Kavaratti Island Research Articles

Successful establishment of a coral nursery for active reef restoration in Kavaratti Island, Lakshadweep archipelago

Successful establishment of a coral nursery for active reef restoration in Kavaratti Island, Lakshadweep archipelago

Environmental and ecological risk of microplastics in the surface waters and gastrointestinal tract of skipjack tuna (Katsuwonus pelamis) around the Lakshadweep Islands, India.

The presence of microplastics (MPs) in marine ecosystems is widespread and extensive. They have even reached the deepest parts of the ocean and polar regions. The number of articles on plastic pollution has increased in recent years, but few have investigated the MPs from oceanic islands which are biodiversity hotspots. We investigated the possible microplastic contamination their source and characteristics in surface waters off Kavaratti Island and in the gastrointestinal tract (GT) of skipjack tuna, Katsuwonus pelamis collected from Kavaratti Island of the Lakshadweep archipelago. A total of 424 MP particles were isolated from the surface water samples collected from off Kavaratti Island with an average abundance of 5 ± 1nos./L. A total of 117 MPs were recovered from the GT of skipjack tuna from 30 individual fishes. This points to a potential threat of MP contamination in seafood around the world since this species has a high value in local and international markets. Fiber and blue color were the most common microplastic morphotypes and colors encountered, respectively, both from surface water and GT of fish. Smaller MPs (0.01-1mm) made up a greater portion of the recovered materials, and most of them were secondary MPs. Polyethylene and polypropylene were the most abundant polymers found in this study. The Pollution Load Index (1.3 ± 0.21) of the surface water and skipjack tuna (1 ± 0.7) indicates a minor ecological risk for the coral islands, while the Polymer Hazard Index highlights the ecological risk of polymers, even at low MP concentrations. This pioneer study sheds preliminary light on the abundance, properties, and environmental risks of MPs to this highly biodiverse ecosystem.

A new species of spiny eel of the genus Notacanthus Bloch 1788 (Notacanthiformes: Notacanthidae) from the Indian Ocean.

The deep-sea spiny eels of the genus Notacanthus Bloch 1788 are currently represented by six valid species, of which only one, Notacanthus indicus, has been described so far from the Arabian Sea, part of the Western Indian Ocean. This paper reports the discovery of a new species, described herein as Notacanthus laccadiviensis, from the outer reef drop-off, off the Kavaratti Island, Lakshadweep Archipelago, Arabian Sea. The new species differs from its congeners in the shape of the head; morphology of dorsal, pectoral and anal fins; number of gill rakers; number of vertebrae; and body colour, and specifically from N. indicus (the only known congener from the Indian Ocean) in the unusual morphology of the dorsal fin, and number of rays in the dorsal and pectoral fins.

Seven new distributional records of cryptobenthic reef fishes in Lakshadweep, India

Abstract Investigations on the diversity of cryptobenthic reef fishes resulted in observation of seven new geographic records for Lakshadweep waters, India: halfbarred goby Amblygobius semicinctus, target shrimpgoby Cryptocentrus strigilliceps, thread shrimpgoby Ctenogobiops mitodes, eye-bar goby Gnatholepis anjerensis, Miki's dwarfgoby Eviota mikiae, Erythrops goby Bryaninops erythrops, and Enneapterygius sp. Ctenogobiops mitodes is a new record to Indian waters. The genera Cryptocentrus and Bryaninops are reported from Lakshadweep for the first time. The observations were conducted in the lagoon and reef slope of Kavaratti Island, one of the 12 atolls of the Lakshadweep archipelago, from January–March 2021. The cryptobenthic reef fishes were observed and recorded through underwater photography and videography.

