Workshop on Age Reading of European and American Eel (WKAREA)

• Other Authors: CEMAGREF BORDEAUX UR EPBX FRA
• Format: Other/Unknown Material
• Language: English
• Published: 2009
• Subjects: ANGUILLA ANGUILLA; OTOLITHE; AGE; STATOLITHS; Anguilla anguilla
• Online Access: https://irsteadoc.irstea.fr/cemoa/PUB00028463

A cooperative effort lead to the collection of a large European length-at-age dataset (N = 43993, 15 countries) for eel, covering almost one century (from 1913 to 2006) and the fitting of a global growth model at the scale of the species distribution area (Lat. 36-61 Long. 10W-27E). The whole dataset was randomly divided into a calibration dataset (two third) and a validation dataset (one third). A Generalized Additive Model was designed to predict eel length as a function of age. A procedure of model selection was applied to select the best predictors among sex, age of the fish, protocol of age estimation, temperature parameters (means, minimums, maximums, cumulated temperatures), habitat parameters (depth, tide, salinity, distance to the sea) and the period of the century. The model predicted eel length with a good accuracy. Sex and habitat had the greatest predictive power in the model, before cumulated temperature and protocol. Growth was faster in habitats close to the sea and in deep habitats. Within the range tested, temperature had a positive effect on eel growth. The investigation of the effect of the period of the century revealed an interesting pattern with an eel growth increase during the 1960-1980 period.