Relationship between biological, pathological and toxicological parameters and the cause of death in harbour porpoises (Phocoena phocoena) stranded on the coast of Belgium and northern France

in Proceeding of the annual conference (2010)

Toxicodynamic of pollutants in poïkilotherm species

Poster (2009, November 27)

Methylmercury in vitro exposure of harbor seal (Phoca vitulina) lymphocytes: a multidisciplinary approach

Poster (2009, June 09)

Methylmercury in vitro exposure of harbor seal (Phoca vitulina) lymphocytes: A multidisciplinary approach

Conference (2009, June 08)

Development of a strategy to study toxicodynamic of pollutants in spawning sea turtles

Poster (2009, February)

Concentrations of chlorinated and brominated contaminants and their metabolites in serum of harbour seals and harbour porpoises

in Environment International (2009), 35(6), 842-850

Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of ... [more ▼]

Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) were measured in serum of wild harbour seals (n=47) and captive harbour porpoises (n=21). Both species exhibit long life spans and do not have extreme situations, such as complete fasting during periods of lactation, in their annual cycles. For PCBs, concentrations in adult males were slightly higher than in juveniles and lowest in juvenile females. For PBDEs, juveniles have higher levels than adult males and females, probably as a consequence of lactational transfer. However. differences between these age-gender groups were not statistical significant, indicating that individual variation was limited within each species, even without knowing the feeding status of the animals. Body condition. particularly emaciation, has a major influence on the levels of chlorinated and brominated contaminants in serum. Profiles of PCBs were CB 153>CB 138>CB 187>CB 180 and CB 153>CB 138>CB 149>CB 187>CB 180 for harbour seals and porpoises respectively. For PBDEs, BDE 47 was the predominant congener followed by BDE 100 and 99 in both species. In harbour seals, concentrations of sum PCBs (median: 39,200 pg/ml) were more than 200 times higher than levels of sum PBDEs (median: 130 pg/ml) and almost 10 times higher than concentrations of sum HO-PCBs (4350 pg/ml). In harbour porpoises, concentrations of sum PCBs (median: 24,300 pg/ml) were about 20 times higher than concentrations of PBDEs (median: 1300 pg/ml). HO-PCBs were detected in only 4 harbour porpoises and this at very low concentrations. Naturally-produced MeO-PBDEs were only found in harbour porpoises at concentrations ranging from 120 to 810 pg/ml. HO-PBDEs were not found in any species. In general, harbour seals accumulate less compounds and have mostly lower concentrations than harbour porpoises possibly as a result of a better developed metabolism. (C) 2009 Elsevier Ltd. All rights reserved. [less ▲]

Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 1. Accumulation patterns in harbour seals and harbour porpoises

in Environmental Pollution (2009), 157

Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are two representative top predator species of the North Sea ecosystem. The median values of sum of 21 polychlorinated biphenyl ... [more ▼]

Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are two representative top predator species of the North Sea ecosystem. The median values of sum of 21 polychlorinated biphenyl (PCB) congeners and sum of 10 polybrominated diphenyl ether (PBDE) congeners were 23.1 mg/g lipid weight (lw) and 0.33 mg/g lw in blubber of harbour seals (n ¼ 28) and 12.4 mg/g lw and 0.76 mg/g lw in blubber of harbour porpoises (n¼ 35), respectively. For both species, the highest PCB concentrations were observed in adult males indicating bioaccumulation. On the contrary, the highest PBDE concentrations were measured in juveniles, likely due to better-developed metabolic capacities with age in adults. A higher contribution of lower chlorinated and non-persistent congeners, such as CB 52, CB 95, CB 101, and CB 149, together with higher contributions of other PBDE congeners than BDE 47, indicated that harbour porpoises are unable to metabolize these compounds. Harbour seals showed a higher ability to metabolize PCBs and PBDEs. [less ▲]

Modelling the habitat suitability of cetaceans:Example of the sperm whale in the northwestern Mediterranean Sea

in Deep-Sea Research Part I, Oceanographic Research Papers (2009), (56), 648657

Cetaceans are mobile and spend long periods underwater. Because of this, modelling their habitat could be subject to a serious problem of false absence. Furthermore, extensive surveys at sea are time and ... [more ▼]

Cetaceans are mobile and spend long periods underwater. Because of this, modelling their habitat could be subject to a serious problem of false absence. Furthermore, extensive surveys at sea are time and money consuming, and presence–absence data are difficult to apply. This study compares the ability of two presence–absence and two presence-only habitat modelling methods and uses the example of the sperm whale (Physeter macrocephalus) in the northwestern Mediterranean Sea. The data consist of summer visual and acoustical detections of sperm whales, compiled between 1998 and 2005. Habitat maps were computed using topographical and hydrological eco-geographical variables. Four methods were compared: principal component analysis (PCA), ecological niche factor analysis (ENFA), generalized linear model (GLM) and multivariate adaptive regression splines (MARS). The evaluation of the models was achieved by calculating the receiver operating characteristic (ROC) of the models and their respective area under the curve (AUC). Presence–absence methods (GLM, AUC=0.70, and MARS, AUC=0.79) presented better AUC than presence-only methods (PCA, AUC=0.58, and ENFA, AUC=0.66), but this difference was not statistically significant, except between the MARS and the PCA models. The four models showed an influence of both topographical and hydrological factors, but the resulting habitat suitability maps differed. The core habitat on the continental slope was well highlighted by the four models, while GLM and MARS maps also showed a suitable habitat in the offshore waters. Presence–absence methods are therefore recommended for modelling the habitat suitability of cetaceans, as they seem more accurate to highlight complex habitat. However, the use of presence-only techniques, in particular ENFA, could be very useful for a first model of the habitat range or when important surveys at sea are not possible. [less ▲]

Toxicodynamique des polluants et des métaux traces chez la tortue verte (Chelonia mydas) et la tortue imbriquée (Eretmochelys imbricata)

Scientific conference (2008, December 19)

Development of a strategy to study toxicodynamic of pollutants in spawning sea turtles from French West Indies (Guadeloupe and Martinique)

Conference (2008, November)

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant ... [more ▼]

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant lack of data dealing with toxicants such as metals and persistent organic pollutants (POPs) in sea turtles. We developed a strategy to apprehend levels, effects and transfer to offspring of several pollutants in sea turtles. Sampling of blood, subcutaneous tissue and eggs of 15 gravid C. mydas and E. imbricata was carried out between July and September 2008 in Martinique (Diamant’s beach) and Guadeloupe (Petite Terre and Marie-Galante). Blood was collected from the dorso-cervical sinus and subcutaneous tissue was sampled in shoulder of the spawning females using a 5 mm biopsy punch (Kai Europe GmbH, Germany). Total blood and serum were successfully taken for metal, POP and biomarker investigations. T-mercury was analyzed by DMA milestones while PCBs, DDT and chlordecone were analyzed by EDC Ni63 high performance gas chromatography HPLC. Samples of serum were analyzed for vitamins (A and E) by HPLC and for thyroid hormones (triiodothyronine and thyroxine) by radioimmunoassay. In parallel to this field study, a cell model using 3T3-L1 cell line was built up to test in vitro effects of PCBs and mercury as well as the relationship between in vitro exposure and fat mobilization. Preliminary results showed a dose-response relationship between increased Aroclor 1234 and 1252 concentrations (0.5 ppb, 1 ppb and 1.5 ppb) and adipocyte mortality (Nucleocounter). The strategy we propose here will bring further insights on levels and potential impact of pollutants on female sea turtles and their offspring. [less ▲]