Assessment of claw growth-layer groups from ringed seals (Pusa hispida) as biomonitors of inter- and intra-annual Hg, delta N-15, and delta C-13 variation

作者：Ferreira Elizabeth O; Loseto Lisa L; Ferguson Steven H^*

来源：Canadian Journal of Zoology, 2011, 89(9): 774-784.

DOI：10.1139/Z11-047

The ringed seal (Pusa hispida (Schreber, 1775)) is a sentinel species of arctic marine mammals; therefore, methods to monitor its life-history changes are crucial to establish effective conservation strategies. We evaluate the potential use of claws of ringed seals as a proxy for counts of tooth growth-layer groups (age) and a biomonitor of total mercury burden (THg) and diet (stable isotope ratios expressed as delta N-15 and delta C-13). The count of claw growth-layer groups was indicative of age up to 8 years and we infer differentiation of dark and light annuli as being associated with the spring moult. No differences of THg, delta N-15, or delta C-13 were observed among flipper digits. The proximal claw annulus representing the most recent growth had delta C-13 values that were correlated to both muscle and liver delta C-13, supporting the use of claws to monitor visceral delta C-13. Claw log(10)THg from the proximate annulus was significantly correlated to liver and whisker log(10)THg, while significant interannual THg accumulation was observed in 18 of 32 seals >= 4 years, suggesting the claws receive and disperse Hg from active tissues of the body. Results support the use of claw tissue from ringed seal to provide a chronological record of inter- and intra-annual variations representing seal diet, contaminant load, and life history.

• 出版日期2011-9