Contaminant Residues in Snapping Turtle (Chelydra s. serpentina) Eggs from the Great Lakes?St. Lawrence River Basin (1999 to 2000)

Abstract

To determine temporal and geographic variations of environmentally persistent pollutants, the concentrations of several contaminants were measured in snapping turtle eggs in 1999 and 2000. Contaminants included polychlorinated biphenyls (PCBs), non- ortho PCBs, polychlorinated dibenzodioxins and furans, organochlorine pesticides, and total mercury. Egg collection sites within the St. Lawrence Area of Concern (AOC) and the Territory of Akwesasne included Turtle Creek, Snye Marsh, and Raquette River. Additional contaminated sites were Gray's Creek (within the St. Lawrence AOC boundary), Coote's Paradise (Hamilton Harbour AOC), and the Territory of Walpole Island (St. Clair AOC). Reference sites were Lake Sasajewun, Algonquin Provincial Park in central Ontario, and in close proximity to the St. Lawrence Area AOC, Hoasic Creek and Cooper Marsh. Eggs from clutches collected from Akwesasne contained the highest concentrations of contaminants. Mean total PCB concentrations for Akwesasne clutches ranged from 1,900 to 61,000 ng/g wet weight (w.w.), which was 360 to 3,100 times higher than the mean concentrations at the reference sites. The high levels of contaminants in eggs, from sites within Akwesasne, were consistent with trends reported in the past and reflect the influence of the proximity of heavy industry. Current contaminant concentrations in clutches from Coote's Paradise are comparable with those recorded in 1989 and 1990 but are 200 to 800 times lower than concentrations reported in 1984 and 1988. Eggs from Lake Sasajewun contained relatively low contaminant levels, which is consistent with atmospheric deposition. Our results support that snapping turtles are good indicators of temporal and geographic contaminant trends.

Accumulation and maternal transfer of polychlorinated biphenyls in snapping turtles of the upper Hudson River, New York, USA

“…At the same site, a clutch sampled in the previous year was found to have an astonishingly high PCB concentration of 737,700 ng/g wet weight (5,083,000 ng/g lipid)-almost 1% the wet mass of the egg [29]. The reported t-PCB concentrations in eggs from reference areas sampled during the studies of the Great Lakes-St. Lawrence River Basin ranged from 15.7 to 272 ng/g wet weight [9,[28][29][30], similar to the concentrations we observed in reference areas. Otherwise, average t-PCB concentrations in nearby Canadian Great Lakes-St. Lawrence River Basin areas of concern (AOCs) generally ranged from 340 to 11,000 ng/g wet weight [27][28][29][30], similar to those that we observed in the contaminated area of the upper Hudson River.…”

“…Most notably, studies conducted in Canadian portions of the Great Lakes and the St. Lawrence River Basin have found PCB concentrations in eggs that are similar to those we observed or, in some cases, exceed them [9,[27][28][29][30]. Most notably, studies conducted in Canadian portions of the Great Lakes and the St. Lawrence River Basin have found PCB concentrations in eggs that are similar to those we observed or, in some cases, exceed them [9,[27][28][29][30].…”

“…In two instances, eggs were found to have exceptionally high t-PCB concentrations that far exceeded those observed in the upper Hudson River; Ashpole et al [30] detected 61,000 ng/g wet weight of t-PCBs (1,034,000 ng/g lipid) in a clutch of eggs collected in 1999 from a contaminated site on the south side of the St. Lawrence River. Otherwise, average t-PCB concentrations in nearby Canadian Great Lakes-St. Lawrence River Basin areas of concern (AOCs) generally ranged from 340 to 11,000 ng/g wet weight [27][28][29][30], similar to those that we observed in the contaminated area of the upper Hudson River. These values were much greater than the values we obtained (12,100 ng/g wet wt or 127,000 ng/g lipid), but they were restricted to a single waterway with, perhaps relatedly, a very sparse snapping turtle population.…”

Mercury concentration in different tissues of Podocnemis unifilis (Troschel, 1848) (Podocnemididae: Testudines) from the lower Xingu River – Amazonian, Brazil

“…In another example observed in a study with Trachemys scripta (Schoepff, 1792) and Chelonia mydas (Linnaeus, 1958), adults were herbivorous, and opportunistic carnivores while juveniles were more carnivorous (Clark and Gibbons, 1969;Bezerra et al, 2012Bezerra et al, , 2013. Additionally, another hypothesis is that smaller individuals could obtain some Mercury from their eggs, such as has been observed for Chelydra serpentina (Linnaeus, 1758) (Ashpole et al, 2004) and also Trachemys scripta (Burger and Gibbons, 1998).…”

Mercury and other heavy metals in free-ranging mink of the lower Great Lakes basin, Canada, 1998–2006

“…Further studies of biomagnification of methylmercury in wetland environments, where top predators such as mink may be at an increased risk of mercury exposure, are warranted. It is worthwhile to note that these three sites have not stood out as particularly high in mercury in previous Great Lakes surveys of snapping turtles (Chelydra serpentina) and tree swallows (Tachycineta bicolour) from these three wetlands (Bishop et al 1998;Martinovic et al 2003;Ashpole et al 2004). This may be more related to differences in trapping locations for Great Lakes mink in this study (i.e., marsh versus more terrestrially-related creek and ditch habitat) compared to similar habitat types (i.e., large wetlands) surveyed for Great Lakes snapping turtles and tree swallows.…”