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We present here the first study documenting the variability in growth and pigment signature with fluctuating light in a tropical surf-zone (coastal Bay of Bengal) phytoplankton assemblage. In response to an 8.5 times light cut-off for 3 days, 50% of the particulate organic matter (POC)-based growth rate (μPOC d−1) was maintained. Chlorophyll a (Chla) and light-harvesting pigment (LHP) contents exhibited a reverse trend without increasing POC contents, suggesting that the Chla-based growth rate can be biased under fluctuating light. Certain commonly occurring diatoms like Skeletonema, Leptocylindrus and Chaetoceros exhibited high light preference, whereas another diatom Thalassiosira proliferated at low light. Phytoplankton pigment signature was also monitored on an hourly basis over a day and the lowest LHP contents were associated with the highest photon flux densities, whereas the highest values were noticed during morning and evening hours. The ratio between photo-protective to LHP remained

The biogeochemistry of the Arabian Sea, the northwestern part of the Indian Ocean, is directly impacted by monsoonal wind reversal and is an area of strong ocean-atmospheric interaction. During the summer monsoon, coastal as well as open ocean upwelling occurs in the western, southeastern, and central parts of the Arabian Sea. The highest primary productivity rates are documented in these areas compared to the global oceans. Phytoplankton-derived particulate organic matter (POM) [Particulate organic carbon (POC) and nitrogen (PN)] play a central role in supporting the food chain as well as carbon export flux to the deep sea. Hence understanding the dynamics of POM concentrations and its stable carbon (δ13CPOC) and nitrogen (δ15NPN) isotopic ratios are important in delineating its sources and recycling. However, such studies are scarce from the Indian Ocean region. Here we present the first study describing the POM dynamics during the summer monsoon from the central Arabian Sea, addressing the interannual variability. We studied the monsoonal changes in POM and its isotopic signatures in the central Arabian Sea (21–11°N; 64°E) during August 2017 and 2018. A strong, low-lying atmospheric jet (Findlater Jet) blows across the basin during the southwest (SW) monsoon. Positive wind stress curl resulted in “open ocean upwelling” to the north of the jet’s axis, characterized by substantially shallower Mixed Layers Depths (MLDs) and higher POM contents relative to the jet’s axis and its south. The highest wind speeds were observed in the center of the transect due to the presence of the jet’s axis. And the negative curl to the south of the jet’s axis resulted in downwelling and, consequently, the deepest MLDs. The molar ratio between POC and PN (6.2 ± 1.9 in 2017; 6.4 ± 0.9 in 2018) was close to the canonical Redfield ratio (6.63). The δ13CPOC values (−26.3 ± 1.4‰ in 2017; 25.5 ± 1.4‰ in 2018) exhibited typical marine signature and a noticeable inter-annual difference. Relatively higher δ15NPN values in the north (7.68 ± 2.6‰ in 2017; 9.24 ± 3‰ in 2018) indicated the uptake of regenerated dissolved inorganic nitrogen from the oxygen minimum zone (OMZ). The lower δ15NPN values along the jet’s axis and to its south were attributed to the eastward advection of upwelled waters from the western Arabian Sea. Higher wind speeds and jet-induced wind stress curl in 2018 resulted in lower sea surface temperatures (SST) and higher nutrient concentrations. Despite the higher nutrient availability in 2018, POC contents did not exceed the values in 2017. However, considering the total nitrogen consumption (according to C:N: P = 106:16:1), the potential POC development in 2018 could be double the value in 2017. The interannual differences in SW monsoon onset and wind speeds seemed to directly control the nutrient supply, affecting plankton community structure and POM variability. Thus, any future changes in the physical forcing may directly influence the POC pool and consequent export flux to the mesopelagic.

The Arabian Sea, a productive oceanic region in the North Indian Ocean, is under the direct influence of monsoon winds that impact the surface ocean processes. High biological productivity occurs due to natural nutrient enrichment events via coastal and open ocean upwelling (summer monsoon) and convective mixing (winter monsoon). Ample studies from this basin addressed the diatom community from the surface ocean, yet the key contributing diatom frustules to sedimentary phytodetritus has been overlooked. These microscopic biosilcifiers play an important role in the biological carbon pump by exporting significant organic carbon from the surface waters to the deep sea due to their ballasted silica shell (frustule). Hence, this is imperative to document the diatom genera that are transported efficiently to the sediment. The present study analyzed diatom frustule abundance (valves g-1) and identified the major diatom genera in core top sediments (0.5cm) of 10 locations from the Central (21, 19, 15, 13, and 11 °N along 64 °E) and Eastern Arabian Sea (21, 17, 15, 13, and 11 °N at 200 m isobath). This is the first of this kind and found a comparable frustule distribution from the surface sediments of both Central (av. 5.16±1.23×104 valves g-1) and Eastern Arabian Sea (av. 5.80±7.14×104 valves g-1). Size-based classification revealed that the contributions of medium-sized (30-60 µm) frustules from both the central (49 %) and eastern (51%) Arabian Sea were quite high. And the contribution of large-sized frustules (>60 µm) was higher in the central Arabian Sea (39%) compared to the eastern part (19%). A total of 40 diatom genera with 18 in common from both locations were detected from the sedimentary phytodetritus with Coscinodiscus and Thalassiosira being the dominating ones. In the north-central (21, 19, 15 °N) Arabian Sea, the prevalence of large-sized diatoms (Coscinodiscus) was attributed to open ocean upwelling as well as convective mixing during summer and winter monsoons, respectively. Such large species can easily escape grazing and sink rapidly due to higher ballasting. Further, the presence of the oxygen minimum zone at the intermediate depth in this region might reduce the remineralization and grazing pressure within the mesopelagic during their transport to the abyss. Whereas relatively smaller diatoms (Thalassiosira, Pseudo-nitzschia, Fragilaria, Nitzschia) were in high abundance towards the south-central (13, 11 °N) that area remains nutrient-poor. In the Eastern Arabian Sea, Thalassiosira was noticed in high abundance towards the southeast (15, 13, 11 °N), whereas the northeast (17, 21 °N) was dominated by Coscinodiscus and mostly due to the prevalence of coastal upwelling and convective mixing, respectively. Likely, these diatoms (Coscinodiscus, Thalassiosira, Pseudo-nitzschia, Fragilaria, Nitzschia) play a key role in transferring the organic matter from the surface to sediments and thus actively contribute to carbon capture, elemental cycling, and supplying food source for the benthic biota. This study highlights for the first time the biogeochemical significance of these diatoms from this highly productive oceanic province.

