Exposure and Effects of Chemical Contaminants on Tree Swallows Nesting Along the Housatonic River, Berkshire County, Massachusetts, Usa, 1998–2000

Abstract

Hatching success of tree swallows (Tachycineta bicolor) was assessed for three years in relation to chemical contamination along the Housatonic River, Berkshire County (MA, USA), in 1998, 1999, and 2000. Nest boxes were erected at five sites along the Housatonic River and its tributaries and at one reference location. Concentrations of total polychlorinated biphenyls (PCBs) were some of the highest ever reported in bird eggs. Mean concentrations at sites along the Housatonic River ranged between 32 and 101 microg/g wet weight. A significant negative relationship was observed between concentrations of total PCBs in clutches and hatching success. A significant negative relationship was also observed between hatching success and the sum of the total dioxins and furans and the associated toxic equivalents (TEQs) for dioxins and furans. In a combined model with PCB TEQs and dioxin/furan TEQs, PCB TEQs were not significantly correlated to hatching success, whereas dioxin/furan TEQs were. Contamination of tree swallows was from local food sources. Accumulation rates of total PCBs in 12-d-old nestlings averaged between 34 and 76 microg/d at the sites along the main stem of the Housatonic River compared to <1 microg/d at the reference location.

Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in spotted sandpiper eggs from the upper Hudson River basin, New York

“…We hypothesized that three toxicant classes (PCBs, PCDD-Fs, and DDE) might adversely affect reproductive success of spotted sandpipers (Custer et al 1999(Custer et al , 2003(Custer et al , 2005. We estimated the effects of PCBs and PCDD-Fs using measured concentrations as well as TEQs.…”

“…A number of studies have documented that birds can accumulate PCBs through their diet (Custer et al 1998(Custer et al , 1999(Custer et al , 2003(Custer et al , 2005Drouillard and Norstrom 2001;Froese et al 1998;Secord et al 1999). Effects of PCBs on birds, and especially on chickens (Gallus domesticus), which are extremely sensitive, have been clearly demonstrated in laboratory studies (Hoffman et al 1996b).…”

“…Effects of PCBs on birds, and especially on chickens (Gallus domesticus), which are extremely sensitive, have been clearly demonstrated in laboratory studies (Hoffman et al 1996b). PCB effects in field studies have also been demonstrated (Custer et al 2003(Custer et al , 2007, but many field studies are problematic because of the multiplicity of chemicals that a species is exposed to and the difficulty of assigning causality. The nature and severity of effects can depend on the dosage, PCB congener composition, and the bird species (Barron et al 1995;Fernie et al 2001;Hoffman et al 1996aHoffman et al , b, 1998.…”

“…in eggs, respectively (Henny and Elliott 2007). Additionally, hatching success in tree swallows on the Housatonic River, MA was reduced beginning at about 20 lg/g PCBs (Custer et al 2003).…”

“…Because of the high concentrations of PCBs reported in spotted sandpiper eggs from the Hudson River (Hudson River Natural Resource Trustees 2005) and several studies suggesting adverse effects of PCBs on avian reproduction (Custer et al 2003(Custer et al , 2007Henny and Elliott 2007), our working hypothesis was that there would be a negative association between PCB contamination and reproductive success.…”