Abstract

The distribution and dispersion of ichthyoplancton collected in the North Yucatan Shelf during four oceanographic research were analized, each one representing the climatic seasons: September (autumn) and November (winter) of 2003, April (spring) and July (summer) of 2004. Forty-three stations were covered in average during the campaigns. A total of 13,155 larvae of fish were captured, being the Clupeidae family the most abundant in the sampling area. The maximum abundance was observed during the spring; this agrees with the time at which most of the coastal fishes tend to spawn, this was associated with the maximum intensity of the upwelling. Also, during this season, several sites were observed with high concentration of larvae; whereas in summer a similar distribution pattern was observed, but it was of less intensity and the greater concentrations tend to disperse in the direction of the coastline. On the other hand, during the autumn the influence and intensity of the upwelling were less, thus the larvae are associated with the greater amount of food available (zooplankton biomass) and the abundance diminishes in comparison with summer, this is mainly because of a minor number of species that spawn during this period. Finally, during the winter is when the upwelling has its minimum influence on the study area and the distribution of the abundance of the larvae was uniform but scarce in comparison with the other seasons. The graphs of continuous distribution of the abundance of ichthyoplancton indicate that the larvae of fish were influenced by the upwelling phenomenon and that the direction of the Yucatan Current also influences in the dispersion of these organisms mainly in spring and summer, whereas for autumn and winter the movement is favored by the subsurface water of this current

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