POND MANAGEMENT, WATER SOURCES AND ITS IMPACT ON THE ACCUMULATION OF HEAVY METALS AND CONTAMINANTS OF MICROBIAL CONTENT IN WATER, SOIL AND FISH IN POLYCULTURE
Ibrahim M. Shaker1; Alam El Deen Farouk1;
Zakar A.H.2 and Eman A.A. Abd El Hamid1
1Limnology Department; 2Fish Processing and quality Control Department.
1,2Central Laboratory for Aquaculture Research, (CLAR) Agriculture Research Center, Ministry of Agriculture, Egypt.
Corresponding author: [email protected]
|Received 17/ 2/ 2017||
Accepted 5/ 4/ 2017
Heavy metal pollution is one of the most serious environmental issues globally. The present study aimed to evaluate some heavy metal concentration and bacterial load in water, soil depth and some organs of Nile tilapia (Oreochromis niloticus) and mullet (mugil cephulus) reared in earthen ponds with different water sources and pond managements. The study was conducted at six fish farms distributes in three governorates in Egypt, namely as; Kafer el-Sheikh, Ismailia and Port Said, two farms each. At each governorate one farm received artificial feed and other use organic and mineral fertilization. Each farm has four ponds with an area of about two feddans and a depth of 1.25 m. The first fish farm used organic and mineral fertilizers only during the first three months and then adding the artificial feed until harvest. The second fish farm used artificial feed 25% protein only during the whole study period.
The results showed significantly increase in heavy metal levels and microbial content in water, soil and fish organs in Port Said fish farms. Also heavy metals increase in mullet (Mugil Cephulus) than tilapia (Oreochromis niloticus). Concerning fish organs, liver showed significantly increase of heavy metal levels than gills and muscles. This study concluded that water source and management processes play an important role in heavy metal accumulation in soil and fish organ and the microbial content in each different fish pond component. So, a great attention should be when use sewage wastewater to prevent the transmission of pathogenic bacteria and heavy metals from fish to humans.
Key words: pond management, water source, heavy metals, microbial content, tilapia, mullet, water, soil