Long‐term tagging of elvers, Anguilla anguilla, with radioactive europium

• Published in: Journal of Fish Biology
• Main Authors: Hansen, H. J. M., Fattah, A. T. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1986
• Subjects: Anguilla anguilla
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1986.tb04970.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1986.tb04970.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1986.tb04970.x

Elvers were labelled with 152 Eu and 155 Eu. Optimum conditions turned out to be incubation for 3 h at 15°C in artificial sea water containing 2% NaCl and 0.1% KCl, EuCl 3 at 1 mCi (37 MBq) 1 −1 and an eel concentration of about 15%. Laboratory experiments pointed to a biological half‐life of added europium of 1.6–0.5 years. Thirteen hundred 155 Eu‐labelled elvers (50 Bq per eel), each weighing on average 0.21 g, were set out near Oskarshamn on the east coast of Sweden in June 1982. Three of these were caught nearby in May 1985 and one was caught in August 1985. They weighed then on average 56 g and showed no significant loss of label other than the physical half‐life (5.1 years). All the radioactivity was found in bone tissue.