Investigating Dioxins occurrence and (bio)accumulation in The Blanes submarine Canyon (NW Mediterranean)
Submarine canyons are efficient pathways transporting sediments and associated pollutants to deep sea. There are very few studies on the occurrence of persistent organic pollutants (POP) and related contaminants in biota and sediments from submarine canyons.
The objective of this work was to provide with the first assessment of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) levels and accumulation in deep-sea megafauna (crustacean and fish) and sediments in the Blanes submarine canyon (north-western Mediterranean region). The influence of the selected species habitats (pelagic, nektobenthic and benthic) and the trophic chain level on the accumulation of dioxins was also investigated. Bottom sediment and biota samples were collected at different depths and locations inside the canyon and in the adjacent slope outside the canyon influence. This work is a collaborative multi-disciplinary research involving various scientific research institutes such as the Institute of Marine Science (ICM-CSIC) and the Institute of Environmental Assessment and Water Research (IDAEA-CSIC) among others.
sum 2,3,7,8-PCDD/F concentrations in sediments varied from 102 to 680 pg g-1 dry weight (d.w.) (1–6 WHO98-TEQ pg g-1 d.w.). Dioxins are enriched in bottom sediments at higher depths inside the canyon and in particular in the deepest parts of the canyon axis (1700 m depth). Higher sum2,3,7,8-PCDD/F levels were found in crustaceans than in fish, ranging from 220 to 795 pg g-1 lipid weight (l.w.) (13–90 WHO98-TEQ pg g-1 l.w.) and 110 to 300 pg g-1 l.w. (22–33 WHO98-TEQ pg g-1 l.w.) in crustaceans and fish, respectively. While biomagnification exerts a clear influence on the total dioxin concentrations in biota, life habits seem to exert an influence in the differential congener-specific accumulation of dioxins rather than in the total concentration. Thus, pelagic species reflected the estimated congener pattern from the surface water dissolved phase and phytoplankton, whereas the dioxin pattern in benthic and nektobenthic species was more similar to the estimated pattern in the deep-water dissolved phase and the sediment.
Most relevant scientific output:
Castro-Jiménez J., Rotllant G., Ábalos M., Parera J., Dachs J., Company J.B., Calafat A., Abad E (2013). Accumulation of dioxins in deep-sea crustaceans, fish and sediments from a submarine canyon (NW Mediterranean). Progress in Oceanography 118, 260-272.
Communications at conferences / scientific meetings
Castro-Jiménez J., Ábalos M., Rotllant G., Parera J., Sánchez C., J. Dachs, Company J.B., E. Abad. Accumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in deep-sea biota and sediments from a submarine canyon (NW Mediterranean). SETAC Europe 22th Annual Meeting. Berlin, May 2012. Oral.