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Cyclones tracking northward across the Bay of Bengal represent a significant threat to life and safety when they make landfall. Surface moorings of the Ocean Moored Network for the Northern Indian Ocean in the Bay of Bengal have been deployed to provide real-time observations in support of improved alerts and predictions of cyclones. Engineering goals are both to develop robust surface moorings that survive and to field meteorological and oceanographic instruments that reliably provide data in real time. While the mooring design and reliability were previously reported, the focus here is on the motivations for installing the instrumentation, and on experience gained during the passage of cyclone Amphan in May 2020, examining the sensor as well as mooring performance. The paper presents reasons for fielding the chosen sensors, merits, and shortcomings during the effort to observe Amphan, and recommendations for how to better address the challenges of providing real-time observations of cyclones in the Bay of Bengal. [ABSTRACT FROM AUTHOR]

Dominant discourse on India's eastern Partition (1947) has constructed settlement as a masculine prerogative and man as the settler prototype. Women were eligible for rehabilitation on account of being "attached" to a male guardian, who would be assigned the head of the household in granting state benefits. In the case of these attached settler women transported by the state to Andaman Islands, a range of marginalities-region, gender, caste, and class-intersect with each other to create a veiled figure. The essay locates the settler women in the island's post-colonial government archive to bring out the state's construction of gendered settler subjecthood. By pushing the industrious settler women into the peripheral category of attached women, the state's rehabilitation machinery and the island administration made invisible the range of rehabilitation services performed by them. This statist representation of the settler women, seemingly devoid of any agency, is challenged by a deep reading of the archival material focused on highlighting articulations of settler subjectivity. Even after granting the attached women full citizenship, the newly independent post-colonial Indian state continued to treat women as non-actors in this particular trajectory of rehabilitation. Scholars have observed the swift disappearance of women from the state's archives as the focus shifts from the event of Partition to the process of rehabilitation, which this essay interrogates by using previously unexplored archival material to study the representation of attached settler women and their role in the statist schema of settling the heteronormative family, the islands, and the nation. By reading the archival material against the grain and identifying evidence against a statist representation, the essay interrogates the settler women's position as peripheral subjects at the margins of nation. Finally, the essay uses these archival traces to argue for the central position of settler women in the rehabilitation of settler families in the Islands. [ABSTRACT FROM AUTHOR]

Plastic particles have emerged as a growing threat to both ecosystems and human well-being, as they are being ingested and accumulate at different trophic levels. However, microplastic and mesoplastic contamination and its risk to coastal and marine water fish have not been well studied, particularly in the northern Bay of Bengal. In this study, the presence of small-scale plastic particles (micro- and meso-sized) in the gastrointestinal tract (GIT) and muscles of six edible fish species from the northern Bay of Bengal Coast were identified and analyzed. The overall range of microplastics was 1.74 ± 0.23–3.79 ± 2.03items/g in muscle and 0.54 ± 0.22–5.96 ± 3.16 items/g in the GIT, with 16.38 ± 8.08–31.88 ± 12.09 items/individual. No mesoplastics were found in muscle tissue, but they were present in the GIT at concentrations ranging from 0.33 ± 0.27 to 0.03 ± 0.02 items/g and from 0.51 ± 0.05to 1.38 ± 1.01 items/individual. Lepturacanthus savala accumulated the most microplastics in muscle, and Harpadon nehereus had the least. In addition, the highest levels of mesoplastics were detected in the GIT of Polynemus paradiseus and the lowest was detected in the GIT of Lutjenus sanguineus. Omnivorous fish showed higher plastic concentrations than carnivorous fish, which was linked to dietary habits, feeding strategies and digestive processes. Plastic material predominantly accumulated in the GIT rather than in the muscle. The majority of ingested plastic particles were fibres (95.18 %), were violet in color (34 %), and were < 0.5 mm in size (87 %). The dominant microplastic polymers included 38 % PE, 15 % PP, 33 % PU, and 14 % CES. In contrast, the prevalent mesoplastic polymers comprised 45 % PE, 19 % PP, 13 % PS, 16 % PA, and 7 % PET. Subsequently, a hazard analysis using the polymer hazard index (PHI) revealed that plastic contamination was of distinct hazard categories for different polymer types, ranging from grade I (<1) to grade IV (100−1000). The assessment of the contamination factor (1 < CF < 3) and pollution load index (PLI > 1) indicated moderate contamination of fish by the ingestion of plastic debris. This study provides the foremost evidence for the presence of mesoplastics and microplastics in coastal and marine fish in the study region, paving the way for future investigations and policy implementation. • Plastic particles in six marine and coastal fishes were determined from the Bay of Bengal. • Identified particles revealed variations by species, dietary habits and organ specificity. • Majority were fibres that are violet in color and small in size (<0.5 mm). • Polymer types were diverse with PE, PU and PP being dominant. • Distinct hazard categories ranging from minor to dangerous levels were identified. [ABSTRACT FROM AUTHOR]

Warm saline water masses emanating from the Persian Gulf (PG) and the Red Sea (RS) spread across a large area of the northern Indian Ocean upper layers, affecting the thermocline stratification, the circulation, and the air-sea exchanges over the Arabian Sea (AS) and Bay of Bengal (BoB). To explore the significance of these waters, we use numerical simulations to investigate the impact of isolating (closing) the RS and PG. The results show that the differences between the model runs, with and without the RS and PG, have marked effects on the AS and BoB seasonal variability. As expected, the major differences are concentrated in the surface mixed layer and thermocline of the AS. However, differences are also found further east in the BoB, mainly during the boreal summer. Significant differences are present in the air-sea freshwater and heat fluxes calculated by the model. In addition to the seasonality, there are significant interannual variability, with possible correlation with the El Nino-Southern Oscillation. Results of the experiments suggest that the upwelling in the Sri Lanka Dome, in the southwestern Bay of Bengal, would have responded differently to the 2009-2010 El Niño-La Niña in the absence of PG and RS input. [ABSTRACT FROM AUTHOR]

Bangladesh hosts most of what is left of Indian Skimmer (Rhynchops albicollis) populations, a globally endangered species. Each October-March from 2015-2020, 21 surveys of nonbreeding birds were made in Nijhum Dweep National Park, Bangladesh. High tide or evening roosts were counted from vantage points whenever a buildup or breakdown of skimmer concentrations was noticed, and site use noted by marking all observations of presence and activity on maps. The largest single count was 3,108 skimmers on 18 February 2020, constituting 30-50% of the known global population. Indian Skimmers mostly occurred in Damar Char West and at the tip of the Majher Char. Throughout the day with incoming tide, skimmers moved between preferred roosting areas to forage in the shallows. We describe a unique group-foraging strategy in which skimmers chase fish from deep water to shallow water along the shoreline. Circling high over the tidal channel, the flock of skimmers dives down in unison to just above the water surface, then spreading like a net towards the shore. Raptors caused disturbances to roosting skimmers, and we observed one instance of predation of a skimmer by a White-bellied Sea Eagle (Haliaeetus leucogaster). Human fishing activities disturbed nearshore foraging and shoreline roosting skimmers. We suggest protecting Damar Char West by regulating human activities to minimize disturbance from December to March. [ABSTRACT FROM AUTHOR]

