Persistent lead poisoning of waterfowl in the Camargue (southern France) 10 years after the ban on the use of lead ammunition in wetlands

Lead pollution is a worldwide environmental and health issue causing persistent detrimental effects on humans and wildlife. Despite having been identified as detrimental to waterfowl a century ago, in France lead shotgun pellets for hunting were banned only in 2006 and only in wetlands. We used long-term monitoring data from the Camargue (southern France) to (1) assess the local effectiveness of the French regulation at reducing the ingestion of lead shotgun pellets by waterfowl and to (2) assess local hunter compliance with the regulation. We used data on 2187 gizzards from 13 waterfowl species collected from 38 hunters in the Camargue over 20 hunting seasons (1998 to 2017). In addition, from 2008 to 2019, we systematically collected shotgun shell cases at three communal wetland hunting sites and used the ratio of cases indicating lead versus nontoxic shotgun shells to estimate hunter compliance with the ban. Across the 20-year study period that spanned pre- and post-ban, gizzards of harvested waterfowl had a mean lead shotgun pellet prevalence of 12% across the 13 species with no significant reduction over time. There was a slow increase in the use of nontoxic shot shells after the ban; lead shells continued to be used widely, suggesting inadequate policy enforcement. Because the ban was only applied for hunting in wetlands, hunters have to be caught with lead shells in the shotgun while in wetland to be fined. It is still legal to carry lead shells, favoring the circumvention of the regulation. Our results support the need for a complete ban of lead shotgun shells for both wetland and terrestrial hunting. A complete ban would facilitate policy enforcement and would favor compliance, eventually leading to a phase-out of lead shell production and use.