EN PRENSA Influence of physicochemical parameters on phytoplankton distribution in the lagoon system of Mandinga, Mexico. EN PRENSA

In Mexico, coastal systems shelter a variety of wildlife, the distribution of phytoplankton will depend on the relationship of physicochemical parameters, availability of nutrients and the presence of phytoplankton species that control primary and fish productivity. Our objective was to determine the abundance of diatoms and dinoflagellates, and their relationship with physicochemical parameters in the lagoons system of Mandinga on the Mexico’s coast. Sample collection was performed monthly at five sites during windy and dry seasons. physicochemical parameters were recorded in situ . Samples to determine nitrates, phosphates, silicates, chlorophyll- a , and zooplankton also were collected. The samples were refrigerated at 4 °C and transported to a laboratory for analysis. The maximum means for the physicochemical parameters were mainly recorded during the months of March and April 2012. We identified 47 microalgae, 31 genera and 16 species; classifying three dinoflagellates and 28 diatoms. Some genera were known to produce Harmful Algal Blooms (HABs), and included Pseudo-nitzschia , which is a producer of the toxin domoic acid. Results from Canonical Correspondence Analysis (CCA) showed that the abundance and distribution of phytoplankton in the lagoon system of Mandinga accounted for 62.67% of the variance (p = 0.0001) in the physicochemical parameters: silicates, dissolved oxygen, salinity and temperature.