Growth studies on Norway lobster, Nephrops norvegicus (L.), in different areas of the Mediterranean Sea and the adjacent Atlantic

A comparative study of the growth of Nephrops norvegicus among different ar eas in the Mediterranean Sea and the adjacent Atlantic was conducted. MIX a nd Bhattacharya's length-based methods were used for age determination. Bot h methods were used for all the studied areas. For the estimation of the gr owth parameters two non-linear methods, based on the results of the length frequency analysis, were used; the Gauss-Newton method, implemented by the SAS program, was applied using the results of the MIX and the FISHPARM prog ram using the results of the Bhattacharya's method. The identification of t he age groups and their mean lengths-at-age as well as the estimation of th e growth parameters proved to be difficult. A question regarding the adequa cy of the von Bertalanffy model was also posed. Remarkable differences were obvious between sexes in the number of identified age groups and their mea n lengths-at-age as well as in their growth parameters in all areas. The co mparison of the results obtained for the studied areas showed differences, which could not be considered very important except in the case of the Neph rops population of the Alboran Sea, which was characterised by a high growt h rate. All other areas seemed to be close; among them the populations from Euboikos Gulf and Catalan Sea being the most different.