2 research outputs found
Π€ΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΌΠ°ΡΠΊΠ΅ΡΠΈΠ½Π³ΠΎΠ²ΡΡ ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ² Π² Π°Π½Π³Π»ΠΈΠΉΡΠΊΠΎΠΌ ΡΠ·ΡΠΊΠ΅ ΠΈ ΡΠΏΠΎΡΠΎΠ±Ρ ΠΈΡ ΠΏΠ΅ΡΠ΅Π²ΠΎΠ΄Π° Π½Π° ΡΡΡΡΠΊΠΈΠΉ ΡΠ·ΡΠΊ
Π¦Π΅Π»ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΡΠΏΠΎΡΠΎΠ±ΠΎΠ² ΠΏΠ΅ΡΠ΅Π²ΠΎΠ΄Π° Π°Π½Π³Π»ΠΈΠΉΡΠΊΠΎΠΉ ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ»ΠΎΠ³ΠΈΠΈ Π½Π° ΡΡΡΡΠΊΠΈΠΉ
ΡΠ·ΡΠΊ
Mercury Stable Isotopes in Seabird Eggs Reflect a Gradient from Terrestrial Geogenic to Oceanic Mercury Reservoirs
Elevated mercury concentrations ([Hg]) were found in
Alaskan murre
(<i>Uria</i> spp.) eggs from the coastal embayment of Norton
Sound relative to insular colonies in the northern Bering Sea-Bering
Strait region. Stable isotopes of Hg, carbon, and nitrogen were measured
in the eggs to investigate the source of this enrichment. Lower Ξ΄<sup>13</sup>C values in Norton Sound eggs (β23.3β° to β20.0β°)
relative to eggs from more oceanic colonies (β20.9β°
to β18.7β°) indicated that a significant terrestrial
carbon source was associated with the elevated [Hg] in Norton Sound,
implicating the Yukon River and smaller Seward Peninsula watersheds
as the likely Hg source. The increasing [Hg] gradient extending inshore
was accompanied by strong decreasing gradients of Ξ΄<sup>202</sup>Hg and Ξ<sup>199</sup>Hg in eggs, indicating lower degrees
of mass-dependent (MDF) and mass-independent Hg fractionation (MIF)
(respectively) in the Norton Sound food web. Negative or zero MDF
and MIF signatures are typical of geological Hg sources, which suggests
murres in Norton Sound integrated Hg from a more recent geological
origin that has experienced a relatively limited extent of aquatic
fractionation relative to more oceanic colonies. The association of
low Ξ΄<sup>202</sup>Hg and Ξ<sup>199</sup>Hg with elevated
[Hg] and terrestrial Ξ΄<sup>13</sup>C values suggested that Hg
stable isotopes in murre eggs effectively differentiated terrestrial/geogenic
Hg sources from oceanic reservoirs