Polyaromatic hydrocarbons, chlorinated and brominated organic contaminants as tracers of feeding ecology in polar benthic amphipods

Abstract

Concentrations of organochlorines (OCs) such as polychlorinated biphenyls (PCB), dichloro-diphenyl-trichloroethane (DDT), hexachlorocyclobenzene (HCB), chlordanes, and hexachlorocyclohexanes (HCHs) were measured in 3 different species of benthic marine amphipods (Eurythenes gryllus, Anonyx nugax, and Paramphitoe hystrix) from 4 different locations: 2 from the Canadian Arctic and 2 from the Norwegian Arctic. In addition, polycyclicaromatic hydrocarbons (PAHs) and brominated flameretardants (BFR) such as polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) were measured in E. gryllus from the Norwegian Arctic. For all species and locations, concentrations of OCs in the amphipods were higher than those found in zooplankton and other benthic organisms from the same areas. If the amphipods' OC concentrations were determined by sediment exposure, their values would be close to other benthic infauna, suggesting that sediment exposure does not explain the amphipods' higher OC concentrations. In fact, the OC concentrations in benthic amphipods were similar to those in seals and gulls, which provides strong evidence that benthic amphipods are scavengers of higher trophic level carrion. Concentrations of PBDE and PAH were also high in E. gryllus (ΣPBDE 115 to 493 ng g -1 lipid weight [lw]; ΣPAH 269 ng g -1 lw), and were in the same range as measured in marine animals. BFR concentrations correlated with PCB and DDT concentrations (PCBs: r 2 = 0.61 p < 0.0076; DDTs: r 2 = 0.530 p < 0.0171), indicating the same bioaccumulation potential. BFRs are thereby emerging problems as their concentrations increase in Arctic regions.KEY WORDS: Arctic · Benthic amphipods · Organochlorines · Scavenger · PCB · DDT · PBDE · HBCD · PAH Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 337: [155][156][157][158][159][160][161][162][163][164] 2007 in the food web, leading to high concentrations in top predators (Muir et al. 1999).OC levels increase exponentially in the food web (Broman et al. 1992), whereby small invertebrates with a relatively short life span usually have much lower OC concentrations than vertebrate predators located at higher trophic levels. However, studies on the benthic amphipod Eurythenes gryllus from the Canadian Arctic in the late 1980s revealed OC concentrations in the range found in marine mammals and seabirds , Bidleman et al. 1993. Benthic organisms with a close association to the sediment often have higher OC concentrations than pelagic organisms at the same trophic level, due to high affinity of the OCs to the sediment particles and thereby transport from the water column to the sea floor (Bright et al. 1995). However, the OC levels in benthic E. gryllus were unexpectedly high, especially when compared with other benthic organisms such as the blue mussel Mytilus edulis (Christensen et al. 2002). A recent study from the Canadian Arctic confirmed high OC levels in another benthic amphipod, Anonyx nugax (Fisk et al. 2003). These high OC leve...

Scavenging Amphipods: Sentinels for Penetration of Mercury and Persistent Organic Chemicals into Food Webs of the Deep Arctic Ocean

“…collected from the shelf at 150−300 m in the central-west Canadian Arctic in 1986−1988 9 contained mean levels of ∑PCBs, ∑CHLs, and ∑DDTs that were similar to those in E. gryllus from SHEBA-97, SHEBA-98 and SCICEX-96 expeditions, whereas ∑TOX in the "shelf amphipods" were lower, and α-HCH and HCBz were higher. Concentrations of most organochlorines in Anonyx nugax from the eastern Canadian Arctic 6,12,37 were lower than in E. gryllus from all locations and in small amphipods from shelf areas in the central-west Canadian Arctic, but higher for α-HCH and HCBz (SI Table S4). Contaminant Profiles.…”

“…∑PCBs are not comparable because only eight congeners were previously reported. 12 Concentrations of organochlorines were generally, but not always, higher in E. gryllus than in smaller benthic scavenging amphipods (SI Table S4). Mixed amphipods (Andaniexis sp., Anonyx nugax, Onisimus sp., Tmetonyx cicada, Psammonyx sp.)…”

“…The energy from food ingested plus that stored in body lipids is sufficient to sustain basic metabolic processes for up to 6 months in juveniles and more than one year in mature females. 13,17 Previous studies have shown that levels of POPs on a lipid weight basis in E. gryllus collected in the central Arctic Ocean are similar to those in the blubber of marine mammals, 9,10,12 suggesting that these invertebrates could serve as sentinel organisms for accumulation of new and historic POPs in food webs of the arctic and other deep ocean basins. Attempts to construct contaminant budgets and inventories 1,3,4,18,19 show that time scales for declines in these compounds following emission controls depend on amounts stored in the upper ocean and the rates of loss from the photic zone.…”

“…They are large enough to permit analysis of contaminants in individual specimens. 12 E. gryllus up to 8 cm in length have been collected from 2076 m on the Alpha Ridge in the central Arctic Basin 13 and from 1650 m in central Baffin Bay. 14 They have a diverse diet comprised of both invertebrates and vertebrate carrion, 15,16 are able to locate bait placed on the bottom using chemoreception and feed rapidly to satiation.…”

PBDEs in the supralittoral environment: The sandhopper Talitrus saltator (Montagu) as biomonitor?

“…Hites, 2004;Corsolini et al, 2006). Although the key role of amphipods in many aquatic ecosystems, and consequently in the trophic transfer of pollutants to higher trophic levels, only few investigations on freshwater (Viganò et al, 2009) and polar benthic species (Sørmo et al, 2006;Svendsen et al, 2007) have been carried out regarding the accumulation of PBDEs in these species. Because of the importance of amphipods to the energy flow of sandy shore ecosystems (Griffiths et al, 1983) they constitute a potentially good candidate to monitor contamination of PBDEs in the supralittoral environment.…”