Body residues as dose for sublethal responses in alevins of landlocked salmon (Salmo salar m. sebago): A direct calorimetry study

Authors

  • Olli-Pekka Penttinen,

    Corresponding author
    1. Department of Ecology and Environmental Sciences, University of Helsinki, Niemenkatu 73, FIN-15140 Lahti, Finland
    • Department of Ecology and Environmental Sciences, University of Helsinki, Niemenkatu 73, FIN-15140 Lahti, Finland
    Search for more papers by this author
  • Jussi V. K. Kukkonen

    1. University of Joensuu, Department of Biology, Laboratory of Aquatic Ecology and Ecotoxicology, P.O. Box 111, FIN-80101 Joensuu, Finland
    Search for more papers by this author

Abstract

Qestions of organism-specific factors, toxicity endpoints, and their relation to mode-of-action all are related to consistency and applicability of body residue-based approaches. To address this issue, direct calorimetry was used to evaluate metabolic responses of alevins of landlocked salmon (Salmo salar m. sebago) to pentachlorophenol (PCP) exposure ranging from 0 to 1.04 μM for 24 h or 24, 48, and 72 h (0, 0.26, and 0.55 μM, respectively). The body residues were used as a dose metric for sublethal responses. The body size, rapid ontogenetic development, and exposure to a specific pollutant all were heat output-modifying factors. The acute exposure (24–72 h) to PCP led to a heat output-enhancing effect, which directly was related to an internal concentration of PCP in the range of 0.01 to 0.15 μmol/g. Within the treatments, body size per level of metabolic rate and magnitude of physiological response were not correlated, thus the alevins with higher mass-specific metabolic rate were not more sensitive to PCP. Primarily, increasing metabolic rate during posthatch development controls PCP toxicity only by affecting bioaccumulation kinetics, not the toxic potency of the chemical. New information of a relationship between observed natural variation in measured physiological trait offish and PCP-induced response and its body residue-based level is of ecotoxicological importance.

Ancillary