Forecasting of jack mackerel landings (Trachurus murphyi) in central-southern Chile through neural networks

• Published in: Fisheries oceanography Vol. 24; no. 3; pp. 219 - 228
• Main Authors: Naranjo, Laura, Plaza, Francisco, Yáñez, Eleuterio, Barbieri, María Ángela, Sánchez, Felipe
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.05.2015
• Subjects: environment; fishing effort; forecasting; jack mackerel; landings; neural networks
• ISSN: 1054-6006; 1365-2419
• DOI: 10.1111/fog.12105

In the present study, the performance of neuronal networks models in monthly landing forecasting of jack mackerel (Trachurus murphyi) in central‐southern Chile (32°S–42°S) was assessed. Thus, monthly estimations for 10 environmental variables, fishing effort (fe) and jack mackerel landings for the period 1973–2008 were used. A preliminary analysis was done in order to remove strongly correlated variables. Sea surface temperature (SST) and fe are established as input variables, then, a non‐linear cross correlation analysis was performed to estimate the lag between the input variables and jack mackerel landings. Two models were adjusted: model one includes both training and testing cases randomly selected using all data involved in the analysed period; for model 2, the data is divided into two time series: the first from 1973 to 2002 used for training and the second between 2003 and 2008 used for validation. The external validation process for model 1 showed an explained variance of 92%, with a standard forecasting error of 30%. The explained variance for model 2 was 81%, with a standard forecasting error of 38%. Finally, the sensitivity analysis for both models showed the fe as the most influential variable to jack mackerel landings, which presents functionality depending on anthropogenic effects rather than environmental conditions.