Pseudohimantidium pacificum, an epizoic diatom has been reported from different parts of the global oceans, however, has not been reported from the shelf waters of India. This symbiotic association of P. pacificum with a specific copepod species (Ditrichocorycaeus affinis) was repeatedly noticed from the shelf waters of the Arabian Sea during the winter monsoon from three locations in the South East Arabian Sea. Our study suggests towards host specificity of P. pacificum and additionally reveals their preference towards male hosts which is consistent with the earlier reports from other regions. Most importantly, this report extends the range of geographic distribution of the epibiont and this is the third report on this epibiont from the Indian Ocean region. It also suggests that epibiosis in marine zooplankton is much frequent phenomenon that has the potential to play an important role in the marine zooplankton population dynamics.

Marine phytoplankton can be highly sensitive to ocean acidification; however, their responses are diverse and therefore, phytoplankton response study on the regional scale is of high research priority. The present study documented the community shift and growth responses of a natural phytoplankton assemblage from the South West coastal water of India (South Eastern Arabian Sea) under ambient CO2 (A-CO2 ≈ 400 µatm) and high CO2 (H-CO2 ≈ 830 µatm) levels in microcosms during the winter monsoon. A doubling of pCO2 resulted in increased cell density, particulate organic carbon and nitrogen (POC, PON) contents, and C:N ratios. The depleted values of δ13CPOC in the H-CO2-incubated cells indicated a higher diffusive CO2 influx. HPLC marker pigment analysis revealed that the community was microphytoplankton dominated (mostly diatoms); nanoplanktonic prymnesiophytic algae and picoplanktonic cyanobacteria showed insignificant response to the simulated ocean acidification. A high CO2-induced increased growth rate was noticed in 6 diatoms (Leptocylindrus danicus; Rhizosolenia setigera; Navicula sp., Asterionella glacialis, Dactyliosolen fragilissimus, and Thalassiosira sp.). The cell volumes of Thalassionema frauenfeldii, Asterionella glacialis, and Cylindrotheca closterium increased significantly, whereas Rhizosolenia setigera and Thalassiosira sp. showed decreased cell volume at the elevated CO2 levels. These changes in growth rate, cell volume, and elemental stoichiometry could be related to CO2 acquisition and the nutritional status of the cells. Some phytoplankton genera from this region are probably acclimatized to pCO2 fluctuations and are likely to benefit from the future increase in CO2 levels. Higher POC production and increased C:N ratio along with variable cell volume may impact the trophic transfer and cycling of organic carbon in this coastal water. However, a multi-stressor approach in a longer experimental exposure should be considered in future research.

This study analyzed the diversity and abundance of diatom frustules including the ancillary parameters using the core top sediments from five locations (21, 19, 15, 13, and 11°N) along the central Arabian Sea (64°E), an area profoundly influenced by atmospheric forcing (monsoons) and oxygen minimum zone (OMZ) with high spatial variability. Significantly higher organic carbon (0.97 ± 0.05%) and diatom frustules (5.92 ± 0.57 × 10

The worldwide release of excessive nutrients (nitrogen [N], silicon [Si] and phosphorus [P]) into coastal waters is impacting phytoplankton growth and community structure. The coastal Bay of Bengal...

Automated Meter reading systems are an invaluable technological advancement that can lead to a better standard of living, owing to the fact that metering has become a part and parcel of our mundane lives. It solves many issues of the traditional meter reading system like need for human resources, efficiency, accuracy, delayed work, unavailability of customer during metering visit by employee, etc. Moreover it is more economical and helps to save energy in a more efficient and effective way. Furthermore it has a very notable advantage of having the ability to predict the energy demands of the future, starting from every household to the entire planet. The main objective of the smart energy meter is to not only measure the consumer’s power consumption but also to transmit the readings of the meter to utility office every week/day/hour with the help of GSM module or by uploading it onto the cloud. Readings of the meter will be taken out using Rs485 Module and will be given to Raspberry pi and transmitted further to utility office with the help of GSM module or by uploading it onto cloud and at the same time consumption in terms of units as well as rupees will be transmitted to consumer which they can access in SMS or application. Electrical power has become indispensable to human survival and progress which leads to the enhancement of the people’s standard of life by the introduction of automation in to energy distribution and management. With the constant development in technology, the need of automated meter reading systems is also increasing.it is basically Raspberry pi based operational system. The technology of e-metering (Electronic Metering) has gone through rapid technological advancements and there is increased demand for a reliable and efficient Automatic Meter Reading (AMR) system.

Abnormalities and Electricity Theft are a major concern for power and economic chaos of one's country. The reason here is, the fraudulent usage of electricity power by customers and broken electric meters or billing errors. Currently, electrical transmission and distribution losses remain a hurdle to the development and sustainability of the sector despite several techniques of energy conservation and electricity distribution analysis that have been employed. While technical failures are regular and predictable, non-technical losses, which are responsible for 80% energy losses, are random and hard to identify and evaluate. Hence it requires more advanced technology. For these reasons, the problem has attracted research interests in many fields, including artificial intelligence, including machine learning and expert knowledge approaches. Here, we have used a linear regression method for anomaly detection. The project therefore showed that the method has improved detection accuracy, sensitivity and reduced magnitude of data required.

