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Kumar PS, Gopal D, Jha DK, Ratnam K, Jayapal S, Pandey V, Srinivas V, Rathinam AJ. Impact of anthropogenic accumulation on phytoplankton community and harmful algal bloom in temporarily open/closed estuary. Sci Rep 2023; 13:23034. [PMID: 38155171 PMCID: PMC10754910 DOI: 10.1038/s41598-023-47779-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/18/2023] [Indexed: 12/30/2023] Open
Abstract
Spatio-temporal variation in phytoplankton community dynamics in a temporarily open/closed Swarnamukhi river estuary (SRE), located on the South East coast of India was investigated and correlated to that of the adjacent coastal waters. Understanding the seasonal variability of the phytoplankton community and influencing factors are essential to predicting their impact on fisheries as the river and coastal region serve as the main source of income for the local fishing communities. Downstream before the river meets the sea, an arm of the Buckingham Canal (BC), carrying anthropogenic inputs empties into the Swarnamukhi River (SR1). The impact of anthropogenic effects on the phytoplankton community at BC was compared to other estuarine stations SR2 (upstream), SR1 (downstream), SRM (river mouth) and coastal station (CS). In BC station, harmful algal blooms (HABs) of Chaetoceros decipiens (2940 × 103 cells L-1) and Oscillatoria sp. (1619 × 103 cells L-1) were found during the southwest monsoon and winter monsoon, respectively. These HABs can be linked to the anthropogenic input of increased nutrients and trace metals. The HABs of Oscillatoria sp. were shown to be induced by elevated concentrations of nitrate (10.18 µM) and Ni (3.0 ppm) compared to ambient, while the HABs of C. decipiens were caused by elevated concentrations of silicate (50.35 µM), nitrite (2.1 µM), and phosphate (4.37 µM). Elevated nutrients and metal concentration from the aquaculture farms, and other anthropogenic inputs could be one of the prime reasons for the recorded bloom events at BC station. During this period, observed bloom species density was found low at other estuarine stations and absent at CS. The formation of bloom events during the closure of the river mouth could be a major threat to the coastal ecosystem when it opens. During the Osillatoria sp. bloom, both the Cu and Ni levels were higher at BC. The elevated concentration of nutrients and metals could potentially affect the coastal ecosystem and in turn fisheries sector in the tropical coastal ecosystem.
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Affiliation(s)
- Ponnusamy Sathish Kumar
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India.
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
| | - Dharani Gopal
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Dilip Kumar Jha
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Krupa Ratnam
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Santhanakumar Jayapal
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Vikas Pandey
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Venkatnarayanan Srinivas
- Ocean Science and Technology for Islands, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Pallikaranai, Chennai, India
| | - Arthur James Rathinam
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
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2
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Basuri CK, Garlapati D, Chandrasekaran M, Karri R, Ramanamurthy MV. Influence of environmental heterogeneity on the distribution of micro-zooplankton community along the tropical coastal waters. MARINE POLLUTION BULLETIN 2023; 195:115546. [PMID: 37774647 DOI: 10.1016/j.marpolbul.2023.115546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 10/01/2023]
Abstract
This study mainly focused on the water quality variability and distribution of micro-zooplankton (MZP) along the coastal waters of Tamil Nadu. Dendrogram analysis using water quality data categorized the study area into three regions: North (Chennai), Central (Puducherry), and South (Karaikal). The MZP consists of 40 ciliates and 8 dinoflagellates, with spirotrichea (52.4 %) significantly dominant, followed by dinophyceae (21.1 %), phyllopharyngea (14.7 %), and others (11.8 %). Paracyrtophoron tropicum, a new report in the coastal waters of India, was identified by comparing its molecular phylogeny (18S rRNA accession no: MT500569) to previously reported species. Statistical analysis revealed a positive correlation between P. tropicum abundance and water temperature, PO4, SiO4, TP, Chl-a, and Trichodesmium erythraeum, suggesting that they might not directly control the growth of P. tropicum but indirectly influence it via food availability, i.e., T. erythraeum. However, to understand these species interactions and ecological pathways, further long-term monitoring studies are required.
