Reproductive Success and Biochemical Effects in Tree Swallows (Tachycineta Bicolor) Exposed to Chlorinated Hydrocarbon Contaminants in Wetlands of the Great Lakes and St. Lawrence River Basin, Usa and Canada

Abstract

Reproduction and biochemical indicators (vitamin A, ethoxyresorufin‐O‐deethylase [EROD], highly carboxylated porphyrins) of contaminant effects, and concentrations of organochlorine residues were measured in tree swallows from wetlands within the watersheds of the Great Lakes and the St. Lawrence River, USA and Canada. To assess the vitamin A sources in the tree swallow diets, insects were collected, by ligature, from nestlings at four of these sites. Diet samples were analyzed for retinol and α‐ and β‐carotene. Marked differences were found in chlorinated hydrocarbon residues in eggs and nestlings among sites; however, we did not find any significant differences in hatching or fledging success. The maximum polychlorinated biphenyl (PCB) concentration found was 11.1 μg/g in eggs from Akwesasne Reserve, New York, USA, on the St. Lawrence River, whereas the highest p, p′‐DDE concentration of 2.57 μg/g was found in eggs from Mud Creek, Ontario, Canada, in the Lake Erie watershed. Concentrations of other organochlorine pesticides and chlorobenzenes were low and not variable among sites. Significant differences in hepatic EROD activity, retinol and retinyl palmitate, and uroporphyrin in nestling birds existed among sites. Ethoxyresorufin O‐deethylase activity was highest and retinol and retinyl palmitate were lowest at Cornwall Island, Ontario, Canada, in the St. Lawrence River, whereas porphyrins were highest at Toronto and Hamilton harbors, Ontario, Canada, in Lake Ontario. Ethoxyresorufin O‐deethylase induction was significantly and negatively correlated with nestling hepatic retinol concentrations, whereas uroporphyrin concentrations were positively correlated with PCB congener 118 in nestlings. In contrast, few differences occurred in vitamin A concentrations in diet samples among sites. Together, these findings suggest that depressed hepatic vitamin A and elevated highly carboxylated porphyrin concentrations are strongly associated with sites with the highest organochlorine exposure in tree swallows.

Reproductive success of three passerine species exposed to dioxin-like compounds near Midland, Michigan, USA

“…The majority of studies have reported variable or no significant reproductive effects (Bishop et al 1999; Harris and Elliott 2000; McCarty and Secord 1999; Neigh et al 2006b, 2007; Thiel et al 1988), while a significant negative correlation was observed for TRES hatching success and egg concentrations on the primarily PCB-contaminated Housatonic River in Massachusetts (Custer et al 2003) and site-specific hatching success was less on the primarily TCDD-contaminated Woonasquatucket River in Rhode Island (Custer et al 2005). However, studied species along the Tittabawassee River had similar ΣPCDD/DF or TEQ WHO-Avian concentrations in eggs (Fredricks et al 2011d) to the studies on the Housatonic and Woonasquatucket rivers.…”

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

“…Mean concentrations at main stem sites ranged from 31.5 g/g wet weight (Holmes Road, 2000) to 100.9 (Roaring Brook, 1999). In the Great Lakes, annual average concentrations of total PCBs in tree swallow eggs were 0.5 and 1.4 g/ g wet weight at Saginaw Bay, Lake Michigan [14]; 3.2 and 4.2 g/g wet weight in lower Green Bay, Lake Michigan [3,4]; and between 0.3 and 11.1 g/g wet weight in six coastal areas of Lake Erie, Lake Ontario, and the St. Lawrence River [13,20]. Along the upper Hudson River in New York, tree swallow egg average concentrations ranged from 5.9 to 29.5 g/g wet weight [15,21].…”

“…Concentrations of organochlorine chemicals and trace elements were compared among sites and years using standard statistical anal- (31) 12 (31) 18 (31) 26 (54) 32 (52) 18 (31) 40 (53) 37 (53) NS a 15 (18) 25 (38) NS 9 (20) 16 (20) 11 (35) 16 (38) 15 (32) a NS ϭ no sample; nest boxes not present at this location in 1998. yses. Numbers of eggs laid and hatching success were monitored throughout the spring and summer.…”

“…Because they feed near their nest box (ϳ300-400 m [16,17]), primarily on emergent aquatic insects [18], residues in their * To whom correspondence may be addressed (christinecuster@usgs.gov). Data for tree swallows are now available on PCB contaminant levels at a number of locations across the United States and Canada [4,5,8,13,15,20,21] and for other organochlorines [9,10,22], dioxins [8], trace elements [6,11,12], and polycyclic aromatic hydrocarbons [7]. They also nest relatively densely so that adequate sample sizes can be obtained.…”

“…Studies of tree swallows at two other PCB-contaminated sites in the United States [4] and Canada [13,20] reported no effects of PCBs on hatching success. However, a study along the heavily contaminated Hudson River in New York (USA) [23] suggested effects on reproduction in one of two years [21].…”