Role of microbial and phytoplanktonic communities in the control of seawater viscosity off West Antarctica (30-80°W).
International audience Despitethelong-standingbeliefthatseawaterviscosityisdrivenbytemperatureandsalinity, biologicallyincreasedseawaterviscosityhasrepeatedlybeenreportedinrelationtophytoplankton exudatesinshallow,productivecoastalwaters.Here,seawaterviscositywasinvestigatedinrelationto microbialand...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
---|---|
Main Authors: | , , , , , , , , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2010
|
Subjects: | |
Online Access: | https://hal.science/hal-00767876 https://doi.org/10.1016/j.dsr2.2008.09.018 |
Summary: | International audience Despitethelong-standingbeliefthatseawaterviscosityisdrivenbytemperatureandsalinity, biologicallyincreasedseawaterviscosityhasrepeatedlybeenreportedinrelationtophytoplankton exudatesinshallow,productivecoastalwaters.Here,seawaterviscositywasinvestigatedinrelationto microbialandphytoplanktoniccommunitiesoffthecoastofEastAntarcticaalonglatitudinaltransects located between301E and801E insub-surfacewatersandatthedeepchlorophyllmaximum(DCM).The physicalcomponentofseawaterviscosityobservedalongeachtransectsrangedfrom1.80to1.95cP, while theactualseawaterviscosityrangedfrom1.85to3.69cP.Thisresultedinbiologicallyincreased seawaterviscosityreachingupto84.9%insub-surfacewatersand77.6%attheDCM.Significantpositive correlationswerefoundbetweenelevatedseawaterviscosityand(i)bacterialabundanceinsub-surface watersand(ii)chlorophyll a concentrationandtheabundanceofflowcytometrically-definedauto-and heterotrophicprotistsattheDCM.Amongthe12groupsand108speciesofprotistsidentifiedunder light microscopy,dinoflagellatesandmorespecifically Alexandriumtamarense and Prorocentrum sp. were themaincontributorstothepatternsobservedforelevatedseawaterviscosity.Ourobservations, which generalisedthelinkpreviouslyidentifiedbetweenseawaterviscosityandphytoplankton compositionandstandingstocktotheSouthernOcean,arethefirstdemonstrationofincreasesin seawaterviscositylinkedtomarinebacterialcommunities,andsuggestthatthemicrobially-increased viscositymightquantitativelybeatleastasimportantastheonerelatedtophytoplanktonsecretion. & 2009 ElsevierLtd.Allrightsreserved |
---|