Abstract Concentrations of lipophilic contaminants in biota are frequently corrected for variation tissue lipid content. Usually, this correction is accomplished by dividing contaminant concentration to form lipid-normalized data. This ratio-based approach satisfactory when varies direct proportion However, such a relationship does not exist, erroneous conclusions may be reached. Recent research has emphasized the potential shortcomings use ratio variables. We demonstrate importance...

Of the 13, current-use, non-polybrominated diphenyl ether (PBDE) flame retardants (FRs) monitored, hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and α- γ-isomers of hexabromocyclododecane (HBCD), syn- anti-isomers chlorinated Dechlorane Plus (DP) were quantified in egg pools herring gulls (Larus argentatus) collected 2004 from six sites all five Laurentian Great Lakes North America. α-HBCD concentrations ranged...

The production and use of nonpolybrominated diphenyl ether (non-PBDE), brominated flame retardant (BFR) alternatives have been on the rise, although their assessment in environmental samples is largely understudied. In present study, several non-PBDE BFRs were found egg pools herring gulls (Larus argentatus) from seven colonies five Laurentian Great Lakes (collected 1982 to 2006). Of 19 monitored, hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane...

DecaBDE is a current-use, commercial formulation of an additive, polybrominated diphenyl ether (PBDE) flame retardant composed >97% 2,2′,3,3′,4,4′,5,5′,6,6′-decabromoDE (BDE-209). Of the 43 PBDE congeners monitored, we report on temporal trends (1982–2006) quantifiable PBDEs, and specifically BDE-209, in pooled samples herring gull (Larus argentatus) eggs from seven colonies spanning Laurentian Great Lakes. BDE-209 concentrations 2006 egg pools ranged 4.5 to 20 ng/g wet weight (ww)...

The Great Lakes Herring Gull Monitoring Program has annually provided information concerning levels of environmental contaminants in herring gull eggs since 1974, making it one the longest running biomonitoring programs world. program was initiated response to observations poor reproductive success colonial waterbirds on Lakes. Initial studies examined role halogenated hydrocarbons (HAHs) causing this dysfunction. By late 1970s, gulls had improved greatly and emphasis placed developing more...

Ecosystem change often affects the structure of aquatic communities thereby regulating how much and by what pathways energy critical nutrients flow through food webs. The availability essential to top predators such as seabirds that rely on resources near water's surface will be affected changes in pelagic prey abundance. Here, we present results from analysis a 25-year data set documenting dietary predatory seabird Laurentian Great Lakes. We reveal significant declines trophic position...

Stable nitrogen and carbon isotope analysis was performed on secondary feathers collected from flightless, mallard ducklings (Anas platyrhynchos) 17 locations across western Canada. The delta15N values of ranged +6.1 to +23.7 per thousand (AIR). Mean feather the were strongly correlated with percentage land under agricultural development. Higher in waterfowl areas possibly reflected entry excess fertilizer into local water bodies. However, other processes may have also been important. These...

Stable nitrogen (δ 15 N) and carbon 13 C) isotope values were measured in lipid-free homogenates of herring gull (Larus argentatus) eggs collected from the Laurentian Great Lakes during 1974-1995. δ N provided an indication adult trophic position egg formation. After adjustment for interlake differences baseline food web signatures, significant found among colonies. These results attributed to differing proportions fish diets gulls various Aquatic foods available had greater than terrestrial...

Environmentally important perfluorinated carboxylates and sulfonates, as well per- polyfluorinated precursor compounds including several sulfonamides, telomer acids, alcohols were determined in individual herring gull (Larus argentatus) eggs collected (in 2007) from 15 colonies located at Canadian some American sites across the Laurentian Great Lakes of North America. The pattern perfluorosulfonates (PFSAs; C6, C8, C10 chain lengths) was dominated by PFOS (>90% ΣPFSA concentration)...

Summary 1. Declining abundances of forage fish and the introduction establishment non‐indigenous species have potential to substantially alter resource habitat exploitation by top predators in large lakes. 2. We measured stable isotopes carbon (δ 13 C) nitrogen 15 N) field‐collected archived samples Lake Ontario lake trout ( Salvelinus namaycush ) five prey compared current trophic relationships this predator with historical samples. 3. Relationships between δ N age were temporally...

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet patterns δ15N values acids (AAs) compared to those their tissues (muscle red blood cells) food. Based upon discrimination between kestrel tissues, AAs could mostly be categorized as source (retaining baseline values) trophic (showing 15N enrichment)....

Disruption of natural food webs is becoming a commonplace occurrence as result human activities. Considering this, there need to improve our ability define web structure well detect and understand the implications trophodynamic change. This requires development, validation, application ecological tracers that can provide insights into movement energy, nutrients, contaminants through webs. In this study, we examine utility two groups naturally occurring intrinsic (stable nitrogen isotopes...

In this study, temporal trends and patterns of major C4 to C15 chain length PFCAs PFSAs some sulfonamide, fluorotelomer acid alcohol precursors were determined in herring gull (Larus argentatus) egg pools. Samples analyzed from fifteen collection years including 1990 all 1997 2010, seven colonies located throughout the Great Lakes, ranging remote highly urbanized areas. Other than at Toronto Harbour colony, slopes ∑PFSA concentrations (C6, C8, C10) versus time negative indicating general...

Abstract Temporal trends in levels of biomagnifying contaminants, such as mercury (Hg), top predators can provide insights into changes contaminant bioavailability through time. However, interpreting temporal be confounded by their diets, which, turn, could affect organism trophic position and exposure to contaminants. To address this issue, bulk stable nitrogen isotope analysis, that is, analysis whole tissue, is widely incorporated contaminant‐monitoring programs for the estimation...

Text.Knowledge of the natal origins individual birds could provide valuable information for waterfowl conservation and harvest management programs. We used stable isotopes to differentiate from major western North America production areas, thereby providing a means elucidating waterfowl. multi-isotope approach (δ34S, δ2H, δ13C, δ15N) determine if ducks originating different geographic areas had unambiguous multi-isotopic signatures. During 1999–2001 we took secondary feathers prefledged...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTemporal Trends and Sources of PCDDs PCDFs in the Great Lakes: Herring Gull Egg Monitoring, 1981-1991C. E. Hebert, R. J. Norstrom, M. Simon, B. Braune, D. V. Weseloh, C. MacdonaldCite this: Environ. Sci. Technol. 1994, 28, 7, 1268–1277Publication Date (Print):July 1, 1994Publication History Published online1 May 2002Published inissue 1 July 1994https://pubs.acs.org/doi/10.1021/es00056a014https://doi.org/10.1021/es00056a014research-articleACS...