Factors influencing the production of turbidity by goldfish (Carassius auratus)

Experiments were conducted to determine the effect of body size, population size and structure, and temperature upon the level of turbidity generation by goldfish foraging in laboratory pools. Water temperature correlated with turbidity generation, which peaked at 25 °C but declined at 30 °C. Goldfish exhibited diurnal activity at all temperatures except 25 °C, where nocturnal behaviour predominated. Both body length and population size positively influenced turbidity production. Groups of a few large fish produced significantly more turbidity than groups of many small fish of equal biomass. Biomass was therefore a poor predictor of the level of turbidity, making it difficult to predict the impact of goldfish upon multispecific pond communities following successful colonization.