Automation or IoT is the new technology which is used to making security of different type of firm planning all over the world. The device inaugurated of designing such kind of help for farm owner or farmers and as well as different type of farmhouse holder can get benefited with this device. Structure of device which has arduino based operational function that can make security of farming area from various type of intruders that may reach harm or destruction for farm related goods such as crops, paddy, barley etc, by their activities or nature. As clear words animal can destroy all crops by eating or doing incoherent activities. As same not only animal every kind of intruder can be detected by this device and can be able to notify owner of farms. It is an unconventional approach for giving security to farm for relieving destruction of crops. That will be less costly and as well as more production will be secured by using this device. The farm security method which is right now going that is more unplanned typical way adopted time consuming and as well as laborious. Actually it has been followed from earlier era to till right now as in analog way. This device operation is indication of digitalization, in analog way of security of firm by using arduino, GSM module and ultrasonic sensor etc. There is a fundamental need to develop such environmental friendly device which can give ensure of safety of farm that will be make advantage for farmers as well as farm owners. This device will able to give less physical effort and pollution free output of farm security. Design style device is more simple as with workable capability. the methodology of work of this device is where intruders is recorded by using camera attached with sensors that is capturing images of animals and other intruder and sends the notification to mobile.

This paper attempts to measure and find out the quality of services and customer satisfaction level in terms of private sector banks. The paper also slightly shows the comparison between Public sector and Private sector banks related to the customer satisfaction. The research is based on Gujarat which is a state of India. Data collection, data formulation and structuring and data interpretation is based on 423 samples. In terms of private sector banks ICICI, IDBI, HDFC, AXIS Bank, YES Bank, RBI Bank, Kotak Mahindra Bank, IDFC Banks are taken as they are market leaders. ATM facility, Online banking facility, Mobile Banking Facility, Current account, Fixed Deposit, Saving Account, Physical Environment, Competitive Interest Rate etc. has been taken as parameters. From the research, it has been found that there is relationship between service quality and customer satisfaction. We are living in digital era. Almost all the banks are trying to acquire and implement digital facilities. From our research, we also found that majority of the clients are satisfied with mobile banking, online banking and ATM services of the private sector banks. The paper also reveals that the clients are not much satisfied with the behavior of the bank staff of the public sector banks. Age, gender, occupation of the clients are also taken into consideration while preparing the paper.

Particulate organic carbon and nitrogen (POC, PN, collectively particulate organic matter, POM) and the stable isotopic signature of POC (δ

Understanding phytoplankton community shifts under multiple stressors is becoming increasingly important. Among other combinations of stressors, the impact of trace metal toxicity on marine phytoplankton under the ocean acidification scenario is an important aspect to address. Such multiple stressor studies are rare from the Arabian Sea, one of the highest productive oceanic provinces within the North Indian Ocean. We studied the interactive impacts of copper (Cu) and CO

Monsoonal changes in particulate organic matter (POM) and its isotopic signatures (δ13CPOC and δ15NPN) were studied (Aug 2017 and 2018) in the central Arabian Sea (21–11°N 64°E) . A low-level atmospheric jet (Findlater Jet) forms during the south-west (SW) monsoon and results in “open ocean upwelling” to the north of the jet's axis. Higher wind speed and jet-induced wind stress curl coupled with low sea surface temperature (SST) and higher nutrients were noticed in 2018 than in 2017. The region to the north of the jet was characterized by substantially shallower Mixed Layers Depths (MLDs) and higher POM contents relative to the jet's axis and southern stations. The molar ratio between particulate organic carbon (POC) and nitrogen (PN) (6.2 ± 1.9in 2017; 6.4 ± 0.9 in 2018) was very close to the canonical Redfield ratio (6.63). The δ13CPOC values (−26.3 ± 1.4‰ in 2017; 25.5 ± 1.4‰ in 2018) exhibited typical marine signature reported from this area and revealed a noticeable inter-annual difference. Relatively higher δ15NPN values noticed in the north (7.68 ± 2.6‰ in 2017; 9.24 ± 3‰ in 2018) indicated regenerated dissolved inorganic nitrogen coming from the oxygen minimum zone (OMZ) into the well-lit zone. The lower δ15NPN values along the jet axis and south of it were attributed to lateral advection of nitrogen from the Somali upwelling. Despite the higher nutrient availability, POC contents in 2018 did not exceed the values in 2017. Considering the total consumption of nitrogen (according to C:N: P = 106:16:1), the potential POC development in 2018 could be double the value in 2017. The interannual differences in SW monsoon onset and wind speed seem to directly control the nutrient supply, affecting plankton community structure and POM variability. Thus, any future change in the physical forcing may directly influence the POC pool and consequent export flux to the mesopelagic.

As artificial intelligence has grown rapidly in recent years, picture captioning has attracted the interest of numerous experts, which has become a fascinating and challenging challenge. A critical component of scene analysis which combines machine vision and the natural languages of language processing capabilities is visual subtitles which automatically generate natural language interpretations based on image details. This paper utilizes different NLP strategies for perceiving and clarifying an image meaning in a natural language such as English. The proposed Inception V3 image caption generator model uses CNN (Coevolutionary Neural Networks) and LSTM (Long Short-Term Memory) units. The InceptionV3 model has been educated in 1000 different classes on an ImageNet dataset. The model was imported directly from the Keras module of applications. Remove from the InceptionV3model the last classification layer for the dimension (1343,) vector. The embedded matrix is used for vocabulary connections. A building matrix is the linear transformation of the original space with important relations into a real-life space. Image captions are commonly used and, for example, important in implementing interaction between humans and the computer.

