Bioaccumulation of mercury in pelagic freshwater food webs

Watras, Carl J.; Back, Richard C.; Halvorsen, S.; Hudson, Robert J.; Morrison, K. A.; Wente, Stephen P.

doi:10.1016/s0048-9697(98)00228-9

Cited by 556 publications

(487 citation statements)

References 62 publications

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“…where (20). The published literature generally holds that only the dissolved Hg fraction is available for methylation, an assertion that, if correct, is supported by this study, which generally shows a good correspondence between low K d (high DOC) and elevated levels of MeHg in streamwater.…”

Section: Resultssupporting

confidence: 81%

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Brigham

Wentz

Aiken

et al. 2009

Environ. Sci. Technol.

224

267

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We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and fluvial THg and MeHg transport. Instantaneous concentrations of filtered total mercury (FTHg) and filtered methylmercury (FMeHg) exhibited strong positive correlations with both dissolved organic carbon (DOC) concentrations and streamflow for most streams, whereas mean FTHg and FMeHg concentrations were correlated with wetland density of the basins. For all streams combined, whole water concentrations (sum of filtered and particulate forms) of THg and MeHg correlated strongly with DOC and suspended sediment concentrations in the water column.

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Section: Resultssupporting

confidence: 81%

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Brigham

Wentz

Aiken

et al. 2009

Environ. Sci. Technol.

224

267

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“…[2,119] Although both inorganic Hg and MeHg species may be assimilated by biota at the lowest levels of food chains (bacteria, archaea, phytoplankton and other algae), only MeHg is biomagnified within food chains and thus presents the key exposure risk to Arctic wildlife and humans. [69,120] Therefore, a critical question with respect to the biological uptake of Hg into Arctic food webs concerns the mechanisms and locations where inorganic Hg II is predominantly transformed into MeHg and then assimilated into the lower levels of Arctic food webs.…”

Section: Microbial Carbon Processing and Mercury In The Arcticmentioning

confidence: 99%

“…[208] This variation may be due to the trophic level of the invertebrates, [212] variable MeHg supply to their food webs [120] or taxonomic differences. [208] Taxonomic composition can be an important determinant of MeHg bioaccumulation in zooplankton communities in the Canadian High Arctic; different species vary several-fold in their MeHg concentrations despite low levels of Hg in the water.…”

Section: Freshwater Food Websmentioning

confidence: 99%

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

Douglas

Loseto²,

Macdonald³

et al. 2012

Environ. Chem.

118

147

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Environmental context. Mercury, in its methylated form, is a neurotoxin that biomagnifies in marine and terrestrial foodwebs leading to elevated levels in fish and fish-eating mammals worldwide, including at numerous Arctic locations. Elevated mercury concentrations in Arctic country foods present a significant exposure risk to Arctic people. We present a detailed review of the fate of mercury in Arctic terrestrial and marine ecosystems, taking into account the extreme seasonality of Arctic ecosystems and the unique processes associated with sea ice and Arctic hydrology.Abstract. This review is the result of a series of multidisciplinary meetings organised by the Arctic Monitoring and Assessment Programme as part of their 2011 Assessment 'Mercury in the Arctic'. This paper presents the state-of-the-art knowledge on the environmental fate of mercury following its entry into the Arctic by oceanic, atmospheric and terrestrial pathways. Our focus is on the movement, transformation and bioaccumulation of Hg in aquatic (marine and fresh water) and terrestrial ecosystems. The processes most relevant to biological Hg uptake and the potential risk associated with Hg exposure in wildlife are emphasised. We present discussions of the chemical transformations of newly deposited or transported Hg in marine, fresh water and terrestrial environments and of the movement of Hg from air, soil and water environmental compartments into food webs. Methylation, a key process controlling the fate of Hg in most ecosystems, and the role of trophic processes in controlling Hg in higher order animals are also included. Case studies on Eastern Beaufort Sea beluga (Delphinapterus leucas) and landlocked Arctic char (Salvelinus alpinus) are presented as examples of the relationship between ecosystem trophic processes and biologic Hg levels. We examine whether atmospheric mercury depletion events (AMDEs) contribute to increased Hg levels in Arctic biota and provide information on the links between organic carbon and Hg speciation, dynamics and bioavailability. Long-term sequestration of Hg into non-biological archives is also addressed. The review concludes by identifying major knowledge gaps in our understanding, including:(1) the rates of Hg entry into marine and terrestrial ecosystems and the rates of inorganic and MeHg uptake by Arctic microbial and algal communities; (2) the bioavailable fraction of AMDE-related Hg and its rate of accumulation by biota and (3) the fresh water and marine MeHg cycle in the Arctic, especially the marine MeHg cycle.

