Histopathologic survey of ovaries of plaice, Pleuronectes platessa L., from Aber Wrac'h and Aber Benoit, Brittany, France: long‐term effects of the Amoco Cadiz crude oil spill

Abstract

Abstract. Ovarian samples were collected from plaice, Pleuronectes platessa, captured in the highly oiled Aber Wrac'h and Aber Benoit estuaries at four intervals during 1979–1980, following the Amoco Cadiz crude oil spill. Reference plaice were obtained along the western and southern coasts of Brittany. Tissue samples were fixed, processed and stained by routine histologic procedures. Ovaries were examined for histopathologic changes and for four different types of follicles. The concentrations and percentages of four types of ovarian follicles (primordial, primary, growing and mature) were determined for plaice ovaries within each sampling site at each sampling interval. Reference site ovaries, which were considered representative of the ovarian cyclic events for plaice along the Brittany coast, had primordial and primary follicles in high concentration in the summer season and in low concentration in the winter season. Concentrations of mature ovarian follicles in reference site plaice ovaries were low in the summer and high in the winter seasons. Growing follicles were observed infrequently in the reference site plaice ovaries. The seasonal pattern exhibited by follicles in ovaries from Aber Benoit plaice was similar to that observed in the reference site ovaries, but both the concentrations and percentages of follicle types were lower. The seasonal pattern of follicle types in Aber Wrac'h plaice ovaries was the reverse of that seen in the reference site plaice ovaries. In the Aber Wrac'h samples, concentrations of primordial and primary follicles were high in the winter months and low in the summer season, and no mature follicles were observed at any season. Growing follicles were seen more frequently in Aber Wrac'h and Aber Benoit plaice ovaries than in reference site plaice ovaries at all sampling intervals. Other than atretic follicles with an associated leucocytosis, no histopathologic conditions were observed in any ovary.