Survival and growth of European eels stocked as glass and farm sourced eels in five lakes in the first years after stocking

• Published in: Ecology of Freshwater Fish
• Main Authors: SIMON Janek, DOERNER Hendrik
• Language: English
• Published: WILEY-BLACKWELL 2014
• Subjects: Anguilla anguilla
• Online Access: https://publications.jrc.ec.europa.eu/repository/handle/JRC74133; http://onlinelibrary.wiley.com/doi/10.1111/eff.12050/abstract; https://doi.org/10.1111/eff.12050

European eels Anguilla anguilla stocked as wild-sourced glass eels showed a better overall performanceof growth and survival compared with farm-sourced eels after stocking in five isolated lakes within a 7-year studyperiod. Eels stocked as farm eels lost their initial size advantage over eels stocked as glass eels within 3–5 yearsafter stocking. Population sizes estimated for consecutive stocking batches indicated that 8–17% of eels stocked asfarm eels survived 3–6 years after stocking compared with 5–45% of eels stocked as glass eels. This study coupledwith results of previous studies suggests that stocking of farm eels may have no advantage in growth and survivalcompared with stocking of glass eels if stocking occurs at an optimal time in spring. In addition, the use ofrelatively expensive farm eels may provide no general advantage over stocking of glass eels. However, if glass eelsare only available for stocking purposes very early in the year, lower survival rates than obtained in the presentstudy can be assumed and stocking with relatively more expensive farm eels could possibly be a better option. JRC.G.4 - Maritime affairs