title: Biological response to physical processes in the Indian Ocean sector of the Southern Ocean: a case study in the coastal and oceanic waters.
abstract: The spatial variation of chlorophyll a (Chl a) and factors influencing the high Chl a were studied during austral summer based on the physical and biogeochemical parameters collected near the coastal waters of Antarctica in 2010 and a zonal section along 60°S in 2011. In the coastal waters, high Chl a (>3 mg m(-3)) was observed near the upper layers (∼15 m) between 53°30'E and 54°30'E. A comparatively higher mesozooplankton biomass (53.33 ml 100 m(-3)) was also observed concordant with the elevated Chl a. Low saline water formed by melting of glacial ice and snow, as well as deep mixed-layer depth (60 m) due to strong wind (>11 ms(-1)) could be the dominant factors for this biological response. In the open ocean, moderately high surface Chl a was observed (>0.6 mg m(-3)) between 47°E and 50°E along with a Deep Chlorophyll Maximum of ∼1 mg m(-3) present at 30-40 m depth. Melt water advected from the Antarctic continent could be the prime reason for this high Chl a. The mesozooplankton biomass (22.76 ml 100 m(-3)) observed in the open ocean was comparatively lower than that in the coastal waters. Physical factors such as melting, advection of melt water from Antarctic continent, water masses and wind-induced vertical mixing may be the possible reasons that led to the increase in phytoplankton biomass (Chl a).
authors.affiliation: National Centre for Antarctic and Ocean Research, Ministry of Earth Sciences, Headland Sada, Vasco-da-gama, Goa, 403804, India.
authors.forename: N
authors.initials: N
authors.lastname: Anilkumar
authors.forename: Racheal
authors.initials: R
authors.lastname: Chacko
authors.forename: P
authors.initials: P
authors.lastname: Sabu
authors.forename: Honey U K
authors.initials: HU
authors.lastname: Pillai
authors.forename: Jenson V
authors.initials: JV
authors.lastname: George
authors.forename: C T
authors.initials: CT
authors.lastname: Achuthankutty
mesh_terms: D000864:Antarctic Regions; D018533:Biomass; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D004784:Environmental Monitoring; D019156:Indian Ocean; D055585:Physical Phenomena; D010839:Phytoplankton / Q000502:physiology; D012621:Seasons; D012623:Seawater / Q000737:chemistry
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A
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