Temporal dynamics of Trichodesmium erythraeum (Cyanophyta) in the National Park "Sistema Arrecifal Veracruzano" in the Gulf of Mexico.

ABSTRACT

Trichodesmium erythraeum Ehrenberg ex Gomont is a microalga worldwide distributed in tropical seas. This filamentous microalga was detected in phytoplankton samples collected in the Protected Natural Area “Parque Nacional Sistema Arrecifal Veracruzano”, and because of its ecological importance, its temporal dynamics was studied using net samples (30 Cm) collected in one year period. Samples were studied with a light microscope recording the presence, morphological characteristics, life form and relative abundance. Trichodesmium erythraeum occurred as single filaments and was rare in April 2007 and March 2008; as single filaments from May to August and December 2007; as single filaments and small aggregates in September 2007 and January 2008; in aggregates of large size (> 3 mm) and high relative abundance in October 2007; and was absence in November 2007 and April 2008. Although the relative abundance of the species was not important comparing with other members of phytoplankton, its occurrence was frequent with a bloom at the beginning of the north winds period. The observed temporal dynamics of this microalga in this coral reef region comes up on the alert in the monitoring red tides programs being implemented in Veracruz coast.