Geopolitically and geo-strategically, Myanmar and Thailand are two important countries in the heart of Southeast Asia. Both states are also active members of the Association of Southeast Asian Nations (ASEAN), the Bay of Bengal initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) and Greater Mekong Subregion Economic Cooperation. The 2011 elections in Myanmar have created a lot ot investment potential since the beginning of the democratic government. On the other hand. huge amount of gas and electricity are needed to sustain Thailand's economic growth. One of the biggest sources is Myanmar. Also, Thailand is the third largest investor in Myanmar. Thailand's investment in Myanmar in the 2018-2019 fiscal year is US $6.6 billion. At the same time, the bilateral trade between Thailand and Myanmar is US $5.4 billion. Myanmar is key to implementing Thailand's"Look West Policy" to expand trade and commerce in Asia and Europe, including ASEAN. On the other hand, Myanmar is the connecting point for the implementation of China's Belt and Road Initiative (BRI) program. Through which it will import energy from the Middle East and Africa and will export goods. Myanmar is also the focal point for the implementation of India's -Act East Policy and Neighborhood First Policy". That is why Myanmar-Thailand relations are strategically important in Southeast Asian politics. This is a qualitative study in methodology. The purpose of this research work is to analyze the strategic and economic relations by discussing the historical context ofthe Thai-Myanmar bilateral relations. This study also identifies the problems in Thai-Myanmar relations and makes necessary recommendations for their solution. The research has been completed on the basis of information obtained from both primary and secondary sources. [ABSTRACT FROM AUTHOR]

Remoteness is an attribute that has often been negatively attached to island-spaces like the Andaman Islands, separated from the Indian mainland by the vast Bay of Bengal, located at the ‘liquid borderlands’ of South and Southeast Asia. The Covid-19 pandemic, on the other hand, has popularised the use of ‘remote’ methods of enabling religio-social interaction. The islanders of these geographically ‘remote’ locations use these ‘remote’ ways of connecting to perform their religious practices and maintain their faith networks, which is otherwise compromised due to the pandemic-induced restrictions on social gatherings. By exploring the ‘online’ global faith networks of the little-known Matua religion, as well as, the social, technical and logistical constraints in the devotees’ access to ‘remote’ religion, the paper addresses two questions: first, how do individuals play out their identities, both as islander and as devotee, ‘online’; second, what are the corresponding technological and logistical conditions that enable their ‘presence’ and who are the ‘absent’ actors. Drawing from remotely collected data, particularly online ethnography and telephonic interviews, the paper explores the mediating role of technology in destabilizing, as well as, solidifying concepts of remoteness and isolation, particularly in the peripheries of nation, during times of restricted mobility. [ABSTRACT FROM AUTHOR]

In recent year, the use of plastics has become inevitable due to its unique properties that allow for the production of durable and non-durable goods. Post use, plastics enter the waste stream and now can be found in all compartments of the biosphere as microplastics (MPs). This study presents the abundance of MPs in surface water and within copepods in the southwestern Bay of Bengal during dry (June 2022) and wet season (November 2022). The MPs in the surface water were found in all three regions [Chennai, Tuticorin and Nagapattinam (four locations in each region)] and maximum in wet season (53 particles/m3). Moreover, during dry season the mean ingestion of MPs by copepods in Chennai (0.103 ± 0.04 particles/individual), Tuticorin (0.11 ± 0.07 particles/individual) and Nagapattinam (0.036 ± 0.01 particles/individual) is high compared to the wet season. The maximum level of MPs found in both surface water and ingestion by copepods in Tuticorin and Chennai is subjective to the high maritime activities than Nagapattinam region. Whatever, the anthropogenic activities in the study region increase the bioavailability of MPs pollutant in the copepods and transported to higher trophic levels, endangering marine life and human health. Hence, further studies are needed to determine their potential impact on marine food chain in this alarming situation. • The study presents the seasonal distribution of microplastics (MPs) in copepods in the coastal regions of Bay of Bengal. • MPs in surface water and MPs ingestion by copepods were maximum in near coastal locations of Chennai and Tuticorin. • The mean concentration of MPs in water was higher in wet season and MPs ingested by copepods were higher in dry season. • Compared with the global studies, the MPs ingested by copepods were higher during dry season. • The accumulation of MPs contaminating the food chain extensively along the Indian coast. [ABSTRACT FROM AUTHOR]

An accurate prediction of the spatial distribution of phytoplankton biomass, as represented by Chlorophyll-a (CHL-a) concentrations, is important for assessing ecological conditions in the marine environment. This study developed a hyperparameter-optimized decision tree-based machine learning (ML) models to predict the geographical distribution of marine phytoplankton CHL-a in the Bay of Bengal. To predict CHL-a over a large spatial extent, satellite-derived remotely sensed data of ocean color features (CHL-a, colored dissolved organic matter, photosynthetically active radiation, particulate organic carbon) and climatic factors (nighttime sea surface temperature, surface absorbed longwave radiation, sea level pressure) from 2003 to 2022 are used to train and test the models. Results obtained from this study have shown the highest concentrations of CHL-a occurred near the Bay's coastal belts and river estuaries. Analysis revealed that aside from photosynthetically active radiation, organic components exhibited a stronger positive relationship with CHL-a than climatic features, which are correlated negatively. Results showed the chosen decision tree methods to all possess higher R2 and lower root mean square error (RMSE) errors. Furthermore, XGBoost outperforms all other models in predicting the geographic distribution of CHL-a. To assess the model efficacy on seasonal basis, a best performing XGBoost model was validated in the Bay of Bengal region which has shown a good performance in predicting the spatial distribution of Chl-a as well as the pixel values during the summer, winter and monsoon seasons. This study provides the best ML model to researchers for predicting CHL-a in the Bay of Bengal. Further it helps to improve our knowledge of CHL-a spatial dynamics and assist in monitoring marine resources in the Bay of Bengal. It worth noting that the water quality in the Indian Ocean is very dynamic in nature, therefore, additional efforts are needed to test the efficacy of this study model over different seasons and spatial gradients. • Developed Bayesian optimization decision tree models to estimate CHL-a in Bay of Bengal • Effectively utilized satellite remote sensing data for training and testing models • CHL-a demonstrated a larger positive relationship with POC and CDOM. • XGBoost outperforms other models in predicting spatial distribution of CHL-a. [ABSTRACT FROM AUTHOR]

