Lakshadweep Islands Research Articles

A new free-living marine nematode, Polkepsilonema arabicensis sp. n. (Desmodorida: Epsilonematidae), from Lakshadweep, India.

Polkepsilonema arabicensis sp. n. is discovered from the coralline sand of Lakshadweep island, located off the south-western coast of India. The species differs from other congeners by its unique combination of characters: presence of fine spines along the body curvatures, 5-6 rows of bisinuous ambulatory setae, male with two clusters of ventral copulatory thorns and 14 subcephalic sensilla. The novel species is the fourth discovery of the genus and first record from the coastal areas of Indian subcontinent. A key to species level is provided.

Distribution of mosquito fauna in Minicoy - Lakshadweep islands, India

The aim of the study was to know breeding sources, distribution dynamics, species diversity and entomological indices of mosquito fauna to predict risk of vector borne disease (VBDs) transmission. Immature sampling sites were selected randomly. Houses were inspected for the presence of larval infestation, Immature were collected by dipping and pipetting method. Predominant breeding sources at Minicoy were found to be coconut shells, discarded plastic containers, open wells, discarded drainage tank, flower pot and earthen pot. Four vector and one non-vector species were collected during monsoon season such as Aedes (Aedes) alopictus (53.23%), Aedes (Aedes) aegypti (39.75%), Anopheles (Cellia) stephensi (1.75%), Culex (Culex) quinquefasciatus (5.25%) and Armigeres (Armigeres) subalbatus. Entomological indices such as House Index (HI), Container Index (CI), Breateu Index (BI) and Pupal Index (PI) showed high values such as 25.26, 4.8, 36.02 and 90.86 respectively during monsoon season. As a result of high level of BI risk of disease transmission is high in Minicoy Island. The entomological indices for Dengue vectors are high, hence stringent vector control measures needs to be implemented at Minicoy Island.

A new distribution record of the Pentagonal Sea Urchin Crab Echinoecus pentagonus (A. Milne-Edwards, 1879) (Decapoda: Brachyura: Pilumnidae) from the Andaman Islands, India

First time, a Sea Urchin Crab, Echinoecus pentagonus (A. Milne-Edwards, 1879) is recorded from the rocky intertidal region of the Andaman Islands. It is a symbiotic crab live with Sea Urchin. This species is recorded from the Lakshadweep and Nicobar Islands but still there is no record from mainland India. A detail description of the species with standard photographs and line diagrams is provided.

Propagation of the Sumatra Tsunami in the Southeast Arabian Sea and Inundation along the Lakshadweep and Kerala Coast of India

A study of the propagation of the 2004 tsunami in the South East Arabian Sea (SEAS) and the tsunami induced run-up and inundation along the Kerala and Lakshadweep coasts were taken up using post-tsunami field survey data and numerical modeling. The role of different wave transformation processes like diffraction, refraction, reflection, and total internal reflection in bringing out the observed run-up and inundation characteristics along the Kerala and Lakshadweep coasts are discussed. Simulations using the TUNAMI N2 model were carried out for three different sources viz. Sumatra 2004, Makran 1945 and a hypothetical potentially worst case from Makran. The results of tsunami vulnerability analysis in terms of run-up and inundation for the entire Kerala coast and four selected Islands of Lakshadweep viz. Androth, Chetlat, Kadmat and Kavaratti show strikingly different run-up and inundation characteristics. While the Kerala coast appears to be vulnerable for inundation due to tsunami from different sources, the Lakshadweep coasts do not appear to be vulnerable. The modeling results for Sea Level Rise scenario for selected sectors indicate that sea level rise can definitely make many fold increase in inundation in some of the stretches. For planning mitigation measures, it would be highly essential to carry out numerical simulations for the extreme SLR scenarios for the whole coast by providing high resolution topographic grid for the coastal zone. How to cite this article:SS Praveen, NP Kurian. Propagation of the 2004 Tsunami in the Southeast Arabian Sea (Seas) and Inundation Along the Lakshadweep and Kerala Coast of India. J Adv Res Civil Envi Engr 2019; 6(2): 25-31.

