Spatial dynamics modelling of small-scale fishing fleets with a Random walk approach
AuthorsQuijano Quiñones, D.R; J. López-Rocha; I. Hernández-Herrera; E. Torres-Irineo Download PDF Open PDF in Browser
Date: November, 2020
Event: Proceedings of the Seventy-Three Annual Gulf and Caribbean Fisheries Institute
The understanding of fishing effort allocation has been recognized as a key feature within fisheries’ spatial management. In small-scale fisheries this assessment is challenging because their multiespecific context. Thus has resulted in management regulations that do not fulfill their objectives. Therefore, understanding the relationship between fishing gears and target species is important for the assessment and management of fisheries. To characterize fishing trips from multiespecific small-scale fleet a Random Walk approach was used. The data analyzed here come from 156 fishing trips carried out in three fishing seasons (2018, 2019 and 2020) by the small-scale fleet of Yucatán, México. The activities of three gears (hand net, handline, longline) and two fishing methods (diving, “gareteo”) were recorded with a GPS. The fitness of seven RW’s was evaluated for trajectories data: Brownian (BW), Transpose brownian (TBW), Levy walk (LW), Levy Transpose walk (LTW), Correlated (CRW), Transpose correlated (TCRW) and Composite correlated (CCRW). To compare the relative and absolute fit of the models a delta Akaike and G-Tests were used respectively. A total of 143 trajectories showed conclusive evidence to establish a CCRW-type movement, the remaining 13 trajectories fit for three models (CCRW, TRW and CRW) but G-test was not significant. Our results highlight the usefulness of low-cost tracking devices such as GPS to acquire data from spatial distribution of small-scale vessels as there is no VMS program to monitor these fisheries. For future studies we suggest increasing the base of fishing trips and conducting specific studies by gear and fishing method.