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Affiliation(s)
- Charan Kumar Basuri
- National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, NIOT Campus, Pallikaranai, Chennai 600 100, India.
| | - Deviram Garlapati
- National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, NIOT Campus, Pallikaranai, Chennai 600 100, India
| | - Muthukumar Chandrasekaran
- National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, NIOT Campus, Pallikaranai, Chennai 600 100, India
| | - Ramu Karri
- National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, NIOT Campus, Pallikaranai, Chennai 600 100, India
| | - M V Ramanamurthy
- National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, NIOT Campus, Pallikaranai, Chennai 600 100, India
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Vase VK, Raman M, Sahay A, R S, K R, K R S, Dash G, J J, Rohit P, R RK. Dynamics of environmental variables during the incidence of algal bloom in the coastal waters of Gujarat along the northeastern Arabian Sea. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1238. [PMID: 37736823 DOI: 10.1007/s10661-023-11827-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/04/2023] [Indexed: 09/23/2023]
Abstract
The dynamics of physico-chemical, nutrient, and chlorophyll-a variables were studied in the bloom and non-bloom locations along the off-Gujarat coastal waters to understand the variability in biogeochemistry using multivariate analytical tests. The dissolved oxygen was significantly lower in the bloom stations (3.89 ± 0.44 mgL-1) than in the non-bloom stations (5.50 ± 0.70 mg L-1), due to the biological degradation of organic matter in addition to anaerobic microbial respiration. Nutrients (PO4 and NO3) and Chl-a concentrations were recorded higher in the bloom locations at 0.83 ± 0.21 µmol L-1, 4.47 ± 0.69 µmol L-1, 4.14 ± 1.49 mg m-3, respectively. PO4 and NO3 have shown a significantly higher positive correlation of r = 0.73 and r = 0.69 with Chl-a for bloom data than the non-bloom data. The percentage variance contributed by PC1 and PC2 for both bloom and non-bloom locations were estimated at 52.33%. The variable PO4 explains the highest 24.19% variability in PC1, followed by Chl-a (19.89%). The PO4 triggers the bloom formation and also correlates to the higher concentrations of Chl-a in the bloom locations. The bloom concentration ranges from 9553 to 12,235 trichomes L-1. The bloom intensity has shown a significant positive correlation with Chl-a (r = 0.77), NO3 (r = 0.56), and PO4 (r = 0.30), but a negative correlation was noticed with DO (r = - 0.63) and pH (r = - 0.49). The study also initiates a way forward research investigation on ocean-color technologies to identify and monitor blooms and climate change-driven factors for bloom formation. The occurrence of bloom and its influence on fishery resources and other marine biotas will open many research windows in marine fisheries, oceanography, remote sensing, marine biology, and trophodynamics.
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Affiliation(s)
- Vinaya Kumar Vase
- Mangalore University, Mangalagangotri, Mangaluru, Karnataka, 574199, India.
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India.
| | - Mini Raman
- ISRO-Space Application Center, Ahmadabad, Gujarat, India
| | - Arvind Sahay
- ISRO-Space Application Center, Ahmadabad, Gujarat, India
| | - Shikha R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Rajan K
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Sreenath K R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Gyanaranjan Dash
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Jayasankar J
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Prathibha Rohit
- Mangalore University, Mangalagangotri, Mangaluru, Karnataka, 574199, India
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Ratheesh Kumar R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
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Manuri DB, Chandrasekaran M, Perumal M, Karri R, Mallavarapu VR. Factors regulating phytoplankton biomass along the Indian coast: elucidation with long-term data. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:27409-27420. [PMID: 36378370 DOI: 10.1007/s11356-022-23969-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 10/30/2022] [Indexed: 06/16/2023]
Abstract
Long-term variations in phytoplankton biomass from nine coastal states along the Indian coast were studied and co-related with biotic and abiotic factors. Surface water temperature, dissolved inorganic nutrients (nitrogen and phosphorous), and plankton (phytoplankton and zooplankton) biomass data were collected between 1992 and 2015. Linear regression analysis showed a considerable increase in dissolved inorganic nutrients. A substantial increase in the frequency and intensity of phytoplankton blooms (> 3 mg/m3) was observed along the Indian coast. The considerable increase in dissolved inorganic nutrient concentrations could be the major reason for an increase in phytoplankton bloom occurrences. Availability of light and periodicity in zooplankton population were also regulating phytoplankton biomass. Our results revealed that multiple factors are influencing phytoplankton biomass along the Indian coast; particularly, the increase in nutrient concentrations is promoting plankton biomass. Moreover, significant increase in zooplankton biomass can have substantial impact on the biogeochemical cycling and energy transfer to higher trophic levels.
