BURROW ARCHITECTURE OF RED GHOST CRAB OCYPODE MACROCERA (H. MILNE-EDWARDS, 1852) : A CASE STUDY IN INDIAN SUNDARBANS

A study on burrow architecture and burrow morphology of the red ghost crab (Ocypode macrocera) was carried out at the southern proximity of the Sagar island (21°37.973' N, to E 88° 04.195'), western sector of Indian Sundarbans that faces the regular tidal influences of Bay of Bengal. Ocypode macrocera constructs burrows that are highly species specific and used by single individual. Four types of burrow patterns were observed like ‘I’, ‘J’ ‘U’ and ‘semi-U’ type with different sizes as revealed by POP casting. Important physic-chemical parameters like air temperature, temperature and salinity of the water were significantly varied (P < 0.05) throughout seasons in the Ocypode zone. Burrow sand column temperature were also significantly varied from ambient air temperature thus exhibiting preference for cooler subterranean residential compartment. The digging behaviour of Ocypodes enhances oxygenation in the ground soil and facilitates decomposition of organic materials, nutrient recycling, entrapping the sediments and mangrove seedlings and helps the process of bioturbation. As per the preliminary observations it was suggested that burrow shape is directly related to tidal action and metabolic activities of the crab are strongly correlated with burrow microenvironment. They are adapted to the different sediment conditions, tidal fluctuations, varying salinity gradients, air and water temperatures and other environmental fluctuations

SPATIO-TEMPORAL VARIATION OF MERCURY IN BIDYADHARI RIVER OF SUNDARBAN DELTA, INDIA

Bidyadhari river originates in Nadia district of West Bengal, India and then flows through North 24 Parganas district and now serves as a sewage and excess rainwater outlet from the city of Kolkata and adjacent area, which ultimately empties at the Bay of Bengal through the Indian Sundarban delta. Four different stations situated around the course of the river at considerable distances have been selected from the outfall of sewage canals at Kulti-Ghushighata (S1), where metropolitan sewages discharged and mixed up into water of Bidyadhari river, which ultimately carried through this river via stations Malancha (S2), Kanmari (S3) to Dhamakhali (S4), just before the river confluences with the larger Raimangal river at northern Sundarban delta. This study was conducted to estimate total mercury (Hg) concentration in waters (during high tides and ebb tides) and sediments of Bidyadhari river in pre-monsoon, monsoon and post-monsoon seasons during the period from March, 2012 to February, 2013 at those stations. It is revealed from the estimated data that agricultural runoff, sewage, effluents from various industries and Kolkata metropolitan, Salt Lake City and adjacent areas of North 24 Parganas district carried and discharged in Bidyadhari river through sewage canals are not so high in mercury content for sediment contamination but alarming in respect of water quality, which crosses the permissible limit of Hg for consumption (0.001 ppm) in wide range of areas at Kanmari and Dhamakhali around the estuary. Enhancement of Hg level in this river water and transportation of the metal through tidal effects to and fro mangrove land of Sundarban may be dangerous for aquatic lives and supposed to be grave concern for the ecology of the Sundarban delta including human

Promoting the importance of aquatic foods on human nutrition and public health under APART in Assam

One of the key activities (Deliverable 7) under the APART project is “Improving impact of aquaculture and beel fisheries on human Nutrition”. WorldFish with partners is supporting the implementation of this activity. This consolidated report summarizes all the work done by WorldFish and partners as part of deliverable 7. The project has developed and tested several Social Behavioural Change Communication (SBCC) resources (e.g. banners, leaflets, brochures, calendars, TV spots, and videos) to promote the consumption of aquatic foods by vulnerable communities, PLM, adolescent girls, and children by targeting relevant stakeholders (e.g. Integrated Child Development Services programs, District Social Welfare (DSW) field functionaries, Anganwadi workers, Village communities, primary health centres, and the general public). We have trained 597 trainers to spread the message on the role of aquatic foods. We conducted 36 cluster-level awareness programs where 1994 numbers of women, adolescent girls and community people were given information on the benefits of fish consumption. We also organised 2 zonal workshops and 1 statelevel workshop for different stakeholders to build awareness of the importance of aquatic foods. Based on the demonstrations at the community level, the project documented all the small fish-based recipes cooked locally at the community level and produced a Small Fish Recipes book

