An assessment of total ammonia nitrogen concentration in Alabama (USA) ictalurid catfish ponds and the possible risk of ammonia toxicity

An assessment of total ammonia nitrogen (TAN) concentration was conducted for 31 ictalurid catfish ponds on six farms, in the Blackland Prairie region of Alabama (USA). Five farms that provided production data had average annual feed inputs and harvest weights of 15,579–21,739 kg ha− 1 and 8104–12,344 kg ha− 1, respectively. Concentrations of TAN were measured 26 times (weekly June through September and less frequently other months) between May...