Simple macro-models are used in a two good output spaces to show that, under certain conditions that occur in very poor countries, fisheries policies aimed at concentrating rent and rationalizing excess capacity may result in declines in economic growth. In cases where displaced labour has nowhere else to go, such policies may be welfare decreasing for the country as a whole. The second best policy in these cases would be to encourage open access fishing with controls on overall output. An example based upon information gathered on the shrimp fishery in Madagascar describes the relations between the relative price between artisanal and industrial fishing sectors, and differential effects of the leakage of rents through the net exports equation due to policies favouring capacity rationalization.