Allocations, quota and abalone fishery management: the Tragedy of the commons revisited

Fisheries management uses a variety of methods to assess stocks, assign quota or allocations, and calculate potential for sustainability. In the New Zealand abalone (paua) fishery, neither the total stocks nor amount removed in any fishing year are well-known because a major portion is fished 'recreationally', for which there is no requirement for a licence or catch reporting. Actual harvests relative to allocations cannot be established until well after the fishing season, and require data not typically collected. This was demonstrated over a 3-month fishing season opened after a 5-year closure along the earthquake-affected northeastern coast of the South Island. Recreational fishers removed c.74% of nearshore biomass of Haliotis iris populations. This was, in effect, a Tragedy of the Commons, whereby a common resource is exploited by those who harvest first, with scant regard for what remains. The underlying weakness is in the recreational fishing management rules which, in this instance, provide stark lessons in why abalone populations have come under pressure worldwide. We discuss concepts, prior knowledge, inertia in management, and a potential way forward, with the aim of preventing serial depletion of paua populations and fostering more effective management that ends the Tragedy of the Commons.