Interactions of chemical and natural stresses in the abalone (Haliotis rufescens) as measured by surface-Probe localized 31P NMR

Application of nuclear magnetic resonance spectroscopy (NMR) for elucidating the sublethal actions of toxicants in intact aquatic organisms, and the influence of natural stress factors, has recently been demonstrated. Using a flow-through chamber, red abalones (Haliotis rufescens) were exposed (at 14 °C) to ambient (35%.), hyposaline (25%.), or hyper saline (45%.) seawater, with and without a sublethal concentration (1.2 mg l−1) of pentachlorophenol (PCP). They were then maintained in clean seawater (at the same salinity) to check both rate and degree of recovery; phosphagen changes in foot muscle were monitored by surface-probe localized 31P NMR. Whereas different water salinities alone did not produce measurable effects, upon PCP exposure phosphoarginine levels declined, inorganic monophosphate levels increased, and intracellular pH decreased. Whereas during recovery all biochemical endpoints returned to normal, both onset and intensity of effects were significantly influenced in an unexpected manner by changes in seawater salinity. Application of 31P NMR represents a powerful new tool for elucidating the influence of natural stress factors on pollutant actions in vivo, providing a more accurate assessment of environmental effects.