Análisis bioeconómico de la pesquería de calamar gigante <em>Dosidicus gigas</em> en el noroeste de México

Bioeconomic analysis of the jumbo squid <em>Dosidicus gigas</em> fishery in northwestern Mexico

Abstract

Objective: Perform a bioeconomic analysis of the fishery of jumbo squid fishery Dosidicus gigas in northwestern Mexico. Methodology: The population dynamics was modeled using Schaefer´s algorithm (1954). This was with two pairs of values for the intrinsic population growth rate (r). Those represents the increase of a population in a given period. Also represents the carrying capacity: (k); r = 1.23 year^-1, k = 243,836 t and r = 1.68^-1, k = 190,468 t. Official data were used for total annual catch (1974-2012), and fishing effort (2010-2012), differentiated for small boats and ships, as 2012 is the last year with commercial catches, prior to the collapse that began in 2013 and that remains. Fishing costs and selling prices were obtained through interviews with anglers in the region. The Schaefer´s biological model and the bioeconomic model of two-fleet competing for a stock, with fishing power, costs and product value different for each fleet were appliqued. Results: Total effort in 2012 was close to that needed for the maximum economic yield fMEY in both fleets, and the total authorized effort was operating in suboptimal levels between the effort in fMEY and the effort in bioeconomic equilibrium fBE, reaching a population equilibrium PE at 34 % of k, regardless the values of r and k. The estimated biomass in economic equilibrium BEEC was very low, in the order of 16 % of k for small boats and 32 % of k for ships, with small boats being below the required limit reference point of 20 % of k, established in the National Fishing Chart of Mexico. Limitations: There are no official data available after 2012: The study assumes a constant catchability coefficient. Conclusions: If density-dependent catchability exists, the estimated biomass must have been smaller than the one obtained with the biological model (19 %), meaning that small boats could have already reached their fMEY, at a biomass level that is risky to the stock.

Objective: Perform a bioeconomic analysis of the fishery of jumbo squid fishery Dosidicus gigas in northwestern Mexico. Methodology: The population dynamics was modeled using Schaefer´s algorithm (1954). This was with two pairs of values for the intrinsic population growth rate (r). Those represents the increase of a population in a given period. Also represents the carrying capacity: (k); r = 1.23 year^-1, k = 243,836 t and r = 1.68^-1, k = 190,468 t. Official data were used for total annual catch (1974-2012), and fishing effort (2010-2012), differentiated for small boats and ships, as 2012 is the last year with commercial catches, prior to the collapse that began in 2013 and that remains. Fishing costs and selling prices were obtained through interviews with anglers in the region. The Schaefer´s biological model and the bioeconomic model of two-fleet competing for a stock, with fishing power, costs and product value different for each fleet were appliqued. Results: Total effort in 2012 was close to that needed for the maximum economic yield fMEY in both fleets, and the total authorized effort was operating in suboptimal levels between the effort in fMEY and the effort in bioeconomic equilibrium fBE, reaching a population equilibrium PE at 34 % of k, regardless the values of r and k. The estimated biomass in economic equilibrium BEEC was very low, in the order of 16 % of k for small boats and 32 % of k for ships, with small boats being below the required limit reference point of 20 % of k, established in the National Fishing Chart of Mexico. Limitations: There are no official data available after 2012: The study assumes a constant catchability coefficient. Conclusions: If density-dependent catchability exists, the estimated biomass must have been smaller than the one obtained with the biological model (19 %), meaning that small boats could have already reached their fMEY, at a biomass level that is risky to the stock.