The Suitability of Oiled Guillemots ( Uria aalge ) as Monitoring Organisms for Geographical Comparisons of Trace Element Contaminants

Abstract

The influence of the nutritional state (condition factor), age, and sex of Common Guillemots (Uria aalge) on trace element levels was examined to investigate the validity of geographical comparisons of metal accumulations in dying and dead oiled seabirds. A quotient of liver mass to kidney mass was calculated as a condition factor. Condition factors ranged from 0.85-4.74. Sex did not alter the distribution of any of the elements analyzed in immature or adult birds. Cadmium concentrations in soft tissues were strongly influenced by the age of the birds, with adult birds containing significantly higher amounts (0.025-88.28 ppm) than immature ones (0. 004-17.9 ppm). When simultaneously considering age and nutritional condition of the birds, selenium levels were highest in liver samples in immature guillemots (7.37-41.27 ppm) as compared to adult birds (7.22-36.84 ppm). Mercury, copper, and zinc were independent of age. The condition factor had no effect on cadmium levels in birds. In contrast, copper and zinc concentrations in kidney, liver and feathers were negatively correlated with the nutritional condition. In the case of mercury a similar relationship was found only in feathers. On the basis of these results guillemots collected in the German Bight showed significantly higher mercury values (0. 81-20.87 ppm) in soft tissues than birds collected in Brittany (0. 85-17.95 ppm). In general, cadmium levels were higher in the liver of immature birds from the German Bight than in those from Brittany. With regard to copper and zinc only kidney samples had higher values in the German Bight than in Brittany. Selenium levels were lower in feathers of birds from the German Bight (0.09-2.20 ppm) than in those from Brittany (0.67-6.64 ppm). The results indicate that beached guillemots can be used to monitor geographical differences in the contamination with certain metals provided that birds of the same age and/or nutritional condition are compared.

Trace Elements in Three Marine Birds Breeding on Reunion Island (Western Indian Ocean): Part 1—Factors Influencing Their Bioaccumulation

“…), or (ii) the echo of distant pollution which has reached this part of the Wester Indian Ocean by aereal and/or marine currents, or indirectly though the migration of prey species from polluted zones. Physiological studies of the Reunion seabird species would be useful to distinguish healthy birds from those in bad physiological condition in relation to their body condition index (Wenzel and Adelung 1996) in order to better apprehend the influence of the bird's physiological condition on elemental levels.…”

“…Emaciation was estimated by evaluating the muscular condition (MC) which was given a range from 1 to 3 in relation to the shape of the pectoral muscles : 1, well developed pectoral muscles ; 2, slight pectoral muscle atrophy ; 3, severe pectoral muscle atrophy (Bolton et al 1991). Body condition (BC) was also evaluated using a condition index proposed by Wenzel and Adelung (1996). This condition index is the ratio of liver to kidney masses.…”

Body distribution of trace elements in black‐tailed gulls from Rishiri Island, Japan: Age‐dependent accumulation and transfer to feathers and eggs

“…A likely explanation for this is that Cd and Hg, which are nonessential elements, are not controlled by homeostatic mechanisms in these tissues of the animals. Similar intertissue relationships, as in the present study, have been reported in other studies: Positive correlations for Pb in bone‐kidney of bald and golden eagles from Canada [34]; for Cr in liver‐kidney and Zn in kidney‐bone of great tits from Spain [35]; for Pb in liver‐kidney of rock buntings from Spain [35]; for Hg in kidney‐liver and liver‐muscle of herring gulls and great skuas, and kidney‐muscle and liver‐muscle of great skuas [33]; and for Cd in liver‐kidney, liver‐muscle, and kidney‐muscle, Hg in liver‐kidney, liver‐muscle, and kidney‐muscle, and Se in liver‐kidney of common guillemots from the northern coast of Brittany [36].…”

Trophic ecology of marine birds and pelagic fishes from Reunion Island as determined by stable isotope analysis

“…Only adults were sexed during dissection, as the gonads were not developed enough in fledglings to differentiate males from females. The nutritional condition of each bird was also evaluated using the body condition index (BCI) proposed by Wenzel & Adelung (1996) that corresponds to the ratio of liver to kidney masses. BCI is significantly negatively correlated to the degree of emaciation, such that a smaller index indicates a more emaciated bird.…”