New protocol to avoid bias in otolith readings of Atlantic bluefin tuna juveniles
dentification of the first annual increments in otoliths of Atlantic bluefin tuna juveniles is difficult due to the frequent appearance of numerous sub-annual bands which can be easily misinterpreted. Instead, the pattern of deposition of the annuli on the first dorsal fin rays (spines) is very dist...
| Autores: | , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/326112 |
| Acceso en línea: | http://hdl.handle.net/10261/326112 |
| Access Level: | acceso abierto |
| Palabra clave: | Pesquerías Age estimation Sede Central IEO Reading criteria Otolith spine Thunnus thynnus |
| Sumario: | dentification of the first annual increments in otoliths of Atlantic bluefin tuna juveniles is difficult due to the frequent appearance of numerous sub-annual bands which can be easily misinterpreted. Instead, the pattern of deposition of the annuli on the first dorsal fin rays (spines) is very distinct during the first years. Furthermore, the bias vector for correcting otoliths age, and developed from paired otolith-spine samples, allowed a better tracking of cohorts in the 2017 assessment. With this background, 262 paired structures with identical age estimates were used to revise reading criteria for annual increments of juvenile bluefin otoliths and to create a template. A table with first annuli measurements was built to serve as a reference and help identifying the first otolith annual bands. For this, it was necessary to establish the location of origin of the measurements (anchor point) and define them. In addition, otoliths from this set of paired structures can be used as a collection that will serve to test the new reading criteria and template. |
|---|