Organochlorines and possible biochemical effects in glaucous gulls (Larus hyperboreus) from Bjørnøya, the Barents Sea.

To study possible biochemical effects of organochlorine contaminants (OCs) in glaucous gulls (Larus hyperboreus), 40 adult individuals were collected from colonies on Bjornoya in the Barents Sea. OCs (four pesticides and nine PCB congeners), microsomal 7-ethoxyresorufin O-deethylase (EROD) activity, microsomal testosterone hydroxylation, highly carboxylated porphyrins (HCPs), retinol, and retinyl palmitate were quantified in liver samples. The hepatic vitamin A stores in glaucous gulls were larger than in herring gulls (Larus argentatus) from other studies conducted in contaminated locations in North America. No significant relationships were found between liver retinoid concentrations and OC levels. The hepatic EROD activity was low compared to other studies on fish-eating birds and only marginally associated with PCB levels. Microsomal testosterone hydroxylase activity was only observed at the 6beta-position and could not be related to OC levels. The low P450-associated enzyme activities in the glaucous gull suggests that they have a low capacity for metabolizing OCs, which may contribute to the high accumulation of OCs in this species. HCPs were only elevated (138 pmol g(-1)) in the sample with highest OC levels, whereas the remaining samples contained low levels of HCPs (<30 pmol g(-1)). The weak association between EROD activity and PCB levels and the low level of HCPs suggest that these biochemical parameters were unaffected by OCs in most of the sampled gulls. Thus, the glaucous gull seems not to be particularly sensitive toward Ah-receptor mediated effects.

Congener specific PCB and polychlorinated camphene (toxaphene) levels in Svalbard ringed seals (Phoca hispida) in relation to sex, age, condition and cytochrome P450 enzyme activity.

Congener specific PCB and toxaphene (polychlorinated camphene, PCC) analyses were performed in seal blubber, collected in Svalbard, Norway. The concentration, body burden and metabolic index (PCB congener concentration in seal relative to their prey) were calculated. Multiple regression analyses were carried out to evaluate the influence of age, sex, blubber (as a percentage of total body weight) and cytochrome P450 activities on PCB and PCC levels. Levels of total PCBs found were five times higher than in ringed seals from the Canadian Arctic, corresponding with the relatively high contaminant levels in the European Arctic. The dominant PCB congeners (> 70% of the total PCBs measured) were 153, 138, 99, 180 and 101. The observed PCB and PCC accumulation patterns were very similar to patterns in seals from other studies, suggesting a large resemblance in contaminant metabolism. A decrease in the relative abundance of the lower chlorinated PCBs, was associated with higher concentrations of PCB 153. Since there was no indication for selective PCB excretion by lactating females, this suggests metabolism of these PCBs in ringed seals due to xenobiotic metabolising enzymes. The metabolic index confirmed the model of persistency of the different PCBs except for congener 128 and 138. These congeners, considered persistent in seals, could to some extent be metabolised in ringed seals. However, co-elution of PCB 138 with PCB 163 and of PCB 128 with TOX 50 possibly has resulted in an underestimation of the metabolic index for these congeners. Multiple regression analyses revealed a significant positive effect of age and a negative effect of the blubber content on the PCB concentrations. Since large fluctuations of body lipids occur between seasons in pinnipeds, PCB measurements should account for the total blubber content to avoid biased results. PCBs with vicinal H-atoms in the o, m or the m, p positions showed in addition a relation with cytochrome P450 enzyme activities. Surprisingly, no effect of sex on the PCB concentrations was observed, probably because female ringed seals, unlike other pinnipeds, continue feeding during lactation. This results in only small amounts of lipid and lipid-associated contaminants being mobilised from the blubber. Consequently, contaminant excretion with the milk will be low. Toxaphene concentrations found were low compared to levels found in the Canadian Arctic. Two congeners, TOX 26 and TOX 50 were predominant (15 and 18%, respectively of total toxaphene). There was no effect of sex, age, total blubber, or cytochrome P450 activities on the toxaphene levels. There was also no correlation between toxaphene and PCB levels, which may indicate differences in exposure and metabolism between these contaminants. Toxaphenes did not bioaccumulate to any substantial extent in ringed seals.

