“…The ammoniac is considered as the most toxic fraction of TAN that is defined by the sum of ammonium ion and ammoniac (EPA, 1998). The ammoniac effect is related to temperature, salinity, oxygen and pH (Randall and Tsui, 2002;Fang et al, 2017), on this basis, the temperature observed in the present study was, within the optimal tolerance level (Randall and Tsui, 2002), and whereas at salinity level at high NaCl concentration the ammoniac toxic effect is lower (Randall and Tsui, 2002;Rodrigues et al, 2007;Fang et al, 2017). Also, in increment condition of sodium and calcium in oxygen saturated water the ammoniac effect decreased (Foss et al, 2007).…”