Potentially toxic element assessment and biological accumulation in two sea cucumbers species Holothuria poli and Holothuria tubulosa

Abstract

Knowledge of Potentially Toxic Elements (PTEs) and tissue accumulation profiles of holothurians is limited, especially in Greek seas, so there is no complete picture of their role as bioindicators. This will result in an understanding of their ecology and by extension, their contribution to the marine ecosystem. In this particular study, a total of 7 elements (As, Cd, Cr, Cu, Mn, Pb, and Zn) were analyzed from the edible muscle tissue and gut contents of two species of sea cucumbers, Holothuria poli and Holothuria tubulosa, as well as surface sediment samples in the marine area of Pagasitikos Gulf. According to the results presented, H. tubulosa for the majority of PTEs had significantly higher values than H. poli in the edible muscle tissue, while in the gut content, H. poli had the highest values. The Biota Sediment Accumulation Factor (BSAF) was calculated to determine the elemental uptake of sea cucumbers. As Cd and Mn showed the highest BSAF values in both species. In addition, the sediment results were compared to sediment quality guidelines, and it was found that Cr exceeded the Medium Impact Range (ERM) values in 80% of the samples, while other elements were found between the Low Impact Range (ERL) and ERM values. The aim of the study was to present the increasing accumulation of elements in the tissues of sea cucumbers so that they represent a significant challenge for their commercial and economic use.