title: Environmental dynamics of red Noctiluca scintillans bloom in tropical coastal waters.
abstract: An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll-a biomass as the bloom declined, with diminishing picoplankton abundance likely the result of high predation by the ciliate Mesodinium rubrum. Together, these data illustrate factors that can disrupt ecosystem balance in this critically important Indian coastal region.
authors.affiliation: Indian National Centre for Ocean Information Services (INCOIS), Ocean Valley, Pragathi Nagar (BO), Nizampet (SO), Hyderabad 500090.
authors.forename: S K
authors.initials: SK
authors.lastname: Baliarsingh
authors.affiliation: Indian National Centre for Ocean Information Services (INCOIS), Ocean Valley, Pragathi Nagar (BO), Nizampet (SO), Hyderabad 500090. Electronic address: aneesh@incois.gov.in.
authors.forename: Aneesh A
authors.initials: AA
authors.lastname: Lotliker
authors.affiliation: National Oceanic and Atmospheric Administration (NOAA), Northwest Fisheries Science Center, Seattle, Washington, USA.
authors.forename: Vera L
authors.initials: VL
authors.lastname: Trainer
authors.affiliation: School of Marine Sciences, University of Maine, Orono, ME, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Wells
authors.affiliation: Department of Marine Sciences, Berhampur University, Odisha -760007, India.
authors.forename: Chandanlal
authors.initials: C
authors.lastname: Parida
authors.affiliation: Department of Marine Sciences, Berhampur University, Odisha -760007, India.
authors.forename: Biraja K
authors.initials: BK
authors.lastname: Sahu
authors.affiliation: Department of Marine Sciences, Berhampur University, Odisha -760007, India.
authors.forename: Suchismita
authors.initials: S
authors.lastname: Srichandan
authors.affiliation: Department of Marine Sciences, Berhampur University, Odisha -760007, India.
authors.forename: Subhashree
authors.initials: S
authors.lastname: Sahoo
authors.affiliation: Department of Marine Sciences, Berhampur University, Odisha -760007, India.
authors.forename: K C
authors.initials: KC
authors.lastname: Sahu
authors.affiliation: Indian National Centre for Ocean Information Services (INCOIS), Ocean Valley, Pragathi Nagar (BO), Nizampet (SO), Hyderabad 500090.
authors.forename: T Sinivasa
authors.initials: TS
authors.lastname: Kumar
mesh_terms: D000641:Ammonia / Q000032:analysis / Q000378:metabolism; D000818:Animals; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D016798:Ciliophora / Q000502:physiology; D033342:Copepoda; D004141:Dinoflagellida / Q000254:growth & development*; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D005068:Eutrophication; D020387:Food Chain; D007194:India; D010839:Phytoplankton / Q000254:growth & development; D011157:Population Dynamics; D037401:Scyphozoa / Q000502:physiology; D014329:Tropical Climate; D015048:Zooplankton
chemical_list: D002734:Chlorophyll; D000641:Ammonia; D000077194:Chlorophyll A
keywords: Bay of Bengal; Noctiluca scintillans; bloom; chlorophyll; nutrient; picoplankton