Video painting is designed to fill video holes with plausible material. Despite the enormous success of deep-neural networks for image paint, owing to the additional time factor, it is difficult to apply these approaches to the video domain. In this job, we introduce a new, profound, video painting learning algorithm. Screen painting is a video procedure that completes corrupt or incomplete areas. The need for the maintenance of time consistency as well as the need to keep video painting in comparison to picture painting poses additional difficulties. The network is qualified to mask and adhere to the relevant contents into reference frames Inpaint the void in the mark framework. The D-network proposed similarly comprises a network for arrangement framing matrices toward permit the net toward gather information for robust after reserved settings aimed at the purpose of calculating affinity matrices. In comparison to the sophisticated picture painting algorithm our system makes videos even more semierect and temporally smooth. The Deep Network proposed approach is near-real-time and competitive

This study examines the relationship between the isotopic signature of phytoplankton-derived particulate organic matter (POM) (δ 13CPOC ) and estimates of growth rate and community composition along a north-south gradient in the western Indian shelf waters which possess contrasting biogeochemistry and mixed layers depths. The Eastern Arabian Sea/western Indian shelf turns highly productive due to the SW monsoon induced upwelling at its southern region and experiences drastic seasonal reversal. We have characterized the POM pool by quantifying Chl a , particulate organic carbon (POC) and particulate nitrogen (PN), C:N ratios, along with δ 13CPOC values during the SW Monsoon. The prevailing physicochemical features contrasted between the southern (8°N to 12°N) and northern (13°N to 21°N) stations. Close couplings between POC, PN, and Chla contents indicated the autochthonous nature of POM. Low temperature, shallow mixed layer depths (MLDs), high concentrations of nutrients, POM, and Chla, marked the upwelling signature in the south. Conversely, relatively higher temperatures, salinity, deeper mixed layers (MLs), lower concentrations of nutrients, POM, and Chla were evident at the northern stations. Five times higher POC concentrations were noticed in the south (65.5 ± 22.0 μmol L−1) than in the north (12.8± 5.4 μmol L−1) within the MLs. Phytoplankton community shift (based on marker pigment analysis) and the δ13CPOC values were closely coupled. The nutrient replete microphytoplankton (diatoms) dominated southern stations were associated with higher values of δ13CPOC (−23.0 ± 2.3‰) which was attributed to faster growth rate; conversely, the oligotrophic nitrogen-limited waters in the north dominated by pico and nanophytoplankton (haptophytes and cyanobacteria), were characterized by distinctly lower δ13CPOC values (−26.6 ± 0.9‰). Phytoplankton growth rates based on a model were consistent with this trend. Our results show that the autochthonous POC is the primary source of organic matter, and the contrasted biogeochemistry induced phytoplankton communities and their growth rates mostly governed the δ13CPOC variability in this region. However, the lower values in the subsurface waters at the south were likely to be influenced by light limitation and heterotrophy .

The flora and fauna is facing a social disaster owing to the fast transfer of (Corona Virus). The disease with COVID-19 is mainly transmitted by respiratory droplets that are inhaled when people smell, talk, hack or sting. Wearing a veil is an incredible, powerful and easy way to prevent 82% of all respiratory infections. In this way, a number of cover protection structures and recognition structures have been put in place to provide compulsory provision for emergency clinics, air terminals, courier transport, sports offices, and retail outlets. Upper and lower tests have shown unusual strengths in specific real-world projects. Some of this may have been highlighted in the article. Ongoing revelations of articles relying on higher and lower reading models have yielded promising results by finding something found in the pictures. This paper focuses on a response to help to support a larger social request and to wear public covers using the revelation of the YOLO c4 object continuously engraved with images. The proposed Yolo v4 learning model has been pre-programmed with good program limitations. The organization ensures fast access that can deliver consistent results without resolving accuracy, or in complex arrangements. The proposed strategy will be divided into three categories: No dress, cover, and no veil. The model has outdone some of the proposed strategies in the past by gaining 99.98% accuracy during the preparation / testing.

This article proposes an all-encompassing picture sewing that works continuously at the installed climate by applying ROI and PROSAC calculation. The ordinary picture was sewed to apply SURF or SIFT calculation which contains convoluted tasks and bunches of information, and this is performed to distinguish the pictures. Likewise, it applies a RANSAC calculation to eliminate anomalies with the goal that consumes extra time to check the needed pictures because of its arbitrariness. In this article, pointless information is elimated by setting ROI dependent on the attributes of scene pictures, and the PROSAC calculation is applied for eliminating exceptions to decrease the checking time. This examination presents the advancement of a 360° framework adjusted to transports. Here, four cameras were placed around the vehicle, and an elevated top view is made to get the driver”s environmental factors. The advancement has been centered on actualizing a twisting calculation that creates the best arrangement between camera pictures. The investigation is based on the cutting-edge twisting calculations. Here, an adjusted strategy to the particular 360° vision framework is planned and executed. Likewise, this undertaking has tried distinctive alignment designed both in static and genuine conditions, and an adjustable design for the latest application is proposed.

PC vision is the one that causes the machine to comprehend the highlights of different photographs and recording. The division of picture is progressively getting a matter of PC vision and Artificial Intelligence [AI] experts. Many climbing applications requires unique and more beneficial highlights: programmed driving, inward route, and reasonable edges that are not to be given explicit models. It is making incredible steps in the field of car, mechanical, and robotization. By parting the video outline for utilizing semantic segmentation, the route framework can settle on an unmistakable choice. Mental confinement is considered as the initial phase. In this research work, there are different organizations that makes semantic order characterized. While utilizing distinctive fix size things, it tends to be utilized widely. Here, this examination has showed the viable preparing of 5 × 5 based pat-net patches. The deep neural network gives an amazing commitment to semantic isolation regarding the intersection over union boundaries. In the impacts and examination area, the impacts are applied to the picture and video in 5 × 5-pixel size from CityS cape and CamVid photograph arrangements. From the examination and analysis, it has been proposed that the 5 × 5 size fix gives the union's most noteworthy junction in contrast to other profound organizations.