Ulva lactuca, commonly known as sea lettuce is a green macroalgae (chlorophyta) and its uncontrolled proliferation forms a bloom, which causes ecological imbalances and adversely impacts brackishwater ecosystems. Algal bloom can harm the environment and aquatic organisms, but it can also be beneficial if harvested and utilized for industrial purposes. A massive bloom of green macroalgae was observed in the Muttukadu lagoon, located along the southeast coast of India in the Bay of Bengal. A comprehensive study was taken up to assess the spatial distribution, proximate, nutrients, minerals, heavy metals, and factors inducing the bloom. For this study, high-resolution satellite images (Sentinel 2) were used. The spatial distribution of seaweed was mapped using Floating Algae Index (FAI), Modified Floating Algae Index (MFAI), Normalized Difference Red Edge (NDRE) Index and Seaweed Index (SI) models. Results were validated using the MAVIC 3 pro drone and field survey. The SI model was found to be more accurate compared to other models. The bloom exhibited notable temporal dynamics, with peak coverage observed in the last week of May 2023 with a spread area of about 100.05 ha, the bloom intensity was found to be high till the last week of June 2023, after which it gradually declined. The proximate composition (%) of Ulva lactuca showed the moisture content is about 80.00 ± 2.98, crude protein 24.17 ± 1.80, crude lipid 0.81 ± 0.05, Total Ash 37.45 ± 1.44, Fiber (8.92 ± 0.41), and Acid Insoluble Ash (16.18 ± 1.16). The mineral concentration was in the order Ca > Na > Mg > K > P. Iron (Fe) was observed to be high compared to other micronutrients, with a concentration of 1164.40 mg/kg. Rich nutrients and low heavy metal concentration significantly can boost the selling cost of Ulva lactuca providing livelihood support for the coastal fisherfolk. [ABSTRACT FROM AUTHOR]

A sediment core (ABP24/05), collected at a water depth of 3520 ​m from the southeastern Bay of Bengal was studied to determine the change in chemical weathering during the last glacial to deglacial periods and the factors of sedimentary environment which controlled earliest diagenetic changes in the sediment after its deposition. High ratios of K/Rb, Ti/Al and Zr/Rb during ~45 to ~18 ​cal ​kyr B.P. in the core sediments may be attributed to the stronger physical erosion and turbidity currents activity during this period. This might have brought a higher quantity of unaltered minerals to the study area. Low ratios of K/Rb, Zr/Rb, and Ti/Al and increase of SiO 2 /TiO 2 , Rb/Al and Cs/Al from ~18 ​cal ​kyr B.P. to present may be indicating an increase in the rate of chemical weathering during this period. The time of increased chemical weathering in the study area is consistent with deglaciation warming in the tropical Indian Ocean and strengthening of river runoff into the Andaman Sea. Climate change during the interglacial period by increased solar insolation thereby strengthened the summer monsoon which might have led to intensified chemical weathering in the source region since ~18 ​cal ​kyr B.P. The low organic carbon (OC), high Mn/Al, Fe/Al and the Mn-oxides minerals precipitation indicate prevailing of oxic conditions during ~11 ​cal ​kyr B.P. in the core sediments, which is contradictory to suboxic conditions developed in the deep ocean sediments in the western Bay of Bengal and the equatorial Indian Ocean. The low terrigenous influx and export of less OC to the bottom sediments might have created a favorable condition for the formation of Mn-oxides in the study area during Holocene. Image 1 • Decrease in K/Rb, Zr/Rb and Ti/Al ratios after ~18 cal kyr B.P. indicating an increase in the rate of chemical weathering. • Low OC, high Mn/Al, Fe/Al and Mn-oxides minerals indicate prevailing oxic conditions during early Holocene. • Increased chemical weathering at ~18 ​cal ​kyr B.P. is consistent with deglaciation warming and strengthening of river runoff. • The oxic conditions at early Holocene in the southeastern BoB is contrary to suboxic conditions in western BoB. [ABSTRACT FROM AUTHOR]

Pycnocraspedum squamipinne Alcock, 1889 is a rare species of pelagic cusk eel described from specimens collected off the Bay of Bengal. The descriptive literature on P. squamipinne is limited to the original description owing to the rarity in collections. The genus and the species need a thorough revision to identify specific characters of taxonomic importance as the descriptive information regarding the species in the genus Pycnocraspedum is limited to the holotypes and syntypes. Fifteen fresh specimens of P. squamipinne were collected from the Chennai coast, Tamil Nadu, Bay of Bengal region. The syntypes of P. squamipinne (ZSI F 11700 and ZSI F 11703) available at the Zoological Survey of India, Kolkata were examined. The morphometric and meristic characters of P. squamipinne were compared with those of syntypes and other species of the genus. Molecular analysis was carried out using partial mtDNA cytochrome oxidase subunit I gene (COI). The specimen is deposited in the national fish repository of the ICAR, National Bureau of Fish Genetic Resources, Lucknow, India. A detailed redescription of P. squamipinne based on the syntypes and fifteen recently collected specimens are provided. A detailed comparison with other species of the genus is also provided which helps in establishing the taxonomic identity of P. squamipinne. Molecular information was generated which would help in the species identification of this rare deep-sea species. This study provides morphological and molecular information of the rare cusk eel, P. squamipinne, which would help in the precise identification of the species. However, due to paucity, the majority of species of the genus are still only known from single specimens and comprehensive examination of holotypes and intensive sampling is needed to better understand the species identity and distribution. [ABSTRACT FROM AUTHOR]

Colonial and postcolonial imaginaries of the Andaman Islands have represented the islands as a natural prison, a terra nullius, a site of nationalist martyrdom in the Indian anti-colonial struggle, and a repository of indigenous "exotica." The islands are both a "melting pot" and a "frontier." Successive waves of migration since 1858 have created a multiethnic and multilingual mosaic referred to as "Southeast India" and "Mini-India." Convicts incarcerated by the British were joined by partition refugees from eastern Bengal, Adivasis from Chota Nagpur, and Telugu- and Tamil-speaking migrants from southern India. The 500-odd remaining indigenous people of tribal ethnicity are confined to reserved territories, depend on government support, or refuse contact. Strategically located at the juncture of the Bay of Bengal and the Andaman Sea, the islands play a crucial role in India's current military expansion with its aim of countering the Chinese naval presence in the Indo-Pacific. Once the site of British "civilizing" missions, a coercive penal system, violent Japanese occupation during WWII, and a formerly thriving but now outlawed timber industry, the Andamans are the location of conflicting postcolonial imaginaries. From environmentalists' pleas to "save" the "fragile" islands, to marketing for tourists portraying them as a tropical paradise holiday destination, the Andamans are a poly-semiotic place at the friction point of center-periphery tensions. I focus on three questions in this article: Firstly, how does the Indian mainland/center see the islands? Secondly, how do different islanders see, on the one hand, the mainland--both as it is today and in terms of memorialized places of family origin--and, on the other, "their" own islands and their internal divisions? Thirdly, how do marginalized subaltern islanders conceive of their position on the islands' periphery--on the one hand vis-à-vis the political centers of Port Blair and Delhi, and, on the other, the politically dominant groups on the islands? [ABSTRACT FROM AUTHOR]

