Coral reefs have been degrading faster than they have been recovering (Done 1992; Ginsburg 1994; Hughes 1994; Grigg and Birkeland 1997; McManus and Vergara 1998; Wilkinson 1993, 1998) and they have been accruing in their degraded states because they achieve alternate stable states of algae instead of corals (Knowlton et al. 1981; Knowlton 1992; Done 1992; Hughes 1994), and because rates of dama...

The present study was carried out to study gills, liver and kidney histopathology in the freshwater fish, Tilapia zillii which exposed to three levels of aluminum (25, 50, and 100 μg/L) for 96 hour in acidic soft water (pH 6.0). Several histopathological changes were observed in fish organs would serve useful purpose in evaluating the toxic effects of aluminum. Histopathological changes in gill...