Increasing dissolution of CO2 in the surface ocean is rapidly decreasing its pH and changing carbon chemistry which is further affecting marine biota in several ways. Phytoplankton response studies under the combination of elevated CO2 and trace metals are rare. We have conducted two consecutive onboard incubation experiments (R. V. Sindhu Sadhana; August 2017) in the eastern Arabian Sea (SW coast of India) during an upwelling event. A nutrient enriched diatom bloom was initiated onboard and grown under ambient (approximate to 400 mu atm, A-CO2) and high CO 2 levels (approximate to 1000 patm; H-CO2) with different zinc (Zn; 1 nM) and copper (Cu) concentrations (1 nM, 2 nM and 8 nM). Phytoplankton community composition and the dominant genera were different during these two experiments. CO2 enrichment alone did not show any significant growth stimulating impact on the experimental community except enhanced cell density in the first experiment. Addition of Zn at A-CO2 level revealed no noticeable responses; whereas, the same treatment under H-CO2 level significantly reduced cell number. Considerably high protein content under H-CO2+Zn treatment was possibly counteracting Zn toxicity which also caused slower growth rate. Cu addition did not show any noticeable impact on growth and biomass production except increased protein content as well as decreased carbohydrate: protein ratio. This can be attributed to relatively higher protein synthesis than carbohydrate to alleviate oxidative stress generated by Cu. The centric diatom Chaetoceros and toxin producing pennate diatom Pseudo-nitzschia showed no significant response to either CO2 or Zn enrichment. Large centric diatom Leptocylindrus and Skeletonema responded positively to Zn addition in both CO2 levels. The former species showed the most sensitive response at the highest Cu and H-CO2 treatment; whereas, the pennate diatoms Mtzschia and Pseudo-nttzschia (toxigenic diatom) showed higher resilience under elevated CO2 and Cu levels. This observation indicated that in future ocean, increasing CO2 concentrations and trace metal pollution may potentially alter phytoplankton community structure and may facilitate toxigenic diatom bloom in the coastal waters.

International audience; Marine life is controlled by multiple physical and chemical drivers and by diverse ecological processes. Many of these oceanic properties are being altered by climate change and other anthropogenic pressures. Hence, identifying the influences of multifaceted ocean change, from local to global scales, is a complex task. To guide policy‐making and make projections of the future of the marine biosphere, it is essential to understand biological responses at physiological, evolutionary and ecological levels. Here, we contrast and compare different approaches to multiple driver experiments that aim to elucidate biological responses to a complex matrix of ocean global change. We present the benefits and the challenges of each approach with a focus on marine research, and guidelines to navigate through these different categories to help identify strategies that might best address research questions in fundamental physiology, experimental evolutionary biology and community ecology. Our review reveals that the field of multiple driver research is being pulled in complementary directions: the need for reductionist approaches to obtain process‐oriented, mechanistic understanding and a requirement to quantify responses to projected future scenarios of ocean change. We conclude the review with recommendations on how best to align different experimental approaches to contribute fundamental information needed for science‐based policy formulation.

The Arabian Sea, a land-locked low latitude high productive oceanic province, is characterized by strong seasonality due to the reversal of monsoon winds. “Open ocean upwelling” occurs during the southwest monsoon (SWM) in the northern part of the Findlater Jet, (a low-level atmospheric jet that forms in the Arabian Sea), and consequently, the southern part experiences downwelling. Moreover, the hydrography of this region can be further modulated by coupled ocean-atmospheric events such as ENSO and IOD which eventually lead to changes in biological production. After two decades of joint global ocean flux studies (JGOFS), this is the first report on the phytoplankton community from the central Arabian Sea during the SWM. We tried to interlink the north-south gradient in hydrography as well as the physicochemical features with the phytoplankton community structure (within 60 m) along 64° E (11–21° N) during two consecutive SWM cruises (August 2017 and 2018). The variability in surface wind forcing directly influenced the nutrient stoichiometry and phytoplankton dynamics, through the changes in open ocean upwelling and mixing. Significant spatial and inter-annual variability in phytoplankton abundance, diversity, ratios of diatom: dinoflagellate and centric: pennate diatoms were noticed and were closely coupled with the nutrient availability (bottom-up control). Relatively low phytoplankton cell density in 2017 was coupled with high zooplankton biomass (top-down control). During 2018, higher dissolved silicate (DSi) supply due to stronger open-ocean upwelling along with the advection of upwelled water from the Somali coast likely promoted larger diatoms capable of escaping grazing and have led to higher export production. The large centric diatoms occupied the upwelled regions (21–20° N) (e. g. Rhizosolenia imbricata, R. hebetata and Coscinodiscus radiatus) whereas, small pennate diatoms (Pseudo-nitzschia spp., Navicula spp. Nitzschia spp.) and dinoflagellates (Gymnodinium spp.) were pronounced in the south (11–15° N). And while comparing the trends with the JGOFS reports, no considerable community shift was noticed. However, in the context of ongoing climate change, the rapid warming of the Arabian Sea may potentially influence the hydrography and biogeochemistry of this region and thus may impact phytoplankton community structure, trophic transfer, and organic carbon export flux.

