Trace metals, stable isotope ratios, and trophic relations in seabirds from the North Pacific Ocean

Abstract

Trace elements including mercury, cadmium, selenium, and stable nitrogen isotope ratios (sigma15N) were measured in tissues of Pacific seabirds. Two species of albatross (Diomedea immutabilis, Diomedea nigripes), four species of shearwaters (Puffinus bulleri, Puffinus carneipes, Puffinus griseus, Puffinus tenuirostris), northern fulmar (Fulmarus glacialis), and horned puffin (Fratercula corniculata) were collected opportunistically by an experimental fishery in the North Pacific Ocean. Two species each of petrels (Oceanodroma leucorhoa, Oceanodroma furcata) and auklets (Ptychoramphus aleuticus, Cerorhinca monocerata) were collected at breeding colonies on the north coast of British Columbia, Canada. Concentrations of toxic trace metals varied considerably among the pelagic nonbreeders; highest concentrations consistently were in D. nigripes (e.g., Hg), 70-fold greater than F. corniculata (e.g., Cd), eightfold greater than P. tenuirostris (e.g., Se), and fourfold greater than F. corniculata. Most essential trace elements varied little among species, consistent with physiological regulation. Values for sigma15N correlated positively with hepatic Se (r = 0.771, p = 0.025) and negatively with Co (r = 0.817, p = 0.013). Among the four breeding species, there were significant positive associations for sigma15N in muscle and hepatic Se (r = 0.822, p = 0.002), Hg (r = 0.744, p = 0.0001), and Cd (r = 0.589, p = 0.003). Differences in time scales integrated by sigma15N versus trace metals in tissues probably reduced the apparent associations between trace-metal exposure and diet.

Trace element and metallothionein concentrations in seabirds from the Canadian Arctic

“…The Cd concentrations in livers of Arctic seabirds reported in the present study were at the higher end of the range of Cd levels reported for other seabird species from both the Canadian Pacific coast [7,30] and Atlantic coast [6], with the exception of the storm‐petrels from the Pacific coast, which had considerably higher concentrations (Leach's storm‐petrel, 82‐100 μg/g dry wt, fork‐tailed petrel [ Oceanodroma furcata ], 142 μg/g dry wt) than all other species on both the eastern and western coasts. The hepatic Cd concentration for northern fulmars from the present study was approximately fourfold higher than that found for northern fulmars from the northern Pacific Ocean [30].…”

“…Lead. Concentrations of hepatic Pb were either not detectable or very low in all seabird species from all of Canada's coasts [6,7,22,30] (present study).…”

Correlates between Feeding Ecology and Mercury Levels in Historical and Modern Arctic Foxes (Vulpes lagopus)

“…Northern fulmars and storm petrels became the main food resource, the use of other bird species, marine invertebrates and otarid products having significantly decreased [7]. The Northern fulmar ( Fulmarus glacialis ) breeds on Siberian and Alaskan islands and winters widely throughout the Pacific, feeding mainly on invertebrates and some fish [39] whereas the two storm petrels species ( Oceanodroma furcata and O. leucorhoa ) are pelagic plankton eaters [40]. Due to their relatively lower position within the food chain it is very likely that these bird species are generally less contaminated with Hg or other pollutants than seals.…”

Survival rates and blood metal concentrations in two species of free‐ranging North American sea ducks

“…If king eiders and whitewinged scoters are similar to common eiders in this regard, it is plausible that Hg could exacerbate the adverse effects of other environmental stressors. Total Hg levels in eiders, scoters, and other sea ducks are relatively low, however, especially compared to pelagic marine birds and fish-eating birds [5][6][7]43]. Moreover, marine birds, presumably including sea ducks, generally are well-adapted for coping with exposure to elevated Hg levels [44].…”