Comparative assessment of trace element accumulation and biomonitoring in seaweed Ulva lactuca and seagrass Posidonia oceanica

The present research compared the capability of the green seaweed Ulva lactuca and the seagrass Posidonia oceanica to accumulate and biomonitor the levels of six trace elements: Cd, Cr, Cu, Ni, Pb, Zn. The concentrations of these elements were analyzed in seawater, bottom sediments, U. lactuca thalli and P. oceanica leaves, in four sites of Sicily (Italy) with different levels of pollution. The results showed that P. oceanica is able to accumulate greater concentrations of trace elements compared to U. lactuca. Both species, instead, acted equally as good bioindicators of marine pollution, showing significant correlations with the levels of trace elements in the surrounding environment. The use of P. oceanica and U. lactuca as bioindicators is still limited in biomonitoring programs, and should be further encouraged given the ever-increasing marine pollution.