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Variability of key biological parameters of round sardinella Sardinella aurita and the effects of environmental changes
Author(s) -
Baldé Bocar S.,
Sow Fambaye N.,
Ba Kamarel,
Ekau Werner,
Brehmer Patrice,
Kantoussan Justin,
Fall Massal,
Diouf Malick
Publication year - 2019
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.13903
Subject(s) - sardinella , upwelling , biology , zooplankton , productivity , ecology , reproduction , fishery , oceanography , aurelia aurita , fish <actinopterygii> , jellyfish , macroeconomics , sardine , economics , geology
We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995–2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length‐frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March–April off Senegal). Peak reproduction corresponds to periods of low sea‐surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal waters when upwelling brings nutrient‐rich water to the surface ( i.e ., it increases its growth rate and accumulates energy reserves for spawning). Growth performance appears to be strongly dependent on environmental conditions. The timing of spawning seems to occur when food (zooplankton) is most available for supplying the energy requirements needed by adults for spawning and early development of larvae. Environmental changes seem to have a significant effect on S. aurita growth and reproduction, which endorses their high phenotypic plasticity.