Search

Insular grids are fragile owing to lower inertia and the absence of interconnection with other grids. With the increasing penetration of non-dispatchable renewable energy sources, the vulnerability of such insular grids increases further. The government of India has proposed several projects to improve the photovoltaic systems (PV) penetration in the Andaman and Nicobar Islands' grid. This paper investigates joint stochastic scheduling of energy and reserve generation for insular grids fed from diesel and gas-based generators, PV, and battery energy storage systems (BESS). The proposed stochastic scheduling model considers a wide range of probabilistic forecast scenarios instead of a deterministic model that assumes a single-point forecast. Hence, it provides an optimal solution that is technically feasible for a wide range of PV power forecast scenarios. The striking feature of the model developed in this work is the inclusion of stochastic constraints that represent (i) the coordination between PV and BESS, (ii) reserve constraints, (iii) battery charging/discharging limit constraints, and (iv) non-anticipatory constraints that ensure technical viability of scheduling decisions. The proposed model is validated on the dataset for South Andaman Island. Results reveal the applicability and feasibility of the proposed stochastic dispatch model for different generation mix scenarios. [ABSTRACT FROM AUTHOR]

Mangroves are one of the most productive coastal ecosystems, which act as natural barriers against natural calamities such as cyclones, tide upsurges and tsunamis. Mangrove ecosystems provide natural habitat for a wide variety of flora and fauna, whilst the economic contribution by mangroves for tourism, fisheries and other natural resources is also of paramount importance. This study focusses on the biodiversity of four major regions of Indian mangroves, namely, Bhitarkanika (Odisha), Pichavaram (Tamil Nadu), Chorao Islands (Goa) and Porlob Jig (Andaman and Nicobar Islands). The study aims to monitor the present status of mangroves in Southern and Eastern coasts of India, with the synergistic use of optical and SAR data. The aerial extents of all the Dominant vegetation spatial maps generated revealed that the Bhitarkanika mangroves had the largest extent (14425 ha) among the four mangrove regions. The second largest area recorded was by the Porlob Jig mangroves of the Andaman and Nicobar Islands (9972 ha), followed by the Pichavaram mangroves (788 ha) and the mangroves of Chorao Islands of Goa (603 ha). Decision makers, for taking the necessary conservation and management actions to protect these fragile, vital habitats can ultimately use this data. This paper provides an insight into the major mangrove species of India. It gives a detailed account of the varying mangrove biodiversity in the Eastern and Western coast of India. The prevalence of various kinds of mangroves from different ecosystems were documented. Among these, Rhizophora annamalayana specious was found indigenously in Tamil Nadu. [ABSTRACT FROM AUTHOR]

Three decades before, the gillnet was the major gear in Andaman and Nicobar Islands(ANI), India, because of the less expensive and simple method of operation with non-motorised small dinghies or without craft. Earlier, the gillnet landing was 39% of the total landings and a further report said 27%, which indicated the decrease in gillnet landings. The present study was carried out from 2014 to 2018 at four main fish landing centers (FLCs) Junglighat, Dignabad, Guptapara and Wandoor of ANI to investigate the present status of major gillnet landings. Altogether 1097 visits were carried out at all FLCs and 63.1% of visits occurred at Junglighat. The total landings of all FLCs were 3880.6 tons, of which 98.6% were recorded at Junglighat. The total gillnet landings were 330.4tons, of which Driftnet covered 82.1%, followed by bottom plastic(9.8%) and bottom nylon(8%) gillnets. Significant landings (P<0.0001) of Scombridae family were recorded through Drift gillnet (182.47tons) compared to other families. The family of Carangidae(7.71tons) and Clupeidae(16.54tons) were recorded dominantly through bottom plastic and bottom nylon gillnets, respectively. The gillnetters explored 31 fishing grounds in the South, Middle, North and Little Andamans sectors. The significant (P<0.0001) fish catch was recorded from the South Andaman sector. A total of 17 validation experiments carried out in each Potential Fishing Zone (PFZ) and Non-PFZ by using PFZ advisories indicated a significant(P<0.0001) catch from PFZ(3.5:1). There was a decline of 18.5% in the landings of gillnet than earlier studies. It is suggested that the fishermen may follow the PFZ forecast for a better catch. The gillnet fishing to be promoted to under-exploited pelagic fishes of these islands will benefit the gillnetters. [ABSTRACT FROM AUTHOR]

