Original paper
Effects of urban spatial and temporal heterogeneity on benthic macroinvertebrate and diatom communities
Saffarinia, Parsa; Anderson, Kurt E.; Palenscar, Kai T.
Fundamental and Applied Limnology Volume 196 Nr. 1 (2022), p. 57 - 73
77 references
published: Nov 2, 2022
published online: Sep 16, 2022
manuscript accepted: Sep 1, 2022
final revised version received: Aug 30, 2022
manuscript revision requested: Aug 28, 2022
manuscript received: Jun 21, 2022
Open Access (paper may be downloaded free of charge)
Abstract
Water quality, distribution, and flow are often highly altered in rivers in urban watersheds, subjecting aquatic communities in the environment to novel spatial and temporal heterogeneity. An understanding of how novel spatial and temporal heterogeneity impacts aquatic communities is of paramount concern since these taxa are foundational to the urban food web. In this study, we documented the effects of flow perturbations on benthic macroinvertebrate and diatom communities relative to wastewater treatment plant outflows in a transect of an urbanized river in Southern California, USA. In particular, we analyzed trends in the richness and density of diatom and benthic macroinvertebrate communities in relation to novel flow heterogeneity introduced by wastewater treatment plants and urban storm runoff events. We found that diatom density decreased after a disturbance but quickly returned to its pre-disturbance levels, while the benthic macroinvertebrate community showed minimal shifts in composition and density after the disturbance, yet the sites had low richness of predominantly tolerant taxa. The locations of wastewater treatment plant outflows were found to exert a constant negative effect on density and richness in both communities. These results have implications for the conservation of endangered fish species in the urban Santa Ana River that depend on a thriving basal food web for survival.
Keywords
disturbance • effluent • benthic macroinvertebrates • diatoms • heterogeneity