Laboratory of Environmental Toxicology and Aquatic Ecology, Department of Applied Ecology and Environmental Biology, Ghent University , Plateaustraat 22, 9000 Gent, Belgium.
Environ Sci Technol. 2013 Oct 15;47(20):11793-801. doi: 10.1021/es402898t. Epub 2013 Oct 4.
It is widely accepted that body concentrations of persistent organic pollutants (POPs) tend to increase with trophic level (TL). Yet, little attention has been paid to the causes in the underlying differences in POP body concentrations between species occupying similar TLs. In this paper we use two modeling approaches to quantify the importance of migration and opportunistic feeding, relative to that of trophic level, in explaining interspecific differences in polychlorinated biphenyl (PCB) body concentrations between 6 Arctic seabird species breeding in the Barents Sea: Little Auk (Alle alle), Black Guillemot (Cepphus grylle), Brünnich's Guillemot (Uria lomvia), Common Eider (Somateria mollissima), Black-legged Kittiwake (Rissa tridactyla), and Glaucous Gull (Larus hyperboreus). As a first approach, we use additive models to analyze two independent data sets (n = 470 and n = 726). We demonstrate that migration, opportunistic feeding, and TL significantly (p < 0.001) increase PCB body concentrations by a factor 3.61-4.10, 2.66-20.95, and 2.38-2.41, respectively. Our second approach, using a mechanistic bioaccumulation model, confirmed these positive effects on the body burdens but suggested lower effects of migration, opportunistic feeding, and TL (1.55, 2.39, and 2.38) than did our statistical analysis. These two independent approaches demonstrate that the effects of migration and opportunistic feeding on seabird body burdens can be similar to that of an increase of one TL and should therefore be accounted for in future analyses.
人们普遍认为，持久性有机污染物（POPs）的体内浓度往往随营养级（TL）的升高而增加。然而，对于处于相似营养级的物种之间体内 POP 浓度差异的根本原因，关注甚少。在本文中，我们使用两种建模方法来量化迁移和机会性摄食相对于营养级在解释北极 6 种海鸟物种（繁殖于巴伦支海）体内多氯联苯（PCB）浓度的种间差异方面的重要性：小绒鸭（Alle alle）、黑眉信天翁（Cepphus grylle）、角嘴海雀（Uria lomvia）、普通绒鸭（Somateria mollissima）、黑脚三趾鸥（Rissa tridactyla）和北极鸥（Larus hyperboreus）。作为第一种方法，我们使用加性模型分析了两个独立的数据集（n = 470 和 n = 726）。我们证明，迁移、机会性摄食和 TL 分别使 PCB 体内浓度增加了 3.61-4.10、2.66-20.95 和 2.38-2.41 倍（p < 0.001）。我们的第二种方法，使用一种基于机制的生物积累模型，证实了这些对体内负荷的积极影响，但表明迁移、机会性摄食和 TL 的影响较低（1.55、2.39 和 2.38），低于我们的统计分析。这两种独立的方法表明，迁移和机会性摄食对海鸟体内负荷的影响可以与营养级升高 1 级的影响相似，因此在未来的分析中应予以考虑。