The ongoing increase in surface seawater CO 2 level could potentially impact phytoplankton primary production in coastal waters; however, CO 2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO 2 level, light and zinc (Zn) addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO 2 supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ 13 C POM values at elevated CO 2 suggested increased CO 2 diffusive influx inside the cell. Trace amount of Zn added under low CO 2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO 2 . Almost identical values of δ 13 C POM in the low CO 2 treated cells grown with and without Zn indicated a low discrimination between 13 C and 12 C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO 2 . A minimum growth rate was observed at low CO 2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO 2 level, growth response was maximum. The cells grown in the low CO 2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO 2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO 2 ). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO 2 supply and thus may enhance primary production in response to any further increase in coastal water CO 2 levels and can have large biogeochemical consequences in the study area.

Responses of tropical coastal phytoplankton assemblages to increasing CO2 levels are poorly known. The Arabian Sea (AS), the western part of the north Indian Ocean, is an upwelling-induced, highly ...

In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters.

The present study investigated the impacts of treated effluent discharge on physicochemical and biological properties of coastal waters from three pharmaceuticals situated along the coast of Visakhapatnam (SW Bay of Bengal). Seawater samples were collected (during the months of December 2013, March 2014 and April 2014) from different sampling locations (Chippada (CHP), Tikkavanipalem (TKP) and Nakkapalli (NKP)) at 0- and 30-m depths within 2-km radius (0.5 km = inner, 1 km = middle and 2 km = outer sampling circles) from the marine outfall points. Physicochemical and biological parameters, which differed significantly within the stations, were likely to be influenced by strong seasonality rather than local discharge. Dissolved oxygen variability was tightly coupled with both physical and biological processes. Phytoplankton cell density and total chlorophyll (TChla) concentrations were significantly correlated with dissolved inorganic nutrient concentrations. CHP (December) represented a diatom bloom condition where the highest concentrations of diatom cells, total chlorophyll (TChla), dissolved oxygen coupled with lower zooplankton abundance and low nutrient levels were noticed. The centric diatom, Chaetoceros sp. (> 50%) dominated the phytoplankton community. TKP (March) represented a post-diatom bloom phase with the dominance of Pseudo-nitzschia seriata; zooplankton abundance and nutrient concentrations were minimum. Conversely, NKP (April) represented a warm well-stratified heterotrophic period with maximum zooplankton and minimum phytoplankton density. Dinoflagellate abundance increased at this station. Relatively higher water temperature, salinity, inorganic nutrients coupled with very low concentrations of dissolved oxygen, TChla and pH were observed at this station. Copepods dominated the zooplankton communities in all stations and showed their highest abundance in the innermost sampling circles. Treated effluent discharge did not seem to have any significant impact at these discharge points.

Copper (Cu) is a transition metal with multi-oxidation states, and though it plays numerous roles in vital physiological and biochemical pathways including both photosynthesis and respiration, it can potentially be toxic at high concentrations. Coastal waters receive significant Cu input from a variety of anthropogenic sources which may affect fundamental biological processes including phytoplankton growth. We investigated the responses of the coastal diatom Chaetoceros gracilis to variable Cu concentrations using a local isolate from the SW coastal Bay of Bengal. The results suggested that Cu acted as a growth-promoting factor up to concentrations of 125 nM Cu (growth-promoting range), and became inhibitory thereafter (growth-inhibiting range). The cells in the control treatments had high ratios of photoprotective to light harvesting pigments (PP:LH) and high BSi:Chl-a, both indicative of Fe stress. Within the growth-promoting range, an increase in Cu supply significantly increased Chl-a concentrations, and decreased the ratios of PP:LH and BSi:Chl-a. Interestingly, iron (Fe) supplemented cells of C. gracilis revealed similar responses. We speculate that C. gracilis may utilize Cu to enhance Fe acquisition when Fe levels are inadequate. However, in the presence of Fe, the growth response of C. gracilis to variable Cu concentrations was not significant. We infer that, under Fe sufficient conditions, the need for Cu is minimized. Our study suggests that Cu plays a significant role in the physiology of coastal diatoms beyond the simple toxicological effects often investigated.

The role of microzooplankton (MZP) in the pelagic trophodynamics is highly significant, but the responses of marine MZP to increasing CO2 levels are rather poorly understood. Hence the present study was undertaken to understand the responses of marine plankton to increasing CO2 concentrations. Natural water samples from the coastal Bay of Bengal were incubated under the ambient condition and high CO2 levels (703–711 μatm) for 5 days in May and June 2010. A significant negative correlation was obtained between phytoplankton and MZP abundance which indicated that phytoplankton community structure can considerably be controlled by MZP in this region. The average relative abundances of tintinnids under elevated CO2 levels were found to be significantly higher (68.65 ± 5.63% in May; 85.46 ± 9.56% in June) than observed in the ambient condition (35.68 ± 6.83% in May; 79 ± 5.36% in June). The observed dominance of small chain forming diatom species probably played a crucial role as they can be potentially grazed by tintinnids. This fact was strengthened by the observed high negative correlations between the relative abundance of major phytoplankton and tintinnids. Moreover, particulate organic carbon and total bacterial counts were also enhanced under elevated CO2 level and can serve as additional food source for ciliates. The observed responses of tintinnids to increasing CO2 might have multiple impacts on the energy transfer, nutrient and carbon cycling in the coastal water. The duration of the present study was relatively short and therefore further investigation on longer time scale needs to be done and might give us a better insight about phytoplankton and MZP species succession under elevated CO2 level.

