Draft...Draft 2 14 ABSTRACT 15 Construction of artificial channels to divert water is common in a variety of natural resource 16 development projects, however, the length of time required

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Invertebrate colonization of a newly-constructed diversion channel in the Canadian Shield

Journal: Canadian Journal of Fisheries and Aquatic Sciences

Manuscript ID cjfas-2020-0026.R1

Manuscript Type: Article

Date Submitted by the Author: 21-Apr-2020

Complete List of Authors: Chapelsky, Andrew; Fisheries and Oceans Canada Central and Arctic Region, Guzzo, Matthew; University of Manitoba, Biological SciencesHrenchuk, Lee; International Institute for Sustainable DevelopmentBlanchfield, Paul; Fisheries and Oceans Canada, Freshwater Institute

Keyword: Boreal Shield, compensation, fish habitat, fishway, macroinvertebrates

Is the invited manuscript for consideration in a Special

Issue? :Not applicable (regular submission)

https://mc06.manuscriptcentral.com/cjfas-pubs

Canadian Journal of Fisheries and Aquatic Sciences

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1 Invertebrate colonization of a newly-constructed diversion channel in the Canadian Shield

2

3 Andrew J. Chapelsky1, 2, Matthew M. Guzzo3, Lee E. Hrenchuk4, Paul J. Blanchfield1, 2, 4

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5 1 Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada

6 2 Freshwater Institute, Fisheries and Oceans Canada, Winnipeg, MB, Canada

7 3 Department of Integrative Biology, University of Guelph, Guelph, ON, Canada

8 4 IISD Experimental Lakes Area Inc., Winnipeg, MB, Canada

9

10 Correspondence

11 Andrew J. Chapelsky, Arctic Aquatic Research Division, Fisheries and Oceans Canada, 501

12 University Crescent, Winnipeg, MB, R3T 2N6 Canada.

13 Email: [email protected]

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file:///C:/Users/ChapelskyA/Documents/Andrew%20Chapelsky/Work/Projects/Diversion%20stream%20samples/Manuscript/submission%20CJFAS_2020-01-20/[email protected]

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14 ABSTRACT

15 Construction of artificial channels to divert water is common in a variety of natural resource

16 development projects, however, the length of time required for these stream channels to become

17 productive fish habitat remains an understudied aspect. The creation of a bedrock channel (~150

18 m) to drain a third-order Boreal lake and its watershed (~300 ha) offered the unique opportunity

19 to study colonization by comparing habitat and invertebrate metrics to a reference stream. The

20 amount of riparian vegetation on the banks of the diversion channel steadily increased, but

21 remained much lower than the reference stream after five years. The channel was quickly

22 colonized by benthic macroinvertebrates, which were of comparable abundance to the reference

23 stream starting in the first year, and thereafter were greater in abundance. Taxa diversity and

24 richness responded more slowly, becoming similar to the reference stream after three years.

25 Results from this study suggest that newly-created, lake-outlet channels can become productive

26 small stream habitats in a relatively short time period (

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32 INTRODUCTION

33 The re-routing of rivers and streams or construction of artificial channels to divert water flow is a

34 common industry practice associated with resource development projects. For example, artificial

35 channels are created to divert water from rivers for hydroelectric power generation (Rosenberg et

36 al. 1997; Larinier 2008; Gabriel et al. 2010; Warner 2012) and for resource extraction industries,

37 such as metal or diamond mining (Jones et al. 2003; Vandenberg et al. 2016). In Canada,

38 artificial channels have often served as a form of habitat compensation to achieve “no net loss”

39 of fish productive capacity following a Fisheries Act authorization allowing for the harmful

40 alteration, disruption, or destruction of fish habitat (Harper and Quigley 2005). However, the

41 length of time required for these newly created stream channels to become productive fish

42 habitat comparable to natural streams is not well studied.

43 Macroinvertebrate colonization is a key variable that influences the time it takes for

44 newly created stream channels to resemble natural streams capable of supporting fish

45 populations. The colonization of streams by macroinvertebrates is a species-specific process that

46 is influenced by a suite of physical and biological factors. For example, hydrological

47 characteristics (e.g., length, size, shape, substrate), connectivity, seasonality (Peckarsky 1983;

48 Mackay 1992; Jones 2010) and water quality parameters, including temperature, discharge,

49 depth, and ultraviolet and visible light (Peckarsky 1986; Griffith and Perry 1993; Kiffney et al.