• First study of modern pollen-vegetation relationship from South Andaman, India. • Pollen and NPP distribution, environmental variables and plant cover are compared. • Pollen of local vegetation predominates and regional vegetation represents poorly. • Modern pollen data is usable to interpret past vegetation and climate. This paper presents the first modern pollen, non-pollen palynomorphs and grain size data from a pristine mangrove tidal creek on the South Andaman Island, Andaman and Nicobar Islands, India. The surface sediment samples were collected from different mangrove environments of the Wright Myo Creek, South Andaman to study the relationship between the pollen-spore data and present vegetation cover. Results show that pollen from local vegetation more abundant, whereas regional vegetation surrounding the depositional site is poorly represented. Heritiera littoralis , Ceriops tagal , Excoecaria agallocha and Bruguiera gymnorrhiza are markedly abundant in the landward zone. The transitional and seaward pollen assemblages are characterized by Rhizophora mucronata, Avicennia marina and Bruguiera gymnorrhiza pollen types. Pollen from mangroves are locally restricted and reflect the distributions of the source plants and mangrove types. However, the greatest concentrations of allochthonous taxa of evergreen, deciduous and montane components are derived from the surrounding lands. This area receives high rainfall during monsoon favouring long distribution of palynomorphs i.e. allochthonous species from hinterland to the depositional site through connecting drainage system. Abundance of non-pollen palynomorphs suggest not only humid as well as wet conditions, but also the particular salinity and pH characteristics of mangrove types in the area. Such relationships were evident in the Redundancy Analysis (RDA), which revealed that the first two axes of the RDA with self-values of 0.63 and 0.06 respectively explained 68.4% of data variation and 95.2% of the correlation between pollen and the environment. Additionally, the RDA analysis between Non-Pollen Palynomorph (NPP) data and the environmental variables showed that the first and second axes with self-values of 0.60 and 0.04 respectively, explained 68.4% and 96.1% of NPP data variance, respectively. The granulometric analysis clearly indicates that sand fraction is maximum towards sea, whereas suspended sediments (silt and clay) are significantly higher towards transitional and landward zones. This is well corroborated with pollen preservation in this area. At the mouth of the creek, strong hydrodynamic flow and low pollen percentages is observed, while abundant pollen are noticed in the suspended sediments probably due to weak hydrodynamic forces towards land. Therefore, the effects on pollen assemblages from sediment dynamic conditions must be taken into consideration during the reconstruction of palaeovegetation and palaeoclimate. The presented dataset provides new information on modern pollen assemblages and their relationship to the vegetation types and environmental conditions, which can also be effectively applied to other mangrove ecosystems of South and South East Asian regions to reconstruct palaeovegetation and palaeoclimatic changes. [ABSTRACT FROM AUTHOR]

Mesoscale eddies are important ocean phenomena that enhance biological productivity by mixing of water column and influence fishery catches, especially in stratified seas such as Bay of Bengal and Andaman Sea. The current study was conducted around the Andaman and Nicobar Islands (ANI), India located in the Eastern Indian Ocean. The study tested the feasibility of targeted fishing in eddies, by characterizing the mesoscale eddies in the region, towards developing operational altimetry-based fishery advisories for the fishers. We analysed fish catch data from 15,370 commercial fishing trips from the Islands using five fishing gears during 2014–17 spatially vis-à-vis the eddies delineated from Maps of Sea Level Anomaly (M-SLA). We show that 5-24% of the routine commercial catches occurred in eddies, fishery catches are positively influenced by different eddy zones and the fish catch using different fishing gear are significantly higher in some of the eddy zones. We generated experimental advisories showing locations of eddies and their zones, identified using Near Real-Time M-SLA data and guided the commercial fishers for targeted fishing in eddies. The fish Catch Per Unit Effort (CPUE) from the experimental fishing within the eddy zones was significantly (p < 0.01) higher than that from the traditional fishing grounds in the non-eddy areas. The spatio-temporal analysis of eddies around ANI during 2009–16 showed the occurrence of higher number of anticyclonic eddies, majority of which move westward and have a lifespan of less than 2 weeks and amplitude less than 4 cm. In the current study, the areas around ANI with frequent eddy occurrence and eddy density have been identified, which could aid in increasing the fishing intensity by targeting the pelagic fishes, using longlines, gillnets and ringnets. Thus, we show the possibility of using eddy fishing advisories generated from altimeter data, for augmenting the currently operational Potential Fishing Zone (PFZ) advisories that are generated using optical/thermal remote sensing data and disseminated to the coastal fishers in India. This will be helpful especially for the regions with and during periods of persistent cloud cover. [ABSTRACT FROM AUTHOR]

Using PCR and sequencing, we found Plasmodium knowlesi in the malaria vector Anopheles sundaicus mosquito collected from Katchal Island in the Andaman and Nicobar Islands, India. We cannot rule out natural transmission of this parasite to humans through this mosquito species. An in-depth investigation is needed to prevent disease outbreaks. [ABSTRACT FROM AUTHOR]

The article discusses a study conducted by the authors, related to production of Shigella spp. in childhood diarrhea from Andaman Islands by VIM- and IMP-type metallo- β -lactamase. Topics discussed include widening of the spectrum antibiotics to which shigellae acquired resistance, spread of carbapenem resistance as a potential public health challenge and strengthening the surveillance against antibiotic resistance among enteric pathogens.