Planform Island change assessment for inhabited Lakshadweep Islands

Impacts of coastal processes and anthropogenic activities threaten the archipelago of low-lying reef islands. In this study, long-term (1972–2015) and short-term (2000–2015) shoreline change analyses of ten inhabited Lakshadweep Islands were done using linear regression rates. Of significance, the results highlight that all ten islands are erosional in the long term, with Androth Island being the highest erosional in both the periods, but it shows a stable platform in the short-term periods. More than 50% of the islands indicate shrinkage in planform change in both ocean and lagoon sides of the islands. Construction of artificial structures (seawalls/tetrapods) along the shoreline has helped to reduce the erosion in some localised areas. However, adverse effect of these armoured structures has caused loss of beaches, valuable coastal resources and marine habitats. Although natural reefs protect the lagoon side of island, it is clear that widespread erosion is along both the sides due to anthropogenic activities that are susceptible to the sea-level rise.

The peopling of Lakshadweep Archipelago

The archipelago of Lakshadweep is considered as a stopover to the maritime route since ancient time. It is not very clear when the human first occupied these islands, however in the long history of the islands, the local legends suggest that Lakshadweep has been ruled by different kingdoms. To have a better understanding of peopling of Lakshadweep, we have analysed 557 individuals from eight major islands for mitochondrial DNA and 166 individuals for Y chromosome markers. We found a strong founder effect for both paternal and maternal lineages. Moreover, we report a close genetic link of Lakshadweep islanders with the Maldives, Sri Lanka and India. Most of the Lakshadweep islands share the haplogroups specific to South Asia and West Eurasia, except Minicoy Island that also shares haplogroups of East Eurasia. The paternal and maternal ancestries of the majority of island populations suggest their arrival from distinct sources. We found that the maternal ancestry was closer to South Indian populations, whereas the paternal ancestry was overwhelmed with the haplogroups, more common in the Maldives and North of India. In conclusion, our first genetic data suggest that the majority of human ancestry in Lakshadweep is largely derived from South Asia with minor influences from East and West Eurasia.

Women Enterprising in Seaweed Farming With Special References Fisherwomen Widows in Kanyakumari District Tamilnadu India

Seaweeds are not weeds as the name implies. But they are the renewable marine resources of value, growing well in shallow waters where suitable substratum for its growth exists. They are exploited from the south east coast of Tamil Nadu from Mandapam to Kanyakumari, Gujarat Coast, Lakshadweep islands and the Andaman and Nicobar Islands and few other places like Chilka and Pulicat. Seaweed collection renders extensive employment to the coastal fisher folk. The estimation of seaweed resources indicate that only a negligible quantity is harvested. At present nearly 5000 women depend on the seaweed industries for their livelihood. If the available resources are harvested to its optimal level, it can provide employment to another 20,000 coastal fisher folk in harvesting sector and an equal number in post-harvest activities. Since the domain of seaweed collecting industry is mainly dominated by women, special efforts should be taken for its optimum exploitation and market expansion through diversified product development and their popularization. Seaweed mariculture offers an economically sustainable livelihood option for fisherwomen, who, with little effort can contribute significantly to the household income. Today seaweed cultivation techniques have been standardized, improved and made economically viable. Corporate backed by institutional and financial support led to the expansion of seaweed farming, through Self Help Groups (SHG) model (mostly women). This paper deals with the employment potential of fisher women in seaweed industries and to evaluate the economic performance of seaweed farming, including the empowerment of fisherwomen widows in Muttom, Kanyakumari District of Tamil Nadu, India.

