Biomonitoring potential of trace metal accumulation and bioavailability in coral skeletons and reef sediments of Persian Gulf: A comparative study

Abstract

Nayband Marine National Park in the northern Persian Gulf is an important ecological areas, significantly impacted by industrial activites that poses risk of trace metal pollution to living organisms. In this study, we investigated the bioaccumulation of trace metals in scleractinian corals using annual growth bands and biota-sediment accumulation factor to assess their potential as biomonitoring organisms. Furthermore, to assess the sediment quality, sediment pollution indices and international guidelines was employed. To achieve this, three Faviidae coral and sixteen sediment samples were collected in March 2023 from three sites: an industrial zone (site I), a rural fishing zone (site II), and a marine protected area (site III). In first step, coral samples washed, sun-dried, sliced into 1-cm slabs, X-rayed to reveal annual growth bands, and powder was prepared from each growth band. Then freeze-dried sediments and coral powder were ground, sieved (63 μm), digested (using United States Environmental Protection Agency - Method 3050b) and filtered (Whatman No. 42). Finally, trace metals were analyzed using Inductively Coupled Plasma Mass Spectrometry instrument. The results show severe anthropogenic pollution at sites I and II compared to site III and significant differences between their sampling stations. Mg and Sr concentrations were highest in sediments and corals, respectively, while, Co is lowest in both. According to the sediment pollution indices, Site I showed the highest potential toxicity to biota, followed by Site II and then Site III. The results also suggest that the Faviidae corals are effective bio-indicators for Pb, Li, Cu, and Ni contamination.