Abstract
A simulation study of the influence of variations in food and predator abundance on growth and survival of larval fish was conducted to determine whether changes in the abundance of either variable could be detected from analysis of size frequency data or from growth histories. The results indicate that estimates of the mean and variance in size frequency distribution would have to be very precise to detect changes in predator abundance. The mean and variance in individual growth rates appear to be useful tools to determine whether changes in predator or food abundance are influencing larval fish survival. As food abundance increases, the mean and variance in growth rates increase. However, as predator abundance increases, the variance in growth rates, for any given mean, decreases.