Sustainable desalination technologies: Avenues for cooperation in the Indo-Pacific

ABSTRACTDesalination technologies using ocean thermal energy are a sustainable method of producing fresh water, especially for ecologically fragile regions and small island nations. India has tested this technology in the Lakshadweep Islands and has the capability to share it with its Indo-Pacific partners. This paper explores the benefits, market and prospects of sustainable desalination technologies in the Indo-Pacific region. It outlines the possible multilateral platforms that can be used to share this technology and the various challenges that this endeavour faces. The paper concludes that such technology sharing will have a positive impact on regional integration and will strengthen India’s position as a responsible regional power promoting the blue economy.

Assessing rabies-free status of Andaman, Nicobar, and Lakshadweep Islands, India.

The Indian Islands of Andaman, Nicobar, and Lakshadweep have been historically rabies-free. However, reliable laboratory evidence to substantiate rabies-free status was lacking. In this background, the study was conducted as a component of the World Health Organization-Association for Prevention and Control of Rabies in India, Indian Multi-Centric Rabies Survey; to assess the rabies-free status of the two Islands and to examine the feasibility of initiating laboratory surveillance for rabies in dogs in Andaman, Nicobar, and Cats in Lakshadweep Islands. A team of medical and veterinary investigators visited these Islands in 2017. A review of 10 years records (2007-2017) in medical and veterinary institutes and interviews with different stakeholders were conducted. Based on the review of records, there was no evidence of human/animal rabies in the Islands. Eight dog brain samples from Andaman, Nicobar Islands, and ten cat brain samples from Lakshadweep Islands were tested negative for rabies by fluorescent antibody test at two rabies diagnostic laboratories at Bengaluru.

Feasibility analysis of renewable energy options for the union territory of Lakshadweep Islands

The power generation of most islands depends mainly on costly oil. Since the cost of energy is very high so these are the best test place for the implementation of the new technologies. We have considered the case of Lakshadweep Island which is one of a union territory of India. In Lakshadweep electricity is mainly generated from diesel generator sets. In this paper, an investigation has been made to find out total available potential of solar, wind and biomass in five islands of union territory of Lakshadweep. If we start generating up to the available potential then some islands will become renewable islands and this will increase the reliability, employment and decreases the cost of energy generation and pollution. Pearl and Logistic models have been used to find out the growth rate of SPV power generation. Using these models we find out that in how many years we will achieve the total available potential. After this, we have proposed a model of hybrid energy power generation for Kavaratti Island. The simulations and techno-economic evaluations have been done with the help of hybrid optimisation model for electric renewables software. Thousands of simulations have been carried out to achieve an optimal autonomous system configuration, in terms of system net present cost and cost of energy.

Understanding the Indian mainland–island biogeography through plant dispersal mechanism

The plant–disperser relationship and its key predictors in Indian tropical archipelagos are understudied. East of the Indian mainland (the Eastern coast, EC) are the Andaman and Nicobar Islands (AN, about 1221 km away at the shortest distance), which exhibit a great plant diversity, with 848 unique species. West of the Indian mainland (the Western Ghats, WG) are another group of islands, the Lakshadweep Islands (LD, about 320 km away at the shortest distance), which exhibit less diversity (102 unique species) than do the AN. We compared these two mainland–island pairs (EC–AN, WG–LD), which exhibit different insular isolation conditions, to understand the plant dispersal mechanisms and their determining predictors (plant richness, geographic area, perimeter, elevation, and shortest distance). We found epizoochory (adherence to an animal surface), ornithochory (birds), and hydrochory (water) to be the dominant dispersers of both the pairs. Additionally, the plant dispersal in the WG–LD pair is predominantly driven by anemochory (wind), possibly denoting the effects of the northeasterly trade winds. The major role of biotic dispersers in the EC–AN pair may be explained as resulting from plant dispersal to more remote islands through biotic dispersers being more rapid and efficient. The plant commonality was found to be positively correlated with the plant richness, geographic area, and perimeter; whereas it was negatively correlated with the shortest distance and elevation of the selected mainland–island pairs. Both linear (R2 = 0.85) and non-linear (R2 = 0.95) regression with maximum accuracy found island plant richness, geographic area, and shortest distance to the nearest mainland pool to be the determinants in explaining plant-dispersal mechanisms. These predictors are important to maintain the habitat suitability and connectivity and thereby support more newly dispersed plants. The plant–disperser relationship (epizoochory, ornithochory, anemochory, and hydrochory) and the key predictors (plant richness, geographic area, and shortest distance) found in this study could be useful for conservation, planning, and monitoring of biodiversity.

