Seasonal patterns of polycyclic aromatic hydrocarbons in digestive gland and arm of octopus (Octopus vulgaris) from the Northwest Atlantic

Abstract

Among organic pollutants existing in coastal areas, polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their ubiquity and carcinogenic potential. The aim of this study was to evaluate the seasonal patterns of PAHs in the digestive gland and arm of the common octopus (Octopus vulgaris) from the Northwest Atlantic Portuguese coast. In the different seasons, 18 PAHs were determined and the detoxification capacity of the spe-cies was evaluated. Ethoxyresorufin O-deethylase (EROD) and ethoxycoumarin O-deethylase (ECOD) activities were measured to assess phase I biotransformation capacity. Individual PAH ratios were used for major source (pyrolytic/petrogenic) analysis. Risks for human consumption were determined by the total toxicity equivalence approach. Generally, low levels of PAHs were detected in the digestive gland and in the arm of octopus, with a predominance of low molecular over high molecular weight compounds. PAHs exhibited seasonality in the con-centrations detected and in their main emission sources. In the digestive gland, the highest total PAH levels were observed in autumn possibly related to fat availability in the ecosystem and food intake. The lack of PAH elimina-tion observed in the digestive gland after captivity could be possibly associated to a low biotransformation capac-ity, consistent with the negligible/undetected levels of EROD and ECOD activity in the different seasons. The emission sources of PAHs found in the digestive gland varied from a petrogenic profile observed in winter to a pyrolytic pattern in spring. In the arm, the highest PAH contents were observed in June; nevertheless, levels were always below the regulatory limits established for food consumption. The carcinogenic potential calculated for all the sampling periods in the arm were markedly lower than the ones found in various aquatic species from different marine environments. The results presented in this study give relevant baseline data for environmental monitoring of organic pollution in coastal areas.

The Role of the Cephalopod Digestive Gland in the Storage and Detoxification of Marine Pollutants

“…Also, Cheah et al (1995) disclosed modest induction of CYPs in Octupus pallidus digestive gland after exposure to known inducers like β-naphtoflavone and Aroclor, with increased activity of ethoxycoumarin- O -deethylase (ECOD) but not for ethoxyresorufin O -deethylase (EROD), which is one of the best accepted biomarkers of exposure to bioactive pollutants in vertebrates. This finding is in agreement with the work by Schlenk and Buhler (1988) with chitons, even though Semedo et al (2014) found negligible activities of both enzymes in wild Octopus vulgaris .…”

“…Although far less common than for metals, some studies addressed the issue of bioaccumulation of various organic hazardous substances in the cephalopod digestive gland, from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) to amnesic shellfish toxin (Costa et al, 2005, 2009; Danis et al, 2005; Storelli et al, 2006; Semedo et al, 2014). Nevertheless, the pathways of detoxification and elimination of organic substances, pollutants and toxins (endogenous or exogenous) that are called bioactive compounds are strikingly more complicated than metal chelation and expression of chelators.…”

Temporal Variability of Polycyclic Aromatic Hydrocarbons in Deep-Sea Cephalopods of the Northern Gulf of Mexico

“…In addition, cephalopods have high growth rates, short life spans, and high sensitivity to environmental changes (Rodrigo and Costa, 2017). Cephalopods have a high capacity to bioaccumulate and concentrate contaminants at higher levels than other aquatic groups, thus are potentially useful bioindicators of aquatic contamination over short periods (Gomes et al, 2013;Semedo et al, 2014). During the DWHOS, an unprecedented amount of PAHs was released, with PAHs remaining mostly offshore and contaminating the deep-pelagic domain of the northern GoM (U.S. District Court, 2015;Wade et al, 2016;Romero et al, 2017Romero et al, , 2018.…”

Commercial octopus species from different geographical origins: Levels of polycyclic aromatic hydrocarbons and potential health risks for consumers

“…Cephalopods present a very small capability of metabolization and, as a consequence, they are very sensitive to the variability of their aquatic environment, reason why Semedo et al (2012) proposed Octopus vulgaris as marine sentinel species. Thus, the presence of aquatic pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls among others, raises major health concern due to the potential health risks associated with a regular consumption of seafood including cephalopods, principally for the populations that appreciated them the most (Domingo et al, 2007;Gomes et al, 2013;Gu et al, 2017Gu et al, , 2018bHwang et al, 2012;Kalogeropoulos et al, 2012;Llobet et al, 2006;Martí-Cid et al, 2007, 2008Martorell et al, 2010;Ramalhosa et al, 2012a;Semedo et al, 2012Semedo et al, , 2014Storelli, 2008;Unger et al, 2008;Vieira et al, 2011).…”

“…The contents of PAHs in the edible tissues of cephalopods have been evaluated by several authors, being squids and cuttlefish the most well characterized species (Bordajandi et al, 2004;Domingo et al, 2007;Fontcuberta et al, 2006;Gomes et al, 2013;Hwang et al, 2012;Ke et al, 2017;Martí-Cid et al, 2007, 2008Martorell et al, 2010;Moon et al, 2010;Perugini et al, 2007aPerugini et al, , 2007bRodríguez-Hernández et al, 2016;Semedo et al, 2014;Unger et al, 2008). To the best of our knowledge, limited information exists concerning the assessment of PAHs in the edible tissues of octopus; only common octopus (Octopus vulgaris) from northeast Atlantic Ocean (Semedo et al, 2014), argonauta argo from South China Sea (Ke et al, 2017), and seven-arm (Haliphron atlanticus) octopus from western Atlantic Ocean (Unger et al, 2008) were characterized. Other authors also assessed the levels of PAHs in common (Octopus vulgaris), giant Pacific( Octopus dofleini), and whiparm (Octopus variabilis) octopuses that were acquired from local fish markets and retailers not specifying the origin of species (Hwang et al, 2012;Moon et al, 2010;Rodríguez-Hernández et al, 2016).…”