Abstract
Aquaculture is the fastest growing food production sector, according to FAO report. Romanian aquaculture has an estimated production of 10000 tones per year, most of it being provided by cyprinids pond aquaculture production systems. However, pond aquaculture rises certain problems regarding the sustainability, as large concentrations of nitrogen and phosphorus may be recorded in effluents. Therefore, the aim of our study is to evaluate the sustainability of a single pond based cyprinids production system, situated in Galaţi - Romania, by analysing the water quality of the effluent. Water samples were collected from the pond effluent and the following analysis were determined: temperature (T°C), dissolved oxygen (DO), pH, nitrites (NO2), ammonia (NH3), orthophosphates (PO4), total zinc (Zn) chlorides (Cl-), bicarbonates (HCO3-), electro conductivity (EC) and total dissolved solids (TDS). The results were compared to the present national legislation (HG no. 202/2002) regarding the water quality in cyprinid farming and also to water quality criteria for aquaculture. Statistical analysis included normality test Kolmogorov Smirnov in order to determine the distribution of the registered data and Pearson correlation coefficient was applied for the analyzed parameters. The main conclusion of this research was that the technological water of the studied fish pond is suitable for fish rearing and sustainable for the environment, in terms of temperature, DO, pH, Cl-, HCO3-, Zn, EC and TDS. However, NO2, NH3 and PO4 concentrations were above the admissible limit imposed by the romanian legislation. Therefore, in order to improve sustainabily it is recommended that various modern multi-trophic technics should be applied, so that phosphorus and nitrogen compounds are valorized at maximum capacity.
Rezumat
Acvacultura este unul dintre sectoarele producţiei alimentare cu cea mai rapidă dezvoltare. Acvacultura de tip heleşteu ridică anumite probleme în ceea ce priveşte sustenabilitatea, deoarece concentraţii mari de azot şi fosfor pot fi înregistrate în efluenţi. Obiectivul studiului nostru este de a evalua sustenabilitatea unui sistem unic de producţie ciprinicolă de tip heleşteu, situat în Galaţi - România, prin analizarea calităţii apei a efluentului. Probele de apă au fost prelevate din efluentul heleşteului şi au fost determinate următoarele analize: temperatura (T° C), oxigenul dizolvat (DO), pH, nitriţi (NO2), amoniac (NH3), ortofosfati (PO4), zinc total (Zn) cloruri (Cl-), bicarbonaţi (HCO3-), electroconductivitate (EC) si solide totale dizolvate (TDS). Rezultatele au fost comparate cu legislaţia naţională în vigoare (HG nr. 202/2002) privind calitatea apei ciprinicole în activitatea de piscicultură. Principala concluzie a acestei cercetări a fost că apa tehnologică a heleşteului studiat este potrivită pentru creşterea peştilor şi sustenabilă pentru mediu, din punct de vedere al temperaturii, DO, pH, Cl-, HCO3-, Zn, EC şi TDS. Cu toate acestea, concentraţiile de NO2, NH3 şi PO4 au fost peste limitele impuse de legislaţia naţională. Prin urmare, se recomandă aplicarea diverselor tehnici moderne multitrofice, astfel încât compuşii de fosfor şi azot să fie valorificaţi la capacitate maximă.