Implications of a regional-scale process (the Lakshadweep low) on the mesozooplankton community structure of the Arabian Sea

The Arabian Sea, a major tropical ocean basin in the northern Indian Ocean, is one of the most productive regions in the global ocean. Although the classical Arabian Sea ‘paradox’ describes the geographical and seasonal invariability in zooplankton biomass in this region, the effect of the Lakshadweep low (LL), a regional-scale physical process, on the zooplankton community has not yet been evaluated. The LL, characterised by low sea surface height and originating around the vicinity of the Lakshadweep islands during the mid-summer monsoon, is unique to the Arabian Sea. The present study investigated the effect of the LL on the zooplankton community. The LL clearly had a positive effect, with enhanced biomass and abundance in the mixed-layer depth of the LL region. Copepods and chaetognaths formed the dominant taxa, exhibiting strong affinity towards the physical process. Of the 67 copepod species observed, small copepods belonging to the families Paracalanidae, Clausocalanidae, Calanidae, Oncaeidae and Corycaeidae dominated the LL region. Phytoplankton biomass (chlorophyll-a) was the primary determinant influencing the higher preponderance of the copepod community in this region.

Compact high-gain composite horn antenna for space-borne beacon application

ABSTRACTThe growing interest in higher capacity communications satellite necessitates the development of compact and lightweight other antennas (such as beacon horn antenna) at Earth-viewing deck due to crowded accommodation and weight limitation. In this article, we describe an innovative and compact high-gain composite horn antenna for space-borne beacon application. We have designed, manufactured and measured beacon horn antenna operating from 10.7 GHz to 12.5 GHz. The beacon horn antenna is devised by combining stepped section at input, axial corrugated in mid and finally radial corrugated sections. This engineered multiple sections provide extra flexibility of optimisation, leading to high edge of coverage (EoC) gain for Indian mainland, Lakshadweep Islands and Andaman & Nicobar Islands. The radial corrugated section is specially profiled using multi-profile subsections. The mode-matching technique (MMT)-based software CHAMP and ‘minimax optimiser’ have been used to analyse and optimise the Beacon horn antenna. Manufacturing of the horn using a turning machine over aluminium alloy helps to reduce its cost. Characterisation of the beacon antenna confirm predicted electrical results (return loss> 17 dB, cross-polarisation discrimination < −40 dB, EoC gain > 24 dB). The Accommodation of the Ku-Beacon antenna on spacecraft is discussed with help of its near field from the scattering point of view and its tilt.

Description of a new species of Haminoea (Gastropoda: Cephalaspidea) from India, with an account of the diversity of the genus in the Indo-West Pacific

In this paper current knowledge on the diversity of the gastropod cephalaspidean genus Haminoea from India is revised. A comprehensive literature review was undertaken and novel specimens were collected. Specimens from India were DNA barcoded using the gene cytochrome c oxidase sub-unit I and a Bayesian gene tree together with an Automatic Barcode Gap Discovery (ABGD) species delimitation analysis were inferred to compare Indian samples with species from the Indo-West Pacific. The most comprehensive DNA data set to date of the genus Haminoea is included and new morpho-anatomical features of Indo-West Pacific species were generated through fine anatomical work and scanning electron microscopy. A critical appraisal of previous records of the country is included and a new species, Haminoea aptei sp. nov., is described from the Andaman Islands and Lakshadweep Islands, India.www.zoobank.org/urn:lsid:zoobank.org:pub:90C191A9-5CA6-4BC6-84E3-B1A26674FA1B

