Effects of PCBs and hydrazine on life processes in microscopic stages of selected brown seaweeds

Abstract

Laminarian and fucalean algae (Phaeophyta) are often of considerable importance as producers and habitat-formers in shallow marine communities of temperate waters (Clendenning, 1971; North, 1979; Mann, 1973). We have investigated toxic thresholds for gametophytes and early sporophytes of seven laminarian and three fucalean species toward two classes of anthropogenic compounds, the pervasive polychlorinated biphenyls (PCBs) and a specialized oxidant, hydrazine. Use of PCBs is now banned in the USA, but their former extensive use, substantial manufacture, and non-degradability have resulted in widespread distributions of persistent residues at low (ppb) levels in sediments, natural waters, and discharged liquid wastes. Hydrazine is routinely used to scavenge dissolved oxygen in high-pressure boilers, thereby reducing corrosion. Excess hydrazine may find its way into natural waters when boiler water is discharged into a waste stream. Hydrazine reacts very rapidly with oxygen at elevated temperatures, but degrades at ca 0.15%·h⁻¹ in coastal seawater at 22°C (MacNaughton et al., 1978; D. E. James, unpubl.). In our studies we tested ten phaeophyte species with hydrazine. These ten species included most of the ecologically important Phaeophyta in southern and central California. Our studies of PCB effects utilized only Macrocystis pyrifera, a dominant primary producer in Californian coastal waters.