The Southern Oscillation,environmental anomalies,and mortality of two Southern African seabirds

Mass mortalities and breeding failures of seabirds in the Pacific Ocean have been directly or indirectly linked to local manifestations of the Southern Oscillation. Similar seabird mortalities have been reported in the Benguela upwelling system along the southern African coast. A Boolean factor analysis of binary data (occurrence vs. non-occurrence) showed that certain worldwide and southern African anomalous climatic events tended to co-occur in the same year, and that seabird mortalities and scarcities of small fish along the southern African coast occurred in either the same year, or the year before, the anomalous climatic events. The environmental conditions leading up to warm-water events in southern Africa appear as detrimental to seabird populations as the warm-water events themselves.