Evidence of maternal offloading of organic contaminants in white sharks (Carcharodon carcharias)

PLoS One. 2013 Apr 30;8(4):e62886. doi: 10.1371/journal.pone.0062886. Print 2013.

Abstract

Organic contaminants were measured in young of the year (YOY) white sharks (Carcharodon carcharias) incidentally caught in southern California between 2005 and 2012 (n = 20) and were found to be unexpectedly high considering the young age and dietary preferences of young white sharks, suggesting these levels may be due to exposure in utero. To assess the potential contributions of dietary exposure to the observed levels, a five-parameter bioaccumulation model was used to estimate the total loads a newborn shark would potentially accumulate in one year from consuming contaminated prey from southern California. Maximum simulated dietary accumulation of DDTs and PCBs were 25.1 and 4.73 µg/g wet weight (ww) liver, respectively. Observed ΣDDT and ΣPCB concentrations (95±91 µg/g and 16±10 µg/g ww, respectively) in a majority of YOY sharks were substantially higher than the model predictions suggesting an additional source of contaminant exposure beyond foraging. Maternal offloading of organic contaminants during reproduction has been noted in other apex predators, but this is the first evidence of transfer in a matrotrophic shark. While there are signs of white shark population recovery in the eastern Pacific, the long-term physiological and population level consequences of biomagnification and maternal offloading of environmental contaminants in white sharks is unclear.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • California
  • Chlorine / analysis
  • Diet
  • Ecosystem
  • Female
  • Geography
  • Maternal Exposure*
  • Models, Theoretical
  • Seawater / analysis
  • Seawater / chemistry
  • Sharks*
  • Water Pollutants, Chemical*

Substances

  • Water Pollutants, Chemical
  • Chlorine

Grant support

Funding for this project was provided, in part, by Monterey Bay Aquarium, University of Southern California Sea Grant and the California Ocean Protection Council. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.