δ13C and δ15N in yellow and silver eels (Anguilla anguilla, 1758) from different Mediterranean local stocks and their variation with body size and growth

2021 ◽  
pp. NULL
Author(s):  
F. Capoccioni ◽  
C. Leone ◽  
F. Giustini ◽  
M. Brilli ◽  
L. Buttazzoni ◽  
...  
2018 ◽  
Vol 14 (7) ◽  
pp. 20180269 ◽  
Author(s):  
Kazuki Yokouchi ◽  
Françoise Daverat ◽  
Michael J. Miller ◽  
Nobuto Fukuda ◽  
Ryusuke Sudo ◽  
...  

Many diadromous fishes such as salmon and eels that move between freshwater and the ocean have evolved semelparous reproductive strategies, but both groups display considerable plasticity in characteristics. Factors such as population density and growth, predation risk or reproduction cost have been found to influence timing of maturation. We investigated the relationship between female size at maturity and individual growth trajectories of the long-lived semelparous European eel, Anguilla anguilla . A Bayesian model was applied to 338 individual growth trajectories of maturing migration-stage female silver eels from France, Ireland, the Netherlands and Hungary. The results clearly showed that when growth rates declined, the onset of maturation was triggered, and the eels left their growth habitats and migrated to the spawning area. Therefore, female eels tended to attain larger body size when the growth conditions were good enough to risk spending extra time in their growth habitats. This flexible maturation strategy is likely related to the ability to use diverse habitats with widely ranging growth and survival potentials in the catadromous life-history across its wide species range.


1985 ◽  
Vol 26 (1) ◽  
pp. 37-41 ◽  
Author(s):  
O. Haraldstad ◽  
L. A. Vollestad ◽  
B. Jonsson

2011 ◽  
Vol 95 (1) ◽  
pp. 264-267 ◽  
Author(s):  
C. Vinagre ◽  
C. Máguas ◽  
H.N. Cabral ◽  
M.J. Costa
Keyword(s):  

<em>Abstract.—</em>To evaluate mortality factors and potential mitigative measures during downstream passage of silver European eel Anguilla anguilla in the River Meuse, an integrated study was performed consisting of: 1) telemetric experiments where the descent of 150 transpondered eels was tracked at 14 detection stations; 2) monitoring daily commercial catches; 3) testing a system to predict migration events from activity of captive eels in riverside tanks (the Migromat system); and 4) measuring turbine mortality by netting eels at turbine outlets. Migromat systems installed at two hydropower stations predicted 41 migration events. Most warnings (58.5%) were false positives, but Migromat failed to predict only one migration event. Mortality of eels passing through a turbine at the Linne Hydropower station was 24%. However, part of the downstream migrating population bypassed the turbines by descending over adjacent weirs. Descending eels moved primarily in brief pulses that were associated with increasing discharge and especially during the first half of the night. Thirty-seven percent of transpondered eels released at Ohé en Laak reached the sea. Because both fisheries mortality (estimated at 22–26% by fishing recoveries) and hydropower mortality (estimated at 16–26%) were considerable, a reduction in fisheries harvest and implementation of turbine management by application of the Migromat warning system would substantially increase escapement of silver eels from the River Meuse.


2011 ◽  
Vol 69 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Fabien Charrier ◽  
Virgile Mazel ◽  
Jean-Marie Caraguel ◽  
Yann Abdallah ◽  
L. Laëtitia Le Gurun ◽  
...  

Abstract Charrier, F., Mazel, V., Caraguel, J-M., Abdallah, Y., Le Gurun, L. L., Legault, A., and Laffaille, P. 2012. Escapement of silver-phase European eels, Anguilla anguilla, determined from fishing activities in a Mediterranean lagoon (Or, France). – ICES Journal of Marine Science, 69: 30–33. Escapement of silver eels from a Mediterranean lagoon was estimated by a capture–tagging–recapture and automated tag-reading study. The population of silver-phase eels in the lagoon was estimated to be 13.2 kg ha−1, with an escapement rate from the commercial fishery of 76.8%.


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