Effects of seabird vectors on the fate, partitioning, and signatures of contaminants in a High Arctic ecosystem.

Seabirds bioaccumulate contaminants from prey, transport them to their nesting sites, and deposit them in their excreta and carcasses, thereby focusing marine-derived contaminants into remote, terrestrial receptor sites. In the case of organochlorine chemicals transported by northern fulmars (Fulmarus glacialis) to a High Arctic seabird colony on Devon Island, Nunavut, Canada (76°13'N, 89°14'W), this contaminant pathway dominates all others. In freshwater ponds below the nesting cliffs, concentrations of organochlorine contaminants characteristic of fulmar input were 2- to 45-fold higher in sediments and water (depending on seabird input to the particular pond) than in ponds remote from the colony. Air-water fugacity quotients for the ponds decreased with seabird input, indicating that fulmar contaminant input shifts air-water partitioning to increasingly favor volatilization to air. Although contaminant evasion from water was favored, direct evidence of it was not detected in air samples. For PCBs, congener profiles of pond sediments or water became more similar to seabird sources as seabird input increased, and less similar to air profiles. Based on measurements of contaminants in fulmars and other local environmental media, this study presents the first application of fugacities and multivariate source apportionment statistics to resolve seabird biological vectors.

High arctic ponds receiving biotransported nutrients from a nearby seabird colony are also subject to potentially toxic loadings of arsenic, cadmium, and zinc.

The role of northern fulmars (Fulmarus glacialis) was investigated for the transport of nutrients and trace elements to a series of 10 ponds located along a gradient of seabird influence below a fulmar colony in the high Arctic (Cape Vera, Devon Island, Canada). Phosphorus, Cd, K, Zn, and As were identified as seabird-derived elements, having both a high concentration in fulmar guano and a low concentration in background pond sediments (i.e., a high biogenic enrichment factor). Fluxes of these elements were highest in the pond closest to the colony and declined exponentially with distance. Sediments in several of the ponds exceeded Canadian Sediment Quality Guidelines for the Protection of Aquatic Life set for As (5.9 mg/kg) and Cd (0.6 mg/kg), and in the pond closest to the colony, which receives the most seabird subsidies, sediments contained 343 mg/kg Zn, exceeding the threshold for probable adverse biological effects. Although nutrient subsidies from fulmars create an Arctic oasis at Cape Vera, which supports a variety of flora and fauna, the same biological transport pathway puts at risk some of these species by creating sedimentary As, Cd, and Zn concentrations at this remote site similar to those usually observed only near industrialized locations.