tailieunhanh - BÁO CÁO " BIẾN ĐỘNG CÁC YẾU TỐ MÔI TRƯỜNG TRONG AO NUÔI CÁ TRA (Pangasianodon hypophthalmus) THÂM CANH Ở AN GIANG "

In the non-infected ponds, however, pH was significantly higher compared to the infected ponds (P0,05), và đạt giá trị cao nhất vào mùa mưa (274,2 mg/L). OSS dao động từ 1,3 - 207,0 mg/L và khác biệt không có ý nghĩa giữa các ao cá bệnh và cá khỏe nhưng lại thấp nhất vào mùa khô. Ao cá bệnh có %OSS và BOD cao hơn các ao cá khỏe (P | Tạp chí Khoa học 2008 1 1 -9 Trường Đại học Cần Thơ BIẾN ĐỘNG CÁC YẾU TỐ MÔI TRƯỜNG TRONG AO NUÔI CÁ TRA Pangasianodon hypophthalmus THÂM CANH Ở An giang Huỳnh Trường Giang1 Vũ Ngọc Út1 và Nguyễn Thanh Phương2 ABSTRACT Study on water quality was conducted in 64 intensive catfish ponds in An Giang province from March 2005 to December 2006. Data obtained were analyzed and compared between seasons dry and rainy seasons and fish health status infected and non-infected fish ponds . The results showed that pH fluctuated from to and not significantly different among seasons P . In the non-infected ponds however pH was significantly higher compared to the infected ponds P . There was no significant difference in TSS between infected and noninfected ponds. Highest value of TSS mg L was obtained in the rainy season. The concentration of OSS fluctuated dramatically over the sampling period from to mg L . However no significant difference was found between the infected and non-infected ponds. OSS concentration was lowest in the dry season. The results also indicated that OSS and BOD of the infected ponds were significantly higher P . However OSS was not significantly different between seasons. OSS varied from to while BOD reached highest levels of mg L and mg L for infected and non-infected ponds respectively. TAN NO2 and POf were not significantly different between seasons and fish health status. However NO3 concentration was highest in the dry season and significantly different to the other seasons. Keywords Water quality Pangasianodon hypophthalmus An Giang season. Title Study on water quality of intensive catfish culture Pangasianodon hypophthalmus ponds in An Giang province TÓM TẮT Nghiên cứu sự biến động các yếu tố môi trường trong các ao nuôi cá tra thâm canh đã được thực hiện trên 64 ao tại tỉnh An Giang từ tháng 3 2005 đến tháng 12 2006. Số liệu được phân tích và so sánh theo mùa và theo tình trạng cá. Kết .