Premium
Large‐scale impact of the island mass effect through nitrogen fixation in the western South Pacific Ocean
Author(s) -
Shiozaki Takuhei,
Kodama Taketoshi,
Furuya Ken
Publication year - 2014
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 - 10.1002/2014gl059835
Subject(s) - trichodesmium , terrigenous sediment , environmental science , oceanography , upwelling , ocean gyre , subtropics , nitrogen , ecosystem , nitrogen fixation , new production , nutrient , geology , ecology , chemistry , biology , diazotroph , sedimentary rock , geochemistry , phytoplankton , organic chemistry
We describe a new mechanism for the island mass effect fueled by nitrogen fixation. The nitrogen fixation activities and δ 15 N of suspended particles in the surface water in the South Pacific were examined. Active nitrogen fixation and abundant Trichodesmium spp. were observed near islands in the western subtropical region, which was attributable to the material supplied by land runoff. High primary production was extensively centered around the islands and was characterized by low δ 15 N of suspended particles and a reduction in phosphate concentrations at the surface compared with the subtropical gyre and eastern equatorial upwelling. This suggested that Trichodesmium spp. were advected to areas remote from these islands, and consequently, the elevated primary production fueled by nitrogen fixation extended over a large area around them. Because the proposed island mass effect is triggered by a terrigenous nutrient supply, this ecosystem is potentially vulnerable to human activity on small islands.