Probability sampling design for the artisanal fishery of the red grouper (Epinephelus morio) Off Yucatan, Mexico

Abstract

The purpuse of this paper is to propose an optimum sampling design using probabilistic techniques to obtain estimators of the average weight of fishes, total number, proportion and number of individuals per length class, and the respective variances. A sampling design based on two strata composed of the ports on both the east and west coasts of Yucatán is suggested, which are separated mainly by the size of fishes within the capture. Within each strata, a three-stage sampling design was defined with primary units (ports), secondary units (boats) and tertiary units (fishes), and their variances obtained. A sample size was fixed for each port, and an optimum sample size for secondary and tertiary units is calculated using the graphical method proposed by Chester and Waters.