Pesticide contamination of bird species from Donana National Park (southwestern Spain): Temporal trends (1999-2021) and reproductive impacts*

Donana National Park (DNP) is a protected area renowned for hosting a wide variety of birds. However, the agricultural practices in its surroundings might cause pesticide contamination of the park biota. This work aimed to assess temporal trends of a wide variety of pesticides, including organochlorine (OCPs), organophosphate (OPPs) and pyrethroid (PYRs) pesticides, in bird eggs collected for more than twenty years (1999-2021) in DNP. Twenty-six pesticides were detected, being 4,4 '-DDE the most frequently detected and also the one with the highest concentrations (up to 2.55 mu g g(-1) ww), exceeding in some cases the values usually reported to cause detrimental health and reproductive effects in avian species. An overall decreasing trend of OCPs was observed. In contrast, an apparent increase in PYRs was detected from 2013 onwards, especially for fenvalerate, whose median concentration was 3-5 orders of magnitude higher in the most recent samples. Moreover, other pesticides such as oxadiazon, oxyfluorfen and fenitrothion were first detected in 2021 samples. Finally, two variables estimating the cumulative impact of pesticides significantly decreased the breeding performance of a top predator such as the booted eagle. Therefore, it is essential to control the use of pesticides in the agricultural practices surrounding DNP and to study their potential negative impact on the bird populations breeding in this protected area.

Automated summary

Donana National Park (DNP) is a protected area known for its diverse bird species. However, the use of pesticides in the surrounding agricultural practices has led to contamination of the park's bird eggs, with detrimental effects on their health and reproduction. A study conducted over a span of more than twenty years (1999-2021) identified 26 pesticides in the collected bird eggs, including commonly detected organochlorine and newly detected pyrethroid pesticides. The concentrations of these pesticides varied, with some exceeding levels known to be harmful to avian species. The findings call for control measures to limit pesticide use and further investigation into the impact on bird populations in this protected area.