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Affiliation(s)
- Durga Bharathi Manuri
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, 2nd Floor, NIOT Campus, Pallikaranai, Chennai, 600100, India.
| | - Muthukumar Chandrasekaran
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, 2nd Floor, NIOT Campus, Pallikaranai, Chennai, 600100, India
| | - Madeswaran Perumal
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, 2nd Floor, NIOT Campus, Pallikaranai, Chennai, 600100, India
| | - Ramu Karri
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, 2nd Floor, NIOT Campus, Pallikaranai, Chennai, 600100, India
| | - Venkata Ramanamurthy Mallavarapu
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, 2nd Floor, NIOT Campus, Pallikaranai, Chennai, 600100, India
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Wu C, Narale DD, Cui Z, Wang X, Liu H, Xu W, Zhang G, Sun J. Diversity, structure, and distribution of bacterioplankton and diazotroph communities in the Bay of Bengal during the winter monsoon. Front Microbiol 2022; 13:987462. [PMID: 36532434 PMCID: PMC9748438 DOI: 10.3389/fmicb.2022.987462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/03/2022] [Indexed: 10/31/2023] Open
Abstract
The Bay of Bengal (BoB) is conventionally believed to be a low productive, oligotrophic marine ecosystem, where the diazotroph communities presumed to play a vital role in adding "new" nitrogen through the nitrogen fixation process. However, the diazotroph communities in the oceanic region of the BoB are still poorly understood though it represents most of the seawater volume. The present study investigated a detailed account of the bacterioplankton community structure and distribution in the oceanic BoB during the winter monsoon using high throughput sequencing targeting the 16S rRNA and nifH genes. Our study observed diverse groups of bacterioplankton communities in the BoB including both cyanobacterial and non-cyanobacterial phylotypes. Cyanobacteria (Prochlorococcus spp. and Synechococcus spp.) and Proteobacteria (mainly α-, γ-, and δ-Proteobacteria) were the most abundant groups within the bacterial communities, possessing differential vertical distribution patterns. Cyanobacteria were more abundant in the surface waters, whereas Proteobacteria dominated the deeper layers (75 m). However, within the diazotroph communities, Proteobacteria (mainly γ-Proteobacteria) were the most dominant groups than Cyanobacteria. Function prediction based on PICRUSt revealed that nitrogen fixation might more active to add fixed nitrogen in the surface waters, while nitrogen removal pathways (denitrification and anammox) might stronger in deeper layers. Canonical correspondence analysis (CCA) indicated that temperature, salinity, and silicate were major environmental factors driving the distribution of bacterial communities. Additionally, phosphate was also an important factor in regulating the diazotroph communities in the surface water. Overall, this study provided detailed information on bacterial communities and their vital role in the nitrogen cycles in oligotrophic ecosystems.
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Affiliation(s)
- Chao Wu
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Dhiraj Dhondiram Narale
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Zhengguo Cui
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xingzhou Wang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China
| | - Haijiao Liu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China
| | - Wenzhe Xu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Guicheng Zhang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Jun Sun
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
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6
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Identifying Algal Bloom ‘Hotspots’ in Marginal Productive Seas: A Review and Geospatial Analysis. REMOTE SENSING 2022. [DOI: 10.3390/rs14102457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Algal blooms in the marginal productive seas of the Indian Ocean are projected to become more prevalent over the coming decades. They reach from lower latitudes up to the coast of the northern Indian Ocean and the populated areas along the Arabian Gulf, Sea of Oman, Arabian Sea, and the Red Sea. Studies that document algal blooms in the Indian Ocean have either focused on individual or regional waters or have been limited by a lack of long-term observations. Herein, we attempt to review the impact of major monsoons on algal blooms in the region and identify the most important oceanic and atmospheric processes that trigger them. The analysis is carried out using a comprehensive dataset collected from many studies focusing on the Indian Ocean. For the first time, we identify ten algal bloom hotspots and identify the primary drivers supporting algal blooms in them. Growth is found to depend on nutrients brought by dust, river runoff, upwelling, mixing, and advection, together with the availability of light, all being modulated by the phase of the monsoon. We also find that sunlight and dust deposition are strong predictors of algal bloom species and are essential for understanding marine biodiversity.
