Allison Creek Dam Removal and Stream Restoration Near Valdez Alaska

Dam removal is an increasingly common stream restoration tool. Yet, removing dams from small streams also represents a major disturbance to rivers that can have varied impacts on environmental conditions and aquatic biota. We examined the effects of dam removal on the structure, function, and composition of benthic macroinvertebrate (BMI) communities in a temperate New England stream. We examined the effects of dam removal over the dam removal time-series using linear mixed effects models, autoregressive models, non-metric multidimensional scaling, and indicator and similarity analyses. The results indicated that the dam removal stimulated major shifts in BMI community structure and composition above and below the dam, and that the BMI communities are becoming more similar over time. The mixed model analysis revealed that BMI functional groups and diversity were significantly influenced by sample site and several BMI groups also experienced significant interactions between site and dam stage (P < 0.05), while the multivariate analyses revealed that community structure continues to differ among sites, even three years after dam removal. Our findings indicate that stream restoration through dam removal can have site-specific influences on BMI communities, that interactions among BMI taxa are important determinants of the post-dam removal community, and that the post-dam-removal BMI community continues to be in a state of reorganization.

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Evaluating Stream Restoration Options after Dam Removal Using HEC-RAS

Building Partnerships ◽

10.1061/40517(2000)345 ◽

2000 ◽

Author(s):

Michael E. Barber ◽

Dwight E. Perkins

Keyword(s):

Stream Restoration ◽

Dam Removal

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Prioritizing dam removal and stream restoration using critical habitat patch threshold for brown trout (Salmo truttaL.): a catchment case study from Sweden

Ecoscience ◽

10.1080/11956860.2017.1386523 ◽

2017 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Johan Törnblom ◽

Per Angelstam ◽

Erik Degerman ◽

Carl Tamario

Keyword(s):

Brown Trout ◽

Stream Restoration ◽

Dam Removal ◽

Habitat Patch ◽

Critical Habitat

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Response of benthic macroinvertebrates to dam removal in the restoration of the Boardman River, Michigan, USA

10.1101/2020.12.22.423935 ◽

2020 ◽

Author(s):

David C. Mahan ◽

Joel T. Betts ◽

Eric Nord ◽

Fred Van Dyke ◽

Jessica M. Outcalt

Keyword(s):

Community Composition ◽

Stream Restoration ◽

Dam Removal ◽

Total Density ◽

Macroinvertebrate Communities ◽

Mixed Effect ◽

Taxa Richness ◽

Before And After ◽

Stream Macroinvertebrate ◽

New Zealand Mud Snail

AbstractDam removal is an increasingly important method of stream restoration, but most removal efforts are under-studied in their effects. In order to better understand the effects of such removals on the stream ecosystem, we examined changes in stream macroinvertebrate communities from 2011-2016 above, below, and before and after the October 2012 removal of the Brown Bridge Dam on the Boardman River in Michigan (USA), and to new channel sites created in its former reservoir (2013-2015). Using linear mixed-effect models on the percent abundance of ecologically sensitive taxa (% Ephemeroptera, Plecoptera, Trichoptera (EPT)), total density of all macroinvertebrates, and overall taxa richness, along with multivariate analyses on the community matrix, we examined differences in community composition among sites and years. EPT declined downstream of the dam immediately after dam removal, but recovered in the second year, becoming dominant within 2-4 years. Downstream sites before removal had different community composition than upstream sites and downstream sites after removal (p<0.001), while upstream and downstream sites after removal converged towards similarity. New channel (restored) %EPT, density, and taxa richness were not different from upstream sites in any year following removal, but new channel sites were the most distinct in community composition, possessing multiple indicator taxa characteristic of unique new conditions. The invasive New Zealand mud snail (Potamopyrgus antipodarum) was absent from all sites prior to dam removal, but appeared at low densities in upstream sites in 2013, had spread to all sites by 2015, and showed large increases at all sites by 2016. Managers employing dam removal for stream restoration should include post-removal monitoring for multiple years following removal and conduct risk analysis regarding potential effects on colonization of invasive invertebrate species.

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Response of benthic macroinvertebrates to dam removal in the restoration of the Boardman River, Michigan, USA

PLoS ONE ◽

10.1371/journal.pone.0245030 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0245030

Author(s):

David C. Mahan ◽

Joel T. Betts ◽

Eric Nord ◽

Fred Van Dyke ◽

Jessica M. Outcalt

Keyword(s):

Community Composition ◽

Stream Restoration ◽

Dam Removal ◽

Functional Feeding Groups ◽

Total Density ◽

Macroinvertebrate Communities ◽

Mixed Effect ◽

Taxa Richness ◽

Before And After ◽

New Zealand Mud Snail

Dam removal is an increasingly important method of stream restoration, but most removal efforts are under-studied in their effects. In order to better understand the effects of such removals on the stream ecosystem, we examined changes in stream macroinvertebrate communities from 2011–2016. Comparisons were focused above, below, and before and after the October 2012 removal of the Brown Bridge Dam on the Boardman River in Michigan (USA), as well as to new channel sites created in its former reservoir (2013–2015). Using linear mixed-effect models on the percent abundance of ecologically sensitive taxa (% Ephemeroptera, Plecoptera, Trichoptera (EPT)), total density of all macroinvertebrates, overall taxa richness, and Functional Feeding Groups, along with multivariate analyses on the community matrix, we examined differences in community composition among sites and years. EPT declined downstream of the dam immediately after dam removal, but recovered in the second year, becoming dominant within 2–4 years. Downstream sites before removal had different community composition than upstream sites and downstream sites after removal (p<0.001), while upstream and downstream sites after removal converged towards similarity. New channel (restored) %EPT, density, and taxa richness were not different from upstream sites in any year following removal, but new channel sites were the most distinct in community composition, possessing multiple indicator taxa characteristic of unique new conditions. The invasive New Zealand mud snail (Potamopyrgus antipodarum) was absent from all sites prior to dam removal, but appeared at low densities in upstream sites in 2013, had spread to all sites by 2015, and showed large increases at all sites by 2016. Managers employing dam removal for stream restoration should include post-removal monitoring for multiple years following removal and conduct risk analysis regarding potential effects on colonization of invasive invertebrate species.

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