The greater concern, I think, is the impact on other species of a change in the nutrient content of their food. Ecosystems can be quite fragile and such a shift could have ramifications we can't foresee. Food chains may break down. And all this takes place in ecosystems that are already stressed due to temperature change, atmospheric change, the effects of agriculture, ocean acidification, ocean deoxygenization, etc. We're applying so much stress across the whole planet that it's unpredictable where breakages are going to take place. The nutrient issue is one more source of stress, and one more reminder that these systems are so complex that our actions have unpredictable effects.