Mr. Mohammad Taghi Ajir, the certain researcher of the Coldwater Fishes Research Center of Tonekabon, followed the previous planning and after coordination with Mr. Abolhassani, the head of the Organization of Agriculture - Jahad of the Abbasabad County, along with Ms. Shafiei, the regional expert, and Mr. Mehri, the fisheries extension expert of the research center, to the Parchur village in Abbasabad County and visited the coldwater fish farms of Mr. Behrang Yousefinia, Mr. Hamid Bilal Habashi and Ms. Masoumeh Shahmiri. During this visit, various issues were discussed regarding the existing conditions and aquaculture capacities. The water source on Mr. Behrang Yousefinia's farm was a well with a flow rate of 5 liters per second and equipped with the water recycling and ozone system. But despite having the water recycling system, the ponds did not have a separate outlet to direct water out of the system. The water source on Ms. Masoumeh Shahmiri's farm was a well with a flow rate of 5 liters per second and was equipped with the water recycling system and the media method was used. The biggest drawbacks of this farm were the lack of drum filter to remove large debris, the presence of many algae due to reuse of water, high organic load and suspended solids in the recycled water and most importantly, multi - species aquaculture and using the effluent of all the ponds in the water recycling system. Mr. Hamid Bilal Habashi's farm was a simple, rectangular farm with two ponds of about 20 cubic meters, with spring water and no aeration system. The manager of the farm was preparing the farm to stock fish after a period (three years) of farm closure.
It is worth mentioning that the main problems observed in this visit include the following:
-Farm managers were unaware of the exact amount of the water inflow rates
-Farms used recycled water with high organic load. The fish were sick. In addition, it was possible for contaminants from agriculture to enter the farms through the inflow of water
-Farm managers were unaware of the physical and chemical parameters of water
-Purposeless use of antibiotics and disinfectants for fish
At the end of the visit, the following technical recommendations were provided:
-The temperature and pH of the inlet water and outlet water should be recorded daily
-Salt baths should be used at least twice a week to treat fish
-The nets in the aeration tower should be repaired and replaced at the water inlet of the farm
-The required water should be provided using water recycling system in full compliance with principles of hygiene
-The drum filter machine should be installed to use the recycled water
-In the event of any problems, farmers should contact an expert and use their guidance