Brominated Flame Retardants: Spatial and Temporal Patterns and Trends in Seabird eggs from the Nearshore Pacific Coast of Canada

Brominated flame retardants (BFRs) have been widely used to reduce fire hazards. One class, the polybrominated diphenyl ethers (PBDEs), are particularly persistent bioaccumulative and toxic chemicals, now classified as POPs under the Stockholm Convention. Marine ecosystems are the ultimate sink for POPs, and thus there is a continuing need to monitor such contamination. Eggs of marine birds have proven to be an efficient and effective means of measuring and tracking xenobiotic compounds which are transferred from the female bird to the egg via yolk lipids or proteins. Here we report and discuss data from long term monitoring of and mercury in seabird eggs from the northeast Pacific. For this program, the marine system was divided, and representative species selected. The nearshore subsurface is monitored using two cormorant, Phalacrocorax, species, auritus and pelagicus, both feed on a variety of benthic and pelagic fish. The inshore and estuarine zone is monitored using the great blue heron, Adea Herodias. Nearshore data will be compared to data from the offshore subsurface monitored using the rhinoceros auklet, Cerorhinca monocerata, a feeder mainly on small pelagic fishes, and the offshore surface species, the Leach’s storm-petrel, Oceanodroma leucorhoa, which feeds mainly on surface plankton and larval fishes. At three breeding colonies each along the Pacific coast of Canada and at four year intervals 15 eggs are collected and archived. Data from a recent retrospective study, using archived samples collected from 1990 to 2011, shows, as reported for more polluted environments, that PBDEs increased in continental shelf ranging auklet eggs until the early 2000s and have declined since then, in response to restrictions on usage. In contrast, another BFR compound, HBCD (hexabromocyclododecane), increased steadily in eggs of both near and offshore species. The possible role of dietary variation, potentially related to marine regime shifts, will be examined by use of stable isotopes in variation in contaminant levels in these monitored seabirds