ABSTRACT
The white-tailed eagle (Haliaeetus albicilla) suffered a severe population decline due to environmental pollutants in the Baltic Sea area ca. 50 years ago but has since been recovering. The main threats for the white-tailed eagle in Finland are now often related to human activities. We examined the human impact on the white-tailed eagle by determining mortality factors of 123 carcasses collected during 2000-2014. Routine necropsy with chemical analyses for lead and mercury were done on all carcasses. We found human-related factors accounting for 60% of the causes of death. The most important of these was lead poisoning (31% of all cases) followed by human-related accidents (e.g. electric power lines and traffic) (24%). The temporal and regional patterns of occurrence of lead poisonings suggested spent lead ammunition as the source. Lead shot was found in the gizzards of some lead-poisoned birds. Scavenging behaviour exposes the white-tailed eagle to lead from spent ammunition.
Subject(s)
Eagles , Extinction, Biological , Human Activities , Lead Poisoning/mortality , Lead Poisoning/veterinary , Animals , Automobile Driving , Electric Injuries/etiology , Environmental Pollutants , Finland , Firearms , Humans , Kidney/chemistry , Kidney/pathology , Liver/chemistry , Liver/pathology , Mercury Poisoning/mortality , Mercury Poisoning/veterinary , Mortality , Power Plants , Wounds and Injuries/etiology , Wounds and Injuries/veterinaryABSTRACT
Eleven white-tailed sea eagles (WSEs) (Haliaeetus albicilla) collected in Finland between 1994 and 2001 were examined for their causes of death, including analyses of ubiquitous environmental contaminants and parasites. Four WSEs died due to electrocution. Two were lead poisoned and another had fragments of a lead bullet in its gizzard. An 11-year-old female drowned entangled in fishing gear, but also had mercury levels in its liver and kidneys known for detrimental physiological effects. One WSE was evidently killed by an intraspecific conflict, which was also assumed to be with another bird. The mortality factors of two WSEs could not be clarified, but one had a lead level of 4.604 microg g(-1) in its liver, indicating high lead exposure at a clinically relevant concentration. All organ levels of chlorinated pesticides, polychlorinated biphenyls, and cadmium were moderate and not harmful for birds of prey. Seven helminth species, but no ectoparasites or coccidians, were found in 8 of 10 WSEs investigated for parasites. The highest prevalence of 40% was found for the liver fluke Metorchis billis, but no severe parasitosis was diagnosed for the eagles. The two acanthocephalan species Corynosoma semerme and Polymorphus meyeri are both new records for WSEs.
Subject(s)
Eagles/parasitology , Environmental Pollutants/analysis , Helminthiasis, Animal/mortality , Helminthiasis, Animal/parasitology , Helminths/isolation & purification , Animals , Color , Environmental Pollutants/toxicity , Female , Finland , Helminthiasis, Animal/chemically induced , Helminthiasis, Animal/diagnostic imaging , Kidney/drug effects , Liver/drug effects , Male , Metals, Heavy/analysis , Metals, Heavy/toxicity , Pesticides/analysis , Pesticides/toxicity , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/toxicity , Radiography , Time FactorsABSTRACT
The effect of ditching of boreal forest land (W. Finland) on P and N dynamics and export was assessed using a paired catchment approach (response stream + control stream) for a 4-year study period. After the ditching operations, there was a small but significant increase in the NH4+ export, but no significant changes in the concentrations and loads of total reactive P, total non-reactive P, total organic N and NO3-. In both streams, the reactive P fraction largely followed the Fe concentrations. High input to output ratios, and thus, high retention was a typical feature of the inorganic N compounds. Total organic N and the TOC/TON ratio were positively correlated with the total organic carbon.
