1 Title: 2 Persistent organic pollutant burden, experimental POP exposure and tissue properties 3 affect metabolic profiles of blubber from grey seal pups. 4 5 Authors: 6 Kelly J. Robinson1*, Ailsa J. Hall1, Cathy Debier2, Gauthier Eppe3, Jean-Pierre Thomé4 7 and Kimberley A. Bennett5 8 9 Affiliations: 10 1Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews 11 2Louvain Institute of Biomolecular Science and Technology, Université Catholique de 12 Louvain 13 3Center for Analytical Research and Technology (CART), B6c, Department of 14 Chemistry, Université de Liège 15 4Center for Analytical Research and Technology (CART), Laboratory of Animal 16 Ecology and Ecotoxicology (LEAE), Université de Liège 17 5Division of Science, School of Science Engineering and Technology, Abertay 18 University 19 20 *Corresponding Author: Kelly J. Robinson, email:
[email protected] 21 22 Keywords: 23 Dioxin-like PCBs; glucose uptake; lipolysis; lactate production; blubber depth; 24 energetic state; environmental contamination; fasting; feeding 25 1 26 Abstract 27 Persistent organic pollutants (POPs) are toxic, ubiquitous, resist breakdown, 28 bioaccumulate in living tissue and biomagnify in food webs. POPs can also alter energy 29 balance in humans and wildlife. Marine mammals experience high POP concentrations, 30 but consequences for their tissue metabolic characteristics are unknown. We used 31 blubber explants from wild, grey seal (Halichoerus grypus) pups to examine impacts of 32 intrinsic tissue POP burden and acute experimental POP exposure on adipose metabolic 33 characteristics. Glucose use, lactate production and lipolytic rate differed between 34 matched inner and outer blubber explants from the same individuals and between 35 feeding and natural fasting.