Contribution of larval growth rate vairability to the recruitment of the Bay of Málaga anchovy (SW Mediterranean) during 2000-2001 spawning seasons

Abstract

Daily growth rates were estimated from larval anchovy (Engraulis encrasicolus) sampled in their main nursery grounds off the Bay of Málaga (SW Mediterranean) during the 2000 and 2001 spawning seasons. Significantly higher growth rates were observed in the 2001 larval population, representing a 20% increase through the larval size classes analysed. The decimated SW Mediterranean anchovy population experienced a successful anchovy recruitment during this year estimated at 13,000 tons for the Bay of Málaga by the acoustic evaluation of small pelagic resources. The size distribution of the recruited anchovy juveniles during 2000 and 2001 showed an increase of approximately 2 cm. Their corresponding anchovy spawning seasonality agrees with the estimates from the growth model fits of each year. Data on the environmental background for the two years sampled are provided by a historical quarterly monitoring project. Zooplankton showed a two-fold significant increase during July 2001, coastwise as well as offshore. No significant changes in surface temperature were observed between years. Instead of the usual summer spawning peak, anchovy peak spawning shifted towards early spring during the 2001 spawning season. The study provides evidence from field data on the relationships of larval growth variability and recruitment.