Potential biomass and distribution of octopus in the eastern part of the Campeche bank (Yucatán, Mexico)

Abstract

The octopus fishery on the Campeche Bank (Yucatán, Mexico) is considered the third largest in the world. In Yucatán, two fleets target this resource: an artisanal fleet and a semi-industrial fleet. The artisanal fleet only catches Octopus maya, while the semi-industrial fleet catches two species, O. maya and O. “vulgaris” Type II, because it operates at deeper waters (>30 m). Since there is no information on the abundance of O. “vulgaris” Type II, management is based only on O. maya. In order to generate information about the abundance of this species, four fishing research cruises were carried out in the northeastern area of the continental shelf off the Yucatán Peninsula. Four methods (a stratified random method, a swept area, geostatistics and a weighted swept area) were applied and compared to determine the instantaneous abundance and biomass of both species in the study area. The lowest potential biomass was calculated with the geostatistical method, with values between 18.5% and 36.7% lower than the other three methods. O. “vulgaris” Type II showed the lowest biomass (37.8±3.36 t) during May and July and the highest (189.56±11.6 t) in December. Our findings revealed that the total abundance of both species was similar in the study area, with a geographic overlap whose amplitude changed throughout the year according to the geographic position: O. maya dominated at approximately 88°W, while O. “vulgaris” Type II dominated towards the southeast at 87°W.