Long-term fishing impact on the Senegalese coastal demersal resources: diagnosing from stock assessment models
|Author(s)||Ba Kamarel1, 2, Thiaw Modou1, Fall Massal1, Thiam Ndiaga1, Meissa Beyah3, Jouffre Didier4, Thiaw Omar Thiom2, Gascuel Didier5|
|Affiliation(s)||1 : ISRA Senegal, CRODT, Pole Rech ISRA Hann, Dakar 2241, Senegal.
2 : Univ Cheikh Anta DIOP, Fac Sci & Tech, Dep Biol & Anim, Dakar 5005, Senegal.
3 : IMROP, Nouadhibou 22, Mauritania.
4 : Univ Montpellier, Unite MARBEC, IRD, Pl E Bataillon, F-34095 Montpellier 5, France.
5 : Univ Bretagne Loire, Ecol & Ecosyst Hlth UMR985, Agrocampus Ouest, 65 Rue St Brieuc,CS 84215, F-35042 Rennes, France.
|Source||Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2018-01 , Vol. 31 , N. 8 , P. 13p.|
|WOS© Times Cited||1|
|Keyword(s)||Coastal demersal species, delta-GLM models, surplus production models, Bayesian approach, overexploitation, West Africa|
For the first time in Senegal, assessments based on both stochastic and deterministic production models were used to draw a global diagnosis of the fishing impact on coastal demersal stocks. Based one national fisheries databases and scientific trawl surveys data: (i) trends in landings since 1971 were examined, (ii) abundance indices of 10 stocks were estimated using linear models fitted to surveys data and commercial catch per unit efforts, and (iii) stock assessments were carried out using pseudo-equilibrium Fox and Pella-Tomlinson models and a Biomass dynamic production model fitted in a Bayesian framework to abundance indices. Most stocks have seen their abundance sharply declining over time. All stocks combined, results of stock assessments suggest a 63% reduction compared to virgin state. Three fifth of demersal stocks are overexploited and excess in fishing effort was estimated until 75% for the worst case. We conclude by suggesting that the fishing of such species must be regulated and an ecosystem approach to fisheries management should be implemented in order to monitor the whole ecosystem.