Exposure to Persistent Organic Pollutants Reduces Testosterone Concentrations and Affects Sperm Viability and Morphology during the Mating Peak Period in a Controlled Experiment on Farmed Arctic Foxes (Vulpes lagopus)

Abstract

We investigated testosterone production and semen parameters in farmed Arctic foxes by dietary exposure to persistent organic pollutants (POPs) for 22 months. Eight male foxes were given a diet of POP-contaminated minke whale blubber, whereas their eight male siblings were fed a control diet containing pig fat as the main fat source. The minke whale-based feed contained a ∑POPs concentration of 802 ng/g ww, whereas the pig-based feed contained ∑POPs of 24 ng/g ww. At the end of the experiment, ∑POP concentrations in adipose tissue were 8856 ± 2535 ng/g ww in the exposed foxes and 1264 ± 539 ng/g ww in the control foxes. The exposed group had 45-64% significantly lower testosterone concentrations during their peak mating season compared to the controls (p ≤ 0.05), while the number of dead and defect sperm cells was 27% (p = 0.07) and 15% (p = 0.33) higher in the exposed group. Similar effects during the mating season in wild Arctic foxes may affect mating behavior and reproductive success. On the basis of these results, we recommend testosterone as a sensitive biomarker of POP exposure and that seasonal patterns are investigated when interpreting putative endocrine disruption in Arctic wildlife with potential population-level effects.

Mandibular shape in farmed Arctic foxes (Vulpes lagopus) exposed to persistent organic pollutants

“…Previously published results from the present cohort of exposed and control foxes have shown that plasma level of multiple hormones, such as testosterone, thyroid hormones and vitamins, were affected by POP exposure in the exposed group (Hallanger et al 2012;Rogstad et al 2017;Sonne et al 2017).…”

“…Data on biometrics mean±SD (Min-Max) and concentrations of persistent organic pollutants (POPs) in adipose tissue of farmed Arctic foxes dietary exposed to POPs for up to 22 months. POP data are given as mean±SD (Sonne et al 2017).…”

“…Abdominal adipose tissue for POP analyses was only available from 16 of the 21 animals (Sonne et al 2017). The analyses were conducted using methods described in Johansen et al (2004).…”

“…This results in adverse effects on several organ-tissue systems, which presumably influences their overall health (Letcher et al 2010;Sonne 2010;Sonne et al 2012). Of the affected systems, the immune, skeletal, and endocrine systems may be of the greatest concern because of their potential population-level effects in species such as polar bears (Ursus maritimus) and Arctic foxes (Desforges et al 2016;Letcher et al 2010, Sonne 2010Sonne et al 2015Sonne et al , 2017. As climate warming accelerates the melting of the polar ice caps, POPs can be remobilized into the atmosphere and further biomagnify in Arctic food webs (Letcher et al 2010).…”

A veterinary perspective on One Health in the Arctic

“…For example, the presence of orchitis in polar bear testes [ 88 ] may be of importance while studying testicular dysgenesis syndrome in Inuits. Seasonal hormone and semen production in Arctic fox was found to be affected by POPs [ 89 , 90 ]. Similarly, there are indications that the size of polar bear penis bone, testicles and ovaries may be inversely correlated to PCB concentrations [ 66 , 88 ].…”