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Predicting downstream migration of silver eels in a large river catchment based on commercial fishery data
Author(s) -
DURIF C. M. F.,
ELIE P.
Publication year - 2008
Publication title -
fisheries management and ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 55
eISSN - 1365-2400
pISSN - 0969-997X
DOI - 10.1111/j.1365-2400.2008.00593.x
Subject(s) - hydroelectricity , environmental science , fishery , drainage basin , downstream (manufacturing) , fish migration , geography , spatial distribution , ecology , biology , fish <actinopterygii> , cartography , operations management , remote sensing , economics
Worldwide, populations of catadromous eels are in decline. Knowledge on downstream migration patterns is needed to mitigate damage caused by hydroelectric stations. Silver eel migration and its relation with environmental factors were investigated using data from a fishery located in the lower reaches of a large catchment (110 000 m 2 ). Migration days, indicative of different proportions (50%, 75% and 95%) of the annual run of eels (i.e. represented by the annual catch), were predicted using discriminant analyses. Efficiency of prediction was 58–95% depending on the proportion of the run targeted. The onset of migration was correlated with sunshine hours, August temperature and discharge. Julian days (i.e. photoperiod) was significantly correlated with migration days, indicating between‐year similarity in the dynamics of the runs. The size of migrants varied within the migration season, reflecting differences in their initial spatial distribution.