The prevalence and correlates of anticoagulant rodenticide exposure in non-target predators and scavengers in Finland

Abstract

The most common rodent control method worldwide is anticoagulant rodenticides (ARs), which cause death by internal bleeding. ARs can transfer to non-target predators via secondary exposure, i.e. by consuming contaminated rodents. Here we quantify the prevalence of seven AR substances in the liver tissues of altogether 17 mammalian or avian predator or scavenger species in Finland. In addition, we identify the environmental and biological factors potentially linked to secondary AR poisoning. No previous AR screenings have been conducted in the country, despite the widespread use of ARs and their potential impacts on the high levels of the ecosystem food chain. ARs were detected (≥0.3 μg/kg) in 82% of the 131 samples. The most prevalent and the AR with highest concentrations was bromadiolone (65% of samples). In 77% of the positive samples more than one (2-5) different ARs were detected. Of the environmental variables, we only found a weakly positive relationship between the coumatetralyl concentration and the livestock farm density. Conversely, overall AR concentration and number, as well as the concentration of three separate ARs (coumatetralyl, difenacoum and bromadiolone) differed among the three species groups tested, with the group "other mammals" (largely represented by red fox and raccoon dog) having higher values than the groups presented by mustelids or by birds. ARs are authorized only as biocides in Finland and a national strategy on risk management (e.g. for minimising secondary poisoning of non-target species) of ARs was adopted in 2011. Based on these results it appears that the risk mitigation measures (RMMs) either have not been followed or have not been effective in preventing wide scale secondary exposure. Continued monitoring of AR residues in non-target species is needed in order to evaluate the effectiveness of current RMMs and a need for new ones to reduce the risk of secondary poisoning.

Prevalence of Anticoagulant Rodenticides in Feces of Wild Red Foxes (Vulpes Vulpes) in Norway

“…We did not find a significant relation between prevalence of ARs in foxes and human population density. This is in accordance with a study in Finland with no significant relationship between overall AR concentration and environmental variables such as farm density and industrial surroundings (Koivisto et al 2018). In contrast, San Joaquin kit fox (Vulpes macrotis mutica) demonstrated the highest AR exposure in low-density development areas (Nogeire et al 2015).…”

“…However, coumatetralyl was not analyzed in that study. In Sweden and Finland, bromadiolone and coumatetralyl were the most common residues found in foxes (Tjus 2014;Kiovisto et al 2016). We suspect the difference between the countries in occurrence of these ARs is caused by higher sale of brodifacoum in Norway compared to other Scandinavian countries.…”

Koripallotähti vai tuholainen? Rottien tulkitseminen kulttuurisissa konteksteissa

“…Valmisteesta riippuen jyrsijän odotetaan menehtyvän 4-10 päivän sisällä myrkyn syömisestä (Tukes n. d.). Vuonna 2014 antikoagulantteihin perustuvia jyrsijämyrkkyjä myytiin Suomessa 250 000 kiloa, ja myös luonnonvaraiset eläimet altistuvat niille laajamittaisesti (Koivisto et al 2016).…”

Trends and Perspectives in Immunosensors for Determination of Currently-Used Pesticides: The Case of Glyphosate, Organophosphates, and Neonicotinoids

“…Pesticides are applied mainly by spraying directly to the plants or to the soil. Therefore, they can also reach other environmental compartments, such as the atmosphere, the surface, and underground waters where they can be absorbed by aquatic and terrestrial biota [10,11] among birds, fish, and mammals [12,13,14,15]. It is very complicated, currently, to reduce the use of pesticides [1] and the implementation of mitigation strategies [4,11,16].…”