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Insights into Prokaryotic Community and Its Potential Functions in Nitrogen Metabolism in the Bay of Bengal, a Pronounced Oxygen Minimum Zone. Microbiol Spectr 2022; 10:e0089221. [PMID: 35579458 PMCID: PMC9241787 DOI: 10.1128/spectrum.00892-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ocean oxygen minimum zones (OMZs) around the global ocean are expanding both horizontally and vertically. Multiple studies have identified the significant influence of anoxic conditions (≤1 μM O2) on marine prokaryotic communities and biogeochemical cycling of elements. However, little attention has been paid to the expanding low-oxygen zones where the oxygen level is still above the anoxic level. Here, we studied the abundance and taxonomic and functional profiles of prokaryotic communities in the Bay of Bengal (BoB), where the oxygen concentration is barely above suboxic level (5 μM O2). We found the sinking of Trichodesmium into deep water was far more efficient than that of Prochlorococcus, suggesting Trichodesmium blooms might be an essential carbon and nitrogen source for the maintenance of the BoB OMZ. In addition to the shift in the prokaryotic community composition, the abundance of some functional genes also changed with the change of oxygen concentration. Compared to oxic (>60 μM O2) Tara Ocean and high-hypoxic (>20 to ≤60 μM O2) BoB samples, we found more SAR11-nar sequences (responsible for reducing nitrate to nitrite) in low-hypoxic (>5 to ≤20 μM O2) BoB waters. This suggested SAR11-nar genes would be more widespread due to the expansion of OMZs. It seems that the nitrite-N was not further reduced to nitrogen through denitrification but likely oxidized to nitrate by Nitrospinae in the BoB OMZ and then accumulated in the form of nitrate-N. However, the lack of N2 production in the BoB would change if the BoB OMZ became anoxic. Together, these results suggested that reduction of oxygen concentration and OMZ expansion may increase the use of nitrate by SAR11 and N2 production in the BoB. IMPORTANCE Recognizing the prokaryotic community and its functions in hypoxic (>5 to ≤60 μM O2) environments before further expansion of OMZs is critical. We demonstrate the prokaryotic community and its potential functions in nitrogen metabolism in the Bay of Bengal (BoB), where oxygen concentration is barely above suboxic level. This study highlighted that Trichodesmium might be an essential carbon and nitrogen source in the maintenance of the BoB OMZ. Additionally, we suggest that the lack of N2 production in the BoB would change if the BoB OMZ became anoxic, and the expansion of OMZs in the global ocean may potentially increase the use of nitrate by SAR11.
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B R S, Sanjeevan VN, Padmakumar KB, Hussain MS, Salini TC, Lix JK. Role of mesoscale eddies in the sustenance of high biological productivity in North Eastern Arabian Sea during the winter-spring transition period. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151173. [PMID: 34699830 DOI: 10.1016/j.scitotenv.2021.151173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 10/09/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
Convective mixing, mesoscale eddies and regenerated production sustain an above-average biological productivity in the North East Arabian Sea (NEAS) during the winter-spring transition period. Satellite-derived long-term data sets on Chlorophyll-a (Chl-a), Sea Surface Height Anomaly (SSHA), Sea Surface Temperature (SST) and Okubo-Weiss parameterization show existence of number of mesoscale eddies, propagating and non-propagating, that contribute to the regional production. The dominance of Eddy Kinetic Energy (EKE) over the Available Potential Energy (APE) in the core depth and the diameter (120km) of the observed eddy being wider than the Rossby Radius of Deformation (RRD, 55 km), it is suggested that the baroclinic instability is a possible mechanism for the eddy formation. Spatial variation in APE and its influences on the regional dynamics, including chemical and biological response are explained. In the non-eddy areas, where convective mixing is active, diatoms (96.74%) dominated than dinoflagellates (3.14%), and the Chl-a in the Cold Core Eddy (CCE) were two to three folds higher to non-eddy regions. The abundance increased from core (58,152 cells L-1) to periphery (5.95 × 105 cells L-1) where the water column is less dynamic. Extensive blooms of the dinoflagellate green Noctiluca (N. scintillans) contribute to the very high cell density in the periphery of the CCE, where the currents were comparatively weak, and water column was more stable. Active mixing is associated with diatom dominance, followed by Noctiluca when the mixing slackens, making use of the available nutrients and supported by regenerated production. The bloom dynamics is explained for pre-bloom, bloom and post-bloom conditions with measurements on nutrients and plankton assemblages. The Noctiluca bloom (mid-March) is succeeded by Trichodesmium (April-May), in the stratified nutrient depleted, abundant light environment and propagated southwards. Observed increasing trends in the SSHA over the period indicate strengthening of stratification and hence altered production patterns in the NEAS.
