Lawrence J. Buckley, Elaine M. Caldarone, Kathleen R. Lindner, and R. Gregory LoughWe estimated recent growth rates of cod and haddock larvae on Georges Bank from data on biochemical composition of larvae collected each spring between 1992 and 1995, coupled with a model relating temperature, RNA/DNA ratio and larval growth. We used a second regression model relating temperature, growth and starvation mortality to estimate mortality rates arising for sources other than predation. Both models were derived from data on laboratory reared larvae. Additionally, the prevalence of starvation mortality was estimated from the distributions of RNA/DNA ratio values of field sampled larvae. Estimates of minimum RNA/DNA ratio values just prior to death due to starvation were derived from laboratory observations. Growth and starvation mortality were evaluated in reference to larval size, location, water mass characteristics, Julian day, and year.
Two hypotheses were addressed:
To address the second hypothesis we assumed that growth was a function of temperature and prey availability. Estimates of maximum growth rates for a given temperature were derived from laboratory, mesocosm and field estimates of larval growth. These hypotheses are critical to understanding the processes that determine recruitment variability of cod and haddock on Georges Bank.