A rogue ocean fertilization experiment carried out in 2012 may well prove to be the saviour of the world-renowned Fraser River sockeye salmon run.
When details of this experiment emerged it was widely condemned by scientists, and environmentalists.
And yet, here’s the thing; it appears that this rogue experiment may have worked, and worked much more dramatically than anyone could have foreseen.
One of the most critical nutrients required by phytoplankton is iron.
For this reason, it has been suggested by a number scientists that adding iron to the ocean could have a beneficial effect on marine life. However the scientists who suggested this approach urged caution, since the effects of ocean fertilization on a large-scale are largely unknown.
Another potential benefit of ocean fertilization is that it could offer a way of sequestering atmospheric carbon. As phytoplankton multiply they use carbon in the process of photosynthesis, just as land-based vegetation does. The theory is that eventually the phytoplankton die and sink to the bottom of the ocean, where the carbon becomes locked up in sediments on the sea floor. Though not yet scientifically verified, there is reason to believe that large-scale ocean fertilization could sequester significant amounts of atmospheric carbon.
After the experiment became public, it was roundly condemned by environmentalists and scientists alike. However within a few months, satellite imagery showed that a massive 10,000 square kilometer phytoplankton bloom had developed in the Gulf of Alaska, centered around the area which was seeded with iron sulfate. The following year, in 2013, catches of pink salmon from the Pacific Northwest showed a 400% increase over the previous year. The latest estimates for the 2014 Fraser River sockeye run are more than double the numbers for 2010. This would be unprecedented, and would represent by far the biggest ever recorded run of sockeye salmon on the Fraser River.
While its potential effectiveness in removing CO2 from the atmosphere remains unproven, many scientists believe that ocean fertilization may be an inexpensive way of countering a significant percentage of anthropogenic CO2 emissions.
There have also been charges that ocean fertilization constitutes geoengineering. If this is the case, what about fertilization of agricultural crops, and the runoff of fertilizer into the ocean? This is unintentional geoengineering, with largely negative consequences.
The removal of atmospheric carbon is not about finding an excuse to carry on with business as usual. It needs to be carried out in parallel with decarbonising our economy. Moving to a low carbon economy does nothing about the extra carbon we have already added to the atmosphere. The only way to deal with that is through direct removal of CO2 from the atmosphere, and the take up of CO2 by photosynthesizing phytoplankton is analogous to encouraging forest growth on land, in that natural processes are being used to reduce atmospheric carbon levels. The process of ocean seeding has exactly the same effect as a large dust storm blowing iron-rich dust into the sea, a process which occurs frequently in the natural world.