ISSN: 2577-4050
Authors: Gárate-Lizárraga I, Verdugo-Díaz G and Okolodkov YB*
The Magdalena-Almejas Lagoon System is considered an area of interest both from biological and fishing points of view. This study deals with the variation of phytoplankton assemblages and total and partial cell abundance in three circadian cycles during the winter of 1989. The results obtained showed that there are short timescale changes (circadian rhythms) in water temperature, species composition, total and partial abundance, resulting from the tidal phase. Diatoms and dinoflagellates were the most abundant taxonomic groups. In total, 99 species and infraspecific taxa from 60 genera were found: 79 diatoms, 14 dinoflagellates, 2 cyanobacteria, 2 silicoflagellates, an ebridean and an euglenophyte. Proliferation of some diatom species, such as Eucampia zodiacus, Chaetoceros compressus, C. curvisetus, Coscinodiscus radiatus, Detonula pumila and the dinoflagellate Prorocentrum koreanum, was responsible for the maximal phytoplankton abundances, the alternating dominance of size fractions and the low species diversity. The remaining groups (cyanobacteria, silicoflagellates, ebrideans and euglenophytes) were not well represented either in number of species or abundance. In general, the high availability of food (phytoplankton) for sardine larvae during their reproductive period was noted; therefore, food is not a limiting factor for their development.
Keywords: Baja California Peninsula; Circadian Rhythm; Microphytoplankton; Phytoplankton blooms; Sardinops sagax; Upwelling
