Relating Land Cover Characteristics and Common Loon Mercury Levels Using Geographic Information Systems

Kramar, David; Goodale, Wing; Kennedy, Lisa M.; Carstensen, Laurence W.; Kaur, Taranjat

doi:10.1007/s10646-004-6272-z

Cited by 20 publications

(11 citation statements)

References 26 publications

(14 reference statements)

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“…Relationships may have been evident if there was more variation in watershed land cover classes. For example, Kramar et al (2005) reported a stronger relationship ( r 2 = 0.55, p < 0.0001) between Hg concentrations in common loon and land cover classes, (i.e., crop land, shrub land, wetlands) for the major lakes and eleven smaller ponds in northwest Maine.…”

Section: Resultsmentioning

confidence: 99%

“…Indeed, previous studies have focused on three categories of factors affecting Hg bioaccumulation in aquatic biota: lake physico-chemistry (e.g., pH, DOC), biology (e.g., taxa presence, trophic status), and landscape characteristics (e.g., land cover class, amount of connected wetlands, elevation) (George and Batzer 2008). Few studies have been conducted to evaluate spatial factors that influence the bioaccumulation of Hg across the entire aquatic food chain (Kramar et al 2005; Kamman et al 2005). …”

Section: Introductionmentioning

confidence: 99%

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Spatial patterns of mercury in biota of Adirondack, New York lakes

et al. 2011

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We studied the spatial distribution patterns of mercury (Hg) in lake water, littoral sediments, zooplankton, crayfish, fish, and common loons in 44 lakes of the Adirondacks of New York State, USA, a region that has been characterized as a “biological Hg hotspot”. Our study confirmed this pattern, finding that a substantial fraction of the lakes studied had fish and loon samples exceeding established criteria for human and wildlife health. Factors accounting for the spatial variability of Hg in lake water and biota were lake chemistry (pH, acid neutralizing capacity (ANC), percent carbon in sediments), biology (taxa presence, trophic status) and landscape characteristics (land cover class, lake elevation). Hg concentrations in zooplankton, fish and common loons were negatively associated with the lake water acid-base status (pH, ANC). Bioaccumulation factors (BAF) for methyl Hg (MeHg) increased from crayfish (mean log10 BAF = 5.7), to zooplankton (5.9), to prey fish (6.2), to larger fish (6.3), to common loons (7.2). MeHg BAF values in zooplankton, crayfish, and fish (yellow perch equivalent) all increased with increasing lake elevation. Our findings support the hypothesis that bioaccumulation of MeHg at the base of the food chain is an important controller of Hg concentrations in taxa at higher trophic levels. The characteristics of Adirondack lake-watersheds (sensitivity to acidic deposition; significant forest and wetland land cover; and low nutrient inputs) contribute to elevated Hg concentrations in aquatic biota.Electronic supplementary materialThe online version of this article (doi:10.1007/s10646-011-0717-y) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spatial patterns of mercury in biota of Adirondack, New York lakes

et al. 2011

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“…Lakes in this region are characterized by low dissolved organic carbon (\5 mg C/l), low pH (\6.3), and low acid neutralizing capacity (ANC\100 ueq/l) (Yu et al 2011); these lake physicochemical properties appear to increase bioavailability of Hg at the base of the aquatic food web (Adams et al 2009;). Watershed features, such as percent wetland adjacent to waterbodies, also appear to be important drivers for MeHg transfer through aquatic food webs into fish (St Louis et al 1994) and avian piscivores, such as the common loon (Kramar et al 2005). Because this region, particularly the area within Adirondack State Park, is sensitive to Hg inputs it has the highest average MLU Hg concentration of the four focal areas; over 20% of the loon population is estimated to be at potential risk to significant losses in reproductive abilities (Table 2).…”

Section: Northern New Yorkmentioning

confidence: 99%

Spatial gradients of methylmercury for breeding common loons in the Laurentian Great Lakes region

et al. 2011

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Much of the Laurentian Great Lakes region is a mercury-sensitive landscape, in which atmospheric deposition and waterborne sources of mercury (Hg) have led to high concentrations of bioavailable methylmercury (MeHg) in predatory fish and piscivorous wildlife. Efforts since the early 1990s have established the common loon (Gavia immer) as the primary avian indicator for evaluating the exposure and effects of MeHg in North America. A regional Hg dataset was compiled from multiple loon tissue types and yellow perch (Perca flavescens), a preferred prey fish species for loons. Hg exposure in loons and perch was modeled to develop male and female loon units (MLU and FLU, respectively), standardized metrics that represent the estimated blood Hg exposure of a male or female loon for a given loon territory or water body. Using this common endpoint approach to assess loon Hg exposure, the authors demonstrate spatial trends in biotic Hg concentrations, examine MeHg availability in aquatic ecosystems of the Great Lakes region in relation to landscape-level characteristics, and identify areas with potentially significant adverse reproductive impacts to loons and other avian piscivores. Based on 8,101 MLUs, seven biological Hg hotspots were identified in the Great Lakes region. Policy-relevant applications are presented.

