Mercury concentrations in tidal marsh sparrows and their use as bioindicators in Delaware Bay, USA

National parks are used worldwide as a means to protect the ecological integrity of unique ecosystems. Dilek National Park in western Turkey is a protected habitat for several endangered and severely threatened species. Thirty-seven water and 59 sediment samples were collected and analyzed for pesticides at two different sampling depths. The park is contaminated with 16 different organochlorine pesticides, with more pesticides detected in sediments than in water. The most prevalent pesticides in the 30–60-cm depth were DDT (69.5% of the samples), heptachlor (62.3%), a-endosulfan (55% of samples), and endrin (37%). Lindane isomers were present, but at <30% of the sediment samples. These pesticides could be a long-term contamination source that enters the food web used by the very species the park is trying to protect.