| Summary: | The spawning stock biomass (SSB) of the Atlantic Iberian sardine (stock pil.27.8c9a, ICES divisions 8c and 9a) has been estimated using the Daily Egg Production Method (DEPM) since the late 90s. The surveys and analyses are internationally coordinated in the framework of ICES-WGACEGG where IEO (Instituto Español de Oceanografía, Spain) and IPMA (Instituto Português do Mar e da Atmosfera, Portugal) are represented. Every three years the two institutes conduct a coordinated survey covering the Iberian shores. The Portuguese campaign surveys the waters from the entrance of the Strait of Gibraltar to the border of Portugal and Galicia (ICES area 9a), while the Spanish survey monitors the northern area of the stock from the border, at river Minho, to the south of the Armorican shelf in French waters (ICES areas 9a North and 8c). The DEPM surveys comprise ichthyoplankton, fish and hydrographic sampling. Plankton samples are collected, along a grid of parallel transects perpendicular to the coast, for spawning area estimation and daily egg production calculation. Concurrently, fishing hauls are carried out for estimation of daily fecundity (sex ratio, female weight, batch fecundity and spawning fraction) for the mature sardines in the population. This working document provides a description of the Portuguese survey, including the laboratory analyses and estimation procedures used to obtain the egg and adults parameters for the 2020 DEPM.
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