The incidence of SST and SSTA on the small pelagic catches from the Canary Islands

Abstract

The evolution of catches by month of mackerel (Scomber japonicus Houttuyn, 1782), round sardinella (Sardinella aurita Valenciennes, 1847), horse mackerel (Trachurus picturatus Bowdich, 1825), sardine (Sardina pilchardus Walbaum, 1792), flat sardinella (Sardinella maderensis Lowe, 1838) and anchovy (Engraulis encrasicolus Linnaeus, 1758) in areas located north and south of Tenerife and Gran Canaria (Canary Islands) during 2005 and 2006 and monthly satellite-derived sea-surface temperature (SST) and oscillations of sea surface temperature anomalies (SSTA) were analysed together, trying to detect analytically changes in the oceanographic conditions tha t may affect the level of catches. Annual mean value of SST from 1982 to 2006 around the Canary Islands waters showed an increase of temperatures from 1994, reaching a maximum in 1997. After this period, in 2000 a decrease was observed, followed by a new increase, reaching in 2006 the maximum value in the whole series. In 2005 and 2006 lower SST values were observed in February−March (18.0º C−20.0º C) and in September−October (23.5º C−25.0º C) the greatest. With the exception of January and February 2005, SSTA values were always positive. An inverse relationship was noted between catch-index (CI) and SSTA series. Increments of CI were associated with negative SSTA events and vice versa, always with some lag of time. Certain stability of SSTA coincided with the lowest CI values along the studied period.