Relationship between metal enrichments and a biological adverse effects index in sediments from Todos Santos Bay, northwest coast of Baja California, México

► Relationships between metals enrichment factors and adverse effects in sediments.► Cu enrichment factors > 1 are enough to provoke adverse effects to flora and fauna.► Cd enrichment factors > 5.5 are necessary to provoke adverse effects. ► Zn enrichment factors > 1.5 are necessary to provoke adverse effects.