Heavy metals concentration in rock oyster Crassostrea cattuckensis from Ratnagiri coast

Rock oyster Crassostrea cattuckensis of medium (88.99 mm shell length) sizes from Bhatye estuary at Ratnagiri were collected in monsoon, winter and summer seasons. The soft body parts on dry weight basis showed more amounts of zinc (μg/gm) during monsoon from siphon (196.89) followed by mantle (186.61), hepatopancreas (177.19), gill (171.43), gonad (171.28) and adductor muscle (158.62). The lead content was more in mantle (1.52) and hepatopancreas (0.76). The metal was not detected in monsoon. The cadmium was more in hepatopancreas (12.77) than siphon (11.05), gill (10.40), gonad (8.09), mantle (6.65) and adductor muscle (6.17). The copper metal showed more in gill (7.71) followed by siphon (6.89), hepatopancreas (6.46), gonad (4.45), mantle (4.38) and adductor muscle (3.40). The zinc metal during winter was more in siphon (193.51) followed by mantle (179.95), hepatopancreas (175.01), gill (160.28), adductor muscle (155.78) and gonad (145.82). The lead content was more in mantle (31.49) than gill (25.42), siphon (24.66), gonad (16.32), hepatopancreas (14.80) and adductor muscle (14.42). The cadmium was more in gill (23.33) than hepatopancreas (20.88), siphon (18.92), gonad (17.16), mantle (16.95) and adductor muscle (14.94). The copper metal showed more in gill (12.54) followed by siphon (10.22), mantle (7.29), hepatopancreas (7.24), gonad (5.73)and adductor muscle (4.71). During summer zinc metal was more in gills (152.12) followed by siphon (143.86), adductor muscle (118.57), mantle (109.21), gonad (109.10) and hepatopancreas (102.38). The lead content was more in adductor muscle (11.76) than gill (11.39), gonad (11.01), siphon (9.87), mantle (8.73) and hepatopancreas (5.32). The cadmium was more in gonad (8.80), gill (8.38), siphon (7.41), hepatopancreas (6.18), adductor muscle (4.76), and mantle (4.60). The copper metal showed more in gills (6.41) followed by gonad (4.93), siphon (4.55), mantle (3.29), adductor muscle (3.27) and hepatopancreas (2.96). Among the metals zinc was high in monsoon followed by winter and summer seasons. The level of lead was high in winter and low in monsoon. The cadmium and copper metals were high in winter and low in summer.