Spatial and temporal variations of mercury levels in Okefenokee invertebrates: Southeast Georgia

George, Bagie; Batzer, Darold P.

doi:10.1016/j.envpol.2007.04.030

Cited by 24 publications

(19 citation statements)

References 42 publications

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“…However, our study found lower rather than higher total mercury concentrations post-fire, albeit only in selected organisms. When comparing our results with those collected several years before the fire (George & Batzer, 2008), mercury levels declined in all taxa sampled including a 91% decline in amphipods, and 67% in odonates and crayfish. This post-fire decline occurred in both burned and non-burned areas, suggesting either that fire had a pervasive effect, even beyond the areas burned directly, or that the decline was caused by factors other than fire (e.g., fluctuating water levels, temporal variation in sediment mercury levels, methylation rates, or rates of mercury input; variation between the analytical laboratories providing data).…”

Section: Total Mercury Of Selected Organisms After Wildfirementioning

confidence: 58%

“…Mercury occurs at moderately high levels for alligators (average 0.8 ppm in muscle; Jagoe et al, 1998) and invertebrates (0-86 ppm; George & Batzer, 2008). Due to high mercury levels, the Georgia Department of Natural Resources has issued fish consumption advisories for Amia calva (bowfin), Centrarchus macropterus (flier), and Esox niger (chain pickerel).…”

Section: Study Sitementioning

confidence: 99%

“…In some areas, fire moved quickly across the surface of the peat and vegetation causing little damage. Because most areas previously sampled for invertebrate community composition (Kratzer & Batzer, 2007) and mercury content (George & Batzer, 2008) burned, this fire presented a unique opportunity to assess the impacts of fire on aquatic invertebrates and mercury accumulation.…”

Section: Study Sitementioning

confidence: 99%

“…1). The sites were composed of a mixture of the three dominant vegetative habitats of scrub-shrub thickets (5 burned; 3 reference), cypress stands (5 burned; 3 reference), and sedge prairies (3 burned; 2 reference) and were in the same general areas as those sampled by Kratzer & Batzer (2007) and George & Batzer (2008). Sites were centered in the following sub-regions: Chesser Prairie, Chase Prairie, Billy's Lake, Double Lakes, and Durden Prairie ( Fig.…”

Section: Study Sitementioning

confidence: 99%

“…We repeated sampling protocols from the previous study (for details see George & Batzer, 2008) to collect odonates (dragonfly nymphs, Libellulidae and Corduliidae), crayfish (Cambaridae), and amphipods (scuds, Crangonyx), with additional protocols for collecting mosquitofish (Gambusia). Mosquitofish were collected and euthanized with MS222 buffered with calcium carbonate in accordance with the UGA Fig.…”

Section: Total Mercury Content Of Selected Organismsmentioning

confidence: 99%

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Wildfire induced changes in aquatic invertebrate communities and mercury bioaccumulation in the Okefenokee Swamp

Beganyi

Batzer

2011

Hydrobiologia

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Fire is an important natural disturbance in the Okefenokee Swamp. From April-June 2007, wildfire burned 75% of the wetland area. With the existence of extensive pre-fire data sets on community structure and total mercury of invertebrates, the fire presented an opportunity to assess impacts of wildfire on invertebrates. Post-fire collection of samples occurred in September, December, and May, 2007-2009. Sample sites included 13 burned and 8 non-burned (reference) sites. Comparisons of data among pre-fire, post-fire reference, and post-fire burned sites revealed that the major difference between pre-fire communities and post-fire communities was a decrease in the number of water mites. We also found a decrease in mercury concentrations in amphipods, odonates, and crayfish post-fire. The differences between pre-fire and post-fire samples may be confounded by drought conditions during the baseline study. NMDS ordinations and ANOSIM tests suggested that habitat was an important factor; communities in burned cypress differed from reference cypress. Unexpectedly, burned sites had lower mercury concentrations in odonates and crayfish, with variation again being greatest in cypress stands. These findings and others suggest mercury levels do not follow a predictable pattern but can vary with pre-fire concentrations, variation in water levels, and burn intensity. We found that wildfire in the Okefenokee had little impact on invertebrates in prairies and scrubshrub thickets, but can affect indicator organisms (Oecetis, Ischnura, and Sigara) in cypress stands. Our study suggests that vegetation type and burn intensity may have impacts on the invertebrate communities and mercury concentrations of organisms.

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Section: Total Mercury Of Selected Organisms After Wildfirementioning

confidence: 58%

Section: Study Sitementioning

confidence: 99%

Section: Study Sitementioning

confidence: 99%

Section: Study Sitementioning

confidence: 99%

Section: Total Mercury Content Of Selected Organismsmentioning

confidence: 99%

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Wildfire induced changes in aquatic invertebrate communities and mercury bioaccumulation in the Okefenokee Swamp

Beganyi

Batzer

2011

Hydrobiologia

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The effects of hydrologic fluctuation and sulfate regeneration on mercury cycling in an experimental peatland

et al. 2015

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A series of severe droughts during the course of a long-term, atmospheric sulfate-deposition experiment in a boreal peatland in northern Minnesota created a unique opportunity to study how methylmercury (MeHg) production responds to drying and rewetting events in peatlands under variable levels of sulfate loading. Peat oxidation during extended dry periods mobilized sulfate, MeHg, and total mercury (Hg T ) to peatland pore waters during rewetting events. Pore water sulfate concentrations were inversely related to antecedent moisture conditions and proportional to past and current levels of atmospheric sulfate deposition. Severe drying events caused oxidative release of MeHg to pore waters and resulted in increased net MeHg production likely because available sulfate stimulated the activity of sulfate-reducing bacteria, an important group of Hg-methylating bacteria in peatlands. Rewetting events led to increased MeHg concentrations across the peatland, but concentrations were highest in peat receiving elevated atmospheric sulfate deposition. Dissolved Hg T concentrations also increased in peatland pore waters following drought but were not affected by sulfate loading and did not appear to be directly controlled by dissolved organic carbon mobilization to peatland pore waters. Peatlands are often considered to be sinks for sulfate and Hg T in the landscape and sources of MeHg. Hydrologic fluctuations not only serve to release previously sequestered sulfate and Hg T from peatlands but may also increase the strength of peatlands as sources of MeHg to downstream aquatic systems, particularly in regions that have experienced elevated levels of atmospheric sulfate deposition. DROUGHT INCREASES MERCURY IN PEATLANDS 1697 PUBLICATIONS

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Fluvial geomorphology and aquatic‐to‐terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

Sullivan

Boaz

Hossler

2016

Water Resources Research

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Although mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic‐to‐terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic‐to‐terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller‐bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic‐to‐terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

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Spatial and temporal variations of mercury levels in Okefenokee invertebrates: Southeast Georgia

Cited by 24 publications

References 42 publications

Wildfire induced changes in aquatic invertebrate communities and mercury bioaccumulation in the Okefenokee Swamp

Wildfire induced changes in aquatic invertebrate communities and mercury bioaccumulation in the Okefenokee Swamp

The effects of hydrologic fluctuation and sulfate regeneration on mercury cycling in an experimental peatland

Fluvial geomorphology and aquatic‐to‐terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

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