So I was just reading over at Mostly Open Ocean about the recent iron fertilization “experiment” in the North Pacific. I did not know too much about it so I went looking for news articles (such as this one from National Geographic) about what was happening. My personal opinion is that this is a dangerous stunt being pulled by the Haida Salmon Restoration Corporation and is most definitely not a well designed, controlled scientific experiment. However, it sparked a curious thought about what happens when we mess with bottom up processes.
What I am referring to is Rosenzweig’s paradox of enrichment, whereby increasing the carrying capacity of a prey species leads to the destabilization of the system. By increasing a major limiting nutrient in the ocean (iron) the carrying capacity of phytoplankton will increase. Provided the predator isocline is vertical (as in Lotka-Volterra dynamics), which in many cases is an unrealistic assumption, we should expect the paradox to occur. I think that in this case LV predator isocline is likely for zooplankton predators, since in their case the law of mass action on which LV dynamics is fundamentally based is an apt description of the system. Based on the paradox, is this company going to be doing more harm than good?
I, and i think many others, would say yes. For a better example of what happens when we fertilize our oceans just look to the Gulf of Mexico and the massive hypoxic zone caused by fertilizer runoff from the Mississippi.