Heavy metal levels in water, brown algae (Cystoseira barbata), and eelgrass (Zostera marina) from the Southern Black Sea coast of Bulgaria

Abstract

The heavy metals concentration in algae and marine water can be used as a bioindicator of an ecosystem pollution. In the present study, we determined the levels of the elements As, Pb, Cd, Hg, Mn, Zn, and Al in brown algae of the species Cystoseira barbata (Agardh, 1820), eelgrass Zostera marina (Linnaeus, 1753) and also in cooled seawater. The samples were collected during the summer period of 2020 from the region of the Southern Bulgarian Black Sea coast. Our results showed low levels of heavy metals in seawater and much higherin the studied plant species, especially of aluminum in brown algae.