title: Massive outbreaks of Noctiluca scintillans blooms in the Arabian Sea due to spread of hypoxia.
abstract: In the last decade, the northern Arabian Sea has witnessed a radical shift in the composition of winter phytoplankton blooms, which previously comprised mainly of diatoms, the unicellular, siliceous photosynthetic organisms favoured by nutrient-enriched waters from convective mixing. These trophically important diatom blooms have been replaced by widespread blooms of a large, green dinoflagellate, Noctiluca scintillans, which combines carbon fixation from its chlorophyll-containing endosymbiont with ingestion of prey. Here, we report that these massive outbreaks of N. scintillans during winter are being facilitated by an unprecedented influx of oxygen deficient waters into the euphotic zone and by the extraordinary ability of its endosymbiont Pedinomonas noctilucae to fix carbon more efficiently than other phytoplankton under hypoxic conditions. We contend that N. scintillans blooms could disrupt the traditional diatom-sustained food chain to the detriment of regional fisheries and long-term health of an ecosystem supporting a coastal population of nearly 120 million people.
authors.affiliation: Lamont Doherty Earth Observatory at Columbia University, Palisades, New York 10964, USA.
authors.forename: Helga
authors.initials: H
authors.lastname: do Rosário Gomes
authors.affiliation: Lamont Doherty Earth Observatory at Columbia University, Palisades, New York 10964, USA.
authors.forename: Joaquim I
authors.initials: JI
authors.lastname: Goes
authors.affiliation: National Institute of Oceanography, Dona Paula, Goa 403004, India.
authors.forename: S G P
authors.initials: SG
authors.lastname: Matondkar
authors.affiliation: University of Texas Marine Science Institute, Port Aransas, Texas 78373, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Buskey
authors.affiliation: Department of Microbiology, Goa University, Taleigao Plateau, Goa 403206, India.
authors.forename: Subhajit
authors.initials: S
authors.lastname: Basu
authors.affiliation: Department of Geology, Kent State University, Kent Ohio 44242, USA.
authors.forename: Sushma
authors.initials: S
authors.lastname: Parab
authors.affiliation: Naval Research Laboratory, Stennis Space Center, Mississippi 39529, USA.
authors.forename: Prasad
authors.initials: P
authors.lastname: Thoppil
mesh_terms: D000460:Chlorophyta / Q000502:physiology; D004141:Dinoflagellida / Q000254:growth & development / Q000502:physiology*; D009792:Oceans and Seas; D010100:Oxygen / Q000737:chemistry*; D010788:Photosynthesis / Q000502:physiology; D012621:Seasons; D012623:Seawater / Q000737:chemistry* / Q000469:parasitology; D013559:Symbiosis / Q000502:physiology
chemical_list: D010100:Oxygen