Agro-biodiversity and ethnobotany of Lakshadweep Islands of India

The Lakshadweep is a tiny landmass of 32 km2 area (8o–12oN, 71o–74oE) constituted by a group of 27 small atolls located in the Indian territory of Arabian Sea of Indian Ocean. Studies on crop genetic diversity including wild relatives of crop plants of the region are little known except for coconut palm. This report deals with 106 collections assembled in two exploration and collection missions comprising 46 plant species under 35 genera belonging to 24 families. The plant germplasm collected during the trips are mostly useful as vegetable, fibre, medicinal plant, dye, edible tuber, timber and ecosystem service provider. The crop wild relatives collected during the study include that of sunnhemp, melon, yam, jute, pigeon pea, sugarcane, etc. A set of germplasm accessions was sent to national research institutes for regeneration. Out of the total collection, 64 accessions were assigned with national identity (Indigenous Collection or IC numbers: IC 0572014 to IC 0572077), and conserved in long term storage at National Gene Bank or in the field gene bank of ICAR-NBPGR, New Delhi. The important germplasm assembled from the islands include highly pungent betel leaf and a large fruited noni. Plants of Cajanus scarabaeoides (L.) Thouars, bitter less Cucumis melo L. var. agrestis Naudin saline tolerant Canavalia cathartica Thouars, Vigna marina (Burm.) Merr. and Corchorus trilocularis L. were the unique wild relatives collected. The current report is the first of its kind on the exploration and collection of plant genetic resources (other than coconut) from Lakshadweep Islands. Wild melon accessions collected are currently employed in distant hybridization programs. During the survey, ethnobotanic information of 23 plants for medicinal and other uses was also documented. Novel uses of the native plant species in the islands indicate their potential for exploitation in other coastal ecosystems. This report aims to highlight the potential plant resources of the region for direct human use and in future breeding programs.

Relating abundance of purpleback flying squid Sthenoteuthis oualaniensis (Cephalopoda: Ommastrephidae) to environmental parameters using GIS and GAM in south-eastern Arabian Sea

The distribution pattern of purpleback flying squid and the relationship between its abundance and environmental variables in the south-eastern Arabian Sea were analysed using a geographical information system (GIS) and a generalised additive model (GAM). Highest abundances were observed during December and January within 10 and 13°N and 71 and 72°E around the Lakshadweep Islands. The mean abundance in the area was 4.21 tonnes/km2 and the maximum sustainable yield (MSY) was estimated as 0.63 million tonnes. GAM indicated that very high squid abundance was associated with low values of dissolved oxygen (6.01–6.27 mg/L), sea surface temperature (28.03–28.62°C), pH (7.75–8.56), salinity (30.42–34.48 psu), chlorophyll-a (0.4–0.6 mg/m3), zooplankton biomass (0.23–0.64 mL/m3), and shallow 20°C isotherm (101.2–134.7 m) and mixed layer depth (17.8–29.8 m). As a carnivore from paralarval stages, S. oualaniensis depends on secondary and tertiary production to sustain its population for which primary production is used up. In the tropical Arabian Sea where temperature differences are not so pronounced, S. oualaniensis distribution was found to be related to a low but very narrow sea surface temperature (SST) band. There is sufficient fishable biomass in the area to possibly launch a new targeted oceanic squid fishery from the western seaboard of India.

Length-weight analysis of three needlefish species from the Lakshadweep archipelago

Length-weight relationships (LWRs) of three needlefishes belonging to the family Belonidae viz., Ablennes hians, Tylosurus crocodilus and Tylosurus acus melanotus were estimated based on samples exploited from a gill-net fishery in Androth, an island in the Lakshadweep archipelago. The estimated allometric co-efficient b value ranged from 3.047 (T. acus melanotus) to 3.274 (A. hians), and r2 value ranged from 0.911 (T. acus melanotus) to 0.973 (A. hians). The first estimate of LWR for these three commercially exploited needlefish species from the Lakshadweep islands indicate local populations to be fairly robust and forms a basis for future management of fishing stock in the region.

Conidae (Mollusca, Gastropoda) of Lakshadweep, India.

