That's a very important topic that the science community is actively studying. I'll give you an example. North Sea cod is a resource that historically has been incredibly important for the region. It has been systematically overfished in large part because it straddles various countries' EEZs, so it's hard to get any one country to commit to reducing catches. I understand that most recently that has been alleviated a little bit.
So that stock is at low biomass. Superimposed on that, what is happening is that as the waters in the North Sea have warmed over the last 20 years, some of the food items that cod depend on--so it is not predators--have shifted north towards Iceland, where there's different cod. The North Sea cod has not been able to keep up with those changes. It's well documented that those changes in the ecosystem, a move towards smaller prey species, has impacted the survival of juvenile cod. So they're in a double jeopardy. They are at low biomass and they have increased mortality of juveniles and less survival, which means they will decline further.
This would not be a problem with a much larger stock that produces a larger year-class. If it had some additional mortality through climate change, that wouldn't be a problem. With a very small stock, it becomes a big problem. That's why, for example, Keith Brander, who works for ICES, has published a high-profile paper in Proceedings of the National Academy of Sciences about climate change in fisheries. He says the one thing we can do to brace fish stocks against collapse or further damage from climate change is to rebuild them to above the biomass that would allow for maximum yield. That is exactly the point we're making here. We're saying you have to do it because it makes economic sense and because it provides increased stability for resource users. He says that you also need to do it to brace stocks against increased environmental variability. That's almost invariably true in the literature when people have studied the fluctuations of these stocks.
So stocks respond to climate, and in many cases there are increasing problems through warming waters, but we can help them recover by increasing their biomass through a rebuilding strategy. That's the one thing we can do.