Organic mercury in Greenland birds and mammals

Dietz, Runé; Nielsen, Christian Overgaard; Hansen, Martin Munk; Hansen, Carsten Thye

doi:10.1016/0048-9697(90)90051-u

Cited by 95 publications

(63 citation statements)

References 11 publications

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“…Adult ringed seals from Greenland had significantly higher concentrations of organic mercury (in muscle, liver and kidney tissues) than those of "yearlings" (Dietz et al 1990). Most of the mercury in the muscle tissue of ringed seals was organic mercury.…”

Section: Body Burdens Of Heavy Metalsmentioning

confidence: 99%

“…Smith and Armstrong 1978, Hansen 1981, Dietz et al 1990, 1996, this volume, Muir et al 1992. Besides being delivered locally as a result of normal geological processes, these substances are carried in the atmospheric airflow from southern sources and delivered to the Arctic marine system through precipitation (Muir et al 1992).…”

Section: Body Burdens Of Heavy Metalsmentioning

confidence: 99%

See 1 more Smart Citation

Distribution, abundance and biology of ringed seals (<i>Phoca hispida</i>): an overview

Reeves

1998

NAMMCOSP

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The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as the pup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most ~stimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring and on benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in some areas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about the potential imp...

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Section: Body Burdens Of Heavy Metalsmentioning

confidence: 99%

Section: Body Burdens Of Heavy Metalsmentioning

confidence: 99%

Distribution, abundance and biology of ringed seals (<i>Phoca hispida</i>): an overview

Reeves

1998

NAMMCOSP

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“…In marine mammals, the liver is the organ with the highest reported Hg concentrations (Dietz et al, 1998a). Studies show that demethylation occurs here in marine mammals and birds (Dietz et al, 1990(Dietz et al, , 2000a. For terrestrial mammals, including polar bears, kidney has the highest Hg concentrations and hence may be the main target organ (AMAP, 2011).…”

Section: Mercury Uptake and Demethylationmentioning

confidence: 99%

“…This complex probably represents a direct covalent (or other strong) interaction of Hg and Se. In some wild aquatic predatory bird and mammal species, it has been shown that MeHg predominates in the liver at low total Hg (THg) concentrations whereas at higher concentrations an increasingly large percentage of THg is present as inorganic Hg associated with Se, and some studies have identified this complex as HgSe (tiemanite) (Koeman and van deVen, 1975;Dietz et al, 1990Dietz et al, , 1998aDietz et al, , 1998bDietz et al, , 2000aDietz et al, 2000bScheuhammer et al, 1998Scheuhammer et al, , 2008Wang et al, 2001;Woshner et al, 2001aWoshner et al, , 2001bWoshner et al, , 2008O'Hara et al, 2003;Arai et al, 2004;Ikemoto et al, 2005;Dehn et al, 2005Dehn et al, , 2006Eagles-Smith et al, 2009;Moses et al, 2009;Routti et al, 2011).…”

Section: Mercury-selenium Relationships and Interactionsmentioning

confidence: 99%

What are the toxicological effects of mercury in Arctic biota?

Dietz

Sonne

Basu

et al. 2013

Science of The Total Environment

321

202

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► Unpublished and published data were compiled for Arctic fish, birds, and mammals. ► These data were compared to available toxicological threshold limits. ► Toothed whales, polar bears, and some bird and fish species exceeded the limits. ► Increasing mercury concentrations are observed for some Arctic species. ► These exceeded thresholds and increasing Hg trends are of concern. a b s t r a c t a r t i c l e i n f o This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear to be one of the most vulnerable groups, with high concentrations Science of the Total Environment 443 (2013) [775][776][777][778][779][780][781][782][783][784][785][786][787][788][789][790]

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“…In marine mammals increment of liver Se and Hg occur on a 1: l molar basis (Koeman et al, 1973;1975;Hansen et al, 1990;Dietz et al, 1990). This finding led Koeman et al (1975) to suggest that Se may exert a protective effect by directly binding Hg.…”

Section: Correlation Between Element Concentrationsmentioning

confidence: 97%