Observations on blooms of Mesodinium rubrum in the upwelling area off Ecuador

Resumen

During January 1984, some upwelling water was found in the euphotic zone along the coast of ecuador from 1 degree 20'S to 2 degree 30'S. This water was characterized by a relatively low surface temperature of 23 degree C and the presence of Mesodinium rubrum . The concentration of chlorophyll a was between 0.50 and 1.37 mg/m super(3). Levels of phosphate, nitrate, ammonia and silicate fluctuated between < 0.03 to 0.35 mu g-at PO sub(4)-P/l, 0.6 to 3.5 mu g-at NO sub(3)-N/l, 1.0 to 6.0 mu g-at NH sub(4)-N/l, and 4.0 to 10.3 mu g-at SiO sub(4)-Si/l respectively. In February-March of the same year, a large scale "red tide" bloom of M. rubrum) developed, with dense patches, covering at area of one hundred square miles, though the organism was spread over more than two hundred miles along the coast.