This paper reports for the first time upon the effects of increasing CO2 concentrations on a natural phytoplankton assemblage in a tropical estuary (the Godavari River Estuary in India). Two short-term (5-day) bottle experiments were conducted (with and without nutrient addition) during the pre-monsoon season when the partial pressure of CO2 in the surface water is quite low. The results reveal that the concentrations of total chlorophyll, the phytoplankton growth rate, the concentrations of particulate organic matter, the photosynthetic oxygen evolution rates, and the total bacterial count were higher under elevated CO2 treatments, as compared to ambient conditions (control). δ13C of particulate organic matter (POM) varied inversely with respect to CO2, indicating a clear signature of higher CO2 influx under the elevated CO2 levels. Whereas, δ13CPOM in the controls indicated the existence of an active bicarbonate transport system under limited CO2 supply. A considerable change in phytoplankton community structure was noticed, with marker pigment analysis by HPLC revealing that cyanobacteria were dominant over diatoms as CO2 concentrations increased. A mass balance calculation indicated that insufficient nutrients (N, P and Si) might have inhibited diatom growth compared to cyanobacteria, regardless of increased CO2 supply. The present study suggests that CO2 concentration and nutrient supply could have significant effects on phytoplankton physiology and community composition for natural phytoplankton communities in this region. However, this work was conducted during a non-discharge period (nutrient-limited conditions) and the responses of phytoplankton to increasing CO2 might not necessarily be the same during other seasons with high physicochemical variability. Further investigation is therefore needed.

Inter-annual variations of phytoplankton abundance and community organization were observed over a two-decade period along with the ancillary parameters at the land–ocean boundary associated with the Sundarban mangrove forest (21°32′ and 22°40′ N and 88°05′ and 89° E), along the NE Coast of the Bay of Bengal. The number of definable Bacillariophyceae species exceeded Dinophyceae taxa, and the total number of bloom-forming species declined from a maximum of ten in 2000 and a minimum of two in 2007. Blooms of the diatom Coscinodiscus radiatus were common in 2000 and 2007. Tide cycles and the onset of the monsoon season played important roles in diurnal and seasonal variability of phytoplankton. Phytoplankton biovolume showed seasonality, with the highest levels during post-monsoon periods and lowest levels during the monsoon period. Phytoplankton abundance was correlated to rainfall patterns, which may be altered by long-term changes in climate.

Seasonal and spatial variation of dissolved and atmospheric methane (CH 4 ) was measured in the estuaries of the Sundarban mangrove ecosystem from January to December 2003. This unique mangrove forest ecosystem (9630 km 2 ), a part of the Hooghly–Matla estuarine system (NE coast of Bay of Bengal) comprises about 3% of the total area of the world's mangroves. Dissolved methane concentrations in the mangrove dominated estuarine water (Muriganga, Saptamukhi and Thakuran) were observed between 11.0 and 129.0 nmol L − 1 with emission rates between 1.97 and 134.6 μmol m − 2 d − 1 . Methane emission showed maximum rate during post-monsoon when phytoplankton reached blooming proportion. During post-monsoon materials transported from the mangrove forest could stimulate phytoplankton bloom when transparency of water column was increased and river input of nutrient was low. However, dissolved methane concentrations in the Hooghly estuary, the main river water flushing channel showed lower values between 10.3 and 59.25 nmol L − 1 with emission rates between 0.88 and 148.6 μmol m − 2 d − 1 . Methane concentrations in the salinity gradient zone of the Hooghly estuary did not show any decreasing trend with increased salinity due to its lateral transport from the mangrove forest situated at the lower stretch of the estuary. Dissolved methane concentration in the pore water collected from the virgin mangrove forest showed a maximum concentration of 5769 nmol L − 1 which was considerably lower compared to that of coastal salt marsh, tidal fresh water wetland. This indicated intense oxidation or out competition of methanogenic bacteria by sulfate and nitrate reducing bacteria. Methane emission from the adjacent forest ecosystem (18.36 mmol m − 2 d − 1 ) was higher compared to that in the mangrove water. Considering methane emission rates from the aquatic and forest ecosystems, an area average rate of 47.28 × 10 5 mol km − 2 yr − 1 for Sundarban mangrove environment was obtained. Extrapolating over the global area covered by mangrove forest with area average soil methane emission rate without considering its emission from water could yield inaccurate estimation.

The Ganges drains much of the southern slopes of the Himalayas and yields high-suspended sediment load during the monsoon. The Hooghly estuary, the first deltaic offshoot of the Ganges and flows through the western part of the Sundarbans mangrove forest is a source for inorganic nutrients due to the high input of litter and sediment associated nutrients that are released during estuarine transport. Dissolved inorganic carbon (DIC), dissolved inorganic nitrogen (DIN), dissolved reactive phosphate (DRP) and silicate budgets and fluxes of the coastal zone of the Hooghly River system have been done by biogeochemical modeling and their annual fluxes were calculated to be 230 × 10 9 mol (2.76 × 10 6 t), 4705 × 10 6 mol (65.8 × 10 3 t), 415 × 10 6 mol (12.8 × 10 3 t), 15.28 × 10 9 mol (42.8 × 10 3 t), respectively. Out of the total transport, monsoonal runoff could account 64% for DIC, 71% for DIN and 76% for both DRP and silicate. Annual load of sediment out of the estuary to the NE coast of Bay of Bengal was estimated to be 65.19 × 10 6 t. During the estuarine transport 7.5% of DIC and 7.0% of silicate were removed while addition for DIN and DRP were found to be 59% and 44%, respectively. Occurrence of light limited conditions and auto-heterotrophic coupling within the estuary results regeneration of nutrients from organic matter originated from external source. Comparison was made with the estimates of nutrient fluxes through the some mangrove dominated Southeast Asian estuaries.

