Background: Ammonia toxicity is believed to be a cause of otherwise unexplained losses in fish hatcheries. Excess ammonia may accumulate and cause alteration of metabolism or increases in the body pH of the exposed organism. Tolerance varies among fish species. At lower concentrations, around 0.05 mg/L, un-ionised ammonia is harmful to fish species and can result in poor growth and feed conversion rates, reduced fecundity and fertility and increase stress and susceptibility to bacterial infections and diseases. Exposed to excess ammonia, fish may suffer loss of equilibrium, hyper-excitability, increased respiratory activity and oxygen uptake and increased heart rate. At concentrations exceeding 2.0 mg/L, ammonia causes gill and tissue damage, extreme lethargy, convulsions, coma, and death. Experiments have shown that the lethal concentration for a variety of fish species ranges from 0.2 to 2.0 mg/l.During winter, when reduced feeds are administered to aquaculture stock, ammonia levels can be higher. Lower ambient temperatures reduce the rate of algal photosynthesis so less ammonia is removed by any algae present. Within an aquaculture environment, especially at large scale, there is no fast-acting remedy to elevated ammonia levels. Prevention rather than correction is recommended to reduce harm to farmed fish and in open water systems, the surrounding environment.

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery lost more fish because of ammonia?
Answer: Spruce

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery lost fewer fish because of ammonia?
Answer: Pine

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found more fish with altered metabolisms?
Answer: Spruce

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found fewer fish with altered metabolisms?
Answer: Pine

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found fewer fish with an increased body pH?
Answer: Pine

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found more fish with an increased body pH?
Answer: Spruce

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found more fish with poor growth?
Answer: Spruce

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found fewer fish with poor growth?
Answer: Pine

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found fewer fish with reduced fecundity?
Answer: Pine

Situation: Woodland had two nearby fish hatcheries. Pine hatchery had great result the past few years because they found a way to reduce ammonia water toxicity. Spruce hatchery has big ammonia toxicity problems and hadn't find a way to remediate them.

Question: Which hatchery found more fish with reduced fecundity?
Answer: Spruce