THE IMPACT OF EXTENSIVE AQUACULTURE OVER THE QUALITY OF THE AQUATIC ENVIRONMENT

Elena Mocanu, N. Patriche, Magdalena Tenciu, Veta Nistor, V. Eşanu

Abstract
    The present paper presents the study results regarding the impact of extensive aquaculture on aquatic environment quality. The study was carried out at Cotu Chiului Research and Development Farm. The facility is located in the northern part of Galati county, adjacent to the pier-shore area of the Prut River Dam, in the km 36 protected natural area. The aquatic species ‘structure and age stages of the biological material from Cotu – Chiului farm, is divided as follows: 51% goldfish, 19% catfish, 4% carp at different age stages, 26% plant feeder fish. Different indicators with high levels of pollution potential, such as nitrogen compounds (NO^2-, NO^3-, NH⁴⁺), phosphorus and organic matter, have been monitored to be able to evaluate the physical-chemical changes of the aquatic life environment from Cotu Chiului farm. The study has been carried out on monthly water and soil samples, over the period of one year. The samples were collected from three growth ponds (EC1, EC2, EC3) which have similar morpho-hydrographic characteristics.
    The study concluded that: - EC1 (December and November) - maximum values of nitrites (0.132±0.016 mg/l) and ammonia (0.142±0.008 mg/l), - EC 2 (July) - maximum concentration of phosphorus (0.07±0.004 mg/l), - EC1 and EC3 (August), EC2 (January) - high values of organic matter accumulations (96.63±0.1 mg/l) and respectively (91.95±0.12 mg/l). The physical-chemical parameters of the soil samples taken have registered the same evolution tendencies as the water characteristics from Cotu Chiului farm.

Key words: pollutant, extensive aquaculture, environment