A revision of the daily egg production estimation methods, with application to Atlanto-Iberian sardine 1: daily spawning synchronicity and egg mortality estimates

Assumptions of daily spawning synchronicity and estimation of egg mortality for Atlanto-Iberian sardine are revised in the context of daily estimators of egg production. An extensive database of ichthyoplankton surveys from 1985 to 2008, aggregated at different levels, is used, a set of mortality mo...

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Detalles Bibliográficos
Autores: Bernal, M., Stratoudakis, Yorgos, Wood, S., Ibaibarriaga, Leire, Uriarte-Ramalho, Amaya, Valdés-Santurio, Luis, Borchers, D.
Tipo de recurso: artículo
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/325175
Acceso en línea:http://hdl.handle.net/10261/325175
Access Level:acceso abierto
Palabra clave:Centro Oceanográfico de Cádiz
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Descripción
Sumario:Assumptions of daily spawning synchronicity and estimation of egg mortality for Atlanto-Iberian sardine are revised in the context of daily estimators of egg production. An extensive database of ichthyoplankton surveys from 1985 to 2008, aggregated at different levels, is used, a set of mortality models is derived, and a comparison among them is carried out using standard statistical techniques. Analysis of the database shows Atlanto-Iberian sardine to be a late-evening spawner, in agreement with previous knowledge, but suggests a lengthier daily period of spawning. Comparison among the set of mortality models used suggests that estimates of mortality from single surveys for Atlanto-Iberian sardine are often unreliable, and that the mean estimates obtained after aggregating data from various years are statistically significant, more robust, and in line with existing information gathered from the literature.