Junebug, don't Menhaden stay primarily near the surface? Or, at the very least, can't they easily cope with doing so if DO levels go down? If so, then I don't see how the dead zones would stop Menhaden from swimming north. In fact, Menhaden have regularly swam into even very bad dead zones that extended to the surface in some areas, as was evidenced by massive Menhaden die-offs in the 80s and even moderate one last Summer.
These dead zones are obviously a huge problem, but I do not think they are the reason for the lack of Menhaden in the Bay. Dead zones can kill Menhaden, but where is your evidence that the Menhaden come up the Bay in reduced numbers due to dead zones (or is this not your contention)? I believe that something else (i.e. - Omega) is keeping the Menhaden from coming up the Bay in historical numbers (by historical, I mean only 15-25 years ago).
Another point: You regularly blame increased Striped Bass stocks as causing Menhaden depletion in the Bay, yet have not, to my knowledge, reconciled this with (1) the huge stocks of mostly larger Striped Bass that patrol coastal waters, where the Menhaden stocks are supposedly healthy and (2) the fact that Bluefish were at record levels and Weakfish were much more numerous when the Striped Bass population was down in the 80s. Are you saying that these massive schools of chopper Blues didn't do AT LEAST as big a number on Menhaden as Striped Bass do today?
I think we all agree that increased populations of predators put increased strain on forage, and declining water quality further strains the entire ecosystem --the latter is a situation that MD, VA, PA and NY -- and every citizen thereof -- need to more seriously address, otherwise the Omega debate will soon be moot. However, that does not mean that, knowing all of the other stress factors on the Bay population, it is wise policy to say, “oh well, since there are many issues at play, let's just continue to allow 100,000 tons of critical forage to be removed from an already strained Bay forage base.”