Background:

One of the most severe problems in coastal systems is eutrophication. It is a process of anthropic origin that mainly increases the concentrations of nitrogen, organic matter, and/or phosphorus in bodies of water. The trophic index most used in Mexico to determine the state of coastal or marine systems is the TRIX index.

Goals:

To evaluate the trophic state of the Pom-Atasta (PA) and Palizada del Este fluvial-lagoon systems through the TRIX index.

Methods:

During different months from 2005 to 2014, water samples were collected at ten sampling sites for each fluvial-lagoon system to evaluate a number of physical variables (dissolved oxygen), chemicals (nitrogenous components and reactive phosphorus), and chlorophyll a, both on the surface andeat middle depths. The TRIX index was used to analyze the trophic state of the systems.

Results:

The PA and PE systems were characterized as oligotrophic systems with mesotrophic tendency.

Conclusions:

We recommend that the water quality and the magnitude of cholorophyll a at the Pom-Atasta and Palilzadadel Este systems continue to be monitoredain order to establish seasonal or annual trends of the trophic state of these systems.