Indigenous ornamental freshwater ichthyofauna of the Sundarban Biosphere Reserve, India: status and prospects

Ornamental fishes are the most popular pet throughout the world and high demand for these fishes has made them an important component of the world fish trade. India contributes a very meager percentage to the world ornamental fish trade; but considering the high ichthyofaunal diversity it has the potential to compete with the world’s leading ornamental fish producers in the near future. Sundarban Biosphere Reserve has abundant waterbodies with rich fish diversity. Although some research has been carried out on ichthyofaunal resources of the Sundarban; detailed documentation on freshwater indigenous ornamental ichthyofaunal resources of this region is still not available. To fill this knowledge gap, the present study has been conducted to list the indigenous ornamental ichthyofaunal resources of the Sundarban Biosphere Reserve along with their conservation status and their prospective utilization for improved livelihood of local communities. Eighty four species belonging to 11 orders, 28 families and 59 genera were collected from the study area with species representing the order Cypriniformes dominating the ichthyofauna. Nine species have been listed as Near Threatened in the IUCN Red List of Threatened Species™. Indigenous fish species of the Sundarban having great potential to support domestic as well as the international ornamental fish trade from India in near future. The ornamental fish species would also be able to generate alternate livelihood options for the impecunious communities of the Sundarban. However, serious concern must also be paid to the conservation of these fish species as some of them are under near threatened categories of IUCN Red list. </div

Not Available

Not AvailableLandsat operational land imager (OLI) data and consequent laboratory measurements were used to predict chlorophyll-a (Chl-a) concentration and the trophic states for an inland lake within the East Kolkata Wetland, India (a Ramsar site). The most suitable band ratio was identified by performing Pearson correlation analysis between Chl-a concentrations and possible OLI band and band ratios from the study points. The results showed highest correlation coefficient from the band ratio OLI5/OLI4 with an R value of 0.85. The prediction model was then developed by applying regression analysis between the band ratio OLI5/OLI4 and Chl-a concentration of the study points. The reflectance ratios of the validation points were given as input on the prediction model and the model output was considered as predicted Chl-a values of the validation points to check the efficiency of the prediction model. The regression model between laboratory-derived Chl-a value and model-fitted Chl-a value of the validation points revealed a high correlation with an R² value of 0.78. Trophic State Index (TSI) of the lake was also calculated from laboratory-derived Chl-a value and model-fitted Chl-a value of the validation points. The study presented a high correlation of TSI determined from predicted data with TSI from laboratory reference data (R = 0.88). The TSI values of the lake ranged from 65 to 75 which indicate that the lake is appeared to be eutrophic to hypereutrophic conditions. This empirical study showed that Landsat 8 OLI imagery can be effectively applied to estimate Chl-a levels and trophic states for inland lakesNot Availabl

CONTAMINATION STATUS OF CADMIUM IN DIFFERENT BIOTIC AND ABIOTIC COMPONENTS AROUND THE BIDHYADHARI RIVER OF INDIAN SUNDARBAN DELTA

