakshina Kannada, India.

Restoration of Rhizophora mucronata stand in the Gurupura Estuary resulted in improved water and sediment quality parameters. Monthly monitoring from 2011 to 2016 indicates that the restored mangroves grew to a height of 61.49 ± 5.76 cm. Principal component analysis (PCA) showed that increased duration of salinity in the estuary aided the growth of barnacles in planted mangroves which reduced survival by 10%. The United States Environmental Protection Agency ratings revealed that natural mangrove site in Shambavi River exhibit the maximum good water quality rating though dissolved inorganic phosphorous was rated highest due to non-point pollution sources. The pH, salinity, dissolved oxygen, silicate, phosphate, ammonia, and rainfall demonstrated significant seasonal differences (P < 0.001). Mangrove roots and biomes aided in accumulation of clay and significant difference (P < 0.001) was observed yearly. Land use management, efficient waste disposal system along with restoration of diverse mangroves can improve the water quality of estuarine ecosystem.

Marine plastic litter in certain trawl grounds along the peninsular coasts of India.

Non-biodegradable marine debris such as derelict fishing gears and their parts, polythene covers, carry bags, synthetic packaging materials etc., cause serious damages to the benthic ecosystem including the marine biota. We report here the monthly variation in the marine plastic litter (MPL) and its relative percentage to the quantity of fish caught from the trawling grounds off Cochin, Ratnagiri, Mumbai and Veraval along the west coast as well as Visakhapatnam from the east coast of India. The mean values of MPL from the fishing grounds registered the maximum of 55.2 ± 16.52 kg/km2 off Veraval and the minimum of 2.11 ± 0.55 kg/km2 off Visakhapatnam, registering a national average of 10.95 ± 3.05 kg/km2. The relative percentage of MPL over the fish catch remained highest (3.83%) at Veraval and lowest from Visakhapatnam (0.33%) while, the national average was 1.89 ± 0.28. Monsoon season registered maximum MPL in the fishing grounds of all the coastal regions we studied. Depth of the trawling grounds also influenced the quantity of MPL that 20 m depth registered quantity (24.25 ± 9.16 kg/km2) and the overall mean at 10 m and 40 m depth zone are significantly different from that of 20 m. The database created through this study are discussed in the light of increasing deleterious effects of plastic pollution in the active fishing areas in coastal region and the urgent need to save the sea for sustainable use of its resources.

Temporal and spatial variability of beach litter in Mangaluru, India.

Monthly litter samples were collected from three major beaches in Mangaluru from 2011-2016. Fishing litter persisted at the beaches, resulting in higher abundances by number (59%) and weight (33.4%) relative to all litter in 2016. In addition to plastics, foam comprised 7.14-11.0% of total litter. Significant positive correlations were observed between the amount of plastic on the beaches and rainy days, rainfall, and river discharge. The maximum river discharge coincided with an increase in plastic items on the beach. Yearly quantities of plastic items (p < 0.01), plastic bags (p < 0.001), and plastic footwear (p < 0.05), on the beaches were significantly different indicating clean-up activities reduced the litter quantity. Changes in total beach litter revealed that Panambur Beach, a fishing boat landing centre was the least changed, and thus appropriate incentive-based management options for the resident fishermen could result in collection and elimination of litter.

Photosynthetic Potential and Accumulation of Assimilates in the Developing Chloroembryos of Cyamopsis tetragonoloba (L.) Taub.

The photosynthetic potential of leaves and chloroembryos of Cyamopsis tetragonoloba (L.) Taub as measured by (14)C-bicarbonate fixation, Hill activity, and in vivo fluorescence transients is compared. On a chlorophyll basis, dark fixation of NaH(14)CO(3) in chloroembryos was 1.5 times higher than that of the leaf, whereas carbon fixation under illumination was threefold higher in the leaf than in the embryos. Rates of O(2) evolution were four times more in embryo than in leaf chloroplasts. Shading of developing fruits on the day of anthesis for 10 days induced a 65% reduction in dry matter accumulation in the etiolated embryos, as compared to the normal green embryos of the same fruit half covered by a transparent Polythene sheet. The reduction in dry weight, size of the embryos, and levels of assimilates after shading the developing fruits may be ascribed to partial autotrophy of the chloroembryos.