Ocean Iron Fertilization

Image Source: Woods Hole Oceanographic Institution 1999 Annual Report

Scientists have been exploring many ideas in the last year for reducing carbon dioxide levels in the earth's atmosphere. One idea that has some proponents is called "ocean iron fertilization." This involves sprinkling iron into the ocean to encourage the growth of plankton. The plankton then absorb carbon dioxide from the atmosphere. In theory, when the plankton die, they fall to the bottom of the ocean, but do not release the carbon dioxide like plants do when they die. Instead, they 'sequester' it. Then we can sprinkle more iron and make more plankton. Many people agree that some additional plankton would probably be a good thing for the ocean, as worldwide levels have declined since the 1980s.

There is quite a bit of debate as to whether scientists or private companies should be the ones to lead the way in this research. Several commercial ventures want to use ocean iron fertilization as a way to make money off of carbon credits, explained in an earlier Future Earth Post.

Small-scale experiments are already being conducted. Australian news organization ABC reports that a company called Ocean Nourishment Corporation (ONC) has just completed an experiment involving 1 tonne of nitrogen in the Sulu Sea off the Philippines, says managing director John Ridley. The company is now discussing with the Philippines government plans to scale up the experiment to 1000 tonnes of nitrogen over the next year. Ridley says the company is also talking to the Moroccan government about similar experiments in the Atlantic Ocean.

One American company, Planktos, announced in February that the company has been forced to indefinitely postpone its ocean fertilization efforts once intended to restore marine plant life and generate ecological offsets for the global carbon credit market. A highly effective disinformation campaign waged by anti-offset crusaders has provoked widespread opposition to plankton restoration in the environmental world, and has caused the company to encounter serious difficulty in raising the capital needed to fund its planned series of ocean research trials. The company's wholly-owned research vessel Weatherbird II and crew have been called back from the Portuguese island of Madeira where the ship had been docked awaiting the resources necessary to initiate and monitor its first research plankton blooms. The ship has since been sold.

Another American company, Climos, is attracting investors and moving forward with plans to obtain permits for experiments in 2009. Read more in today's Sacramento Bee.

Natural plankton blooms commonly occur in the ocean, and while they provide a source of food for fish and marine animals, they have also been shown to absorb vast amounts of oxygen, nitrate and phosphate, leading to fish die-offs. Some species of plankton, commonly known as 'red tide' have been shown to be harmful, containing toxins that kill wildlife.

The Vancouver Sun reported that 16 oceanographers from the U.S., Europe, New Zealand and Japan, issued a statement, published published in the journal Science saying that there is, as yet, "no scientific basis" for issuing carbon credits for ocean iron fertilization. They say offsets should not be allowed until there is "better demonstration" that spreading iron dust on the ocean "effectively removes CO2, retains that carbon in the ocean for a quantifiable amount of time, and has acceptable and predictable environmental impacts."

According to Nature News,the parties to the London Convention, an international treaty that governs ocean pollution, have agreed that large-scale ocean ‘fertilization’ isn't yet justified, given gaps in scientific knowledge.


Further reading:
Treehugger.com
Iron Fertilization News
The Vancouver Sun