The results indicate that the sediments of the investigated sites
from the Farasan island, Saudi Arabia can be considered as low,
moderate or high pollution levels. The concentrations of Cd, Cu, Pb
and Zn levels were found to be above the PEL or ERM, indicating
that the biological effects would frequently occur and detrimental
effects to benthic organisms as well as other aquatic organisms are
possible. However, Cr and Ni concentrations in the studied sediment
samples were lower than the probable effect concentrations,
suggesting that these two metals would be not associated with
biological and harmful effects. Moreover, the results revealed that
Cu and Cr were highly bio-accumulated in A. marina. Our results
suggest that A. marina can be classified as potential accumulator
for Cu. Future studies should focus on investigation of metal levels
in sediments and mangrove plants over time. Speciation and
readily available fractions of heavy metals in sediment should be
also investigated. In terms of environmental restoration and
management, moreover, further work is required on the role of
mangrove systems in heavy metal contamination control via
phyto-extraction and phyto-stabilisation strategies.