Research Article

Studying the contribution of different fishing gears to the Sardinella small-scale fishery in Senegalese waters

¹ Université Cheikh Anta Diop (UCAD), Ecole supérieure polytechnique, Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang (LPAO-SF), BP 5085 Fann, Dakar, Senegal
² Institut de Recherche pour le Développement (IRD), UMR 248 MARBEC (Marine Biodiversity, Exploitation and Conservation), CS 30171, 34203 Sète, France
³ Institut Sénégalais de Recherches agricoles (ISRA), Centre de Recherches Océanographiques de Dakar-Thiaroye, PRH, BP 2241 Dakar, Senegal
⁴ Institut de Recherche pour le Développement (IRD), UMR 195 Lemar (Laboratory of Marine Environment), BP 1386 Hann, Dakar, Senegal
⁵ Université Assane Seck de Ziguinchor (UASZ), Laboratoire d'Océanographie, des Sciences de l'Environnement et du Climat (LOSEC), Département de Physique, UFR Sciences & Technologies, BP 523 Ziguinchor, Senegal

^* Corresponding author: ousmane.diankha@ucad.edu.sn

Handling Editor: Verena Trenkel

Received: 27 January 2017
Accepted: 30 June 2017

Abstract

This study investigated variations of landings of two key species, Sardinella aurita and Sardinella maderensis, in Senegalese waters over a ten-year period (2004–2013). Using generalized additive models, it was found that fishing gear played a major role in explaining differences in monthly landings for both species (51–71% deviance explained). Its effect was more significant in the southern part of Senegal. Fishing effort (number of trips) accounted only for 4–18% of variability in landings. Purse seine (PS) fishing was the most important contributor to the landings of both species. In addition, in the southern area, surrounding gillnet fishing was also important for S. maderensis. Modeling results showed that the relationship between monthly effort and landings was generally positive and leveling off, while it was dome shaped for PSs and surrounding gillnets. Thus, when estimating fishing effort indices for management in Senegal, it is necessary to account for differences in fishing gears and the non-linear relationship between fishing effort and landings.