John Wiley & Sons, Ltd.

Mercury‐contaminated terrestrial spiders pose a potential risk to songbirds at Caddo Lake (Texas/Louisiana, USA)

0
Methyl mercury (MeHg) is an environmental contaminant that can have adverse effects on wildlife. Because MeHg is produced by bacteria in aquatic ecosystems, studies of MeHg contamination of food webs have historically focused on aquatic organisms. However, recent studies have shown that terrestrial organisms such as songbirds can be contaminated with MeHg by feeding on MeHg‐contaminated spiders. In the present study, we examined the risk that MeHg‐contaminated terrestrial long‐jawed orb weaver spiders (Tetragnatha sp.) pose to songbirds at Caddo Lake (Texas/Louisiana, USA). Methyl mercury concentrations in spiders were significantly different in river, wetland and open‐water habitats. We calculated spider‐based wildlife values (WVs, the minimum spider MeHg concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Methyl mercury concentrations in spiders exceeded WVs for Carolina Chickadee (Poecile carolinensis) nestlings with highest risk in the river habitat. The present study indicates that MeHg concentrations in terrestrial spiders varies with habitat and can pose a threat to small‐bodied nestling birds that consume high amounts of spiders at Caddo Lake. This MeHg threat to songbirds may not be unique to Caddo Lake, and may extend throughout the southeastern U.S. Environ Toxicol Chem © 2014 SETAC

Customer comments

No comments were found for Mercury‐contaminated terrestrial spiders pose a potential risk to songbirds at Caddo Lake (Texas/Louisiana, USA). Be the first to comment!