We evaluated the taxonomic and functional diversity of zooplankton associated with macrophytes and in the open water zone of two shallow urban canals in the Xochimilco Wetlands in Mexico City, the Cuemanco Canal and the Virgilio Uribe Rowing and Canoeing Canal. Based on previous studies the chemical and biological indicators determine these as eutrophic systems. Zooplankton (rotifers, cladocerans, and copepods) were sampled every month in zones dominated by Typha latifolia, Eichhornia crassipes, or Schoenoplectus americanus. Physical and chemical variables (temperature, Chlorophyll-a, pH, dissolved oxygen, and nutrients, among others) as well as the biomass and size of the dominant zooplankton species, were measured at each site. Differences in environmental parameters and phytoplankton composition were associated with changes in zooplankton community structure. Macrophyte zones supported greater zooplankton diversity compared with the open water zone. Functional diversity indices revealed the dominance of microphagous rotifer species, as has been previously reported in eutrophic waters. This study confirms the key role of macrophytes in maintaining zooplankton diversity despite eutrophic conditions. Environmental factors and phytoplankton composition influence zooplankton community structure and ecosystem functioning under these eutrophic conditions.
Figueroa-Sánchez et al. (Mon,) studied this question.