Interactive effects of pentachlorophenol and temperature in the abalone ( Haliotis rufescens) as measured by in vivo 31P-NMR spectroscopy

Abstract

The influence of temperature on the effects of pentachlorophenol (PCP) was described in red abalones ( Haliotis rufescens) using in vivo 31P nuclear magnetic resonance spectroscopy (NMR). Specifically, two effects were measured: the exposure times required for onset of PCP effects; and both intensity of, and recovery from, such effects. Following acclimation to clean seawater, abalones were exposed to a sublethal water concentration of PCP (1.2 mg l −1) at either 9 or 19°C until the spectral peak area for inorganic monophosphate (P i) was one-half that of phosphoarginine (PA); temperatures represented the seasonal range in California. The endpoint served to compare the times required to reach equivalent metabolic condition, and insured that all individuals were metabolically equivalent at the onset of exposure to clean seawater; abalones were maintained in clean seawater for up to 16 h to monitor recovery. In foot muscle, PCP caused a decrease in concentration of PA and ATP, an increase in that of P i, and acidification of intracellular pH; effects were produced more rapidly at 19°C, as the endpoint was attained in less than half the time (2.4 h) as was that at 9°C (5.4 h; P < 0.05). Both the average response to, and the average extent of recovery from, the biocide were greater in abalones exposed at 19°C. Upon exposure to clean seawater, all effects generally reversed within 10 to 16 h, and control abalones maintained at the two temperatures alone exhibited no adverse effects. Finally, abalones exposed to 120 μg l −1 of PCP for 18 h at both 9 and 19°C exhibited no adverse effects, indicating that PCP does not impact abalones at current environmental concentrations. In conclusion, high temperature potentiates the time both to onset of and for recovery from the sublethal effects of PCP in the red abalone. Use of in vivo NMR allows measurement of multiple-stress interactions in live, intact aquatic organisms, facilitating the detailed elucidation of individual responses and the laboratory assessment of the environmental effects of pollutants.