Mortality of Early Life Stages of Sardine (Sardina pilchardus) Along the South Area (21-26°N) of the Atlantic Coast of Northwest Africa

The purpose of this study was to approximate the natural mortality of embryonic and larval development stage of sardine (Sardina pilchardus) in the southeastern Atlantic coast between Cape Blanc (21°N) and Cape Boujdor (26°N). To determine key environmental conditions for their survival, multivariate analysis was also conducted. Outputs of best fit exponential models with weighted least square method suggested that average daily mortality rate (M) was high among sardine eggs estimated to 2.1, corresponding to 88% of dead eggs per day. On the other hand, M for sardine larvae was estimated to 0.65, corresponding to 47.9% of dead larvae per day. M of small (<7mm) larvae was higher than large (≥7mm) larvae. Difference in larvae mortality rates was observed between north and south parts of the study areathat may be related to the upwelling and food availability. Southward and offshore-ward transport can also be considered as causes of variability in drifting scenario and survival condition of sardine larvae in November 2007.  Since time series of data is lacked in the area to estimate population parameter of sardine in the early life history, future adaptive monitoring may be practical for the sustainability of sardine fisheries of Morocco.