In October, conservation groups, scientists, and the Canadian public were surprised to learn that an ‘ocean fertilization’ experiment had been completed off the coast of British Columbia in July. It made national and international news; sparking debate, anger, and frustration among scientists and the public.
So, what’s the big deal?
The Haida Salmon Restoration Corporation performed what they referred to as a ‘salmon restoration project’. The project involved dumping nearly 100 tonnes of iron sulphate into the ocean off the coast of B.C., claiming it would benefit the local salmon population. Although critics have said the project was really a geoengineering scheme aimed at selling carbon credits.
What is ‘Ocean Fertilization’?
Ocean fertilization is the process of adding limiting nutrients or elements to the ocean in order to promote the growth of microscopic plants, called phytoplankton. Think of it as fertilizing your lawn. By adding nitrogen to your lawn you give the grass what the soil did not have enough of. In the ocean, iron sulphate is often a limiting element that controls the amount phytoplankton that can grow. When we add iron to the water, phytoplankton have been shown to ‘bloom’, that is, they reproduce…a lot!
What does Ocean Fertilization have to do with Climate Change?
In the 1980s John Martin decided to re-investigate an old idea; if we add limiting elements and nutrients to the oceans, can we increase productivity? Basically, the idea was that if you add iron sulphate to the ocean it will promote phytoplankton blooms. Because phytoplankton are plants, they use the carbon dioxide from the air to make oxygen, just like trees. It has been proposed that phytoplankton in these large ‘fertilized’ blooms could help global climate change by removing carbon dioxide from the atmosphere. The amount of carbon dioxide (and other greenhouse gases) in the atmosphere is a leading cause of climate change.
Why is Ocean Fertilization not a great idea?
You may be asking; “if we can remove carbon from the atmosphere and help local salmon populations, why have scientists, along with the United Nations and other conservation organizations (including World Wildlife Fund) said ‘No’ to ocean fertilization?” What’s the problem?
Here’s a brief list:
- A recent research study showed that “up to half” of the plankton bloom may die and sink to the ocean bottom, taking the carbon with them. We don’t know what happens to the other half of that plankton bloom.
- The ocean bottom is not always barren. It can provide important habitat for many organisms, including deep sea corals, juvenile fish, crabs, lobster, and other bottom dwelling animals. This is especially true closer to shore. The home of these bottom dwelling creatures may be impacted by the dying phytoplankton. Bacteria living on the ocean floor use oxygen from the water as they digest the phytoplankton that have rained down on them. This can create an oxygen ‘dead zone’. Dead zones can lead to fish kills as well as harm many of the creatures that live on the ocean floor.
- The cost effectiveness of ocean fertilization is very low. It costs a lot of money to get all of the necessary material out to sea, because a large amount of iron must be added to see any change in phytoplankton abundance.
- Some research shows that methane and nitrous oxide may be released back into the atmosphere when some of the phytoplankton die. You guessed it, those gases also influence climate change!
- All life in the ocean is connected. We call this the food web. If you add a lot of biomass to the bottom of the food web there may be untold implications for every rung on the web. What’s not clear is, how much bottom biomass is too much? What species would benefit, or be harmed? How long will a single phytoplankton bloom influence the local food web? Scientists are still looking for answers to these questions.
Overall, the scientific community has been clear: right now, the risk of ocean fertilization far outweighs the benefits. All signatory countries of the UN convention on biological diversity, including Canada, voluntarily agreed to NOT participate in ocean fertilization. What is not clear, however, is how involved was the Canadian government in this project? Why was no action taken to stop the ‘non-experiment’? Did the project really occur outside of Canada’s 200-mile territory? We’ll be waiting to see if the enforcement branch of Environment Canada takes action to find out answers to these important questions. Unfortunately, all we can do now is wait to see if the world’s largest ocean fertilization ‘experiment’ has any effect on carbon sequestration, salmon rehabilitation, or the larger food web.