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Affiliation(s)
- Smitha B R
- Centre for Marine Living Resources and Ecology, Kochi, Kerala, India.
| | - V N Sanjeevan
- Kerala University of Fisheries and Ocean Studies, Kochi, Kerala, India
| | - K B Padmakumar
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Kochi, Kerala, India
| | - Midhun Shah Hussain
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Kochi, Kerala, India
| | - T C Salini
- Department of Physical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi, Kerala, India
| | - J K Lix
- Department of Physical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi, Kerala, India
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Wu C, Sun J, Liu H, Xu W, Zhang G, Lu H, Guo Y. Evidence of the Significant Contribution of Heterotrophic Diazotrophs to Nitrogen Fixation in the Eastern Indian Ocean During Pre-Southwest Monsoon Period. Ecosystems 2021. [DOI: 10.1007/s10021-021-00702-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Li L, Pujari L, Wu C, Huang D, Wei Y, Guo C, Zhang G, Xu W, Liu H, Wang X, Wang M, Sun J. Assembly Processes and Co-occurrence Patterns of Abundant and Rare Bacterial Community in the Eastern Indian Ocean. Front Microbiol 2021; 12:616956. [PMID: 34456881 PMCID: PMC8385211 DOI: 10.3389/fmicb.2021.616956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 07/15/2021] [Indexed: 11/16/2022] Open
Abstract
Microbial communities are composed of many rare species and a few abundant species. Considering the disproportionate importance of rare species for ecosystem functioning, it is important to understand the mechanisms structuring the rare and abundant components of a diverse community in response to environmental changes. Here, we used a 16S ribosomal RNA gene sequencing approach to investigate the bacterial community diversity in the Eastern Indian Ocean (EIO) during the monsoon and intermonsoon. We employed a phylogenetic null model and network analysis to evaluate the assembly processes and co-occurrence pattern of the microbial community. We found that higher bacterial diversity was detected in the intermonsoon with high temperature and low Chlorophyll a concentrations and N/P ratios. The balance between ecological deterministic processes and stochastic processes varied with seasons in the EIO. Meanwhile, conditionally rare taxa (CRT) were more likely modulated by variable selection processes than always rare taxa (ART) and abundant taxa (AT) (CRT > ART > AT). By linking assembly process and species co-occurrence, we demonstrated that the microbial co-occurrence associations tended to be higher when deterministic processes (mainly variable selection) were weaker. This negative trend was observed in rare species rather than abundant species. The linkage could enhance our understanding of the underlying mechanisms underpinning the generation and maintenance of microbial community diversity.