This study has been conducted to estimate the concentration of total Cadmium (Cd) in different biotic and abiotic substrates including human in and around the Bidyadhari river of Sundarban delta. Bidyadhari river presently serves as a sewage and excess rainwater outlet from Kolkata metropolitan and adjacent area, which ultimately empties at the Bay of Bengal. The study reveals that the Cd content in surface water of the river and ponds as well as ground water was generally high up to 0.294 µg/ml and 0.205 µg/ml respectively during most of the seasons, which was above the maximum permissible level for drinking water as per various national and international standards like Indian Standard Specification, European Union, WHO, USEPA etc. Though, range of Cd in sediment of the river and ponds was 0.025 to 0.281µg/g and 0.018 to 0.317µg/g respectively but that was considerably higher in grasses up to 0.324µg/g. Backyard hen demonstrated considerably high levels of Cd in their egg up to 0.247µg/g in albumen and 0.272 µg/g in yolk. Goat and cattle demonstrated Cd content in meat up to 0.295µg/g and milk up to 0.295µg/ml respectively which crosses the permissible levels recommended by different international standards. High Cd content in human hairs up to 1.11µg/g indicated considerably bioaccumulation of the metal in local inhabitants resides in the northern part of Sundarban mangrove eco-region. This whole observation may be considered as base line study to know the present status of Cd contamination and bioaccumulation in flora and fauna including humans in Sundarban mangrove eco-region to prepare mitigation planning against this carcinogen from the biota immediately

WATER CLARITY ASSESSMENT FOR A REGIONAL LAKE USING LANDSAT OPERATIONAL

Not AvailableLandsat operational land imager (OLI) data and consequent laboratory measurements were used to predict water clarity for an inland lake within the East Kolkata Wetland, India (a Ramsar site). Total suspended sediment (TSS) and turbidity was considered as responsible parameters for assessment of lake clarity. The most suitable band ratio was identified by performing Pearson correlation analysis between water clarity concentrations and possible OLI band and band ratios from the ‘study points’. The OLI 4 band (636-673 nm) showed the best ‘r’ value, 0.96 and 0.89 in case of TSS and turbidity respectively. The two separate prediction models (using non-transformed and logarithmically transformed water clarity data) was developed by applying regression analysis between the band reflectance value of OLI4 and water clarity concentrations of the study points. The band reflectance value of the ‘validation points’ was given as input in the prediction model and model predicted dataset was considered as predicted water clarity parameters. The model predicted dataset exhibit lower standard error of estimates (SEE) with contemporaneous in situ measurements. The validation of the multi-temporal competence of the best models indicated that it is feasible to apply the linear regression model using OLI 4 band to estimate water clarity concentrations across the seasons in Nalban Lake without any in situ data. The water clarity mapping of the lake was then developed using the predicted dataset. This empirical study showed that Landsat 8 OLI imagery could be effectively applied for the mapping of TSS and turbidity for inland lakes.Not Availabl

Dataset of biological community structure in Deepor Beel using eDNA approach–A RAMSAR wetland of Assam, India

Deepor Beel, located in the state of Assam in India, is a Wetland of International Importance with a Wildlife Sanctuary and is the only RAMSAR site in the state. Though of invaluable ecological significance, the wetland is facing anthropogenic stressors, leading to rapid degradation of ecological health. In December 2022, surface water was collected from six stations of Deepor Beel to elucidate biological communities using the eDNA approach. At the time of sampling, in-situ environmental parameters were measured in triplicates. The dissolved nutrients and concentrations of metals and metalloids were estimated using UV–Vis Spectrophotometry and ICP-MS approaches respectively. The study revealed a high concentration of dissolved nitrate in the surface water. High-throughput sequencing using Nanopore sequencing chemistry in a MinION platform indicated the overwhelming abundance of Moraxellaceae (Prokaryotes) and Eumetazoa (Eukaryotes). The abundance of Cyprinidae were also encountered in the studied wetland reflecting the biodiversity of fish populations. High nitrate along with elucidated microbial signals are crucial to designate ecological health status of Deeper Beel. This study is aimed at generating baseline information to aid long-term monitoring and restoration of the Deepor Beel as well as the first comprehensive assessment of a RAMSAR Site located in northeast of India

Adaptation for changing deltas

Deltas have provided fertile farmland, productive fishing, and access to trade routes for millennia. Today, more than five hundred million people live on deltas and coastal urban areas. Yet deltas are also incredibly vulnerable to the pressures of climate change