Based on core, logging, lab test and seismic data, sedimentary characteristics and pattern of marine hyperpycnal flow, the distribution rules of hyperpycnal flow reservoir, prediction method of favorable hyperpycnal flow reservoir zones, hydrocarbon accumulation model in hyperpycnal flow reservoir in D block of Bay of Bengal were investigated, and the favorable exploration zone and well sites were predicted. Pliocene in D block has typical hyperpycnal flow sediment, which is a set of fine-medium sandstone held between thick layers of marine mudstone and features a series of reverse grading unit and normal grading unit pairs. The hyperpycnal flow sediment appears as heavily jagged box shape, bell shape and tongue shape facies on log curves with linear gradient, and corresponds to multiple phases of deep channels on the seismic section and high sinuous channel on stratal slices. The sedimentary bodies formed by a single phase hyperpycnal flow which include five types of microfacies, namely, supply channel (valley), channel complex, branch channel, levee and sheet sand. The hyperpycnal flow sediments appear in multiple branches, multiple generations and stages in space, forming high-quality reservoirs in strips on the plane and superposition vertically, with fairly good physical properties. The channel complex sandstone, with large thickness, coarse particle size and good physical properties, is the most favorable exploration facies. Based on the guidance of the sedimentary model, distribution of the channel complex microfacies was delineated in detail by seismic reflection structure analysis, spectrum waveform characteristic analysis, slice and attribute fusion, and combined with the structural feature analysis, the favorable drilling zone was sorted out, effectively guiding the exploration deployment of the block. [ABSTRACT FROM AUTHOR]

At-sea observations of seabirds and cetaceans provide essential baseline information about their biogeography and behaviour, facilitating marine spatial planning and management. Much of the world's oceans have been surveyed, yet some regions remain particularly data-poor for seabirds and cetaceans, including the Bay of Bengal. We performed 39 d of vessel-based observations within the Bay of Bengal from 2012 to 2014, surveying an overall linear distance of 4722.3 km. We observed 2697 seabirds of 17 species and 1441 cetaceans of at least eight species. Among the seabirds, Sooty Terns Onychoprion fuscatus (n = 2282, 85% of all birds) and Wedge-tailed Shearwaters Ardenna pacifica (n = 327, 12%) predominated, whereas cetacean numbers were dominated by Spinner Dolphins Stenella longirostris (n = 772, 54% of all cetaceans) and Indo-Pacific Bottlenose Dolphins Tursiops aduncus (n = 533, 37%). Other seabirds and cetaceans accounted for only 4% and 7%, respectively, of all sightings. The abundance and diversity of both groups was low compared to other tropical areas. We propose that low seabird and cetacean abundance results from low productivity due to stratification in the Bay of Bengal, as well as long-lasting disturbance, overexploitation of marine resources, possible impacts of longline fisheries, and the near absence of seabird breeding sites. [ABSTRACT FROM AUTHOR]

Safe levels of heavy metals in the surface water and sediment of the eastern Bay of Bengal coast have not been universally established. Current study characterized heavy metals such as arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb) in surface water and sediments of the most important fishing resource at the eastern Bay of Bengal coast, Bangladesh. Both water and sediment samples were analyzed using inductively coupled plasma mass spectrometer. Considering both of the seasons, the mean concentrations of Cr, As, Cd, and Pb in water samples were 33.25, 8.14, 0.48, and 21.14 μg/L, respectively and in sediment were 30.47, 4.48, 0.20, and 19.98 mg/kg, respectively. Heavy metals concentration in water samples surpassed the acceptable limits of usable water quality, indicating that water from this water resource is not safe for drinking, cooking, bathing, and any other uses. Enrichment factors also directed minor enrichment of heavy metals in sediment of the coast. Other indexes for ecological risk assessment such as pollution load index (PLI), contamination factor (CF), geoaccumulation index (I geo), modified contamination degree (mC d), and potential ecological risk index (PERI) also indicated that sediment of the coastal watershed was low contamination. In-depth inventorying of heavy metals in both water and sediment of the study area are required to determine ecosystem health for holistic risk assessment and management. • Cr, As, Cd, and Pb in water and sediments of the Bay of Bengal coasts are low. • Metals in water and sediment during winter season were slightly higher than summer. • Metals were originated mainly from anthropogenic sources. • Ecological risk assessments directed the severity of Cd pollution in the coastal ecosystem. [ABSTRACT FROM AUTHOR]

The Bay of Bengal (BoB) is the largest sink to retain discharges from major rivers and the Sundarbans Mangrove Forest in Bangladesh and upholds significant ecological and resource diversity. This study aims to characterize, and identify sources, spatial dynamics, and the fate of the principal ecological web driver that is fluorescent dissolved organic matter (FDOM) in the BoB using advanced techniques of excitation-emission matrix (EEM) fluorescence spectroscopy and multivariate parallel factor (PARAFAC) analyses. The identified four protein-, two humic- and one detergent-like FDOM components mostly showed higher abundance in the shallow water than deep unlike a protein-like component. Such exceptional protein-like component was identified to form colloidal structure under elevated salinity in deep water. Autochthonous humic-like FDOM originated from primary production and water temperature counteracted microbial polymerization in shallow and deep water, respectively. The annual mass deposition indicated the influx of anthropogenic pollutants from both terrestrial and internal marine systems. [Display omitted] • Four protein-, two humic- and one detergent-like DOM components were identified. • DOM components mostly had higher concentration in the shallow water depth than deep. • Salinity stress played a vital role in bulk molecular weight DOM formation. • Autochthonous DOM originated from primary production in the shallow water. • Both terrestrial and internal marine systems caused anthropogenic inputs. [ABSTRACT FROM AUTHOR]

This study examines how dissolved oxygen (DO) responds to tropical cyclones (TCs) "Wind Pump" in a pre-existing cyclonic and an anticyclonic eddy over the Bay of Bengal (BoB) based on Argo and satellite data. Both TCs induced DO temporal decreases in the subsurface waters (Deep Depression BOB 04 with a pre-existing cyclonic eddy and cyclonic storm Roanu with a pre-existing anticyclonic eddy) owing mainly to the storm-induced upwelling. The deeper oxycline caused by the pre-existing anticyclonic eddy relieved the storm-induced shallow of oxycline during Roanu. On the contrary, the pre-existing cyclonic eddy shoaled the oxycline, intensifying the storm-induced shallow of oxycline during BOB 04. Furthermore, the pre-existing cyclonic eddy induced a long time of DO decrease after BOB 04. This study suggests that the subsurface DO concentrations in the BoB are affected mainly by storm-induced physical processes, and the mesoscale eddies also play an important role. • The intense storm-induced upwelling caused the DO decrease in the subsurface layers. • With a pre-existing cyclonic eddy, storm led to a much shallower oxycline and a long time of DO decrease. • The physical processes played a more important role than the biological processes in the DO distributions under the influence of storms. [ABSTRACT FROM AUTHOR]

Abstract Marine protected areas (MPAs) have become one of the most widely employed marine management tools worldwide for conserving species and habitats, maintaining ecosystem functioning, and ensuring sustainable use of marine resources. In this study, we adopted a science-based, stakeholder-driven and ecosystem based approach to identify coastal and marine habitats for potential MPA declaration towards achieving Aichi target 11. In addition, we also proposed an integrated management approach for MPA management in Bangladesh. Primary data were collected through stakeholder consultations from the three coastal zones of Bangladesh and secondary data were collected from an extensive literature review. We developed a priority index to select the most important habitats for MPA declaration. Our analysis suggests five potential habitats within the maritime boundary of Bangladesh for MPA declaration. These habitats cover an area of 8838 km2 which is about 7.5% of the total maritime area of Bangladesh. Declaration of the MPAs will contribute to conserve the nursing and breeding habitats of fishes, crabs and seabirds, and thus will protect the marine biodiversity. To achieve this goal, local community involvement is required. This study will serve as a baseline for declaring MPAs in a solid scientific way through community engagement. Highlights • MPA is the most widely employed marine management tools. • Five potential habitats selected for MPA declaration in Bangladesh. • These habitats cover 7% of total maritime area of Bangladesh. • Local community involvement is required for a successful implementation of MPA. [ABSTRACT FROM AUTHOR]

