PETROLEUM POLLUTION AND MUTATION IN MANGROVES

Chlorophyll-deficiency has often been used as a sensitive genetic end- point in plant mutation research. The frequency of trees heterozygous for nuclear chlorophyll-deficient mutations was determined for mangrov e populations growing along the southwest coast of Puerto Rico. The fr equency of heterozygotes was strongly correlated with the concentratio n of polycyclic aromatic hydrocarbons in the underlying sediment and w ith both acute and chronic petroleum pollution. Although epidemiologic al studies can seldom prove causation, a strong correlation is certain ly compatible with a cause-effect relationship. Our results suggest th at the biota of oil-polluted habitats may be experiencing increased mu tation.