Heavy metals in coral reef sediments of Kavaratti Island, India: An integrated quality assessment using GIS and pollution indicators

The present study aims to document the contamination levels and ecological risks of heavy metals in the sediments of Kavaratti lagoon, India. A total of 15 sediment samples were collected for the analysis of Al, Pb, Cd, Cu, Cr, Mn, Ni and Zn. The decreasing trend of heavy metals was observed in the lagoon sediment as Pb > Zn > Al > Mn > Ni > Cr > Cd > Cu. The Geo-accumulation index (Igeo) results indicate that Cu, Cr, Mn, Ni and Zn were uncontaminated, while Cd was strong to extremely contaminated and Al and Pb were moderately contaminated. The enrichment factors (EF) of Cd and Pb range from moderate to extremely high (EF > 1) indicating that they have anthropogenic origin on Kavaratti Island. The Contamination factor (Cf) indicated that Cd, Pb and Al belong to a high risk of contamination (Cf > 6). The pollution load index (PLI) value near one suggested that a moderate level of pollution occurs in the study area. The modified degree of contamination (mCd) shows that Al, Cd and Pb have an ultra- higher degree of contamination (mCd ≤ 32). The potential ecological risk (RI) index confirmed that Pb and Cd have considerable to the serious thread of ecological risk (RI > 600). Additionally, multivariate statistical analysis and pollution indexes showed that the Kavaratti lagoon is moderate to considerably polluted by heavy metals. Diesel-based power generation, activities related to shipping, untreated sewage, fishing and tourism activities are the main anthropogenic sources of heavy metal pollution on Kavaratti Island.

Two new species of the codling fish genus Physiculus from Lakshadweep, India (Gadiformes: Moridae).

The genus Physiculus is widespread in the Indo-Pacific with more than 32 valid species, and about 12 species were recorded only from the Indian Ocean. Two new species similar to each other are collected from the outer reef drop off of Kavaratti Island, Lakshadweep, India, Arabian Sea and described. Physiculus indicus sp. nov. is characterised by its light organ situated at about the middle of pelvic-fin base and anus, a small light organ, a rather forward situated anus, no scales on the gular region, dorsal-fin rays 89+5660, anal-fin rays 5560, and 52 vertebrae. This species differs from nearest congeners in lacking gular scales, anus situated closer to the light organ and slightly fewer total vertebrae. Physiculus lakshadeepa sp. nov. is characterised by a relatively high first dorsal fin (51.762.8% HL) and a light organ situated at the middle of the pelvic-fin base and anus. It has a small light organ, a rather forward situated anus, no scales on the gular region, dorsal-fin rays 89+5159, anal-fin rays 5359, and 49 vertebrae. Physiculus lakshadeepa differs from the nearest congeners in lacking gular scales, fewer anal-fin rays and fewer total vertebrae.

Numerical modelling approach for the feasibility of shore protection measures along the coast of Kavaratti Island, Lakshadweep archipelago

Numerical modelling approach for the feasibility of shore protection measures along the coast of Kavaratti Island, Lakshadweep archipelago

First Record of Deepwater Scorpionfish Phenacoscorpius adenensis (Teleostei: Scorpaenidae) from India, Central Indian Ocean

Phenacoscorpius adenensis Norman 1939, a rare deepwater scorpionfish was collected from Kavaratti Island, Lakshadweep Archipelago, and reported for the first time from the Central Indian Ocean and Indian waters. P. adenensis, which is morphologically similar to many closely related species, is described, and the specimen is preserved, catalogued and kept in reference museum.

Fine-scale spatial and temporal acoustic occurrence of island-associated odontocetes near a mid-oceanic atoll in the northern Indian Ocean

Temporal patterns of oceanic predators can provide valuable information on both lunar and diel influences not just on the distributions of these predators, but also on prey patches that are often difficult to study. Mid-oceanic island chains in the northern Indian Ocean have high odontocete occurrence, but the ecology of these animals is not well characterized. We investigated fine-scale spatial and temporal patterns of island-associated odontocetes using passive acoustic monitoring from January 2019 to January 2020 around Kavaratti Island, Lakshadweep, India. Based on opportunistic recordings in the presence of odontocetes, the majority of the detected whistles were likely made by spinner dolphinsStenella longirostris. We identified a resident population whose whistle occurrence was significantly influenced by month, site, and diel and lunar cycles. More acoustic detections were made in the northeast monsoon month of November and fewer during pre-monsoon and southwest monsoon periods. Distinct day-night differences along with fine-scale temporal variability were also observed, suggesting that delphinids use nearshore waters as a daytime resting habitat. Odontocete detections were highest during the new moon period and lowest during the first quarter phase. Detection rates were higher on the south side of the island. Our study shows that solar and lunar cycles modulate odontocete vocal occurrence, presumably through influences on their prey. Similarities of odontocete occurrence around Lakshadweep to other mid-oceanic island chains suggests that an island-associated micronekton community may exist around Lakshadweep that may also be important to other pelagic species targeted by local fisheries.

