Seven Ocean Fertilization Strategies
by William S. Clarke
Buoyant, long-lasting flakes can release nutrients slowly, avoiding nutrients waste and allowing balanced marine ecosystems to develop over a period of about one year. The flakes can be blown from ships’ holds to cover large ocean surfaces.
Seven different strategies have been identified that use these flakes.
1. Phosphate-rich, but iron- and silica-deficient areas of the global oceans south of 42° South, together with some Arctic and sub-Arctic waters, can be addressed with buoyant flakes carrying ultra-slow-release iron and silica minerals to generate albedo increase, marine biomass and carbon biosequestration.
2. The highly stratified and nutrient-impoverished seas of the Caribbean and many tropical waters may be addressed using flakes bearing a mix of nutrients, chief of which are phosphate wastes (from Florida, Morocco and Australia), iron, silica and trace elements. Whilst this provision should help to transport dissolved inorganic carbon (DIC) somewhat deeper into the highly stratified sea by the oceanic carbon pump, its main functions will be to generate increased albedo (reflectiveness) of both the ocean surface and of the marine clouds above it; to generate additional marine biomass; and to make some contribution to reducing ocean acidification, ocean surface temperature and consequently hurricane strength.
3. Some favorable tropical locations, where there are frigid currents running beneath the surface, may use Ocean Thermal Energy Conversion (OTEC) pumping mechanisms to generate power, potable water and the uplifted, nutrient-rich waters needed to fertilize mariculture operations.
4. The temperature/nutrient/salinity stratified waters of the Gulf of Mexico, with their excessively-‐nutriated benthic waters (from the Mississippi) and often impoverished surface waters, together with other oceans where the needed nutrients can be found in deeper water, are probably best addressed by wave or wind powered pumping mechanisms. These bring nutrients to the nutrient-‐deficient surface where they can be used by phytoplankton and in cultivated macrophyta (kelp and sargassum) forests. The process also tends to cool the warm surface water by mixing it with cooler water from the depths and by increased solar reflection.
5. Fertilizing polar waters with buoyant flakes, that include in the fertilizer mix minerals containing tungsten, cobalt, nickel and molybdenum (Glass et al. 2013) plus possibly gypsum (calcium sulfate) and seed methanotrophs (methane eaters), could play a vital part in converting huge and potentially catastrophic methane emissions occurring there into less hazardous CO2 which may itself then be converted into biomass by fertilized phytoplankton. These trace elements, but the tungsten in particular, are necessary for the production of metalloenzymes that catalyze the anaerobic oxidation of methane. Other methanotrophs would oxidize more methane aerobically in the water column above the anaerobic sediments.
6. Temperate oceans will each need to be treated differentially, depending on the mix of the nutrient concentrations already in their water columns and what can be used there near the surface by phytoplankton and macrophyta.
7. Productive ocean areas, coral reefs, seagrass meadows, and most inshore waters should typically not be treated at all, except conceivably when there are seasonal or otherwise temporary nutrient deficiencies that might beneficially be offset by the use of nutritive flakes. In many ocean regions, different combinations of these methods will be optimal.
Buoyant, long-lasting flakes can release nutrients slowly, avoiding nutrients waste and allowing balanced marine ecosystems to develop over a period of about one year. The flakes can be blown from ships’ holds to cover large ocean surfaces.
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| Global biosphere—the ocean's long-term average phytoplankton chlorophyll concentration between September 1997 and August 2000 combined with the SeaWiFS-derived Normalized Difference Vegetation Index over land during July 2000. |
Seven different strategies have been identified that use these flakes.
1. Phosphate-rich, but iron- and silica-deficient areas of the global oceans south of 42° South, together with some Arctic and sub-Arctic waters, can be addressed with buoyant flakes carrying ultra-slow-release iron and silica minerals to generate albedo increase, marine biomass and carbon biosequestration.
2. The highly stratified and nutrient-impoverished seas of the Caribbean and many tropical waters may be addressed using flakes bearing a mix of nutrients, chief of which are phosphate wastes (from Florida, Morocco and Australia), iron, silica and trace elements. Whilst this provision should help to transport dissolved inorganic carbon (DIC) somewhat deeper into the highly stratified sea by the oceanic carbon pump, its main functions will be to generate increased albedo (reflectiveness) of both the ocean surface and of the marine clouds above it; to generate additional marine biomass; and to make some contribution to reducing ocean acidification, ocean surface temperature and consequently hurricane strength.
3. Some favorable tropical locations, where there are frigid currents running beneath the surface, may use Ocean Thermal Energy Conversion (OTEC) pumping mechanisms to generate power, potable water and the uplifted, nutrient-rich waters needed to fertilize mariculture operations.
4. The temperature/nutrient/salinity stratified waters of the Gulf of Mexico, with their excessively-‐nutriated benthic waters (from the Mississippi) and often impoverished surface waters, together with other oceans where the needed nutrients can be found in deeper water, are probably best addressed by wave or wind powered pumping mechanisms. These bring nutrients to the nutrient-‐deficient surface where they can be used by phytoplankton and in cultivated macrophyta (kelp and sargassum) forests. The process also tends to cool the warm surface water by mixing it with cooler water from the depths and by increased solar reflection.
5. Fertilizing polar waters with buoyant flakes, that include in the fertilizer mix minerals containing tungsten, cobalt, nickel and molybdenum (Glass et al. 2013) plus possibly gypsum (calcium sulfate) and seed methanotrophs (methane eaters), could play a vital part in converting huge and potentially catastrophic methane emissions occurring there into less hazardous CO2 which may itself then be converted into biomass by fertilized phytoplankton. These trace elements, but the tungsten in particular, are necessary for the production of metalloenzymes that catalyze the anaerobic oxidation of methane. Other methanotrophs would oxidize more methane aerobically in the water column above the anaerobic sediments.
6. Temperate oceans will each need to be treated differentially, depending on the mix of the nutrient concentrations already in their water columns and what can be used there near the surface by phytoplankton and macrophyta.
7. Productive ocean areas, coral reefs, seagrass meadows, and most inshore waters should typically not be treated at all, except conceivably when there are seasonal or otherwise temporary nutrient deficiencies that might beneficially be offset by the use of nutritive flakes. In many ocean regions, different combinations of these methods will be optimal.
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