Biogeochemical drivers of the dynamic of Vibrio species in two estuaries of the Argentinian Patagonia

KOPPRIO, G. A.; STREITENBERGER, M. E.; OKUMO, K.; BALDINI, M.; YAMASAKI, S.; BIANCALANA, F.; MARTINEZ, A.; GRAEVE, M., KOCH, B. P; LARA, R. J.

Bremen

Congreso; ECSA56: Coastal systems in transition: From a 'natural' to an 'anthropogenically-modified' state.; 2016

ZMT

TheecologyofthemostrelevantVibriospeciesforhumanhealthandtheirrelationtowaterqualityandbiogeochemistry were studied in two estuaries in Argentinian Patagonia. Vibrio cholerae and Vibrio parahaemolyticus were reported in N29% of cases at the Río Colorado and Río Negro estuaries. Neither the pandemic serogroups ofVibriocholeraeO1,VibriocholeraeO139northecholeratoxingeneweredetectedinthisstudy.However,severalstrainsofV.cholerae(notO1orO139)areabletocausehumandiseaseoracquirepathogenicgenesbyhorizontal transfer. Vibrio vulnificus was detected only in three instances in the microplankton fraction of the Río Negro estuary. The higher salinity in the Río Colorado estuary and in marine stations at both estuaries favours anabundanceofculturableVibrio.Theextremepeaksforammonium,heterotrophicbacteriaandfaecalcoliforms intheRíoNegroestuarysupportedamarkedimpactonsewagedischarge.Generally,themorepathogenicstrains of Vibrio have a faecal origin. Salinity, pH, ammonium, chlorophyll a, silicate and carbon/nitrogen ratio of suspended organic particulates were the primary factors explaining the distribution of culturable bacteria after distance-based linear models. Several effects of dissolved organic carbon on bacterial distribution are inferred.GlobalchangeisexpectedtoincreasethetrophicstateandthesalinisationofPatagonianestuaries.Consequently, the distributionandabundanceofVibriospeciesisprojectedtoincreaseunderfuturechangingbaselines.Adaptationstrategiesshouldcontributetosustaininggoodwaterqualitytobufferclimate-andanthropogenic-driven impacts.