Habitat in John’s Creek remained relatively unchanged following culvert replacement. The largest habitat change occurred at the crossing with the removal of a pool created from culvert discharge. Invertebrate assemblage showed a decrease in % dominance, however IBI scores did not detect a reach-scale improvement. It is possible that declines downstream are related to seasonal change or short-term bridge construction activit ies. Fish assemblages showed the largest improvement after culvert replacement, and verified movement of resident and migratory fishes through the new crossing. Thus, these findings indicate that the culvert replacement has restored river connectivity to John’s Creek.

The Nature Conservancy recently led an effort to replace 13 barrier crossings to restore connectivity to 35 river miles in the Two Hearted River Watershed. One such replacement was a perched culvert on John’s Creek, where the goal was to restore connectivity by replacing the poorly functioning culvert with a bridge. To evaluate the effectiveness of the culvert replacement, stream habitat, and fish and macroinvertebrate assemblages were evaluated before (July 2014) and after culvert (November 2014) replacement. Two 100-m reaches were identified, one above, and one below the crossing and sampled for fish stream habitat, macroinvertebrates, and fish. Prior to the culvert replacement, fish assemblages were only comprised of stream residents upstream, but also possessed YOY migratory fish downstream. Macroinvertebrate richness was low, and habitat was dominated by sand substrate. After culvert replacement, fish assemblages included resident and migratory fish both upstream and downstream. Additionally, fish with a downstream fin clip were found upstream of the crossing, indicating movement across the road-stream crossing. Macroinvertebrate assemblages showed little response, possibly due to temporary disturbances associated with construction activities. Overall, the results of this study indicate that The Nature Conservancy’s goal was met and fish now have access to the Two Hearted River watershed.

Changes in stream habitat and biota following a perched culvert replacement in John’s Creek, MI

Austin Wenke1, Emily Clegg2, and Ashley Moerke1 1School of Biological Sciences

Lake Superior State University, Sault Ste. Marie, MI 2The Nature Conservancy, Marquette, MI

Abstract

•  Michigan has 36,000 miles of streams with thousands of road-stream crossings; many of which may act as barriers and disrupt stream connectivity (Sargent and Carter. 1999)

•  Barriers alter natural sedimentation and flow regimes, resulting in degradation of habitat and loss of plant, macroinvertebrate, and fish diversity (Januchowski-Hartley et al. 2013)

•  The Nature Conservancy has been attempting to restore river connectivity in many watersheds, including the Two Hearted River in Michigan

•  John’s Creek previously contained a perched culvert which was one of the last remaining barriers in the Two-Hearted River watershed

Background Results

To evaluate changes in habitat and biotic assemblages after replacement of a perched culvert in John’s Creek (Two Hearted River watershed, Michigan).

Objective Conclusion

Methods

We would like to thank the National Fish and Wildlife Foundation, Sustain Our Great Lakes-Great Lakes Restoration Initiative for funding this project, The Nature Conservancy for logistical support, Nathan Sleight for help with identifying invertebrates, and LSSU students for assistance with sampling.

Januchowski-Hartley , P. B. McIntyre, M. Diebel, P. J. Doran, D. M. Infante, C Joseph and J. D.

Allan. 2013. Restoring aquatic ecosystem connectivity requires expanding inventories of both dams and road crossings. Frontiers in Ecology and the Environment 11:211-217

Sargent, M. S. and K. S. Carter. 1999. Managing Michigan wildlife: A landowners guide. Michigan United Conservation Clubs. pp. 297

Literature Cited

Acknowledgements

•  John’s Creek is a cold water headwater stream in the Two Hearted River watershed

•  Stream reaches 150 m in length were selected above and below the crossing

•  Habitat, macroinvertebrate, and fish data were collected before (July 2014) and after (Nov. 2014) above and below the crossing

•  Three macroinvertebrate samples were collected in each reach •  Identified to family •  Compared IBI scores (MDEQ Proc 51) using a paired t-

test •  Fish were collected using triple pass electrofishing •  Fish were given a unique fin clip for each reach

(above vs. below) to confirm movement •  Community similarity compared using a Sorensen’s

Similarity index

Figure 1. Habitat composition in reaches before and after culvert replacement in John’s Creek.

Figure 2. Substrate composition in reaches before and after culvert replacement in John’s Creek.

Figure 3. Mean IBI score at each sampling site before and after culvert replacement; * indicates statistical difference (p<0.05)

Figure 4. Percent fish composition in each reach before and after culvert replacement.

•  Pool, riffle, run composition remained similar in both reaches before and after culvert replacement (Fig. 1)

•  % sand substrate increased and % detritus decreased in both reaches after culvert replacement (Fig. 2)

•  IBI scores were low at all sites and did not differ before and after replacement, except for sites immediately downstream of the road-stream crossing (Fig. 3)

•  Fish composition improved with fish populations above and below becoming more similar after culvert replacement (Sorensen’s similarity index 63% before, 89% after; Fig. 4)

•  8 marked fish were recaptured, 1 of which (BKT with a RP clip) was marked below and recaptured above the crossing verifying connectivity

•  Spawning salmon were collected above the crossing

Before Before Before BeforeA(er A(er A(er A(er

Above Below Above Below

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