Validation of age determination using otoliths of the European anchovy (Engraulis encrasicolus L.) in the Bay of Biscay
|Author(s)||Uriarte A.1, Rico I.1, Villamor B.2, Duhamel Erwan3, Duenas C.2, Aldanondo N.1, Cotano U.1|
|Affiliation(s)||1 : AZTI Tecnalia, Div Marine Res, Herrera Kaia Portualdea Z-G, E-20110 Pasaia, Spain.
2 : Inst Espanol Oceanog IEO, Promontorio San Martin S-N, E-39080 Santander, Cantabria, Spain.
3 : Inst Francais Rech & Exploitat Mer IFREMER, Lorient Stn, 8 Rue Francois Toullec, F-56100 Lorient, France.
|Source||Marine And Freshwater Research (1323-1650) (Csiro Publishing), 2016 , Vol. 67 , N. 7 , P. 951-966|
|WOS© Times Cited||7|
|Note||SI : Fish Otoliths as Indicators in Ecosystem Based Management|
|Keyword(s)||age estimation, checks, Engraulidae, otolith formation|
|Abstract||Validation of the age determination procedure using otoliths of European anchovy in the Bay of Biscay was achieved by monitoring very strong year-classes in successive spring catches and surveys, as well as the seasonal occurrence of edge types. Historical corroboration of the ageing method was obtained by cross-correlation between successive age groups by year-classes in catches and surveys (1987–2013). Summary annual growth in length is also presented. Yearly annuli consist of a hyaline zone (either single or composite) and a wide opaque zone, disrupted occasionally by some typical checks (mainly at age-0 and age-1 at peak spawning time). Age determination, given a date of capture, requires knowledge of the typical annual growth pattern of otoliths, their seasonal edge formation by ages and the most typical checks. Most opaque growth occurs in summer and is minimal (translucent) in winter. Opaque zone formation begins earlier in younger fish (in spring), and this helps distinguish age-1 from age-2+.|