Development of a stochastic bioeconomic model for the red octopus fishery on the Yucatan Peninsula: Implications for management

Although much effort has been dedicated to the management of the red octopus fishery on the Yucatan Peninsula (Mexico), managers have yet to incorporate economic aspects to ensure sustainable and profitable exploitation of this fishery resource. We developed a bioeconomic model that incorporated the uncertainty for the r and K parameters. We fit 3 models (Schaefer, Fox, and Pella–Tomlinson) to abundance index survey data and used the Akaike information criterion for model selection. The best fit corresponded to the Schaefer model. We built deterministic and stochastic versions of the Gordon–Schaefer model. Economic data (costs and prices) were determined from inter[1]views with fishermen. To estimate the posterior distributions of parameters and indicators, we used Bayesian methods with Markov chain Monte Carlo (MCMC) simulations. The deterministic results suggested that the maximum sustainable income was Mex$851.70 million, with a fishing effort of 3,650 fishing boats, while the maximum sustainable profit was $390.8 million, with a fishing effort of 2,472 fishing boats. The equilibrium point corresponded to an effort of 4,945 fishing boats. Regarding the stochastic model, the MCMC simulation results suggest that the maximum sustainable income distribution was not normal; its average was $856.1 million (SE 1.8) and the most likely value was $849.50 million. The most likely fishing effort at equilibrium was 4,970 fishing boats. Our results suggest the fishery could be operating close to the economic equilibrium point; if this is the case, fishing effort must decrease in order for annual profit to increase. Our approach will help make periodical re-evaluations of the fishery and establish management strategies to ensure the profitable and sustainable exploitation of the red octopus on the Yucatan Peninsula.

Download Full-text

Multiple resource use strategies confer resilience to the socio-ecosystem in a protected area in the Yucatan Peninsula, Mexico

10.1101/2020.01.08.897462 ◽

2020 ◽

Author(s):

Luis Guillermo García Jácome ◽

Eduardo García-Frapolli ◽

Martha Bonilla Moheno ◽

Coral Rangel Rivera ◽

Mariana Benítez ◽

...

Keyword(s):

Management Practices ◽

Yucatan Peninsula ◽

Effective Means ◽

Management Strategies ◽

Conservation Strategy ◽

Multiple Use ◽

Charcoal Production ◽

Management Scenarios ◽

Network Modelling ◽

Yucatán Peninsula

ABSTRACTNatural Protected Areas (NPAs) are the main biodiversity conservation strategy in Mexico. Generally, NPAs are established on the territories of indigenous and rural groups driving important changes in their local resource management practices. In this paper we study the case of Otoch Ma’ax Yetel Kooh, an NPA in the Yucatan Peninsula, Mexico, that has been studied in a multidisciplinary way for more than twenty years. This reserve and its buffer zone is homeland to Yucatec Mayan communities that until recently used to manage their resources following a multiple use strategy (MUS), which involves local agricultural practices and has been proposed as resilience-enhancing mechanism. However, due to the restrictions imposed by the decree of the reserve and the growth of tourism in the region, some of these communities have started to abandon the MUS and specialize on tourism-related activities. We build a dynamical computational model to explore the effects of some of these changes on the capacity of this NPA to conserve the biodiversity and on the resilience of households to some frequent disturbances in the region. The model, through the incorporation of agent-based and boolean network modelling, explores the interaction between the forest, the monkey population and some productive activities done by the households (milpa agriculture, ecotourism, agriculture, charcoal production). We calibrated the model, explored its sensibility, compared it with empirical data and simulated different management scenarios. Our results suggest that those management strategies that do not exclude traditional activities may be compatible with conservation objectives, supporting previous studies. Also, our results support the hypothesis that the MUS, throughout a balanced integration of traditional and alternative activities, is a mechanism to enhance household resilience in terms of income and food availability, as it reduces variability and increases the resistance to some disturbances. Our study, in addition to highlighting the importance of local management practices for resilience, also illustrates how computational modeling and systems perspective are effective means of integrating and synthesizing information from different sources.

Download Full-text