Sediment Flux, Coastal Development, and Industrial Pressure Drive the Historical Vanadium Concentrations in the East China Sea and Two Bays of Shandong

Abstract

Vanadium is a versatile element gaining significant interest due to its distribution, concentrations, accumulation, and risks. Its historical evolution in bays with substantial human populations and industrial development that use vanadium-related products is essential to evaluate environmental pollution events and the pressure on natural ecosystems. Vanadium concentrations in four sediment cores from Jiaozhou Bay (JZB), Laizhou Bay (LZB), and the East China Sea (ECS) were analyzed using inductively coupled plasma optical emission spectrometry. Vanadium was higher in the open sea than in a semienclosed bay; the highest concentrations were found in the ECS (98.01–131.70 μg g–1), followed by LZB (66.35–104.33 μg g–1) and JZB (34.95–75.58 μg g–1). Vanadium concentrations in LZB and ECS showed drastic fluctuations and followed trends similar to those of sediment fluxes caused by anthropogenic activities and the natural courses of the two largest rivers in China, the Yangtze River and the Yellow River. Despite higher concentrations of vanadium in the ECS and LZB, the pollution indices indicated uncontaminated to low-contaminated habitats. Conversely, vanadium concentrations in the JZB illustrate the significant impacts of industries and coastal development, principally after the 1980s. Likewise, the high enrichment and pollution indices suggest that vanadium emission, migration, and circulation of JZB occur at concentrations beyond its natural threshold..