Using bald eagles to track spatial (1999–2008) and temporal (1987–1992, 1999–2003, and 2004–2008) trends of contaminants in Michigan's aquatic ecosystems

Abstract

The bald eagle (Haliaeetus leucocephalus) is an extensively researched tertiary predator. Studies have delineated information about its life history and the influences of various stressors on its reproduction. Due to the bald eagle's position at the top of the food web, it is susceptible to biomagnification of xenobiotics. The Michigan Department of Environmental Quality implemented a program in 1999 to monitor persistent chemicals including polychlorinated biphenols (PCBs) and dichlorodiphenyltrichloroethane (DDE). The objectives of the present study were to evaluate spatial and temporal trends of PCBs and organochlorine pesticides in nestling bald eagles of Michigan. The authors' study found that concentrations of PCBs and DDE were higher in Great Lakes areas with Lakes Michigan and Lake Huron having the highest concentrations of DDE and Lake Erie having the highest concentrations of PCBs. Temporally (1987-1992, 1999-2003, and 2004-2008) the present study found declines in PCB and DDE concentrations with a few exceptions. Continued monitoring of Michigan bald eagle populations is suggested for a couple of reasons. First, nestling blood contaminant levels are an appropriate method to monitor ecosystem contaminant levels. Second, from 1999 to 2008 PCB and DDE concentrations for 30% and 40%, respectively, of the nestling eagles sampled were above the no observable adverse effect level (NOAEL) for bald eagles. Lastly, with the continued development and deployment of new chemistries a continuous long term monitoring program is an invaluable resource. Environ Toxicol Chem 2016;35:1995-2002. © 2016 SETAC.

Retracted: Using bald eagles to track spatial (1999–2008) and temporal (1987–1992, 1999–2003, and 2004–2008) trends of contaminants in Michigan's aquatic ecosystems

“…PCBs. However, the nondetects thresholds for the present study were approximately 2 mg/kg for both DDE and PCBs [5]. The improvement in detection ability and thus lower nondetects levels for T2 and T3 were the result of the establishment of a new lab with better equipment.…”

“…The present study targeted 20 congeners of PCBs, DDT and its metabolites, and 10 other organochlorine pesticides. However, the 10 organochlorine pesticides are not reported here because they failed to be detected in 50% or more of the samples [5]. Because of its pervasiveness and demonstrated ecological effects, the DDT metabolite p,p'-dichlorodiphenyltrichloroethylene (DDE) is reported in the present study.…”

“…Because of its pervasiveness and demonstrated ecological effects, the DDT metabolite p,p'-dichlorodiphenyltrichloroethylene (DDE) is reported in the present study. It should also be noted that 94% of the total DDT in eaglet plasma samples (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008) was DDE [5]. For PCBs, all congeners were examined as the sum of all PCBs found (i.e., total PCB).…”

“…In the 1960s, when Michigan's eagle population was first being monitored, less than 100 nests were occupied (i.e., 100 active breeding pairs existed) [4]. In 2009 there were approximately 500 occupied nests each year and over 700 known breeding areas in the state [5].…”

Use real‐world data to inform the National Coastal and Great Lakes condition

“…For example, concentrations of Hg in piscivorous bird species, purported to cause adverse effects, have not resulted in adverse effects on species in the Great Lakes (e.g., Bowerman et al ). Moreover, PCB and DDE concentrations have declined over time in bald eagles residing in the Great Lakes and in Michigan inland waters (Wierda et al ). Similarly, concentrations of Hg in Great Lakes sediment samples have declined over time (Marvin et al ).…”