The parties to the London Dumping Convention adopted a non-binding resolution in 2008 on fertilization (labeled LC-LP.1(2008)). This single fertilization event preceded an easily observed global decline in atmospheric COĢ and a parallel pulsed increase in oxygen levels. Environmental scientist Andrew Watson analyzed global data from that eruption and calculated that it deposited approximately 40,000 tons of iron dust into oceans worldwide. Perhaps the most dramatic support for Martin's hypothesis came with the 1991 eruption of Mount Pinatubo in the Philippines. The findings suggested that iron deficiency was limiting ocean productivity and offered an approach to mitigating climate change as well. Martin's 1988 quip four months later at Woods Hole Oceanographic Institution, "Give me a half a tanker of iron and I will give you an ice age," drove a decade of research. John Gribbin was the first scientist to publicly suggest that climate change could be reduced by adding large amounts of soluble iron to the oceans. These "desolate" regions came to be called "high nutrient, low chlorophyll" ( HNLC) zones. Little scientific discussion was recorded until the 1980s, when oceanographer John Martin of the Moss Landing Marine Laboratories renewed controversy on the topic with his marine water nutrient analyses. Ĭonsideration of iron's importance to phytoplankton growth and photosynthesis dates to the 1930s when English biologist Joseph Hart speculated that the ocean's great "desolate zones" (areas apparently rich in nutrients, but lacking in plankton activity or other sea life) might be iron-deficient. Ocean trials of ocean iron fertilization took place in 2009 in the South Atlantic by project LOHAFEX, and in July 2012 in the North Pacific off the coast of British Columbia, Canada, by the Haida Salmon Restoration Corporation ( HSRC). Controversy remains over the effectiveness of atmospheric COĢ sequestration and ecological effects. Beginning in 1993, thirteen research teams completed ocean trials demonstrating that phytoplankton blooms can be stimulated by iron augmentation. Multiple ocean labs, scientists and businesses have explored fertilization. Research in the early 2020s suggested that it could only permanently sequester a small amount of carbon. The cost of distributing iron over large ocean areas is large compared with the expected value of carbon credits. The production in these high-nutrient low-chlorophyll (HNLC) waters is primarily limited by micronutrients especially iron. Īpproximately 25 per cent of the ocean surface has ample macronutrients, with little plant biomass (as defined by chlorophyll). Such effects potentially include release of nitrogen oxides, and disruption of the ocean's nutrient balance. This technique is controversial because there is limited understanding of its complete effects on the marine ecosystem, including side effects and possibly large deviations from expected behavior. Iron fertilization attempts to encourage phytoplankton growth, which removes carbon from the atmosphere for at least a period of time. Ocean iron fertilization is an example of a geoengineering technique. These blooms can nourish other organisms. Large algal blooms can be created by supplying iron to iron-deficient ocean waters. It is highly insoluble in sea water and in a variety of locations is the limiting nutrient for phytoplankton growth. Iron is a trace element necessary for photosynthesis in plants. This is intended to enhance biological productivity and/or accelerate carbon dioxide (CO 2) sequestration from the atmosphere. Iron fertilization is the intentional introduction of iron to iron-poor areas of the ocean surface to stimulate phytoplankton production.