Comparing the Fish and Benthic Macroinvertebrate Diversity of Restored Urban Streams to Reference Streams

Abstract

Urbanization is associated with substantial losses to stream biological diversity throughout the United States' midAtlantic. Stream restoration has been used to improve stream conditions and, in part, to ameliorate these losses. However, the relationship between restoration and recovery of biological diversity is unclear. Our objective was to critically examine the efficacy of urban stream restorations with regard to biological diversity. We compared restored urban streams to urban nonrestored, nonurban, and reference (minimally degraded) streams using five measures each of fish and benthic macroinvertebrate diversity. Both multivariate and univariate statistical analyses show biological diversity of restored urban streams to be similar to nonrestored urban streams and lower than nonurban and reference streams. Restored urban sites showed no apparent increase in biological diversity through time, while diversity decreased at two of the reference streams coincident with increased urban development within their catchments. Our results indicate that restoration approaches commonly used regionally as in these urban streams are not leading to recovery of native stream biodiversity. Evidence from several sources indicates a need for dramatic changes in restoration approach, and we argue for a watershed-scale focus including protection of the least impacted streams and adopting other land-based actions within the watershed where possible.

Taxonomic, phylogenetic and functional diversity of leeches (Hirudinea) and their suitability in biological assessment of environmental quality

“…The negative impact of such factors on biological diversity of benthic invertebrates in freshwater environments is frequently assumed in numerous studies (e.g. Reice, 1985;Lorenz et al, 2004;Sánchez-Montoya et al, 2010;Stranko et al, 2012), but the lack of such direct effects was also found (e.g. Heino et al, 2007).…”

Agricultural Rivers at Risk: Dredging Results in a Loss of Macroinvertebrates. Preliminary Observations from the Narew Catchment, Poland

“…Preliminary results presented in this paper require replication, especially in terms of additional sampling of the same river stretches over time (months or years after dredging was implemented), and extension to other elements of the riverine environment in order to provide a comprehensive analysis of rivers' responses to dredging [22]. Extension of the research to, for example, the response of fish communities to dredging-induced changes in mesohabitat structure and macroinvertebrate composition would allow results to reveal the relevance of the maintenance of agricultural rivers to fishery management [23,24]. Research on these aspects is now ongoing.…”

Integrating Limiting-Factors Analysis with Process-Based Restoration to Improve Recovery of Endangered Salmonids in the Pacific Northwest, USA

“…Case studies have typically emphasized the poor success in achieving measurable biological gains solely through manipulation of physical habitat, particularly in the absence of any broader analysis of whether that habitat is truly limiting from a population perspective. Such outcomes have been reported from a variety of locations and watershed contexts, particularly channels in highly disturbed urban watersheds where altered flow regimes and water chemistry are typically as or more impacted than physical habitat (e.g., [6][7][8][9][10][11]; Figure 1). In less disturbed watershed settings, results are commonly more biologically successful, but rarely do they approach full recovery of the instream and biological conditions found in fully undisturbed settings (e.g., [12][13][14][15][16][17][18]).…”