Background:

Due to the lack of knowledge of the normal variation of the physicochemical and biological water parame ters of Mexican coastal systems for classifying their trophic condition, some researchers have categorized these environ ments using norms, standards, or regulations created for environments of other climatic, geological, and social characte ristics, different from those of Mexico; in fact, these values have even been compared with Mexican norms developed for urban or industrial wastewater discharged into rivers and coastal lagoons. The concentration ranges of different chemical elements, methodologies, units, and interpretations of other countries’ regulations are not similar to the conditions of the coastal waters of tropical latitudes and, therefore, their results do not adequately reflect the reality of national coastal aquatic environments.

Goals:

Contribute to the knowledge of the normal spatiotemporal ranges of physicochemical and biological parameters in lagoons, estuaries, marshes, and Mexican bays.

Methods:

We conducted an extensive search of information that allowed us to determine normal ranges of variation for the following parameters: oxygen, nutrients (nitrogen and phosphorus) and phytoplankton biomass (chlorophyll a), which have ecological significance, and can even be considered by some as indicators of water quality.

Results:

We include the average, minimum, and maximum values of different variables of 72 coastal environments in Mexico based on studies carried out from 1968 to 2015.

Conclusions:

The analysis of the information showed that the intervals are the result of local environmental characteristics that are unique for each system. This information will be helpful in the analysis or diagnosis in future environmental studies, and will avoid the use of foreign standards based on different environmental and socioeconomic characteristics.