A mesoscale iron enrichment in the western subarctic Pacific induces a large centric diatom bloom.
We have performed an in situ test of the iron limitation hypothesis in the subarctic North Pacific Ocean. A single enrichment of dissolved iron caused a large increase in phytoplankton standing stock and decreases in macronutrients and dissolved carbon dioxide. The dominant phytoplankton species shifted after the iron addition from pennate diatoms to a centric diatom, Chaetoceros debilis, that showed a very high growth rate, 2.6 doublings per day. We conclude that the bioavailability of iron regulates the magnitude of the phytoplankton biomass and the key phytoplankton species that determine the biogeochemical sensitivity to iron supply of high-nitrate, low-chlorophyll waters.
Tsuda
Atsushi
A
Hokkaido National Research Institute, Kushiro, Hokkaido 085-0802, Japan.
Takeda
Shigenobu
S
Saito
Hiroaki
H
Nishioka
Jun
J
Nojiri
Yukihiro
Y
Kudo
Isao
I
Kiyosawa
Hiroshi
H
Shiomoto
Akihiro
A
Imai
Keiri
K
Ono
Tsuneo
T
Shimamoto
Akifumi
A
Tsumune
Daisuke
D
Yoshimura
Takeshi
T
Aono
Tatsuo
T
Hinuma
Akira
A
Kinugasa
Masatoshi
M
Suzuki
Koji
K
Sohrin
Yoshiki
Y
Noiri
Yoshifumi
Y
Tani
Heihachiro
H
Deguchi
Yuji
Y
Tsurushima
Nobuo
N
Ogawa
Hiroshi
H
Fukami
Kimio
K
Kuma
Kenshi
K
Saino
Toshiro
T
D001110:Arctic Regions; D001272:Atmosphere; D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017377:Diatoms / Q000254:growth & development* / Q000378:metabolism; D017753:Ecosystem; D005068:Eutrophication; D005296:Ferrous Compounds; D007501:Iron / Q000032:analysis; D009566:Nitrates / Q000032:analysis; D010140:Pacific Ocean; D010839:Phytoplankton / Q000254:growth & development* / Q000378:metabolism; D012623:Seawater / Q000737:chemistry; D017640:Silicates / Q000032:analysis
D005296:Ferrous Compounds; D009566:Nitrates; D017640:Silicates; D002734:Chlorophyll; D002245:Carbon Dioxide; C020748:ferrous sulfate; D007501:Iron; D000077194:Chlorophyll A