Mesoscale dynamics and yellofin tuna catches in the Mexican Pacific

• Published in: Ciencias marinas Vol. 31; no. 4; pp. 671 - 683
• Main Authors: Torres Orozco, E, Trasvina, A, Muhlia Melo, A, Ortega Garcia, S
• Format: Journal Article
• Language: English; Spanish
• Published: 01.03.2005
• Subjects: Marine; Thunnus; Thunnus albacares; ISE, Mexico, Jalisco, Marias I; ISE, Mexico, Jalisco, Cabo Corrientes; ISE, Mexico, California Gulf; PSE, Australia, Tasmania, Maria I
• ISSN: 0185-3880

Catch data of the yellowfin tuna (YFT) fishery were used to study the relationship between the seasonal and spatial variation of YFT with or without the presence of mesoscale structures at the entrance to the California Gulf (19 degree -24 degree N, 104 degree -112 degree W). The YFT catches were distributed over the continental shelf and around islands and seamounts. High concentration sets of YFT occurred throughout the year around the Maria islands and Cabo Corrientes, in March and June. A warm (>28 degree C) coastal jet with a width of 1.5 Rossby radius (~20.6 Km) was observed off Cabo Corrientes during Feb and Apr, covering all the continental shelf off Cabo Corrientes. The jet moved at an average speed of 0.31 m s super(-1) and extended northwards to the Roca Corbetera seamount. The interaction with cooler water generated a frontal zone around which the YFT catches were concentrated. During March the wind was favorable for the development of coastal upwelling off Cabo Corrientes. Was observed an upwelling region with sea surface temperature of 18 degree C and an offshore width of about a 3.7 Rossby radius of cold water that covered some 2600 Km super(2). The YFT catches occurred in warmer water north of the upwelling zone.