Trace metal variations in tissues of harbour seals (Phoca vitulina) stranded along Southern North Sea coasts

Poster (2004)

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. The trace metal levels of the harbour seal in the Southern North Sea are poorly known ... [more ▼]

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. The trace metal levels of the harbour seal in the Southern North Sea are poorly known. In this study, trace metal concentrations (Zn, Cu, Fe, Cd, Hg and Se) were measured in tissues (liver, kidney and muscle) of 72 harbour seals collected along the coasts of France, Belgium and Netherlands between 1994 and 2004. Hg levels were significantly higher in seals from the Southern North Sea than in seals from Norwegian waters (1) probably due to the amount of anthropogenic inputs in the North Sea. Hepatic Hg was positively correlated to hepatic Se, both increasing with the length of the seals. Such a relationship reflects an age accumulation process coupled to a detoxication mechanism involving antagonism between Hg and Se in the liver. Increasing Zn and Hg hepatic levels were observed with degrading body condition of the harbour seals, which is reflected by decreasing blubber thickness and high hepatic to total body mass ratio. Body condition was particularly poor in seals which died from infectious diseases. These observations tend to indicate a global redistribution of trace metals from muscle and blubber to liver, as a result of protein and lipid catabolism linked to disease and starvation. [less ▲]

Perfluorinated chemicals infiltrate ocean waters: Link between exposure levels and stable isotope ratios in marine mammals

in Environmental Science & Technology (2003), 37(24), 5545-5550

This is the first study to report on concentrations of perfluorinated organochemicals (FOCs) in marine mammals stranded along the southern North Sea coast in relation to stable nitrogen and carbon isotope ... [more ▼]

This is the first study to report on concentrations of perfluorinated organochemicals (FOCs) in marine mammals stranded along the southern North Sea coast in relation to stable nitrogen and carbon isotope ratios (delta(15)N and delta(13)C). The presence of FOCs in top predators such as marine mammals would indicate a potential biomagnification of these compounds and their widespread occurrence. Liver and kidney tissues of nine marine mammal species have been sampled. Among all the measured FOCs compounds, PFOS (perfluorooctane sulfonate) was predominant in terms of concentration. The highest PFOS concentrations were found in the liver of harbor seal compared to white-beaked dolphin, harbor porpoise, gray seal, sperm whale, white-sided dolphin, striped dolphin, fin whale, and hooded seal. PFOS concentrations differed significantly between sexes and age classes in harbor porpoises. Stable isotope measurements (delta(13)C and delta(15)N) were used in this study to describe the behavior of contaminants in food webs. We found a significant (p < 0.05) linear relationship between PFOS concentrations in livers of harbor porpoises and both Muscle delta(13)C and delta(15)N measurements. Harbor and gray seals and white-beaked dolphin, which displayed the highest trophic position, contained the highest PFOS levels, while offshore feeders such as sperm whales,fin whales, striped dolphin, and white-sided dolphin showed lower PFOS concentrations than inshore species. [less ▲]

Morbillivirus infection among common seals stranded on the coastline of Belgium and northern France in 2002

in annual proceeding (2003)

Polychlorinated dibenzo-p-dioxins and dibenzofurans in livers of an Atlantic seabird, the common guillemot Uria algue: Influence of the general body conditions

in Organohalogen Compounds (2003)

Dioxins, furans and co-planar PCBs in juvenile harbour porpoises (Phocoena phocoena) from the Belgian coasts

Poster (2003)

Dioxins, furans and PCBs are lipophilic anthropogenic contaminants that have found their way into marine food webs and accumulate in top predators such as marine mammals, adding a stress factor to an ... [more ▼]

Dioxins, furans and PCBs are lipophilic anthropogenic contaminants that have found their way into marine food webs and accumulate in top predators such as marine mammals, adding a stress factor to an already vulnerable population. In this study 7 congeners of dioxins (PCDDs), 10 congeners of furans (PCDFs) and 4 congeners of coplanar PCBs (cPCBs) were determined using high resolution gas chromatography and mass spectrometry in the blubber of 19 juvenile harbour porpoises (Phocoena phocoena) stranded along the Belgian North Sea coastline between 1995 and 2001. These results were contrasted with nutritional status (emaciated or not), sex and trophic level (through stable carbon and nitrogen isotope analysis). Mean blubber concentrations of SPCDD/Fs were 12.8 pg/g lw (lipid weight) and mean related toxicity 1.84 pg TEQs/g lw (TEQs = TCDD toxic equivalents). Mean cPCB concentrations were 223,5 pg/g lw and mean related toxicity 4,47 pg TEQs/g lw. The levels detected in these individuals were of the same order as those found in a previous study in the Wadden Sea (Bruhn, 1999). Both sexes show rather similar levels. No significant relationship was observed between stable carbon or nitrogen isotope values and pollutant levels. Concentrations and toxicity show a tendency to be higher in emaciated ndividuals than in nonemaciated ones. This could indicate a possible relationship between the nutritional status of the animals and dioxinlike pollutants (which could participate in weakening the animal). This situation should be further studied on adult individuals in order to obtain a more global view of the possible effects on the population. [less ▲]

Causes of death of small cetaceans and pinnipeds on continental coastlines of the southern North Sea

(2003)

Septicémie à Edwardsiella tarda: rapport de deux cas chez le marsouin commun (Phocoena phocoena)

Conference (2002, September 05)

Involvement of metallothioneins in the dynamic of Zn, Cd, Cu and Hg in harbour porpoises, Phocoena phocoena stranded along the southern North Sea coast

Poster (2002, April)

Stranding of marine mammals: operations guide and necropsy procedures

in Annales de Médecine Vétérinaire (2002), 146(5, OCT-NOV), 261-276

A role for the Clostridium perfringens beta 2 toxin in bovine enterotoxaemia?

in Veterinary Microbiology (2002), 86(3), 191-202

Non-enterotoxigenic type A Clostridium perfringens are associated with bovine enterotoxaemia, but the alpha toxin is not regarded as responsible for the production of typical lesions of necrotic and ... [more ▼]

Non-enterotoxigenic type A Clostridium perfringens are associated with bovine enterotoxaemia, but the alpha toxin is not regarded as responsible for the production of typical lesions of necrotic and haemorrhagic enteritis. The purpose of this study was to investigate the putative role of the more recently described beta2 toxin. Seven hundred and fourteen non-enterotoxigenic type A C. perfringens isolated from 133 calves with lesions of enterotoxaemia and high clostridial cell counts (study population) and 386 isolated from a control population of 87 calves were tested by a colony hybridisation assay for the beta2 toxin. Two hundred and eighteen (31%) C perfringens isolated from 83 calves (62%) of the study population and 113 (29%) C. perfringens isolated from 51 calves (59%) of the control population tested positive with the beta2 probe. Pure and mixed cultures of four C perfringens (one alpha+beta2+, one alpha+enterotoxin-1 and two alpha+) were tested in the ligated loop assay in one calf. Macroscopic haemorrhages of the intestinal wall, necrosis and haemorrhages of the intestinal content, and microscopic lesions of necrosis and polymorphonuclear and mononuclear cell infiltration of the intestinal villi were more pronounced in loops inoculated with the a and beta2-toxigenic C. perfringens isolate. These results suggest in vivo synergistic role of the alpha and beta2 toxins in the production of necrotic and haemorrhagic lesions of the small intestine in cases of bovine enterotoxaemia. However, isolation of beta2-toxigenic C. perfringens does not confirm the clinical diagnosis of bovine enterotoxaemia and a clostridial cell counts must still be performed. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]