Environmental influences on zooplankton diversity in the Kavaratti lagoon and offshore, Lakshadweep Archipelago, India

The present study aimed to analyse the influence of physico-chemical properties on zooplankton assemblages and species diversity in a lagoon system. The study was carried out in coral reef lagoon of Kavaratti Island, Lakshadweep Archipelago, India during the monsoon of the year 2017. Zooplankton assemblages, distributed among 56 taxonomic units, were found to be dominated by copepods (63.27%, 34 taxa) followed by cladocerans (11.14%, 7 taxa), ostracods (9.87%, 2 taxa), ciliates (6.23%, 6 taxa), chaetognaths (4.32%, 3 taxa), leptomedusae, (1.25%, 1 taxa), and appendicularians (3.92%, 3 taxa). Copepods assemblages showed maximum density of 14326 ind m−3 from S1, in which leptomedusea was the lowest abundant taxa (284 ind m−3). Shannon–Wiener-index between 3.725–3.860 attested to the fact that the species diversity and richness predominated in lagoon than that in offshore. Canonical Correspondence Analysis revealed the environmental parameters influencing the abundance and occurrence zooplankton community in the study area.

Seasonal variability of groundwater quality in coastal aquifers of Kavaratti Island, Lakshadweep Archipelago, India

Lakshadweep Archipelago is comprised of several tiny coral atolls and scattered in the Arabian Sea off the south-west of India. Ground water is the only available fresh water resource for the islanders. The groundwater quality is decreased in this island due to population growth and anthropogenic activities like sewage dumping and agricultural activities. For this study, a total of 20 groundwater samples was collected randomly from the open wells that cover the entire area of the island. The physico-chemical parameters of groundwater were analysed in pre- and post-monsoon seasons during the year 2016–2017. The concentration of a majority of the chemical constituents exceeds the standards of WHO during post-monsoon than pre-monsoon season. EC content exhibited the violation of drinking water quality standards. The highest value of EC range 1023–6874 μS/cm recorded in post-monsoon than pre-monsoon. TDS concentration range from 574.6 to 1503.4 mg/l and 665–4468 mg/l in pre and post-monsoon seasons. Geochemical evolution diagram categories the groundwater facies into Na+-K+-Cl--SO42-, Ca2+-Mg2+-HCO3-, and Ca2+-Mg2+-Cl--SO42- in both seasons. Gibbs plot revealed that the evaporation is the dominant factor controlling the mechanism of ground water hydrochemistry. The water quality index suggested that both pre-monsoon and post-monsoon around 93.95% of the samples are unsuitable for drinking purposes. The suitability of groundwater for irrigation was studied by calculating the percent of sodium, sodium adsorption ratio, magnesium hazard and Reveille's index. The Wilcox and USSL plots also indicated that most of the groundwater samples are found to be unsuitable for irrigation. HFE diagram productively delineates that groundwater of the study area has strong influence of sea water in the fresh water aquifers. The highest level of significant correlation was observed between Mg-TH (r = 0.87), EC-TDS (r = 0.86), and Cl–Na (r = 0.77) respectively. As a whole, it is observed that the groundwater is not suitable for drinking, irrigation and industrial purposes due to the exceeding of chemical parameters from their standard limits. Therefore, groundwater management measures may be worked out regionally to improve water quality by artificial recharge, rain water harvesting, periodic disinfection of the wells and saving the fresh water stocks in the island accordingly.

