Metals in the water, sediments, and biota of the Haw and New Hope Rivers, North Carolina

Neutron activation analysis was used to investigate the concentrations of Co, Cr, Fe, K, Mn, Na, Sb, Sc and Zn in the filtrable (<0.45 micrometer), suspended particulate and sediment phases as well as in the benthic macroinvertebrates of two central North Carolina river systems. Data collected provided information on the partitioning of metals among these abiotic and biotic phases. Data from the macroinvertebrates provided information on the importance of feeding habits, species, organism size and metal-metal and metal-sediment interactions on metal concentrations in these organisms. Suspended particulate matter generally had the highest metal concentrations. Filtrable metal concentrations had the least spatial and temporal variation while suspended metal concentrations had the greatest variations. Incorporation into Fe and Mn oxides was the most important mode of metal transport under polluted and low flow conditions while transport as crystalline minerals was most important under control and high flow conditions. Zn and Mn had the highest concentration factors in the benthic macroinvertebrates.