Distribution and composition of suspended particulate material in the clyde estuary and associated sea lochs

Abstract

The composition of suspended particulate material (SPM) from the Clyde Estuary and the Firth of Clyde (including its sea lochs) has been examined. The concentration in SPM of particulate organic carbon (POC), Fe, Mn, Zn, Pb, Cu, Cd are reported. High POC concentrations in surface waters were associated with phytoplankton. Surface water SPM contained higher concentrations of Cd and Zn than that from deeper waters. By contrast concentrations of Fe, Mn, Pb and Cu (enriched in crustal material relative to phytoplankton) were higher in subsurface SPM. Trace metal concentrations in SPM were better correlated to Fe than to Mn. Estuarine particles were enriched in trace metals relative to other areas, the higher iron concentrations in the estuary were, however, insufficient to account for this enrichment. Seasonal variability in the trace metal composition of surface SPM is discussed. Elements enriched in crustal material show higher concentrations in winter than in spring.