Effects of persistent organic pollutants on telomere dynamics are sex and age-specific in a wild long-lived bird.

Chemical pollution is a major man-made environmental threat to ecosystems and natural animal populations. Of concern are persistent organic pollutants (POPs), which can persist in the environment for many years. While bioaccumulating throughout the lives of wild animals, POPs can affect their health, reproduction, and survival. However, measuring long-term effects of POPs in wild populations is challenging, and therefore appropriate biomarkers are required in wildlife ecotoxicology. One potential target is telomere length, since telomere preservation has been associated to survival and longevity, and stressors as chemical pollution can disrupt its maintenance. Here, we investigated the effects of different classes of POPs on relative telomere length (RTL) and its rate of change (TROC) in wild long-lived Alpine swifts (Tachymarptis melba). As both RTL and TROC are often reported to differ between sexes and with chronological age, we tested for sex- and age-specific (pre-senescent vs. senescent, ≥ 9 age of years, individuals) effects of POPs. Our results showed that senescent females presented longer RTL and elongated telomeres over time compared to pre-senescent females and males. These sex- and age-related differences in RTL and TROC were influenced by POPs, but differently depending on whether they were organochlorine pesticides (OCPs) or industrial polychlorinated biphenyls (PCBs). OCPs (particularly drins) were negatively associated with RTL, with the strongest negative effects being found in senescent females. Conversely, PCBs led to slower rates of telomere shortening, especially in females. Our study indicates diametrically opposed effects of OCPs on RTL and PCBs on TROC, and these effects were more pronounced in females and senescent individuals. The mechanisms behind these effects (e.g., increased oxidative stress by OCPs; upregulation of telomerase activity by PCBs) remain unknown. Our results highlight the importance in wildlife ecotoxicology to account for sex- and age-related effects when investigating the health effects of pollutants on biomarkers such as telomeres.

The association between reproductive success with persistent organochlorine pollutants residue in feathers of spur-winged lapwing (Vanellus spinosus L.).

The reproductive and breeding success of wader species is negatively affected by various anthropogenic factors, including persistent organochlorine pollutants (POPs). We aimed to study the association of POPs in feathers with the reproductive success of the spur-winged lapwing (Vanellus spinosus). For this purpose, data on reproductive parameters and feather samples were collected from a breeding population consisting of 19 pairs near Bogazkent district in Antalya, Turkey. Mean concentrations of total polychlorinated biphenyls (ΣPCBs) and organochlorine pesticides (ΣOCPs) were found to be 54 ± 16 ng/g and 520 ng/g in all samples, respectively. In particular, PCB 151 and ß-hexachlorocyclohexane had a negative association the various reproductive parameters in the species under consideration. Fledgling success (n = 25) was calculated to be 37.4%, which was negatively associated with the ΣOCP concentrations (r = - 0.99, p = 0.01). According to the results, POP residues are one of the associated factors on the reproductive success of spur-winged lapwing along, with agricultural activity and predation. It is indicated that the species needs a protection plan for prevention declining reproductive success and population size species in Turkey. Besides, our results suggest that bird feathers are a non-destructive bio-monitoring tools to estimate of contamination levels of organic pollutants in a population.

Persistent Organochlorine Contaminant Residues in Tissues of Hedgehogs from Turkey.

The residues of persistent organochlorinated pollutants (POPs), namely polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) (HCHs, CHLs, HCCPs, DDTs, and dicofol congeners) were investigated in the hair and muscle of road-killed Erinaceus roumanicus and E. concolor in Turkey. Mean residue levels were as follows: in hair, PCBs = 7.43 ± 4.88 ng/g and OCPs = 9.21 ± 1.27 ng/g; in muscle, PCBs = 30.73 ± 2.51 ng/g and OCPs = 145.04 ± 16.59 ng/g. There was no significant difference between species and sex, while there was significant difference between habitats and regions in terms of either total PCB and OCP levels, or POP levels (p < 0.05). Age was a determinative factor for the bio-accumulation of POPs. The contaminant levels were high in the species, sample areas, and habitats. The data also showed that tissues of hedgehogs are suitable for monitoring and evaluating the bioaccumulation of POP levels in Turkey.