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Affiliation(s)
- Liuyang Li
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Laxman Pujari
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Chao Wu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Danyue Huang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yuqiu Wei
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Congcong Guo
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Guicheng Zhang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Wenzhe Xu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Haijiao Liu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Xingzhou Wang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Min Wang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Jun Sun
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China
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Sathishkumar RS, Sundaramanickam A, Sahu G, Mohanty AK, Ramesh T, Khan SA. Intense bloom of the diatom Hemidiscus hardmanianus (Greville) in relation to water quality and plankton communities in Tuticorin coast, Gulf of Mannar, India. MARINE POLLUTION BULLETIN 2021; 163:111757. [PMID: 33272587 DOI: 10.1016/j.marpolbul.2020.111757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 09/30/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
The present study reports a dense bloom of the marine-diatom Hemidiscus hardmanianus observed off the Tuticorin coast in the Gulf of Mannar (GoM), India. The surface water discoloration (pale green) was observed during a coastal survey conducted in the initial period of the northeast monsoon (October 2018). The bloom extended over an area of approximately 5 km2 around the Tuticorin harbor. Distribution and relative abundance of the phytoplankton and zooplankton species together with the water quality and Chlorophyll-a were studied in the area of bloom. H. hardmanianus density was maximum (10.57 × 104 cells L-1) in the bloom site, which was almost 97% of the total phytoplankton population. The present report is the first record of H. hardmanianus bloom in the Gulf of Mannar. The chain-forming diatom Biddulphia biddulphiana was also observed in strong numbers (802 and 432 cells L-1), which has been rarely reported from the Indian coastal waters.
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Affiliation(s)
- R S Sathishkumar
- Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu, India..
| | - A Sundaramanickam
- Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu, India..
| | - Gouri Sahu
- Radiological and Environmental Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, India
| | - A K Mohanty
- Radiological and Environmental Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, India
| | - T Ramesh
- Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu, India
| | - S Ajmal Khan
- Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu, India
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12
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Dias A, Kurian S, Thayapurath S. Optical characteristics of colored dissolved organic matter during blooms of Trichodesmium in the coastal waters off Goa. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:526. [PMID: 32676790 DOI: 10.1007/s10661-020-08494-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Trichodesmium, a marine cyanobacterium, plays a significant role in the global nitrogen cycle due to its nitrogen fixing ability. Large patches of Trichodesmium blooms were observed in the coastal waters, off Goa during spring intermonsoon (SIM) of 2014-2018. Zeaxanthin was the dominant pigment in the bloom region. Here, we present the spectral absorption and fluorescence characteristics of colored dissolved organic matter (CDOM) during these blooms. CDOM concentration was much higher in the bloom patches as compared with nonbloom regions. During the bloom spectral CDOM absorption had distinct peaks in the UV region due to the presence of UV-absorbing/screening compounds, mycosporine-like amino acids (MAAs) and in the visible region due to phycobiliproteins (PBPs). The spectral fluorescence signatures by the traditional peak picking method exhibited three peaks, one was protein-like, and the other two were humic-like. Apart from these, Trichodesmium exhibited strong protein-like fluorescence with 370/460 nm (Ex/Em), which is a signature of cyanobacteria. A parallel factor analysis (PARAFAC) on the fluorescence excitation-emission matrix (EEM) of Trichodesmium dataset fitted a 3-component model of which one was protein-like, and two were humic-like. The fluorescence index (FI) values during Trichodesmium bloom was very high (~ 3) compared with the typical range of 1.2-1.8 observed for the natural waters. Bloom degradation experiments proved that increase in tryptophan fluorescence enhances the CDOM absorption. Our study indicates that Trichodesmium blooms provide a rich source of organic matter in the coastal waters and long-term monitoring of these blooms is essential for understanding the health of ecosystem.
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Affiliation(s)
- Albertina Dias
- CSIR-National Institute of Oceanography, Dona Paula, Goa, 403004, India
- School of Earth, Ocean and Atmospheric Sciences, Goa University, Goa, 403206, India
| | - Siby Kurian
- CSIR-National Institute of Oceanography, Dona Paula, Goa, 403004, India.
