To fill temporal gaps in iron-enrichment experimental data and gain further understanding of marine ecosystem responses to iron enrichments, we apply a fifteen-compartment ecosystem model to three iron-enrichment sites, namely SEEDS (the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study; 48.5 N, 165 E) in the western North Pacific, SOIREE (the Southern Ocean Iron RElease Experiment...

Active #uorescence (fast repetition rate #uorometry, FRRF) was used to follow the photosynthetic response of the phytoplankton community during the 13-day Southern Ocean Iron RElease Experiment (SOIREE). This in situ iron enrichment was conducted in the polar waters of the Australasian}Paci"c sector of the Southern Ocean in February 1999. Iron fertilisation of these high nitrate low chlorophyll...

The bioleachings of chalcopyrite ore were compared after inoculating different cultures enriched from the original acid mine drainage sample. The results showed that the higher bioleaching performance was achieved for inoculation with the enrichment D (0.5 % S, 2 % iron and 1 % chalcopyrite) compared to other enrichment systems. The generated ferric precipitation during bioleaching had a key in...

Geoengineering to mitigate climate change has long been proposed, but remains nebulous. Exploration of the feasibility of geoengineering first requires the development of research governance to move beyond the conceptual towards scientifically designed pilot studies. Fortuitously, 12 mesoscale (approx. 1000 km2) iron enrichments, funded to investigate how ocean iron biogeochemistry altered Eart...

In vast expanses of the oceans, growth of large phytoplankton such as diatoms is limited by iron availability. Diatoms respond almost immediately to the delivery of iron and rapidly compose the majority of phytoplankton biomass. The molecular bases underlying the subsistence of diatoms in iron-poor waters and the plankton community dynamics that follow iron resupply remain largely unknown. Here...

Methanosaeta harundinacea and Methanosarcina barkeri, known as classic acetoclastic methanogens, are capable of directly accepting electrons from Geobacter metallireducens for the reduction of carbon dioxide to methane, having been revealed as direct interspecies electron transfer (DIET) in the laboratory co-cultures. However, whether their co-occurrences are ubiquitous in the iron (III)-reduci...

Iron-reducing bacteria can transfer electrons to ferric iron oxides which are barely soluble at neutral pH, and electron-shuttling compounds or chelators are discussed to be involved in this process. Experiments using semipermeable membranes for separation of ferric iron-reducing bacteria from ferric iron oxides do not provide conclusive results in this respect. Here, we used ferrihydrite embed...

soil reduces the hazardous effects of compounds on the components of ecosystem because of self –purification property and the ability for their fixation. playing such a role in soils under redox conditions is performed by pedogenic fe-mn concentrations. in order to investigate cobalt, copper and lead accumulation in iron and manganese concentrations, at first the concentrations were precisely s...

The response of the heterotrophic bacterial community to iron addition was determined during the mesoscale iron-enrichment experiment conducted in the eastern equatorial Pacific during May–June 1995 (IronEx II). Bacterial abundance and 3H-leucine incorporation rates were measured for samples collected from the middle of the mixed layer (15 m) over the course of the iron-induced phytoplankton bl...