The Sundarban mangrove forest (4264 km 2 ) is about 3% of the total area of the world mangrove is interdependent on the coastal aquatic subecosystem (1781 km 2 ). Ammonia concentration and flux measurements in the mangrove ecosystem and measurements in such tropical land–ocean boundary conditions are few and far between. A micrometeorological method was used to measure ammonia exchange over Sundarban mangrove forest and aquatic subecosystem. Results showed both emission and gaseous dry deposition in the forest area at a rate 1.79×10 3 and 2.26×10 3 kg N km –2 yr −1 , respectively. Flux of ammonia in the aquatic subecosystem was found always from air to water with a rate of 775.7 kg N km –2 yr −1 . The annual particulate dry and wet atmospherically deposited ammonia flux were calculated to be 69.0 and 21.5 kg N km –2 yr −1 , respectively. Exchange of gaseous ammonia in the mangrove forest showed net deposition with a rate of 4.90×10 2 kg N km –2 yr −1 . Annual imported flux from the proximate terrestrial source to this virgin forest was found to be 4.26×10 6 kg N yr −1 out of which 32.9% was deposited to the coastal water. Ammonia compensation point for mangrove vegetation was found to occur between 51 and 421 nmol m −3 and its variation was related to wind velocity, temperature, and humidity.

The Sundarban mangrove forest (4,264 km 2 ) constitutes about 3% of the total area of the world mangrove. We measured diurnal and seasonal variations of air‐water CO2 exchange in relation to the occurrence of phytoplankton during January‐December 2001. Diurnal variations of airflows showed that the minimum and maximum CO2 flux of 216.2 mmol m 22 h 21 and 49.9 mmol m 22 h 21 , respectively, occurred during the higher sea breeze. The average ratio of dissolved inorganic nitrogen (DIN 5 13.85 6 7.19 mmol L 21 ) to dissolved inorganic phosphorus (DIP 5 1.23 6 0.57 mmol L 21 ) was 11 6 4 and the surface water was undersaturated with respect to dissolved oxygen. The mean value of 0.1 6 0.08 for the ratio of phytoplankton production (P) to community respiration (R) indicated that the ecosystem was heterotrophic. The saturation of dissolved carbon dioxide with respect to the atmosphere varied seasonally between 59% and 156%, with minimum levels in postmonsoon and maximum levels in premonsoon/early monsoon (June/July). Out of the 36 genera of diatoms, 1 blue green alga, and 3 dinoflagellates that occurred throughout the year, only 6 reached bloom proportions in postmonsoon, when mangrove water was a sink of atmospheric CO2. Although 59.3% of the emitted CO2 was removed from the atmosphere by biological processes, on an annual basis, the Sundarban mangrove forest supplies 13.8 kg C ha 21 yr 21 of CO2 from water surface to the atmosphere. Even though it is important to compare all in and out fluxes, there is no direct link between CO 2 emission and the later CO2 removal by biological processes.

Diurnal and seasonal variations in carbon dioxide and methane fluxes between Sundarban biosphere and atmosphere were measured using micrometeorological method during 1998–2000. Study of the diurnal variation of micrometeorological conditions in the atmosphere was found to be necessary to determine the duration of neutral stability when flux estimation was reliable. Neutral stability of the atmosphere occurred in the limited micrometeorological conditions, when friction velocity ranged between 0.360 and 0.383 m s −1 . The value of drag coefficient (1.62–20.6)×103 obtained at variable wind speed could be deemed specific for this particular surface. 58.2% drop of carbon dioxide and 63.4% drop of methane in the atmosphere at 1 m height were observed during day time, between dawn and early evening. Diurnal variations in methane and carbon dioxide mixing ratios showed a positive correlation with Richardson's number (Ri). This environment acted as a net source for carbon dioxide and methane. The mixing ratios of methane were found to vary between 1.42 and 2.07 ppmv , and that of carbon dioxide, between 324.3 and 528.7 ppmv during the study period. The biosphere–atmosphere flux of carbon dioxide ranged between −3.29 and 34.4 mg m −2 s −1 , and that of methane, between −4.53 and 8.88 μg m −2 s −1 . The overall annual estimate of carbon dioxide and methane fluxes from this ecosystem to atmosphere were estimated to be 694 Tg yr −1 and 184 Gg yr −1 , respectively. Considerable variations in mixing ratios of carbon dioxide and methane at the NE coast of Bay of Bengal were observed due to the seasonal variations of their fluxes from the biosphere to the atmosphere. The composition was inferred by fitting model prediction to measurements.

In this paper, statistical analysis to examine the links between pollution and the types of kitchen and fuels is carried out for rural houses by first monitoring the indoor air quality (IAQ) followed by regression analysis of 418 households in Tamil Nadu, India. Exposures to the chief cook (females, who are mainly involved in the cooking during monitoring) are measured with personal monitors. The result shows that the values of respirable particles (PM10) ranged from 500–2000 μg/m3 during a two-hour cooking period from burning biofuels. The range depends on the type of kitchen and fuel use. Stationary monitors, placed two metres away from the stove, also recorded similar concentrations. Thus, the individuals who stay inside the houses using biofuels also face high concentrations even if they are not cooking. They could be senior citizens, children or adult males. Thus, there are two major findings from this analysis. Improved house designs that pay attention to kitchen location and put up partitions should also be considered in the intervention portfolio. Secondly, the exposure is not limited to the cooks alone. The rest of the family in the vicinity is also exposed through a “passive cooking effect”.

Diazotrophic (N2-fixing) cyanobacteria provide the biological source of new nitrogen for large parts of the ocean. However, little is known about their sensitivity to global change. Here we show that the single most important nitrogen fixer in today's ocean, Trichodesmium, is strongly affected by changes in CO2 concentrations. Cell division rate doubled with rising CO2 (glacial to projected year 2100 levels) prompting lower carbon, nitrogen and phosphorus cellular contents, and reduced cell dimensions. N2 fixation rates per unit of phosphorus utilization as well as C:P and N:P ratios more than doubled at high CO2, with no change in C:N ratios. This could enhance the productivity of N-limited oligotrophic oceans, drive some of these areas into P limitation, and increase biological carbon sequestration in the ocean. The observed CO2 sensitivity of Trichodesmium could thereby provide a strong negative feedback to atmospheric CO2 increase.