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13
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Jabir T, Vipindas PV, Jesmi Y, Valliyodan S, Parambath PM, Singh A, Abdulla MH. Nutrient stoichiometry (N:P) controls nitrogen fixation and distribution of diazotrophs in a tropical eutrophic estuary. MARINE POLLUTION BULLETIN 2020; 151:110799. [PMID: 32056594 DOI: 10.1016/j.marpolbul.2019.110799] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen fixation and its ecological regulation are poorly understood in the tropical estuaries, which are highly influenced by anthropogenic disturbances. In this study, we investigated the role of nutrient stoichiometry in the diversity, abundance and activity of N2-fixing bacterial community and their seasonal variations in the water column of a tropical eutrophic estuary (Cochin estuary). The N2 fixation rates in the estuary ranged from 0.1 to 2.0 nmol N2 l-1 h-1, with higher activity during post-monsoon and lower during monsoon. The rates are appeared to be primarily controlled by dissolved inorganic nitrogen and phosphorous (N:P) ratio. Clone library analysis of nitrogenase (nifH) gene revealed that the major N2 fixing phylotypes belong to Cluster I and Cluster III diazotrophs. The overall findings of this study suggest that monsoon induced seasonal changes in nutrient stoichiometry control the distribution and activity of diazotrophs in a tropical estuary.
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Affiliation(s)
- Thajudeen Jabir
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi 682016, Kerala, India.
| | - Puthiya Veettil Vipindas
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi 682016, Kerala, India
| | - Yousuf Jesmi
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi 682016, Kerala, India; School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala 686560, India
| | - Sudheesh Valliyodan
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi 682016, Kerala, India; Centre for Marine Living Resources and Ecology, LNG Rd, Puthuvype, Kochi, Kerala, India 682508
| | | | - Arvind Singh
- Physical Research Laboratory, Ahmedabad 380 009, India
| | - Mohamed Hatha Abdulla
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi 682016, Kerala, India.
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14
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Wu C, Kan J, Liu H, Pujari L, Guo C, Wang X, Sun J. Heterotrophic Bacteria Dominate the Diazotrophic Community in the Eastern Indian Ocean (EIO) during Pre-Southwest Monsoon. MICROBIAL ECOLOGY 2019; 78:804-819. [PMID: 31037377 DOI: 10.1007/s00248-019-01355-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 03/05/2019] [Indexed: 06/09/2023]
Abstract
The diazotrophic communities play an important role in sustaining primary productivity through adding new nitrogen to oligotrophic marine ecosystems. Yet, their composition in the oligotrophic Indian Ocean is poorly understood. Here, we report the first observation of phylogenetic diversity and distribution of diazotrophs in the Eastern Indian Ocean (EIO) surface water (to 200 m) during the pre-southwest monsoon period. Through high throughput sequencing of nifH genes, we identified diverse groups of diazotrophs in the EIO including both non-cyanobacterial and cyanobacterial phylotypes. Proteobacteria (mainly Alpha-, Beta-, and Gamma-proteobacteria) were the most diverse and abundant groups within all the diazotrophs, which accounted for more than 86.9% of the total sequences. Cyanobacteria were also retrieved, and they were dominated by the filamentous non-heterocystous cyanobacteria Trichodesmium spp. Other cyanobacteria such as unicellular diazotrophic cyanobacteria were detected sporadically. Interestingly, our qPCR analysis demonstrated that the depth-integrated gene abundances of the diazotrophic communities exhibited spatial heterogeneity with Trichodesmium spp. appeared to be more abundant in the Bay of Bengal (p < 0.05), while Sagittula castanea (Alphaproteobacteria) was found to be more dominating in the equatorial region and offshores (p < 0.05). Non-metric multidimensional scaling analysis (NMDS) further confirmed distinct vertical and horizontal spatial variations in the EIO. Canonical correspondence analysis (CCA) indicated that temperature, salinity, and phosphate were the major environmental factors driving the distribution of the diazotroph communities. Overall, our study provides the first insight into the diversity and distribution of the diazotrophic communities in EIO. The findings from this study highlight distinct contributions of both non-cyanobacteria and cyanobacteria to N2 fixation. Moreover, our study reveals information that is critical for understanding spatial heterogeneity and distribution of diazotrophs, and their vital roles in nitrogen and carbon cycling.
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Affiliation(s)
- Chao Wu
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Jinjun Kan
- Microbiology Division, Stroud Water Research Center, Avondale, PA, 19311, USA
| | - Haijiao Liu
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Laxman Pujari
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Congcong Guo
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Xingzhou Wang
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Jun Sun
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China.
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China.
- College of Marine & Environmental Sciences, Tianjin University of Science and Technology, No.29 13th Avenue, TEDA, Tianjin, 300457, People's Republic of China.
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