Heavy metals occur naturally in estuaries, but high concentrations suggest contamination from another source. The metals can be transported along waterways from urban environments (and, for cadmium, from farmland) and accumulate in estuarine and coastal sediments. They are toxic and accumulate in fish and shellfish. We focus on four heavy metals: lead, copper, zinc, and cadmium.
This dataset relates to the "Heavy metal load in sediment" measure on the Environmental Indicators, Te taiao Aotearoa website.
