Beavers indicate metal pollution away from industrial centers in northeastern Poland

Abstract

Heavy metals are persistent environmental contaminants, and wild animals are increasingly exposed to the harmful effects of compounds of anthropogenic origin, even in areas distant from industrial centers. We used atomic absorption spectrometry to determine levels of cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) in liver and kidney of wild Eurasian beavers (Castor fiber) in Poland. Cd concentrations in liver (0.21 ± 0.44 μg/g) and in kidney (2.81 ± 4.52 μg/g) were lower in juvenile than in adult beavers. Pb concentrations in liver (0.08 ± 0.03 μg/g) and kidney (0.08 ± 0.03 μg/g) were similar among all individuals, while both Cu and Zn levels were higher in liver (Cu 9.2 ± 4.5 μg/g; Zn 35.7 ± 3.5 μg/g) than in kidney (Cu 3.7 ± 1.1 μg/g; Zn 21.5 ± 2.7 μg/g). Cu levels also differed between juveniles and adults. We reviewed the literature reporting metal concentrations in beavers. Our results indicate metal contamination in beavers away from important industrial emission sources and suggest the natural environment should be regularly monitored to ensure their levels are below recommended, legal values.

Can red deer antlers be used as an indicator of environmental and edible tissues’ trace element contamination?

“…Toxic trace elements are present not only in the vicinity of industrial areas but also in natural and agricultural ecosystems away from emission sources (Giżejewska et al 2015). Toxic trace elements such as lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) pose a health threat to organisms even in small doses.…”

“…Contrastingly, cervid antlers have a number of advantages that make them a unique material for monitoring of trace contaminants (Giżejewska 2015; Giżejewska et al 2016, 2015). Antlers are bony cephalic appendages that are cast and regenerated annually, with high demand for minerals in the growing period, during which they accumulate trace elements (Kierdorf and Kierdorf 2006).…”

Chemical composition, amino acid and fatty acid contents, and mineral concentrations of European beaver (Castor fiber L.) meat

“…Although beaver is currently not considered as a consumptive animal in Poland, beaver is classified as a game species in a few European countries (Belarus, Estonia, Lithuania, Latvia, Norway, and Sweden) as well as in Canada and Russia [9]. As a result of damages include tree girdles, grassland flooding, arable crop damages [10], as well as production losses in fisheries, physical destruction at aquaculture facilities and costs of implementing damage prevention methods, the growing beaver population needs to be controlled [11].…”

Variations of selected trace element contents in two layers of red deer antlers

“…Climate is typically temperate with significant influence of the continental climate of Eastern Europe. The region is a popular touring place, located away from the large industrial centres (7,23).…”