Can the physical and chemical characteristics of water affect the abundance of macroinvertebrates in an aquatic environment?

Abstract

The aim of this work was to assess if variation in the abundance of macroinvertebrates is influenced by the physical and chemical characteristics of water during a nycthemeral cycle in the dry and wet seasons. This study took place in a lake with low connectivity to the Paranapanema River, São Paulo, Brazil. Dissolved oxygen, pH, conductivity, temperature of surface water, and depth were measured at  6 hour intervals, and the macroinvertebrates were sampled in stands of Salvinia auriculata, in July 2006 and April 2007. The Canonical Correlation Analysis (CCA) was used to analyze abiotic factors, abundance of the macroinvertebrates, and sampling period. Ceratopogonidae, Chironomidae, Coleoptera, Culicidae, Odonata, and Oligochaeta were the most abundant taxa in the dry season, while Ephemeroptera, Gastropoda, Hemiptera, Hydracarina, Nematoda, Ostracoda, and pupae of Diptera were the most abundant taxa in the wet season. The CCA showed that in the dry season there was a positive correlation between the abundance of Ceratopogonidae, Chironomidae, Coleoptera, Culicidae, Odonata, and Orthoptera and dissolved oxygen and a negative correlation with surface water temperature and depth. We concluded that there was a positive variation in the abundance of Chironomidae, Ceratopogonidae, Coleoptera, Culicidae, Odonata, and Orthoptera and oxygen dissolved and, a negative variation with surface water temperature and depth in the dry season during the nycthemeral cycle.