Predictors of mercury spatial patterns in San Francisco Bay forage fish.
نویسندگان
چکیده
Pollution reduction efforts should be targeted toward those sources that result in the highest bioaccumulation. For mercury (Hg) in estuaries and other complex water bodies, carefully designed biosentinel monitoring programs can help identify predictors of bioaccumulation and inform management priorities for source reduction. This study employed a probabilistic forage fish Hg survey with hypothesis testing in San Francisco Bay (California, USA). The goal was to determine what pollution sources, regions, and landscape features were associated with elevated Hg bioaccumulation. Across 99 sites, whole-body Hg concentrations in Mississippi silversides (Menidia audens) and topsmelt (Atherinops affinis) followed a broad spatial gradient, declining with distance from the Guadalupe River (Pearson's r = -0.69 and -0.42, respectively), which drains historic mining areas. Site landscape attributes and local Hg sources had subtle effects, which differed between fish species. Topsmelt Hg increased in embayment sites (i.e., enclosed sites including channels, creek mouths, marinas, and coves) and sites with historic Hg-contaminated sediment, suggesting an influence of legacy industrial and mining contamination. In 2008, Mississippi silverside Hg was reduced at sites draining wastewater-treatment plants. Fish Hg was not related to abundance of surrounding wetland cover but was elevated in some watersheds draining from historic Hg-mining operations. Results indicated both regional and site-specific influences for Hg bioaccumulation in San Francisco Bay, including legacy contamination and proximity to treated wastewater discharge.
منابع مشابه
Mercury in San Francisco Bay forage fish 1 2 3
23 In the San Francisco Estuary, management actions including tidal marsh restoration could 24 change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were 25 collected and analyzed to identify spatial and interannual variation in biotic 26 methylmercury (MeHg) exposure. The average whole body total Hg concentration was 27 0.052 µg g-1 (wet weight) for 457 composite sample...
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عنوان ژورنال:
- Environmental toxicology and chemistry
دوره 32 12 شماره
صفحات -
تاریخ انتشار 2013