Distribution pattern of anchovy abundance and biomass in Division IXa from research surveys in 2007 and 2008.

Abstract

A total of 4 acoustic surveys (3 Portuguese and 1 Spanish) rendering seasonal estimates of anchovy abundance, either for almost the whole Division IXa (spring and autumn Portuguese surveys) or only for the Subarea IXa South (Algarve + Gulf ofCadiz areas, early summer Spanish survey), were carried out during 2007 and the first half in 2008. In the November 2007 ICES WGACEGG meeting was presented - after detecting some computational errors - a corrected version of the estimates from the early summer 2007 Spanish survey previously provided to the September 2007 WGMHSA meeting. Anchovy total estimates from these surveys with indications of its general distribution patterns were as follow: Portuguese surveys surveying almost the whole Division (except Subarea IXa North): -PELAGO07(2007 Spr. Port. Surv.): 3247 million fish; 40.0 thousand tonnes. Most of anchovy in Gulf of Cadiz. Present but relatively scarce in front of Lisbon. -SAR07NOV (2007 Aut. Port. Surv.): 1921 million fish; 24.8 thousand tonnes. Most of anchovy in Gulf of Cadiz. Present but relatively scarce in front of Lisbon. -PELAGO08 (2008 Spr. Port. Surv.): 2353 million fish; 39.7 thousand tonnes. Most of anchovy in Gulf of Cadiz. Present but relativelyscarce in front of Lisbon and in northernmost coastal waters denoting a northernwards expansion of the population in the Division. Spanish survey surveying the Subarea IXa South only: -ECOCÁDIZ 0707(2007 Summ. Sp. Surv.): 1790 million fish; 28.9 thousand tonnes. Anchovy all over the Gulf of Cadiz, also widely distributed through the Algarve, but mainly concentrated in the Spanish waters.