To commemorate the contributions made by Indian Naval Ship (INS) Kistna during the first International Indian Ocean Expedition programme a scientific cruise was planned in the Bay of Bengal during November 2017 onboard INS Sagardhwani. The objective was to study the thermohaline properties along 10 °N in the Bay of Bengal and understand the sound channel characteristics in the region. A fresh water cap of ~20 m thickness was noticed in the top layers of the Bay of Bengal occupying the region extending from 83 °E - 93 °E. A prominent anti-cyclonic eddy was noticed around 10 °N centered between 90 °E and 93 °E, a negative sea level (west of 90 °E) co-existed with a positive sea level anomaly to its east along the observational tracks along 10 °N. The climatological temperature and salinity sections also showed the same features as observed along the transect. The study also sheds light on the deep sound channel characteristics along 10 °N. [ABSTRACT FROM AUTHOR]

The occurrence of Bennett's stingray, Hemitrygon bennettii (Müller et Henle, 1841), is confirmed from Indian waters, based on a single male specimen (370 mm DW) collected from Visakhapatnam, western Bay of Bengal on 28 January 2017. Existing, updated reports on the distribution of the species, places it in the Indo-Pacific region with the western limit being the Strait of Malacca. With the presently confirmed occurrence from the western Bay of Bengal, the known distribution of the species extends further westwards to the Indian east coast, although it is likely to be a rare species in Indian waters. [ABSTRACT FROM AUTHOR]

The yellow-striped sandlance, Bleekeria kallolepis Günther, 1862, is a poorly known ammodytid fish from the eastern Indian Ocean, known from fewer than five specimens. No detailed description or colour images of B. kallolepis have previously been available. We hereby provide a short taxonomic account of the species from its type locality Chennai, India with morphometrics and colour description. [ABSTRACT FROM AUTHOR]

The Bay of Bengal (BoB) is a low saline basin owing to large influx of freshwater from precipitation and river runoff. To maintain the salt balance of the BoB, the incessant lowering of salinity is to be balanced by the inflow of saltier water into the basin. In the present work, various processes that contribute to the saltening of the BoB, viz. coastal upwelling, eddies and their interaction, lateral advection from Arabian Sea and tropical cyclones are discussed. In the near-shore regions, the coastal upwelling due to wind induced Ekman transport plays a dominant role in increasing the surface salinity. On the other hand, in the open ocean, the divergence induced by eddies and their mutual interaction contributes significantly to the salt water pumping. In the southern BoB, the advection from the Arabian Sea increases the salinity. The formation of cyclones in the BoB also leads to an increase in the surface salinity. However, the magnitude of saltening of the Bay due to these processes varies from north to south. The uplift of saltier water from subsurface levels increases the salinity in the surface layers thereby creating a salinity gradient and a salinity front. [ABSTRACT FROM AUTHOR]

To understand the influence of river discharge on phytoplankton composition along western coastal Bay of Bengal (BoB), surface water samples were collected during peak discharge period. River discharge from the Ganges influences northwest (NW) coastal BoB whereas peninsular rivers (Godavari and Krishna) discharge to the southwest (SW) coastal Bay. River discharge from the Ganges is an order of magnitude higher than peninsular river resulting in low saline, less suspended matter and lower nutrients concentrations in the NW and contrasting to that was observed in the SW. ~50%of the phytoplankton were composed of Thalassiosira spp., Nitzschia spp., Microcystis spp., Amphiprora spp. and Thalassionema spp. in the SW whereas Thalassiosira spp., Nitzschia spp., Chaetoceros spp., Merismopedia spp. and Peridinium spp. in the NW. Significant variability in phytoplankton composition was observed from coast to offshore. Our study revealed that river discharge and associated physico-chemical characteristics governed the phytoplankton community along western coastal BoB. [ABSTRACT FROM AUTHOR]

The present study investigates the distribution of heavy metals (Fe, Cd, Co, Cr, Cu, Ni, Zn and Pb) in the surface sediments along the Coromandel Coast of Bay of Bengal as an indicator of marine pollution. Pollution indices such as Contamination factor (CF), Enrichment factor (EF) and Geo-accumulation index (I) were performed to assess the spatial distribution and pollution status of the study area. The heavy metal concentration in the study area is closely associated with grain size and organic matter. Both geoaccumulation index and metal contamination factor indicate that the sediments are free from contamination with regards to the metals Cr and Ni, followed by uncontamination to moderate contamination of Co, Cu and Zn. However, sediments are found to be extremely polluted with respect to Cd and Pb. Factor analysis reveals that the accumulation of these heavy metals in the shelf sediments are due to anthropogenic inputs from the adjacent land area. [ABSTRACT FROM AUTHOR]

Small-scale fishing in the Bay of Bengal using non-motorized, wooden motorized and mechanized boats without basic safety devices is a risky venture. Fishers developed a long tradition of adaptation to the dynamics of the unpredictable nature of the marine ecosystem. The empirical findings presented in this article are primarily based on a two-year long ethnographic study with the caste-based Hindu coastal fishers of Thakurtala fishing village, Moheskhali Island, Cox's Bazar. The worldviews and popular beliefs associated with fish and fishing epitomize a rich cultural history of fish-loving Bengali societies. The article examines pragmatically obvious notions of luck, risks, and socio-political implications behind observances of rituals in the coastal fishing villages. Observances of rituals at both domestic and community ambits are perceived to improve luck, reduce anxiety level associated with marine fishing, and reinforce pre-voyage psychological preparedness of the sea-faring fishers and their family members. It documents the roles of fish and fishing related worldviews in rural Bengali societies along with the pre-voyage and post-voyage activities and rituals observed by coastal fishers. Some ritual practices are characterised by interfaith fusion, and hence, their observance would positively add to the foundations of secular practices, humanism, and mutually benefitting existential philosophy in rural societies. This ethnographic narrative also examines fishing cultures’ comprehensive articulations of natural and unnatural elements of marine ecosystem within the broader framework of maritime anthropology. [ABSTRACT FROM AUTHOR]

