Estimation of biomass of horse mackerel (Trachurus trachurus L.) in northern-Spain ( Nortbern IXa and VIIIc ) using the daily egg production method.

• Main Authors: Porteiro-Lago, C. (Carmen), Motos, L. (Lorenzo), Franco-Fernández, C. (Concha), Pérez-Pérez, J.R. (José Ramón), Lucio, P. (Paulino)
• Format: Report
• Language: English
• Published: International Council for the Exploration of the Sea (ICES) 1993
• Subjects: North Atlantic; Northeast Atlantic
• Online Access: http://hdl.handle.net/10508/1630

In order to estimate the spawning stock biomass of horse mackerel in the North Atlantic Spanish waters, a series of egg and adult cruises were carried out by lEO (Instituto Español de Oceanografía) and AZTI -SIO (Instituto de Investigación y Tecnología para la Oceanografía, Pesca y Alimentación) . The survey was carried out from 23 April to 25 May 1992. A total of 627 plankton samples and 37 adults samples were collected. A total daily egg production of 3.3 X 1012 egg (SE = 7.26 X 1011 , CV = 0.22) was estimated for the whole area sarnpled (ICES Division Vlllc and subdivision northern IXa north). The estirnate of horse mackerel spawning biornass ranged from 486,549 tons (CV = 0.34, when using adult pararneter estirnates exclusively frorn the Spanish survey, down to 368,814 tn (C = 0.32), when alternatively using an estimate of relative batch fecundity from the southern region of horse rnackerel western stock.