Spatial Distribution and Contamination Assessment of Trace Metals in the Coral Reef Sediments of Kavaratti Island in Lakshadweep Archipelago, Indian Ocean

ABSTRACT Surficial coral reef sediments collected from 17 sampling stations (shore, lagoons, and outer lagoons) of Kavaratti, Island belonging to Lakshadweep Archipelago were analyzed for trace metal concentration, total organic carbon and sediment grain size composition. The predominant grain size constituent of sediments from the sampling stations was medium sand with low organic carbon content. Except Cd and Pb, all the other trace metals selected for the study were below their global average shale concentration. The sediment contamination was assessed on the basis of geochemical and ecological risk indices. Considerable contamination and significantly high ecological risk were reported from all stations and the serious threat was from Cadmium. Diesel-based power generation, untreated sewage, activities related to shipping, fishing, agriculture, and tourism are the main anthropogenic sources contributing to trace metal pollution in Kavaratti. Statistical analysis of the data also supported the anthropogenic sources of origin of trace metals.

Impact of the tropical cyclone Ockhi on ecological and geomorphological structures of the small low-lying Islands in the Central Indian Ocean

Ockhi, was an intense tropical cyclone that devastated parts of Sri Lanka and India in 2017 and was the most intense tropical cyclone in the Arabian Sea, Central Indian Ocean, since Cyclone Megh in 2015. The ninth depression, and the third and strongest named storm during 2017, North Indian Ocean cyclone season, Ockhi, originated from an area of low pressure that formed in the eastern Andaman Sea on November 21, 2017. Here we describe the impacts of Ockhi on benthic coral reef assemblages of an atoll island directly in the path of the cyclone. We assessed the effect of the cyclone in the reefs around Kavaratti Island, by comparing the data from recent pre-Ockhi documentation with its present status. The study provided a unique opportunity to identify and describe the impacts of an intense tropical cyclone on reefs of a small low lying island in the Central Indian Ocean, which is often assumed to be vulnerable to physical disturbance due to their poorly lithified framework. For the present study, the entire Kavaratti atoll was demarcated into three zones (lagoon, western outer reef, and eastern outer reef), and data was gathered from 29 pre-fixed stations. Observed impacts of Ockhi were site-specific and spatially highly heterogeneous, but appeared to have been strongly influenced by the level of exposure, the site received, and the biological make-up of individual reefs sites. Live coral cover on western reefs had a considerably lower impact due to the shelter provided by the land and the trends in the substrate composition before and after Ockhi is almost similar. However, drastic devastation was observed in the eastern reef system, after the Ockhi event. The combination of repeated, intense cyclonic activities and mass bleaching events will act together to significantly hamper the rapid recovery of these reefs and also adversely affect the livelihood of the community.

Spatial variation of phosphorus fractionation in the coral reef sediments of Lakshadweep Archipelago, Indian Ocean

ABSTRACTSurface sediments were collected from the shore and lagoons of Kavaratti, Kadamat and Agatti islands of Lakshadweep Archipelago during May 2015 and analysed for the spatial distribution of the micronutrient element, phosphorus. Phosphorus was separated by sequential extraction procedure into five fractions – exchangeable (Ex-P), iron bound, (Fe-P), calcium bound (Ca-P), organic and residual fractions (OP) and total phosphorus (TP). The average relative contribution of each P species to TP was: OP > Ca –P > Ex – P > Fe – P. The high concentration of organic and residual phosphorus (87–96%) compared to inorganic phosphorus is particularly evident at stations characterised by higher total phosphorus concentrations. Among the three forms of IP in the sediments, Ca-P was dominant at all stations. The OC/OP ratio ranged from 3 to 163 in the sediments, suggesting that the organic matter in sediments had been subjected to degradation. Hence, the major contribution towards organic and residual phosphorus form is from the residual fraction comprising biologically resistant or non-available phosphorus form composed of refractory materials. The concentration of phosphorus reported in the present study is higher than that of the earlier studies in Lakshadweep, indicating a terrestrial and anthropogenic influence on the sediment.

