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Spring awakening? Seasonal controls on halomethoxybenzenes in arctic waters
Danielle Haas Freeman1, Emma Shipley1, Penny Vlahos1
1Department of Marine Sciences, University of Connecticut Avery Point, 1080 Shennecossett Rd, Groton, CT, 06340, USA.
None:
Halomethoxybenzenes (HMBs), including 2,4-dibromoanisole (DBA), 2,4,6-tribromoanisole (TBA), and drosophilin A methyl ether (1,2,4,5-tetrachloro-3,6-dimethoxybenzene; DAME) are bioaccumulative halogenated compounds with natural and anthropogenic sources. This study characterized these three HMBs in seawater and DAME in air in the Bering and Chukchi Seas. The goal was to describe and explain distributions of HMBs as seasonal ice retreated in spring. The results show that concentrations of individual HMBs are sensitive to distinct environmental processes. DBA decreased during spring blooms, while spring freshwater brought DAME into the system. Net volatilization of DAME occurred at a freshwater-influenced site, while all other site samples demonstrated net deposition of DAME from the atmosphere to seawater or equilibrium with respect to gas exchange. The highest concentrations of TBA occurred near freshwater, but there were no statistically significant trends in the levels of this compound. Arctic sampling did not show evidence of a buildup of HMBs under ice from possible production by ice algae or bacteria. The different trends in concentrations of individual HMBs and their sensitivity to environmental variables over a short timescale complicates comparisons across systems, evaluations of ecological function, and potential risk assessments.
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