Search

Oil spills are an importance source of polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. Intertidal communities are particularly sensitive since most organisms from these ecosystems are sessile or present reduced mobility. Hence, it is important to validate the use of resident species as sentinels to characterize the impact of oil spills on the rocky shores and the improvement during the restoration process. Recently the advantages of using the shanny Lipophrys pholis in pollution monitoring within the northwestern Atlantic coast has been pointed out. Therefore, with the aim of further validating the use of L. pholis in pollution monitoring associated with petrogenic hydrocarbon contamination, a multi-biomarker approach study was carried out 1 week after a moderate oil spill from the waste treatment plant (WTP) of the major Portuguese refinery in the north of Portugal (Petrogal). Fish collected at 2km from the accident displayed a significant induction of ethoxyresorufin-O-deethylase activity (EROD) and fluorescent aromatic compounds (FACs) in bile (up to a 5-fold induction) in comparison with the pre-spill scenario, and a 15% induction in erythrocytic nuclear abnormalities (ENA), a biomarker of genotoxicity. In contrast, no significant differences were recorded in the reference site. In order to better characterize the time-course accumulation of FACs in bile after a PAH insult, laboratory exposure of L. pholis to benzo[a]pyrene (B[a]P) was performed. A clear dose-response accumulation of B[a]P metabolites was observed that closely reflected nominal exposure concentrations already after 3. d. Overall, the findings of the present study highlight the potential of L. pholis in pollution monitoring dealing not only with chronic contamination, but also with oil spill accidents of a moderate scale. Taking into consideration that EROD and FACs determinations in L. pholis are cost effective, rapid and easy to use, they offer a great potential to be incorp

The "Prestige" oil spill occurred in November 2002 off the Galician Coast (NW Spain). Soon after the black tide episode, that caused an ecological disaster, several monitoring programs and projects evaluating the acute and longterm toxicity of the crude oil were initiated (see monograph Marine Pollution Bulletin 2006; vol. 53). Characteristics of the "Prestige" oil are described in Albaigés and Bayona (2003). Briefly, it consists of 50% polycyclic aromatic hydrocarbons (PAHs), mostly dominated by 2–3 ringed compounds which, contrarily in contrast to the higher molecular weight PAHs, are not reported as very toxic to fish (Seruto et al. 2005). Also, due to the heavy nature of this oil and its low solubility in water, the dispersion in sea water was very low and it mostly remained in situ forming oil patches adhered to rocks and sediment., Fish, as with all aerobic aquatic organisms, face natural stress conditions when oxygen is not fully reduced, and intermediate reactive oxygen species (ROS) are formed. Enhanced ROS formation can also take place under exposure to some toxicants such as crude oil (Livingstone 2001). In particular, the water-accommodated fraction (WAF) of some crude oils has been responsible for oxidative stress situations in aquatic organisms (Cajaraville et al. 1992). Hence, in order to evaluate if exposure to the WAF of the "Prestige" crude would interfere with the antioxidant defense system of juvenile sole, Solea senegalensis, the activities of indicative enzymes were analyzed. These included: catalase (CAT), total glutathione peroxidase (t-GPX; sum of Selenium dependent and independent forms), glutathione reductase (GR) and DT-diaphorase (DTD), as part of the antioxidant defense system. However, when this natural protective system is saturated, damage to key molecules such as DNA, proteins or lipids can occur. The latter, termed lipid peroxidation (LP), was included in the present study as a biomarker of effect, indicating damage caused by ROS. The enzyme acetylcholinesterase (AChE) regulates nerve impulse transmissions and is used as a marker of exposure to neurotoxic substances (Galloway et al. 2006). Carboxylesterases (CbE) constitute an heterogeneous group of isozymes, dominant in the liver, that play a role in the metabolism and subsequent detoxification of many xenobiotics. In marine fish AChE and CbE are biomarkers used as indicators of neurotoxicity (Lionetto et al. 2004) and enhanced hepatic metabolism (Wheelock et al. 2005). The phase II conjugating enzyme glutathione S-transferase (GST) has also been included in the present work as a measure of the detoxification metabolism., This study is part of a project aiming to evaluate the toxicity of the water-accommodated fraction (WAF) of the "Prestige" oil in juvenile Solea senegalensis after short-term (24, 48 and 72 h) exposure to environmentally realistic PAHs levels. The choice of this species was based on (1) its high economic interest in the affected region, (2) its benthic nature and, therefore, its adequacy for pollution monitoring programs and (3) its ease to rear under laboratory conditions.

Specimens of Bolinus brandaris (neogastropod) were injected with a single dose of 500 ng/g body weight (b.w.) of tributyltin chloride (TBTCl) or triphenyltin chloride (TPTCl), or a mixture of both compounds (250 ng TBT/g b.w.+250 ng TPT/g b.w.), for a period of up to 31 days. At the end of 4 weeks, significant increases in the female penis size of those gastropods injected with TBT (Po0:05), TPT (Po0:05), or the mixture TBT+TPT (Po0:01) were recorded. In parallel, a group of animals was injected with the neuropeptide APGWamide but this compound failed to promote imposex, suggesting that APGWamide is not involved in imposex promotion in B. brandaris. Acetylcholinesterase activity, a biomarker of neurotoxicity, was determined in the neuroganglia at the end of the experiment, but no significant differences among treatments were found. Overall, these results support the hypothesis that TPT also acts as an endocrine disrupter in this neogastropod species. Our observations also highlight, for the first time, synergistic effects of organotin mixtures having imposex promotion as an endpoint.