Contrasted optimal environmental windows for both sardinella species in Senegalese waters
|Author(s)||Diankha Ousmane1, Ba Aliou2, 3, Brehmer Patrice3, 4, Brochier Timothee3, 5, Sow Bamol Ali6, Thiaw Modou4, Gaye Amadou Thierno1, Ngom Fambaye4, Demarcq Herve7|
|Affiliation(s)||1 : UCAD, ESP, LPAO SF, Fann Dakar, Senegal.
2 : UCAD, UCAD 2, IUPA, Dakar, Senegal.
3 : IRD, UMR Lemar 195, Lab Marine Environm, Dakar, Senegal.
4 : CRODT, ISRA, Dakar, Senegal.
5 : Univ Paris 06, Sorbonne Univ, IRD, UMI 209,UMMISCO, Bondy, France.
6 : UASZ, UFR Sci & Technol, Dept Phys, LOSEC, Ziguinchor, Senegal.
7 : IRD, UMR 248, MARBEC Marine Biodivers Exploitat & Conservat, Sete, France.
|Source||Fisheries Oceanography (1054-6006) (Wiley), 2018-07 , Vol. 27 , N. 4 , P. 351-365|
|WOS© Times Cited||11|
|Keyword(s)||recruitment success, Sardinella aurita, Sardinella maderensis, upwelling, West Africa|
|Abstract||We investigate Sardinella aurita and Sardinella maderensis recruitment success relative to the variability of oceanographic conditions in Senegalese waters using generalized additive models (GAM). Results show that recruitment of both species is marked by a strong intra-annual (seasonal) variation with minimum and maximum in winter and summer, respectively. Their interannual variations are synchronous until 2006 (recruitment decreasing), while from 2007 there is no synchrony. The model developed shows that sardinella recruitment variability is closely related to the tested environmental variables in the study area. However, the key environmental variables influencing the recruitment success are different for both species: the Coastal Upwelling Index and the sea surface temperature for S.aurita and S.maderensis, respectively. We report that recruitment success of S.aurita and S.maderensis are associated with distinct ranges of sea surface temperature, upwelling intensity, wind-induced turbulence, concentration of chlorophyll-a and north Atlantic oscillation index. Considering food security and socio-economic importance of both stocks, we recommend that consideration is given to the environmental variability in the small pelagic fish national management plans, particularly in the context of climate change.|