Published online by Cambridge University Press: 11 May 2009
Intertidal organisms are particularly prone to the effects of both crude oil and to the chemicals commonly used to disperse the oil, following an oil spill at sea (Smith, 1968). A large body of literature now exists on the lethal effects of crude oil and dispersants but little progress has been made towards elucidating the toxic mode of action of these chemicals, nor to understanding what effects they exert when present in sub-lethal concentrations. Since the gills of aquatic animals are generally the most delicate of the epithelia exposed to the environment, it is likely that they will be most prone to damage by pollutants. Whilst previous workers using light microscopy (e.g. Clark, Finley & Gibson, 1974; Blanton & Robinson, 1973) have reported gross damage to the gills of mussels and fish following exposure to crude oil, there was no information available on the nature of the cellular damage at the ultrastructural level. In this study, we describe the nature of the lesions produced in the gills of the common intertidal limpet Patella vulgata following exposure to the water soluble fraction of North Sea crude oil and to the dispersants BP 1100 X and BP 1100 WD. A description of the ultrastructure of normal gill plates of Patella has been published previously (Nuwayhid, Davies & Elder, 1978).