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.

First record of the rare Furry Lobster Palinurellus wieneckii (De Man, 1881) (Decapoda: Palinuridae) from the Arabian Sea

Two female specimens of the Furry Lobster Palinurellus wieneckii (De Man, 1881) with a total length of 118mm and 114mm, respectively, were obtained from the coral reefs off Kavaratti Island, Laccadive Islands, west of India. Only two species are currently recognized in this genus, which were described from a small number of specimens. As P. wieneckii is very rare, the present report from the Lakshadweep Archipelago provides a valuable new distribution point, which is the first record for the Arabian Sea. Illustrations and photographs are provided for this rare lobster.

Haemolyticanaemia in Kavaratti island, Lakshadweep: A hospital based study

Background: Anaemia is a major public health problem in developing countries like India. Kavaratti island, Lakshadweep is a remote island located in Arabian sea. There is extreme paucity of data on the type of anaemia here. Objective of this study is to take an in depth look at the various etiologies of anaemia at Kavaratti island, Lakshadweep. Methods: A total of 4526 patients were studied. Data from the anaemic individuals was collected and analyzed. The study group was subsequently divided into smaller subgroups on the basis of age and sex for analysis. The aetiology of anaemia in these cases was further investigated. Result: The prevalence of anaemia in adult males was 21.5% and in females 37%. In pregnant females anaemia was still more common (47.5%). Among children 24.6% were anaemic with female children showing higher percentage (27.4%) than males (22.9%). Anaemia was quite common in the elderly and even higher in elderly females (43%). However, the most significant finding was the high prevalence of haemolytic anaemias especially sickle cell anaemia. Conclusion: Anaemia is not a major public health problem in Kavaratti island, Lakshadweep. However, there is high prevalence of haemolytic anaemias especially sickle cell anaemia. Nutritional anaemia is quite rare. This fact may have major implications for health policy makers.DOI:10.21276/APALM.1673

Prevalence of disease vectors in Lakshadweep Islands during post-monsoon season.

: Increase of vector-borne diseases (VBDs) in India has posed a question on the situation in Lakshadweep Islands, where VBDs are reported from time-to-time. The present investigation was aimed to assess the faunastic situation of the prevailing vectors along with their breeding sites in different islands of the Lakshadweep. : Extensive surveys were carried out from November 2017 to January 2018 (post-monsoon season) randomly in the nine inhabited islands of Lakshadweep for conducting faunastic studies on mosquitoes and to know the basic binomics like breeding and resting preference of mosquitoes. The study islands included, Kavaratti, Agatti, Chetlat, Bitra, Amini, Kadmath, Andrott, Kalpeni and Kiltan. Both immature and adult collections were carried out by standard/appropriate sampling techniques. The obtained data were calculated and analysed in terms of different entomological indices. : A total of 3356 mosquitoes were collected during the study period which comprised of 16 species from nine genera. Out of the 16 species, six belonged to mosquito vectors. The collection included malaria vector, Anopheles stephensi; Japanese encephalitis vector, Culex tritaeniorhynchus; Bancroftian filariasis vector, Cx. quinquefasciatus; Brugian filariasis vector, Mansonia uniformis; and dengue and chikungunya vectors, Stegomya albopicta and St. aegypti. Stegomya albopicta was the most predominant species observed constituting 54% of the catch, followed by Cx. quinquefasciatus, An. stephensi, Cx. tritaeniorhynchus, and St. aegypti constituting 10.5, 6, 3 and 1.2%, respectively. Apart from vector species many non-vectors such as Heizmannia chandi, An. subpictus, An. varuna, Cx. sitiens, Cx. minutissimus, Cx. rubithoracis, Fredwardsius vittatus, Lutzia fuscana, Malaya genurostris and Armigeres subalbatus were also present in the study area. In Kavaratti Island, the capital of Lakshadweep, a non-vector species of sandfly, Sergentomyia (Parrotomyia) babu was observed during the indoor resting collection. The major breeding sites which supported various mosquito species included, discarded plastic containers, tree holes, open sintex tanks (water storage tanks), unused wells, discarded tyres, discarded iron pots, unused and damaged boats, cement tanks, pleated plastic sheets, coral holes, pits and irrigation canals, discarded washing machines, and Colocasia plant leaf axils. Breteau index ranged between 65.3 and 110, CI ranged between 63.64 and 72.41; and HI ranged between 38.46 and 70 among the various islands. : Entomological indices such as house index (HI), breteau index (BI) and pupal index (PI) were high in all the nine islands and exceeded the threshold levels specified by WHO, indicating high risk for dengue virus transmission in case of outbreaks. Occurrence of vector as well as non-vector species indicates that the global change in climate is causing notable changes in terms of breeding of vector and non-vector species in the islands. With the reported cases of VBDs and the presence of vectors species in Lakshadweep Islands, a stringent control measure needs to be implemented at the Lakshadweep Islands.

