Using the polychaete Arenicola marina to determine toxicity and bioaccumulation of PAHS bound to sediments

Equilibrium passive sampling: A novel approach to determine internal tissue concentrations of hydrophobic organic compounds in biota

Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This approach was extended to biological material. In this work, a passive equilibrium sampling method for the measurement of HOCs in biota was developed as an innovative alternative because classical exhaustive extraction techniques are time-consuming and error-prone. The newly developed method is based on the well-proven SPME fiber method for sediment. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. Partition coefficients of PAHs and PCBs between the lugworm tissue and the PDMS sampling phase were determined. Polydimethylsiloxane (PDMS) coated glass fibers were directly inserted in homogenized lugworm tissue and glass fibers were analyzed using gas chromatography coupled to mass spectrometry. The method application on lugworms from tidal sand flats near Wilhelmshaven showed that the mean body residue values of PCBs (4 μg g^-1) and PAHs (256 μg g^-1) were about five times higher for PCBs and more than 22 times higher for PAHs compared to literature data for the North Sea area. This high level of contamination might be a consequence of the oil processing refinery located in direct proximity to the sampling site. This novel approach of applying the SPME method to biota will make biological monitoring more effective and holistic, because seasonally and area-wide changes in all environmental compartments can be recorded quickly.

Biochemical and physiological alterations induced in Diopatra neapolitana after a long-term exposure to Arsenic

Several authors identified polychaetes as a group of marine invertebrates that respond rapidly to anthropogenic stressors. Furthermore, several studies have demonstrated that environmental pollution lead to the impoverishment of benthic communities with species replacement and biodiversity loss, but very few studies have investigated biochemical and physiological alterations that species undergo in response to Arsenic (As) exposure. Therefore, the present study assessed the toxicity induced in the polychaete Diopatra neapolitana after a long-term (28days) exposure to different As concentrations (0.0, 0.05, 0.25 and 1.25mg/L). For this biochemical and physiological alterations were evaluated. Biochemical analysis included the measurement of different biomarkers such as glutathione S-transferase (GST), lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and oxidized glutathione (GSSG) were assessed in order to evaluate oxidative stress. Physiological analyzes included the observation of polychaetes regenerative capacity and the quantification of organisms total protein (PROT) and glycogen (GLY) content. The results obtained allowed to confirm the suitability of these biomarkers to identify the toxicity caused by As and moreover revealed that D. neapolitana is a good bioindicator of As pollution.

Effects of sediment amended with Deepwater Horizon incident slick oil on the infaunal amphipod Leptocheirus plumulosus

Crude oil released from the Deepwater Horizon disaster into the Gulf of Mexico posed potential impacts to infaunal invertebrates inhabiting near shore habitats. The effects of sediment-associated weathered slick oil on the amphipod Leptocheirus plumulosus was assessed using 28-d exposures to total PAH sediment concentrations ranging from 0.3 to 24mg/kg (sum of 50 PAHs or tPAH50). Survival and growth rate were significantly decreased in the 2.6, 11.4 and 24.2mg/kg treatments, but only growth in 5.5mg/kg. Offspring production was dramatically decreased but was variable and significantly different only for 24.2mg/kg. The concentrations associated with 20% decreases relative to reference were 1.05 (95% CI=0-2.89) mg/kg tPAH50 for growth rate and 0.632 (95% CI=0.11-2.15) mg/kg tPAH50 for offspring production. The concentrations of PAHs affecting amphipods are within the range of concentrations measured in marsh areas reportedly impacted by DWH oil after its release.

Bioaccumulation and effects of metals bound to sediments collected from Gulf of Cádiz (SW Spain) using the polychaete Arenicola marina

A short-term whole-sediment test using the polychaete Arenicola marina was conducted under laboratory conditions to assess the bioavailability of metals bound to sediments collected from 12 sites of the Gulf of Cádiz. To achieve this objective, the rate of increase of metal bioaccumulation and the induction of a typical biomarker, metallothioneinlike proteins (MTLPs) were determined. Results of the multivariate analysis showed associated metal-rich sediments, increased rate of Cu and Zn accumulations, but lower toxicity with an increased MTLP induction, whereas sedimentary Ni and Co concentrations were related to higher toxicity to lugworms, although it might be caused by other contaminants present in these sediments. The linear kinetic approach was shown to be valid in certain circumstances, but more validation studies of this parameter are required before it can be recommended for use in evaluating metal bioavailability in sediments.

Sediment-quality assessment using the polychaete Arenicola marina: contamination, bioavailability, and toxicity

The sediment quality of Cádiz Bay, Las Palmas de Gran Canaria (LPGC) Port, Santander Bay, Algeciras Bay, and Huelva Estuary (Spain) was evaluated by analysing a battery of biochemical biomarkers-activities of biotranformation enzymes ethoxyresorufin O-deethylase [EROD], dibenzylflourescein dealkylase [DBF], and glutathione S-transferase [GST]; activity of antioxidant enzyme glutathione reductase [GR]; and lipid peroxidation [LPO]-in the polychaete Arenicola marina after laboratory sediment exposure. Huelva Estuary polychaetes showed significantly (p < 0.05) enhanced LPO, GST, and EROD activities compared with control lugworms related to metals and presumably polychlorinated biphenyls. EROD activity significant (p < 0.05) induction was associated polycyclic aromatic hydrocarbons after Santander Bay sediment exposure. Nickel appeared to significantly (p < 0.05) induce GR activity and LPO in LPGC Port sediment-exposed organisms. DBF activity significantly (p < 0.05) increased in polychaetes exposed to sediments from sewage-contaminated areas. A. marina was sensitive at the biochemical level. Integration of sediment characterization and biomarker results allowed the identification of polluted sites as well as the cause of possible sediment toxicity.

Validation of Arenicola marina in field toxicity bioassays using benthic cages: biomarkers as tools for assessing sediment quality

Sediment toxicity assessments using caged organisms present advantages over using laboratory and native community studies. The use of caged Arenicola marina in sediment toxicity assessments was evaluated. Lugworms were exposed in situ to sediments from coastal and port areas in Spain for seven days, and the activities of the biotransformation enzymes ethoxyresorufin O-deethylase, dibenzylfluorescein dealkylase and glutathione S-transferase, the activities of the antioxidant enzymes glutathione reductase and glutathione peroxidase and lipid peroxidation were then analyzed as biomarkers. Biomarker results and sediment physicochemical data were integrated. Cádiz Bay (SW Spain) sediments presented metal contamination that was not linked to a biochemical response. In LPGC Port (SW Spain), Pb contamination exhibited a moderate toxic potential, while PAHs, and presumably pharmaceuticals, provoked biochemical responses that efficiently prevented lipid peroxidation. In Santander Bay (N Spain), exposure to PAHs and, presumably, pharmaceuticals induced biomarker responses, but lipid peroxidation occurred nevertheless. These results indicated that caged A. marina were effective for the assessment of sediment quality and that the selected biomarkers were sufficiently sensitive to identify chemical exposure and toxicity.