Lakshadweep, the northernmost region of the Chagos-Maldives-Lakshadweep group of islands located southwest of the Malabar coast of India in the Arabian Sea, is the only chain of coral atolls in India. This paper documents the diversity of the molluscan family Conidae from the seas around all ten inhabited islands of Lakshadweep. Of the 78 species of cone snails now reported from Lakshadweep, 49 were recorded in this study. Threeof these had not previously been reported from India, and four are newly reported from Lakshadweep. The results increase the number of Conidae species known from Lakshadweep by 10%.

Calcareous sponges of the Western Indian Ocean and Red Sea.

Past taxonomic studies of Western Indian Ocean and Red Sea Calcarea have been few and sporadic (e.g. Schuffner 1877, Jenkin 1908, Row 1909, Dendy 1913, 1916, Voigt et al. 2017, 2018). Nevertheless, approximately 70 species are known from these studies for the considered region, but the descriptions of the older records often lack sufficient details for reliable identification. We studied the Western Indian Ocean Calcarea collection kept in the Naturalis Biodiversity Center. Available specimens numbered 145, collected in the Red Sea, Seychelles, Maldives, Mayotte and Rodrigues, in addition to incidental samples from Oman, the Lakshadweep Islands, the Mozambique Channel, and Eastern South Africa. Using a combination of techniques (in situ and 'on deck' photography, detailed field notes, light microscopic studies and measurements, SEM microscopy, and selected DNA sequencing) we identified 45 species, divided over the two main classes Calcinea (24 spp.) and Calcaronea (21 spp.). Not all species could be definitely assigned to an already described or a new species, as seven remained qualified as 'spec.' or 'aff.' for reasons of insufficient material or lack of details of in situ habitus. Sixteen species appeared to be new to science: Borojevia voigti sp.nov., Borojevia tubulata sp.nov., Borojevia pirella sp.nov., Clathrina rodriguesensis sp.nov., Clathrina maremeccae sp.nov., Clathrina repens sp.nov., Leucascus schleyeri sp.nov., Leucetta sulcata sp.nov., Ute insulagemmae sp.nov., Leucandra pilula sp.nov., Leucandra mozambiquensis sp.nov., Grantessa woerheidei sp.nov., Sycettusa hirsutissima sp.nov., Vosmaeropsis glebula sp.nov., Paraleucilla erpenbecki sp.nov., and Kebira tetractinifera sp.nov. For a selection of the identified species from the Western Indian Ocean and the Red Sea (30 spp.), as well as from Indonesian material (22 spp.) published previously (see Van Soest De Voogd 2015) we obtained sequences of the partial 28S gene of nuclear rDNA (C2-D2 region, cf. Voigt Wörheide 2016). The sequences of the Western Indian Ocean and Red Sea species were used to assign these to genera and families based on a phylogenetic analysis using MEGA pack vs. 06.6 for Mac of the available dataset. The Indonesian sequences supplemented by partial 28S sequences taken from the Sponge Barcode Project website and the NCBI website were included in the phylogenetic analysis to confirm the assignments. The results were compared and discussed with additional information on regional Calcarea not represented in our material. The latter chapter yielded the discovery of a preoccupied name leading to Sycon oscari nom.nov. for a species described from Mauritius.

Constraint Analysis of Livelihood Systems in Coral Ecosystem

To secure people's livelihood security, it is important to determine the inhibiting factors so that necessary interventions may accordingly be made to create a conducive climate for them. A study was conducted in Lakshadweep islands of India to evaluate various constraints for sustainable livelihood approach. Respondents were classified into three livelihood classes based on their livelihood options. Results of the study showed that personal constraints followed by economic, promotional and infrastructural constraints were significantly different among people engaged in different livelihood options. Ecological and social constraints were not significantly different among groups. Multiple comparison of different groups showed that people depending on non-farm sector only (group 2) and those engaged in both farm and non-farm sector (group3) were on par regarding personal, economic and promotional infrastructural constraints.