A multivariate approach to the spatial and temporal water characterization parameters at the tropical Sontecomapan Lagoon, Mexico

Résumé 0

Sontecomapan is a coastal lagoon in the Gulf of Mexico Southeast which, altough small, due to its geomorphological characters has a complex behaviour. Four surveys were performed: in March and September 2009, and January and June 2010, which comprehend the three climatic seasons of the region, north wind-influenced, dry season and rainy season. Ten sampling points were selected for the measurement of physical, chemical and biological (chlorophyll a) parameters, which included the main environments found at this lagoon. These data were analysed through a multivariate approach. Sontecomapan was hypereutrophic based on total phosphorus (geometric means 0.202 to 0.386 mg L-1), while it was oligotrophic for chlorophyll a (geometric means 0.40 to 2.08 mg m-3). Comparison with chlorophyll a values reported for Sontecomapan since the early 1990’s, show that the data presented here are the lowest for the period and this seems to be related to an increase in the flushing of plankton to the sea. An ordination by principal component analysis showed that for the period reported here, soluble reactive phosphorus and ammonium were negatively correlated or independent from salinity, so these nutrients originated either from streams or runoff. The ordination also confirmed that Sontecomapan can be divided into mesohaline, polyhaline and euhaline zones, with Arroyo La Palma as an independent point.