A growth model that incorporates individual variability for the Norway lobster population (Nephrops norvegicus, L-1758) from the bay of Biscay

The growth of Norway lobster (Nephrops norvegicus) from the bay of Biscay w as modelled through the succession of moults and intermoult periods. First, parameters related to each of these processes were estimated for each sex and maturity stage. Moult increment was modelled as a linear function of ca rapace length, and regression parameters were estimated. For females, inter moult period was assumed to depend on maturity stage whereas for males it w as assumed to be constant throughout their life. Mean intermoult periods we re estimated from radiometric data. The estimations relied on bootstrap pro cedures that take into account both measurement error and individual variab ility. In a second step, 500 individual growth curves were simulated using previous parameter estimates. Finally, an age-length key was calculated fro m simulation outputs, yielding median age-at-length as well as correspondin g confidence interval. (C) 1999 International Council for the Exploration o f the Sea.