One of the arguments I’ve made over the years, one which has annoyed economists no end, has been that catch-to-limit fisheries will always fail. The basic framework of the argument is that while, yes, economists can devise effective rules for fishing given basic knowledge of the fisheries – we don’t actually have that knowledge. We too often fool ourselves into thinking we have the fisheries biology down when there are millions of dollars on the line. Everyone, from the boat captain to the Senator, wants there to be an answer so that someone can get fishing and make some money. On the other hand, there isn’t a real strong constituency for “we don’t really know enough” or “we don’t have the answer.” It’s just a sad flaw in human reasoning that any scientist who says that is shunted off, and a scientist who says “we can catch exactly 1234 tons of cod” is preferred. We foolishly think that a precise answer is an accurate one.
(The second part of the argument is the mathematical intuition that fishing to a limit amplifies errors, and that errors on the “take too many” side are more cumulative than errors on the “take too few” side.)
Anyway, more evidence that not only don’t we know, but that nature can bite us on the butt:
Did the North Atlantic fisheries collapse due to fisheries-induced evolution?
We are becoming more aware that our fishing changes not just the inter-species dynamics, but the species themselves.
[As I wake up a bit, I realize that I should have made clear that by "catch-to-limit" I mean fishing to "maximum sustainable yield." That is sailing too close to the edge. The alternatives are extremely conservative limits, "certain sustainable yield" or going over to rely more on MPAs, Marine Protected Areas. MPAs are better from a black-box perspective. We don't have to know so much about what goes on inside them, just as long as we set them aside and don't mess with them.]