Estimation of growth parameters from published data for several Mediterranean fishes

Abstract

Summary Two sets of von Bertalanffy growth parameter (VBGP) estimates are provided for several Mediterranean fish stocks. All estimates are based on the non-linear least square regression and accompanied by uncertainty measures (i.e. standard errors). The first set consists of growth parameters estimated from 73 published length-at-age data with no previous VBGP estimations; in this case, fitting was possible for 30 length-at-age sets, corresponding to 22 species, two estimates of which (Mycteroperca rubra and Myctophum punctatum) are the first for the Mediterranean. The second set refers to the re-estimation of VBGPs from 69 published length-at-age data with available original VBGP estimates derived from linear methods (i.e. Ford-Walford, von Bertalanffy and Gulland-Holt plots); in this case, fitting was possible for 50 sets. Overall VBGP estimation was not possible for 43 and 19 cases for the first and second sets, respectively. This was because either (a) <4 mean length-at-age data were available, or (b) fitting was not possible because of an exponential or a very slow linear increase of length with age, or (c) estimates were unrealistic (i.e. Lmax/L∞ < 0.7) mainly because of unrealistic length-at-ages and/or insufficient sampling of older individuals. These estimations and re-estimations enrich the available data on growth parameters of Mediterranean fishes, both in terms of quantity and quality of information.