Ocean Nourishment is a form of biomimicry and biological sequestration and is analogous to biosphere carbon stock management through afforestation and avoided deforestation. The aim of Ocean Nourishment is to increase the amount of carbon involved in the naturally occurring organic carbon cycle, through the enhancement of phytoplankton stocks in nitrogen deficient regions of the world's oceans.

The patented Ocean Nourishment™ technology, involves the production of a form of nitrogen that can be delivered to the nitrogen deficient regions of the world's oceans.

Nitrogen is extracted from the air and combined with hydrogen to firstly form liquid ammonia. Liquid ammonia is combined with CO₂ at high pressure to form ammonium carbamate, which is then dehydrated, to form urea and water. The liquid urea is mixed with other limiting nutrients to produce a nutrient mix. The mix is diluted in seawater and can be delivered, via a marine pipeline or ship, to the continental shelf where it is diffused into the photic (sunlit) zone of the ocean.

The nutrient stimulates further growth of standing stocks of phytoplankton through photosynthesis. Phytoplankton form the base of the marine food chain and their increased growth both absorbs CO₂ from the atmosphere and stimulates the marine food web leading to increased ocean productivity. The result is biomimicry of the natural upwelling of nutrients from deep ocean waters.

The phytoplankton lifecycle is short (approximately 5 days). They decompose and either sink directly to the ocean floor or remineralise releasing further nutrients that support further phytoplankton growth. A small percentage of the organic carbon is deposited on the ocean floor where it remains for the long-term defined in hundreds of years.

The benefits of the Ocean Nourishment™ process are twofold:

Firstly, the removal of CO₂ from the atmosphere, the main greenhouse gas driving global warming.

One Ocean Nourishment™ site will remove approximately 5-8 million tonnes of CO₂ from the atmosphere for each year of operation, equivalent to offsetting annual emissions from a typical 1000MW coal-fired power station or the short-term sequestration from one million hectares of new growth forest.

Secondly, stimulation of the base of the food chain, resulting in increased marine productivity.

For every tonne of nitrogen infused into the ocean, 1.1 tonnes of fish (wet weight) may be produced.

The Ocean Nourishment™ process is suitable to areas of the ocean deficient in nitrogen. This applies to approximately 70% of the ocean (as shown in blue in the figure below).


Image: http://www.atmosphere.mpg.de/enid/1vv.html

The process is only applicable to deep ocean sites and is not suitable for shallow bays or coastal waters. Other factors that influence site selection include the distance to the continental shelf, seabed bathymetry, upper ocean temperatures, ocean circulation, dissolved oxygen concentration, location of marine protected areas, chlorophyll content and abundance of fish larvae.

The site selection process also takes into account the political, economic and social conditions of host countries, for example, the political stability, economic environment, imports of NH₄ or urea, availability of suitable feed stock for producing reactive nitrogen, existing fisheries infrastructure and the importance of low cost protein to local diets.