Proper utilization of marine resources towards achieving sustainable economic development has got worldwide attention in recent years. Likewise, the Bangladesh government has also emphasized Blue Growth after settling the permanent maritime boundary with neighboring countries. This study aims to identify the Blue Economy potentials of Bangladesh, evaluate the economic values of these potentials, identify challenges for Blue Growth and finally develop a management framework. To collect data, consultations with different stakeholders related to Blue Growth in Bangladesh were conducted. Secondary data were collected from the review of policy documents, newspaper reports and scholarly articles. Coastal and marine resources i.e. living, non-living and renewable are identified as the main components of Blue Economy in Bangladesh. Moreover, trades and commerce related to the sea and coast, and protection from natural disasters also have economic returns having potential for enhancing Blue Growth. Conversely, sea level rise, climate-driven extreme events, pollution, human interferences and lack of law enforcement are identified as the major challenges for the further development of Blue Economy. To achieve sustainable Blue Growth in Bangladesh, a strategic planning is required which should focus on potential sectors related to Blue Economy, research and ocean governance. The study argues that enhancing Blue Growth and achieving Sustainable Development Goals (SDGs) must go together to ensure that balance does not swing too far towards Blue Growth at the expense of environmental sustainability. Finally, this study submits a management framework for enhancing Blue Growth in Bangladesh. [ABSTRACT FROM AUTHOR]

Many typical neuston trawls can only be used during relatively calm sea states and slow tow speeds. During two expeditions to the Bay of Bengal and the eastern South Pacific we investigated whether the new, high-speed AVANI trawl (All-purpose Velocity Accelerated Net Instrument) collects similar amounts and types of microplastics as two established scientific trawl designs, the manta trawl and the DiSalvo neuston net. Using a 335 μm net, the AVANI trawl can collect microplastics from the sea surface at speeds up to 8 knots as it “skis” across the surface, whereas the manta and DiSalvo neuston trawls must be towed slowly in a less turbulent sea state and often represent shorter tow lengths. Generally, the AVANI trawl collected a greater numerical abundance and weight of plastic particles in most size classes and debris types than the manta trawl and DiSalvo neuston net, likely because these trawls only skim the surface layer while the AVANI trawl, moving vertically in a random fashion, collects a “deeper” sample, capturing the few plastics that float slightly lower in the water column. However, the samples did not differ enough that results were significantly affected, suggesting that studies done with these different trawls are comparable. The advantage of the AVANI trawl over traditional research trawls is that it allows for collection on vessels underway at high speeds and during long transits, allowing for a nearly continuous sampling effort over long distances. As local surface currents make sea surface abundance widely heterogeneous, widely spaced short-tow trawls, such as the manta and DiSalvo trawls, can catch or miss hotspots or meso-scale variability of microplastic accumulations, whereas the AVANI trawl, if utilized for back-to-back tows of intermediate distances (5–10 km), can bridge variable wind conditions and debris concentrations potentially reducing variance and provide a greater resolution of spatial distribution. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate how the legal framework governing the Bangladeshi fishery sector can be reformed through measures such as governance reform, increasing coordination between administrative bodies and educating key stakeholders, including fishermen. In doing so, this paper evaluates how Bangladeshi fishery laws can facilitate sustainable development and improved environmental outcomes for coastal and marine living resources. This study also examined how non-compliance with the legal framework could negatively affect government initiatives to achieve Sustainable Development Goals, particularly SDG 14. To collect empirical data, fieldwork was conducted at two sites in the coastal zone of Bangladesh and was supplemented by a review of the secondary literature on legal documents. The key findings show that despite the strong existing legal mechanisms, non-compliance with regulations is widespread and has resulted in severe degradation of coastal and marine living resources. Thus, the unsustainable exploitation of resources is restricting the ability to achieve the targets of SDG 14, such as eliminating IUU fishing and providing access to small-scale fisheries. After examining the issues that cause non-compliance, this study provides guidelines for the development and effective implementation of legal and policy frameworks to ensure sustainable coastal and marine living resource management in Bangladesh. [ABSTRACT FROM AUTHOR]

A one-year impingement monitoring was conducted at Madras Atomic Power Station (MAPS), Kalpakkam, southeastern coast of India and identified a total of 67 species of marine organisms in the cooling water system. Estimates of total annual impingement contributed about 1.47 × 10 6 individuals and 142.5 t of biomass. Jellyfish contributed about 6.8 × 10 5 individuals and 135.6 t of biomass. Crabs, shrimps and fish were the most vulnerable organisms contributing about 4.29 × 10 5 individuals, 1.39 × 10 5 individuals and 2.16 × 10 5 individuals respectively. Commercially important species namely Trichiurus lepturus , Sardinella longiceps and Portunus pelagicus were found to be impinged 1.88% and 0.29% by number and weight of the total biomass respectively. Out of ~ 327 fish species recorded at Kalpakkam, only about 9.4% of species were impinged at MAPS. Multispecies impingement at MAPS poses the problem of finding the best mitigation options for tropical conditions. [ABSTRACT FROM AUTHOR]

The objective of this study is to understand the impact of cyclone Asani on the coastal dynamics and nesting grounds of Olive Ridley sea turtles in the Rushikulya Estuary and spit in Odisha. The novelty of this study is the need to understand the effects of natural disasters on the marine environment and wildlife. This study provides new and valuable data on the effects of specific cyclones on sea turtle populations and highlights the need for increased attention and protection of these important habitats. The period of shoreline change analyzed in this study was before (May 2, 2022) and after (May 17, 2022) the impact of cyclone Asani. Multi-temporal Sentinel 2A images and Digital Shoreline Analysis System were used to perform such an analysis. Field surveys were conducted using a Leica DGPS ArcPad, and group discussions with relevant stakeholders such as the fishing community, government officials, and coastal conservation guards were also undertaken. The findings of this study showed that the cyclone had a significant impact on the spit, dividing it into four smaller pieces and opening three new mouths. The spit experienced erosion and a significant reduction in length, and local fishing community reported that 15–20% of sea turtle eggs were washed away. This study highlights the severe threat to the survival of Olive Ridley sea turtles in Odisha due to changing cyclone patterns and the potential for degradation of the local ecosystem. The results of this study can aid in coastal conservation and management strategies to protect marine turtle populations in the region. [Display omitted] [ABSTRACT FROM AUTHOR]

The concept ‘blue economy’ refers to ocean based economies. It encompasses conservation in tandem with sustainable usages of maritime resources through seamless and integrate spatial planning. Blue economy transforms the ocean resources into development instruments. In latter days, the realm of Bay of Bengal has veered into a synonym of economic and strategic significance. Settlement of maritime boundary disputes and the potentials of blue economy prospects are spearheading its littoral states for economic growth. However, like other ocean regions, the Bay of Bengal is also rigged with the problems of IUU fishing, marine pollution, ineffective marine regulation and the non-traditional security menace. The proposed paper endeavours to analyse how Bangladesh, as one of the littoral states of the Bay of Bengal region, is responding to the challenges of ocean governance and revving up initiatives to garner blue economy benefits from the Bay of Bengal. The article also highlights the vista and potentials of regional cooperation in the blue economy related areas such as regulation of coastal marine environment; marine protected areas; maritime safety as well as security of ports and sea lanes of communication. [ABSTRACT FROM AUTHOR]

