Since the discovery of oil in early 1900, the Arabian Gulf has experienced a continuous and fast coastal development leading to increase the human pressures on the marine environment and its enrichment with various pollutants. The present study attempts to describe the historical changes of trace elements in the sediments of vegetated coastal habitats in the western Arabian Gulf. 210Pb–dated sediment cores collected from seagrass, mangrove and saltmarsh habitats were analyzed to evaluate historical variations in concentrations and burial rates of 20 trace elements (Al, As, Ba, Ca, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, S, Sr, V and Zn). The highest correlations (Spearman correlation coefficients ≥0.51) were found between crustal elements (Al, Fe, Co, Cr, K, Na, Mg, Mn, Ni, V, and P), suggesting a common crustal source in the Gulf. The increased concentrations of these crustal elements in modern marine sediments of the Arabian Gulf seem to be linked to increased mineral dust deposition in the area. Over the last century, both elemental concentrations and burial rates increased by factors of 1–9 and 1–15, respectively, with a remarkably fast increase occurring in the past six decades (~1960 – early 2000). The considerable enrichment of trace elements in the Arabian Gulf during the last decades is most likely due to an increase in anthropogenic pressures, including industrial, urban and agricultural development. Our study demonstrates that sediments in vegetated coastal habitats provide long-term archives of trace elements concentrations and burial rates reflecting human activities in the Arabian Gulf.
|Original language||English (US)|
|Journal||Science of the Total Environment|
|State||Published - Nov 21 2019|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This study was supported by King Fahd University of Petroleum and Minerals, King Abdullah University of Science and (KAUST) and Saudi Aramco Environmental Initiatives. Funding was provided to PM by the Generalitat de Catalunya (MERS 2017 SGR – 1588) and an Australian Research Council LIEF Project (LE170100219). AAO was supported by a PhD scholarship from Obra Social “LaCaixa” (LCF/BQ/ES14/10320004). This work is contributing to the ICTA ‘Unit of Excellence’ (MinECo, MDM2015-0552). The authors would like to thank the staff of the Center for Environment and Water in King Fahd University of Petroleum and Minerals for their contributions in fieldwork sampling and laboratory analyses, as well as I. Schulz, N. Geraldi, K. Rowe, S. Roth M. Ennasri, D. Prabowo and I. Mendia for helping with processing the cores. We are also grateful to four anonymous reviewers whose comments helped to improve the quality of the manuscript.