Climate variables and spawning migrations of the striped mullet and white mullet in the north‐western area of the Gulf of Mexico

The 'smoothed'(4253e HT smoother) 6 year time series with a monthly periodicity of catches (where the increases of the catches reflect the spawning migration) of Mugil cephalus and Mugil curema , were correlated (Pearson correlation index) against the 'smoothed' data on rainfall, water temperature, daylight and tide monthly averages. Water temperature and M. curema spawning migrations had a negative correlation ( r  = −0·77), while tide monthly averages and M. cephalus spawning migrations were positively correlated ( r  = 0·84). The two environmental variables that showed highly significant correlations were water temperature and daylight ( r  = 0·85, P  < 0·05). Meteorological tides were used as a reflection of the effect of the north winds from the Gulf of Mexico which produce an average tide rise from September to November. The relationship of these variables with spawning migrations is discussed, and it is suggested, in particular, that meteorological tides, as a reflection of the north winds, are the trigger (zeitgebers) for M. cephalus spawning in the ocean.