Accumulation of PAHs in the tissues and algal symbionts of a common Mediterranean coral: Skeletal storage relates to population age structure

• Published in: The Science of the total environment Vol. 743; p. 140781
• Main Authors: Caroselli, Erik, Frapiccini, Emanuela, Franzellitti, Silvia, Palazzo, Quinzia, Prada, Fiorella, Betti, Mattia, Goffredo, Stefano, Marini, Mauro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2020
• Subjects: Balanophyllia europaea; Bioaccumulation; Mediterranean Sea; PAH; QuEChERS; Scleractinian coral; Bioaccumulation; Balanophyllia europaea; Mediterranean Sea; PAH; QuEChERS; Scleractinian coral
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.140781

Polycyclic aromatic hydrocarbons (PAHs) are widespread and harmful environmental pollutants that threaten marine ecosystems. Assessing their level and source is crucial to estimate the potential risks for marine organisms, as PAHs represent an additional threat to organism resilience under ongoing climatic change. Here we applied the QuEChERS extraction method to quantify four PAHs (i.e. acenaphthene, fluorene, fluoranthene, and pyrene) in three biological compartments (i.e. skeleton, tissue, and zooxanthellae symbiotic algae) of adult and old specimens of a scleractinian coral species (Balanophyllia europaea) that is widespread throughout the Mediterranean Sea. A higher concentration of all four investigated PAHs was observed in the zooxanthellae, followed by the coral tissue, with lowest concentration in the skeleton, consistently with previous studies on tropical species. In all the three biological compartments, the concentration of low molecular weight PAHs was higher with respect to high-molecular weight PAHs, in agreement with their bioaccumulation capabilities. PAH concentration was unrelated to skeletal age. Observed PAHs were of petrogenic origin, reflecting the pollution sources of the sampling area. By coupling PAH data with population age structure data measured in the field, the amount of PAHs stored in the long term (i.e. up to 20 years) in coral skeletons was quantified and resulted in 53.6 ng m−2 of acenaphthene, 69.4 ng m−2 of fluorene, 2.7 ng m−2 of fluoranthene, and 11.7 ng m−2 of pyrene. This estimate provides the basis for further assessments of long-term sequestration of PAHs from the marine environment in the whole Mediterranean, given the widespread distribution of the investigated coral species. [Display omitted] •PAHs were quantified by QuEChERS and were of petrogenic origin.•In all biological samples, low molecular weight PAHs prevailed.•Concentration of 4 PAHs was higher in zooxanthellae than in coral tissue and skeleton.•PAH concentration was unrelated to coral skeletal age.•PAH long-term skeletal storage in a coral population was quantified.