Modelling the spatio-temporal distribution of age-1 Bay of Biscay anchovy (Engraulis encrasicolus) at spawning time

Autor: Leire Ibaibarriaga, Andrés Uriarte, Urtzi Laconcha, Miguel Bernal, María Santos, Marina Chifflet, Xabier Irigoien
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Scientia Marina, Vol 77, Iss 3, Pp 461-472 (2013)
Druh dokumentu: article
ISSN: 0214-8358
1886-8134
DOI: 10.3989/scimar.03851.05C
Popis: To efficiently manage and maintain fish stock abundance and age structure, it is necessary to understand variability in its spatial distribution. The main objective of this study was to describe the demographic structure of the Bay of Biscay anchovy during the main spawning period based on adult samples from 15 daily egg production method surveys. The proportion of age-1 individuals was modelled using generalized additive models with a binomial distribution and a logit link in relation to geographical and environmental covariates. The possibility of obtaining different models depending on the average age-1 proportion (low or high) was also explored. In general, age-1 individuals were found in shallow waters close to the coast, especially associated with the Gironde and Adour river plumes, whereas older individuals were prevalent on the shelf break and in oceanic waters. However, in years with a high age-1 proportion the younger individuals were also dominant in oceanic waters. These results could be used for management purposes, such as defining protected areas for particular age groups.
Databáze: Directory of Open Access Journals