Autores: H. Salgado, J. Barrales
In this paper we estimate the extent of uncertainty and illegal _shing in the Jack Mackerel _shery in Chile. Using a structural bioeconomic model, we separate management uncertainty into biological uncertainty about stock growth and uncertainty about unobserved _shing activity. Unobserved illegal fishing is given by under-reporting, by-catches, discarding and harvest by international _eet outside the Chilean regulatory system.
We use the estimated uncertainty to explore how the fishery would have evolved had it been managed e_ciently, and compare these results to the real behavior of the fishery. The results suggest a high degree of biological uncertainty, identifying two major shocks that coincide with major ENSO events. Additionally, the estimated level of illegal fishing accounts for between 10% and 25% of annual quotas. Had the fishery been managed using the optimal policy under a condition of uncertainty, the expected long-run harvest could be close to the maximum sustainable yield at around 2 million tons. The current quota policy reduces welfare by 13% generating a 1.28% risk of collapse of the fishery ery within 50 years. We conclude that quota setting higher than optimal could explain the failure to recover the stock of the ITQs system being used in the _shery since 2001. Additionally, we think that social and political cost of reducing quota to an optimal level could explain the observed suboptimal behavior of the fisheries management in Chile.
Keywords: Uncertainty, _sheries management, Illegal _shing, Jack Mackerel, Chile