Open AccessEffects of iron, silicate, and light on dimethylsulfoniopropionate production in the Australian Subantarctic Zone
Author(s) -
DiTullio G. R.,
Sedwick P. N.,
Jones D. R.,
Boyd P. W.,
Crossley A. C.,
Hutchins D. A.
Publication year - 2001
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jc000446
Subject(s) - dimethylsulfoniopropionate , silicate , incubation , environmental chemistry , algae , limiting , chemistry , oceanography , phytoplankton , nutrient , botany , biology , geology , biochemistry , mechanical engineering , organic chemistry , engineering
Shipboard bottle incubation experiments were performed to investigate the effects of iron, light, and silicate on algal production of particulate dimethylsulfoniopropionate (DMSP p ) in the Subantarctic Zone (SAZ) south of Tasmania during March 1998. Iron enrichment resulted in threefold to ninefold increases in DMSP p concentrations relative to control treatments, following 7 and 8‐day incubation experiments. Additions of Fe and Si preferentially stimulated the growth of lightly‐silicified pennate diatoms and siliceous haptophytes, respectively, to which we attribute the increased DMSP p production in the incubation bottles. Both of these algal groups were previously believed to be low DMSP p producers; however, our experimental data suggest that addition of iron and silicate to the low‐silicate low‐iron waters of the SAZ will result in increased production of DMSP p by lightly silicified diatoms and siliceous haptophytes, respectively. Increased irradiance enhanced DMSP p production in iron‐amended treatments with both low (0.5 nM) and high (5 nM) concentrations of added iron. However, the role of light in stimulating DMSP p production was apparently of secondary importance compared to the effects of iron addition. The combination of high irradiance and high iron enrichment produced the highest DMSP p production in the experiments, suggesting that iron and light may have a synergistic effect in limiting algal DMSP p production in subantarctic waters.