TEMPORAL VARIATION IN CONCENTRATIONS OF HEAVY-METALS IN MARINE-SEDIMENTS

Temporal changes in the distribution of heavy-metal pollutants have be en examined in many studies. Without knowledge of the presence or abse nce of variation at shorter time-scales, however, comparisons among lo nger intervals are always potentially confounded. Temporal variation i n the distribution of copper, lead and zinc in the sediments of Botany Bay, Australia is described, using a nested, hierarchical sampling de sign. Significant variation was found at temporal scales from days to several months. The implications of short-term variation for environme ntal sampling, and the means of overcoming problems associated with it , are discussed. The conclusions of the present study are applicable t o other variables and to other environments.