Fig. 4. Results of the ammonia 96-h LC₅₀ test plotting survivorship of juvenile fish (<16 mm TL) against total ammonia-N concentration (N=30 for each treatment group). Juveniles were reared from eggs harvested in Biscayne Bay and were used within 1 week of full yolk-sac absorption. An arrow depicts the calculated LC₅₀ value. The test was conducted in individual 2-litre chambers for each treatment group with a daily 50% water change, and ammonia concentrations were verified at t₀ and at 24 h intervals thereafter.