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“…Lake hydrology and biogeochemistry largely determine the degree of aquatic MeHg exposure. Lakes with low pH (<6.3, Meyer et al, 1995;Burgess and Hobson, in press), large areas of scrub-shrub and emergent wetlands (Kramar et al, 2005), and large areas of exposed shoreline substrate of organic or sandy soils that are frequently inundated and dried through the summer and fall (i.e., reservoirs; Evers and Reaman, 1998) are predictive of elevated blood Hg levels in the common loon. Although newly created reservoirs are well known for their ability to enhance MeHg production and availability through the decomposition of vegetation (Jackson, 1988;Lucotte et al, 1999;Gerrard and St. Louis, 2001), this phenomenon is generally viewed as short-lived (i.e., <10 years in secondary consumers) (Lucotte et al, 1999).…”

Section: Hg Patterns In Aquatic Habitatsmentioning

confidence: 99%

Patterns and Interpretation of Mercury Exposure in Freshwater Avian Communities in Northeastern North America

et al. 2005

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Abstract. A large data set of over 4,700 records of avian mercury (Hg) levels in northeastern North America was compiled and evaluated. As Hg emissions remain poorly regulated in the United States and Canada, atmospheric deposition patterns and associated ecological responses continue to elicit interest by landscape managers, conservation biologists, policy makers, and the general public. How avian Hg exposure is interpreted greatly influences decision-making practices. The geographic extent and size of this data set is valuable in understanding the factors that affect the exposure of Hg to birds. Featured are differences found among tissues, major aquatic habitats and geographic areas, between age class and gender, and among species. While Hg concentrations in egg and blood reflect short-term Hg exposure, Hg concentrations in liver and feather provide insight into long-term Hg exposure. Blood is a particularly important matrix for relating site-specific exposure to methylmercury (MeHg). The level of MeHg is generally 5-10x greater in adults compared to nestlings. Age also influences MeHg bioaccumulation, particularly for individuals where MeHg intake exceeds elimination. Gender is of interpretive concern when evaluating Hg exposure for species exhibiting sexual dimorphism and niche partitioning. Based on two indicator species, the belted kingfisher (Ceryle alcyon) and bald eagle (Haliaeetus leucocephalus), we found MeHg availability increased from marine, to estuarine and riverine systems, and was greatest in lake habitats. A large sample of >1,800 blood and egg Hg levels from the common loon (Gavia immer) facilitated a suitable comparison of geographic differences. Although some clusters of highly elevated Hg exposure (i.e., blood levels >3.0 lg/g, ww and egg levels >1.3 lg/g, ww) were associated with hydrological and biogeochemical factors known to increase MeHg production and availability, others were not. Geographic areas without a relationship between Hg exposure and biogeochemical processes were associated with emission or waterborne point sources. Differences in Hg exposure among species are primarily correlated with trophic position and availability of MeHg. Although piscivorous species were repeatedly *To whom correspondence should be addressed: Tel.: 207-839-7600; Fax: 207-839-7655; E-mail: david.evers@briloon.org Ecotoxicology, 14, 193-221, 2005 Ó 2005 shown to have some of the highest MeHg levels of the 38 species analyzed, insectivorous birds in both aquatic and terrestrial habitats (such as montane areas) were also found with elevated MeHg levels. A better understanding of the factors confounding interpretation of Hg exposure provides an effective basis for choice of indicator species and tissues according to 12 selected scenarios. This and the national need for spatiotemporal monitoring of MeHg availability require careful consideration of indicator species choice. Only then will local, regional, continental, and even global monitoring efforts be effective.

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Relating Land Cover Characteristics and Common Loon Mercury Levels Using Geographic Information Systems

Cited by 20 publications

References 26 publications

Spatial patterns of mercury in biota of Adirondack, New York lakes

Spatial patterns of mercury in biota of Adirondack, New York lakes

Spatial gradients of methylmercury for breeding common loons in the Laurentian Great Lakes region

Patterns and Interpretation of Mercury Exposure in Freshwater Avian Communities in Northeastern North America

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