Lungworm and stomach worm infection in relation to body fat reserves and blood composition in wild boar (Sus scrofa).

Lung and stomach nematode burden was estimated in 8 juvenile and 12 adult wild boar (Sus scrofa), shot in The Royal Forestry 'Het Loo' between January 1988 and April 1989, in order to study whether body fat reserves or blood composition (i.e., nutritional status) is correlated with the parasite burden. Only bone marrow fat, the last fat reserve to be mobilized, showed a slight negative correlation with the stomach worm burden. Serum urea concentration, an indicator of severe undernutrition, was weakly correlated with the stomach worm burden in juvenile boars. These results suggest a relatively small impact of these parasites on animals with a lowered nutritional status. The burden of lungworms or stomach worms did not provide reliable information about the body condition of wild boar.

Undernutrition in relation to changed tissue composition in wild boar (Sus scrofa).

The effect of long term dietary restriction on the composition of liver, kidney, and several muscles was studied in wild boar (Sus scrofa) in order to evaluate the tissue protein content as an indicator for the nutritional status. Extreme undernutrition was associated with a relatively large weight reduction in liver and kidney. In liver and kidney, total protein content and the protein/DNA ratio were reduced through a reduction in both cell number and cell size. The lower protein/DNA ratios and the increased DNA concentration in the muscle of food restricted animals suggested only a reduction of cell size. The response to undernutrition varied considerably between two muscles. It was concluded that the DNA concentrations and the protein/DNA ratio in several tissues provides an additional tool for assessing nutritional status in living or shot wild boar.

The effect of undernutrition on haematological and serum biochemical variables in wild boar (Sus scrofa).

The effect of induced long term undernutrition on the blood composition of wild boar was studied. During the first weeks, the activity of plasma alkaline phosphatase decreased, while creatinine concentrations increased, and the ratio urea/creatinine decreased, suggesting a renal mechanism as well as recycling of nitrogenous waste products to conserve nitrogen. During the last weeks, haemoglobin and packed cell volume decreased, suggesting protein or mineral deficiencies, and the ratio urea/creatinine increased, indicating substantial endogenous protein catabolism.

Sedation of wild boar (Sus scrofa) and red deer (Cervus elaphus) with medetomidine and the influence on some haematological and serum biochemical variables.

Medetomidine, an alpha-2 agonist, was tested for the sedation of wild boar (Sus scrofa) (n = 6) and red deer (Cervus elaphus) (n = 7). The effectivity of this drug and the dose required for handling, blood sampling, and minor surgery were established for both species. In addition the effect of medetomidine sedation on haematological and serum biochemical variables was studied. All animals used were clinically normal females aged approximately 1.5 years. The minimal dose required to sedate a wild boar was 80 micrograms/kg (i.m.). The induction time was 35-50 min, and the sedation time was between 40 and 55 min; however, the sedation was insufficient. The minimal dose required for red deer was 80 micrograms/kg (i.m.). Blood sampling and minor surgery could be carried out without any problem. The induction time was 21-29 min and the sedation time was between 120 and 210 min. The alpha-2 antagonist atipamezole (300 micrograms/kg) was effective in reversing sedation, with recovery occurring between 3 and 9 min. Medetomidine sedation influenced the blood composition of wild boar. Haemoglobin and packed cell volume decreased by about 20% (P < 0.002), total serum protein content decreased slightly (P = 0.011), and the glucose concentration nearly doubled (P = 0.002).

Nutritional status of wild boar (Sus scrofa): II. Body fat reserves in relation to haematology and blood chemistry.

1. The relationship between body fat reserves and blood variables was calculated in 26 wild boar in order to evaluate blood variables as indicators for the nutritional status. 2. In juveniles only a relationship between bone marrow fat and haemoglobin, packed cell volume, albumin, total globulin, gamma globulin, alkaline phosphatase and urea were found. 3. Urea and packed cell volume accounted (together) for more than 90% of the variance of bone marrow fat.