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“…Entretanto, deve-se observar que neste trabalho empregouse o conceito de bioconcentração e não, o de bioacumulação; uma vez que a bioconcentração se refere à tendência de um determinado agente químico (metilmercúrio) ser acumulado pela biota somente através da água, e a bioacumulação ocorre através de todas as fontes do ambiente, isto é, através da água e do alimento. 16 O fator de bioconcentração foi quantificado através da razão entre a concentração do metilmercúrio presente na biota aquática de interesse e a concentração deste agente químico dissolvido na coluna d'água 17 16 O emprego desse conjunto de diferentes espécies de organismos aquáticos possibilitou se comparar a concentração de MeHg de acordo com a posição trófica de cada espécie, uma vez que é um fator que influi significativamente na acumulação deste contaminante pela biota estudada. Como resultado, tem-se um quadro mais completo das vias de acumulação, transferência e magnificação dessa forma de mercúrio orgânico, tão tóxica para a biota aquática e, consequentemente, para os seres humanos que a consomem.…”

Section: Introductionunclassified

Bioconcentração e biomagnificação de metilmercúrio na baía de Guanabara, Rio de Janeiro

Kehrig¹,

Malm²,

Palermo³

et al. 2011

Quím. Nova

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Recebido em 4/2/10; aceito em 7/10/10; publicado na web em 26/1/11 BIOCONCENTRATION AND BIOMAGNIFICATION OF METHYLMERCURY IN GUANABARA BAY, RIO DE JANEIRO.Methylmercury was determined in water and aquatic biota from Guanabara Bay. Trophic transfer of methylmercury was observed between trophic levels from prey (microplankton, mesoplankton and fish with different feeding habits) to top predator (pelagicdemersal fish). Top predator fish presented the highest methylmercury concentrations (320.3 ± 150.7 µg kg -1 dry wt.), whereas microplankton presented the lowest (8.9 ± 3.3 µg kg -1 dry wt.). The successive amplification of methylmercury concentrations and its bioconcentration factor with increasing trophic levels from base to top indicate that biomagnification may be occurring along the food web. Results suggest the importance of feeding habits and trophic level in the bioaccumulation of methylmercury by aquatic biota.Keywords: biotransference of methylmercury; water and organisms; trophic levels. INTRODUÇÃOExiste uma grande preocupação com relação ao aumento da poluição ambiental resultante do incremento do emprego intensivo e extensivo de produtos químicos, da liberação de substâncias potencialmente tóxicas, dos lançamentos de efluentes industriais e urbanos, bem como de seus efeitos para os ecossistemas e, consequentemente, para o homem. 1 Com o aumento das atividades industriais, agrícolas e mineradoras, bem como o crescimento populacional observados no último século, uma série de contaminantes (matéria orgânica, poluentes orgânicos e um grande número de compostos metálicos) vem sendo liberada para o meio ambiente, principalmente para a atmosfera e os ecossistemas aquáticos. 2 Os contaminantes de compostos metálicos presentes nos efluentes das atividades antrópicas apresentam pouca solubilidade na água resultando, então, em baixas concentrações, mesmo em locais próximos às suas emissões pontuais, via efluente. Entretanto, em ambientes estuarinos, os contaminantes metálicos estão preferencialmente associados ao material particulado em suspensão, que lhes serve de veículo para áreas mais distantes das suas fontes. 3 Dentre os diferentes metais que despertam interesse ambiental, presentes nos efluentes industriais e agrícolas e que, também, em diversas regiões apresentam concentrações naturais relativamente elevadas, encontra-se o mercúrio (Hg). A exposição ambiental ao Hg via cadeia alimentar, principalmente para consumidores de nível trófico superior, incluindo-se o homem, é significativamente maior, uma vez que este metal apresenta alta toxicidade e capacidade de sofrer biomagnificação ao longo das cadeias tróficas. 4 Este metal na sua forma orgânica mais tóxica, metilmercúrio (MeHg), é bioacumulado em até um milhão de vezes ao longo da cadeia trófica aquática, desde a sua base (microorganismos e plâncton) até os organismos de topo (peixes predadores e mamíferos) através de adsorção na superfície corporal e, principalmente, pela ingestão de alimento (peixes, crustáceos e cefalópodes). 5 O metilmercúrio é um age...

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Bioaccumulation of mercury in pelagic freshwater food webs

Cited by 556 publications

References 62 publications

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

Bioconcentração e biomagnificação de metilmercúrio na baía de Guanabara, Rio de Janeiro

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