Assessing abundance and catch selectivity of Octopus cyanea by the artisanal fishery in Lakshadweep islands, India

Subsistence fishery for cephalopods contributes significantly to the local economy of several Asian, African and island states. In addition to being unregulated and undocumented, recent studies indicate that low-scale fisheries can have detrimental effects on marine ecosystems. In the Lakshadweep islands, men, women and children have been involved in spear fishing for octopus for a long time, but there is a paucity of information on the biology and fishery of the octopus species in Indian waters. In this study, we estimated the population abundance, morphometry and sex ratio of Octopus cyanea. Moreover, we examined whether the current octopus spear fishing activity displayed size or sex selectivity, given that larger individuals are easier to spot and brooding females spend more time in crevices. O. cyanea surveys were conducted by snorkeling in the lagoons of Kavaratti and Agatti islands between November 2008 and April 2012. The estimated mean density of O. cyanea was 3 and 2.5 individuals per hectare in Agatti and Kavaratti, respectively. Individual mean weight was 923.36 g and 846.26 g in Agatti and Kavaratti and the male:female sex ratio 1.35:1 and 3.8:1, respectively. Comparison between visual counts and fisheries landings indicated that fishing effort was concentrated in areas of high juvenile abundance but without female-bias. Constructing a long-term database of fishery catches will help with stock assessment and understanding the factors that influence octopus populations. Implementation of a lower size limit of 500 g would act as a precautionary measure against catching very small octopuses.

"Lack of Popularity of Newspapers in Lakshadweep "

We live in an information age where the media has transformed the world into a global village. However it would come as a surprise to many that even in this twenty first century there are isolated pockets in India such as Lakshadweep without adequate newspaper reach, lacking timely newspaper coverage of local issues. The social implications of such glaring inequalities are striking.This study seeks to shed new light on a hitherto sidelined issue which has a lot of significance. The specific objectives of the study are to analyse the lack of popularity of newspapers in Lakshadweep, to study the media habits and media preferences of the islanders and to study the coverage given to local Lakshadweep issues in newspapers.The survey method was utilized to collect data required for the study. It was conducted only in the Kavaratti islands, the capital of Lakshadweep The following reasons are noted for the lack of popularity of newspapers in Lakshadweep. Delay in getting newspaper in time, Lakshadweep local news do not get adequate coverage in newspapers, Regular newspaper readers are less in number, subscribers of newspaper are less in number, few people depend on newspaper for breaking news, After the arrival of electronic media, the natives gradually shifted to electronic media for news. Very few people (4%) prefer newspapers for information purposes, while the vast majority depend on Television. In a region populated by scheduled tribes there is a pressing need to enhance their public awareness, to strengthen democracy at the grassroots and gain a better understanding of media habits in such isolated areas. This exploratory study has thrown fresh light on media coverage and media habits of such marginalised communities. The study is confined to only one island Kavaratti, the capital of Lakshadweep. Perhaps in future more detailed studies on such topics need to be undertaken keeping in mind their social relevance.