Trichodesmium is a bloom-forming, diazotrophic, non-heterocystous cyanobacteria widely distributed in the warmer oceans, and their bloom is considered a ‘biological indication’ of stratification and nitrogen limitation in the ocean surface layer. In the first part of this paper, based on the retrospective analyses of the ocean surface mesoscale features associated with 59 Trichodesmium bloom incidences recorded in the past, 32 from the Arabian Sea and the Bay of Bengal, and 27 from the rest of the world, we have showed that warm-core features have an inducing effect on bloom formation. In the second part, we have considered the environmental preferences of Trichodesmium bloom based on laboratory and field studies across the globe, and proposed a view about how warm-core features could provide an inducing pre-requisite condition for the bloom formation in the Arabian Sea and the Bay of Bengal. Proposed that the subsurface waters of warm-core features maintain more likely chances for the conducive nutrient and light conditions required for the triggering of the blooms. [ABSTRACT FROM AUTHOR]

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This article examines technical aspects of the maritime boundary dispute between Bangladesh and Myanmar (the ‘Bay of Bengal case’). This dispute was the first maritime delimitation determined by the International Tribunal for the Law of the Sea (ITLOS). The 2012 decision was also the first time that a maritime boundary for the seabed and subsoil of the Exclusive Economic Zone (EEZ) and the extended continental shelf (ECS) was determined by international adjudication. This was also therefore the first time that detailed technical quantification of seabed areas within the EEZ and ECS was needed for achieving an equitable division of these maritime zones in an international forum. Following review of the principles of maritime delimitation on which the ITLOS reached its determination, this article analyzes the legal status and delimitation effect of St. Martin's Island. Concerning the question of whether the legal regimes of the EEZ and continental shelf should be treated differently in a single delimitation line, although the ITLOS determined that the legal regimes should not be distinguished in the present case, a different approach is proposed for future cases. The article identifies how quantitative modelling can be used to achieve an equitable boundary and proposes a model to adjust provisional equidistance lines in accordance with the complex geophysical rules prescribed for the outer limits of the ECS in Article 76 of the United Nations Law of the Sea Convention (LOSC). [ABSTRACT FROM AUTHOR]

This study presents an overview of the Vardah cyclone and its impact assessment along the coastal districts of northern Tamil Nadu. The cyclone formed over south-east Bay of Bengal and crossed north of Tamil Nadu near Chennai on December 12, 2016, with a wind speed of about 100 to 110 kmph gusting to 120 kmph. The severe cyclonic storm Vardah caused significant damages along the coast of Chennai, Kanchipuram, and Thiruvalluvar districts. It brought severe damages to buildings and uprooted almost 75% trees. This study revealed various damages to buildings and properties during the cyclone through a field study, which is supported by published secondary data. Further, the article explores the causes of damages and remedial measures to avoid those in future cyclones. [ABSTRACT FROM AUTHOR]

This article investigates the role played by the Bay of Bengal in the Indian Ocean world. It argues that formulations that suggest the Bay’s encounters were ambivalent and sporadic until c.1000 – when there was a trade revolution – and see it as a latecomer in the Indian Ocean world, are wrong. Examples from commerce and cultural flows reveal the Bay world as an active participant in the Indian Ocean world from early times and debunk the notion of passivity. [ABSTRACT FROM AUTHOR]

The feasibility of a potential bioindicator based on functional groups of microzooplankton tintinnids for bioassessments of water quality status was studied during southwest monsoon (June to September) along the coastal waters of Kalpakkam, India during 2012–2015. The work highlights the following features (1) tintinnid community composed of 28 species belonging to 11 genera and 9 families, revealed significant differences among the four study sites (2) maximum numerical abundance (2224 ± 90 ind. l − 1 ) and species diversity (H′ = 2.66) of tintinnid were recorded towards Bay of Bengal whereas minimum abundance (720 ± 35 ind. l − 1 ) and diversity (H′ = 1.74) were encountered in the backwater sites, (3) multivariate analyses [RELATE, Biota-environment (BIOENV) and canonical analysis of principal coordinates (CAP)] reveal that chl a , nitrate and phosphate were the potential causative factors for tintinnid distribution. Based on the results, we suggest that tintinnids may be used as a potential bioindicator of water quality status in marine ecosystem. [ABSTRACT FROM AUTHOR]

Ambient noise time series measurements were recorded in the shallow water of Northwest Bay of Bengal. A few data sets revealed the presence of impact pile-driving noise. The site is also known for the presence of the species Terapon theraps (Family: Terapontidae), and the fish chorus was recorded during the measurement period. Sound metrics of impact pile-driving noise were calculated to assess their potential impacts on fish chorus. Averaged peak sound pressure level reached 162 dB re 1 µPa, and single-strike sound exposure level is about 134 dB re 1 µPa2 s, leading to a cumulative sound exposure level of approximately 148 dB re 1 µPa2 s. The impact pile-driving signal has the highest energy in lower frequency band over 0.05-1 kHz. It is observed that T. therapstlsh chorus also displays their pulse repetition rate and swimbladder spectral peaks at lower frequencies. Detailed analysis of the entire data sets indicates that the fishes were exposed to the pile-driving noise, which would have an impact on the chorus made by them. [ABSTRACT FROM AUTHOR]

The role of submarine groundwater discharge (SGD) in transporting terrestrial-sourced arsenic (As) to the global oceans is not well documented. In the present study, executed on a coast adjoining the extensive groundwater As-contaminated Ganges river delta, we hypothesize that As-enriched groundwater discharges to the adjoining Bay of Bengal (BoB) through SGD flow paths. We conducted high-resolution, field-based investigations and thermodynamic modeling to understand the SGD-sourced As discharge and geochemical cycling of As and other redox-sensitive solutes along the discharge path under varying redox conditions and water sediment interactions. The As distribution and other solutes were measured in a series of multi-depth observation wells and sediment cores, extending from the high tide line (HTL) to 100 m toward the sea, for pre- and post-monsoon seasons. Results reveal the presence of a plume carrying up to 30 μg/L dissolved load of As toward the sea. Arsenic is associated with a plume of Fe and exhibits similar shore-perpendicular variability. Arsenic distribution and transport is controlled by the Fe-Mn redox cycle and influenced by terrestrial groundwater discharge. Field-observations and geochemical modeling demonstrate that Fe-hydroxide precipitates in the subterranean estuary and acts as an interim sink for As , which is eventually mobilized on alteration of geochemical conditions with the season. Fluctuating plume size can be attributed to seasonal variation in fresh groundwater input to the site. Estimates indicate up to 55mg/m2/d As is released to BoB from the site. Based on physicochemical observations this study demonstrates the yet to be studied SGD derived As cycles and the role of SGD dynamics in controlling the fate of redox-sensitive contaminants and their discharge into global oceans. [Display omitted] • Submarine groundwater discharge mediated As transport is documented at a tropical coast. • Discharge zone is characterized by precipitates of Fe, Mn-(oxy)hydroxides. • Arsenic release is modulated by fresh groundwater flux at the site. • Up to 55 mg/m2/d of As is released to the sea. • Seasonally varying freshwater flux controls the degree of As release. [ABSTRACT FROM AUTHOR]

