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Volcanic ash fuels anomalous plankton bloom in subarctic northeast Pacific
Author(s) -
Hamme Roberta C.,
Webley Peter W.,
Crawford William R.,
Whitney Frank A.,
DeGrandpre Michael D.,
Emerson Steven R.,
Eriksen Charles C.,
Giesbrecht Karina E.,
Gower Jim F. R.,
Kavanaugh Maria T.,
Peña M. Angelica,
Sabine Christopher L.,
Batten Sonia D.,
Coogan Laurence A.,
Grundle Damian S.,
Lockwood Deirdre
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl044629
Subject(s) - iron fertilization , subarctic climate , volcanic ash , bloom , oceanography , volcano , geology , phytoplankton , plankton , algal bloom , environmental science , dominance (genetics) , nutrient , geochemistry , ecology , chemistry , biochemistry , gene , biology
Using multiple lines of evidence, we demonstrate that volcanic ash deposition in August 2008 initiated one of the largest phytoplankton blooms observed in the subarctic North Pacific. Unusually widespread transport from a volcanic eruption in the Aleutian Islands, Alaska deposited ash over much of the subarctic NE Pacific, followed by large increases in satellite chlorophyll. Surface ocean pCO 2 , pH, and fluorescence reveal that the bloom started a few days after ashfall. Ship‐based measurements showed increased dominance by diatoms. This evidence points toward fertilization of this normally iron‐limited region by ash, a relatively new mechanism proposed for iron supply to the ocean. The observations do not support other possible mechanisms. Extrapolation of the pCO 2 data to the area of the bloom suggests a modest ∼0.01 Pg carbon export from this event, implying that even large‐scale iron fertilization at an optimum time of year is not very efficient at sequestering atmospheric CO 2 .