[Display omitted] • Weathering activity and paleo-productivity variations in the Mahanadi Basin for the last 200 kyr. • Indian monsoon between the glacial and interglacial periods leads to the different land-sea interactions. • Indian monsoon variability is related to the varying strength of Indonesian throughflow. The orbital-scale variability of the Indian summer monsoon (ISM) has been influenced by multiple factors, such as atmospheric CO 2 concentration, global ice volume, and insolation. Proxies for weathering activity and paleo-productivity provide potential insights into the driving forces of its variability. We documented multi-proxy data at IODP Site U1445, located in the Mahanadi Basin of the northwestern Bay of Bengal, to find out ISM variability over the last 200 ka. The proxy records, such as Nd/Sr isotopes of detrital particles, clay mineral compositions of the fine-grained sediments, biogenic opal and CaCO 3 , organic carbon contents, and carbon isotopes of organic matter, represent sediment sources, weathering patterns, and paleo-productivity related to the ISM variability. Detrital Nd/Sr isotope data and clay mineral compositions suggest that the sediments at Site U1445 originated mainly from the Ganges, Brahmaputra, and Meghna rivers without dramatic provenance change between the glacial and interglacial periods. The weathering activity inferred from clay mineral compositions and the paleo-productivity shift reconstructed by biogenic opal and CaCO 3 contents suggest that the land-sea interactions were closely linked to the ISM precipitation between the glacial and interglacial periods. High precipitation by the strong ISM resulted in intense chemical weathering and dominant biogenic opal deposition during the interglacial periods. In contrast, low precipitation by the weak ISM led to reduced chemical weathering and predominant CaCO 3 deposition during the glacial periods. Further, the ISM variability driving the land-sea interactions in the Mahanadi Basin was modulated by the Indonesian throughflow (ITF). Our study emphasizes the role of low-latitude forcing of climatic changes in the strong relationship between the ISM and ITF over orbital periods, providing a base for future investigations. [ABSTRACT FROM AUTHOR]

Concentrations of trace metals such as iron (Fe), copper (Cu), zinc (Zn), cobalt (Co), nickel (Ni), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), vanadium (V), and selenium (Se) were determined in seawater and zooplankton from the surface waters off Rushikulya estuary, north-western Bay of Bengal. During the study period, the concentration of trace metals in seawater and zooplankton showed significant spatio-temporal variation. Cu and Co levels in seawater mostly remained non-detectable. Other elements were found at higher concentrations and exhibited marked variations. The rank order distribution of trace metals in terms of their average concentration in seawater was observed as Fe > Ni > Mn > Pb > As > Zn > Cr > V > Se > Cd while in zooplankton it was Fe > Mn > Cd > As > Pb > Ni > Cr > Zn > V > Se. The bioaccumulation factor (BAF) of Fe was highest followed by Zn and the lowest value was observed with Ni. Results of correlation analysis discerned positive affinity and good relationship among the majority of the trace metals, both in seawater and zooplankton suggesting their strong affinity and coexistence. [ABSTRACT FROM AUTHOR]

An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3 × 10 5 cells-l − 1 , with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll- a biomass as the bloom declined, with diminishing picoplankton abundance likely the result of high predation by the ciliate Mesodinium rubrum . Together, these data illustrate factors that can disrupt ecosystem balance in this critically important Indian coastal region. [ABSTRACT FROM AUTHOR]

The Machida's snake eel, Ophichthus machidai McCosker, Ide et Endo, 2012, is reported for the first time from the coasts of Bay of Bengal, India. Four specimens (396-457 mm total length) were collected from the Shankarpur fishing harbour, Digha, West Bengal. Principal morphological characters were determined and the specimen was illustrated and described. The species was previously restricted to the northern Pacific Ocean and now is reported for the first time from the Indian coast of the Indian Ocean. [ABSTRACT FROM AUTHOR]

Marine debris is often detected everywhere in the oceans after it enters the marine ecosystems from various sources. Marine litter pollution is a major threat to the marine ecosystem in Bangladesh. A preliminary study was conducted to identify the sources of marine litter (plastics, foamed plastic, clothes, glass, ceramic, metals, paper, and cardboard) along the Bay of Bengal coast. From the observations, the range of abundance of the collected marine litter was 0.14–0.58 items/m2. From the ten sampling sites, the highest amount of marine litter was observed for aluminium cans (3500), followed by plastic bottles (3200). The spatial distribution pattern indicated that all the study areas had beach litter of all types of materials. The present investigation showed that plastics were the dominating pollutants in the marine ecosystem in Bangladesh. The clean-coast index (CCI) value indicated that the Cox's Bazar coast was clean to dirty class. The abundance, distribution, and pollution of marine litter along the coastal belts pose a potential threat to the entire ecosystem. This study will help come up with ways to manage and get rid of marine litter along the coast in an effective way. • Marine litter pollution is a global problem. • The sources of marine litter was identified. • Clean-coast index was used to assess the status of pollution. • This study highlight strategies for efficient coast management. [ABSTRACT FROM AUTHOR]

Baseline marine litter abundance and distribution on Saint Martin Island, Bay of Bengal, were assessed. Seventy-two transects (100–150 m) along 12 km of coastline were surveyed for litter items every two weeks for two months. The most abundant items were polythene bags, food wrappers, plastic bottles/caps, straws, styrofoam, plastic cups, plastic fragments, fishing nets, clothes, and rubber buoys. Tourism, local markets, hotels, domestic waste, and fishing activities were primary sources of marine litter. According to the mean clean coast index (CCI), all transects were clean, of which 11.3 % and 14.1 % of sandy beaches and rocky shores with sandy beaches were reported dirty, respectively. Northern Saint Martin Island comprised sandy beaches (2.8 %) and was extremely dirty. In addition, plastic abundance index (PAI) analysis showed that 24 % of sites, out of 72 sites, were under " very high abundance ", 33 % were " high abundance ", 33 % showed " moderate abundance ", and 4 % were classified as " low abundance ". Establishing baseline results of marine litter abundance and distribution on Saint Martin Island may help improve island conservation and mitigation strategies (e.g., improved waste management, beach cleaning activities to raise public awareness, local government litter reduction policies, and increase local pro-environmental behavioral change). • First evaluation of marine litter reported on coastline of Saint Martin Island. • Clean coast index (CCI) assesses marine litter abundance and distribution. • Plastic abundance index (PAI) was used to measure the abundance of plastic items. • Abundance and distribution of marine litter varied spatially. • Saint Martin Island was considered clean based on the CCI. [ABSTRACT FROM AUTHOR]

Sustained and real-time ocean observation systems using moored data buoys are vital for understanding ocean dynamics and the variability required for improving oceanographic services, including weather prediction, ocean state forecast, and climate change studies. This paper presents the effectiveness of India's moored data buoy network in capturing the response in the ocean during the cyclonic disturbances formed in the Bay of Bengal (BoB) and the Arabian Sea (AS) during the last 5-year period. The moored buoy network provided critical information about the evolution and intensification of low-pressure systems and supported the India Meteorological Department to improve prediction capabilities by incorporating real-time data. The lowest mean sea-level pressure of 920 hPa was recorded in the BoB during the very severe cyclonic storm Phailin. The warning systems adopted for the effective dissemination of the ocean forecast services to the user community have significantly reduced the loss of life and property in coastal states. [ABSTRACT FROM AUTHOR]