50 1997; Milner et al. 2000; Jones 2010) are among essential minimal conditions influential on

51 colonist species. Instream habitat diversity and complexity, including substrate characteristics,

52 pool/riffle sequences, and the presence of woody debris, can have positive effects on

53 macroinvertebrate colonization by increasing the abundance and diversity of organisms (Drury

54 and Kelso 2000; Milner et al. 2000; Palmer et al. 2000; Lepori et al. 2005). Likewise, resource

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55 subsidies from upstream aquatic systems, riparian vegetation, and allochthonous organic inputs

56 play important roles in macroinvertebrate colonization and community structure (Wallace and

57 Webster 1996; Doi et al. 2008; Tiegs et al. 2008; Richardson and Sato 2015; Wallace et al.

58 2015). Invertebrate communities have become an important indicator of habitat quality and

59 productivity in lotic systems because they are found in distinct microhabitats that are influenced

60 by stream characteristics and surrounding riparian vegetation (Malmqvist et al. 1991; Jones et al.

61 2003; Gabriel et al. 2010; Cahill et al. 2015).

62 The most recent changes to the Fisheries Act in Canada have broadened the definition of

63 fish habitat to include “water frequented by fish and any other areas on which fish depend

64 directly or indirectly to carry out life processes, including … food supply” (Government of

65 Canada, 2019 s. 2(1)). Benthic macroinvertebrates are an important component of aquatic

66 systems by providing food for many species of wildlife, including fish, birds, and amphibians,

67 and they contribute to energy and nutrient cycling through their diversity of feeding

68 specializations (functional feeding groups (FFG); Merritt and Cummins 1996; Wallace and

69 Webster 1996; Covich et al. 1999; Suter II and Cormier 2015). As a result, the success of stream

70 restoration efforts are often quantified by assessment of changes in benthic macroinvertebrate

71 metrics (Lepori et al. 2005; Miller et al. 2010). To a much lesser extent, similar approaches from

72 restoration ecology have been used to assess the productivity of newly created stream channels

73 over time. For example, macroinvertebrates from a low productivity diversion channel

74 constructed in Canada’s Barrenlands region had lower abundances and biomass than references

75 streams 14 years later (Scrimgeour et al. 2014), while man-made streams studied from more

76 southerly, forested latitudes (

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78 latitude studies occurred in productive mixed wood forest ecozones that provide more organic

79 input to streams compared to the Barrenlands tundra, and indicate that less time for invertebrate

80 colonization of newly-created streams could be expected in southern latitudes. In Canada, the

81 Boreal Biome covers approximately 58.5% of the land area and is undergoing substantial

82 resource development, including mining for precious metals, diamonds, and minerals, all of

83 which could result in activities that can negatively impact fish habitat (Schindler and Lee 2010).

84 Understanding restoration in these areas will be necessary to adequately mitigate and compensate

85 for these activities (Schindler and Lee 2010).

86 The purpose of this study was to examine the limnological and biological succession of a

87 newly constructed diversion channel in the Boreal shield region of Canada. The channel was

88 constructed by clearing the overlying forest vegetation and blasting through the underlying

89 bedrock to create a new outlet for a third-order lake as part of a watershed-scale manipulation

90 (see Spence et al. 2018). Our specific goals were to quantify and compare temporal changes in

91 (1) stream habitat characteristics, including hydrology and riparian vegetation, and (2)

92 invertebrate community biodiversity and community structure, between the diversion channel

93 and a reference stream typical of the area. We hypothesized that the initial lack of bankside

94 riparian vegetation and food resources in the newly constructed diversion channel would provide

95 limited suitable habitat, and therefore low initial abundance and diversity of benthic

96 invertebrates. However, given the resource subsidies provided by the upstream lake and

97 surrounding forest to the channel, we expected invertebrates to colonize and approach conditions

98 similar to reference streams much more rapidly than has been observed in northern Canada (e.g.

99 Jones et al. 2008). Therefore, we predicted that invertebrate abundance, biodiversity, and

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100 community complexity in the diversion channel would increase rapidly for the first few years of

101 stream succession, while the reference stream would vary slightly around a steady state.

102

103 METHODS

104 Study site

105 The study was conducted at the Experimental Lakes Area (ELA, now IISD Experimental Lakes

106 Area (IISD-ELA)), a pristine, remote area of northwestern Ontario, Canada (49°40´ N, 93°44´

107 W) where 58 lakes and their watersheds have been set aside for research on impacts to aquatic

108 ecosystems (Blanchfield et al. 2009). IISD-ELA lies in the southern Boreal forest and southwest

109 corner of the Canadian Shield. The landscape is underlain by granites with some overlays of

110 quartz, plagioclase, and K-feldspar as sand and gravel (Brunskill and Schindler 1971). The forest

111 is dominated by jack pine (Pinus banksiana) and black spruce (Picea mariana), with balsam

112 poplar (Populus balsamifera), white birch (Betula papyrifera), and red maple (Acer rubrum)

113 frequently found near streams (Schindler et al. 1996).

114 In the autumn of 2010, a 138 m diversion channel (hereafter “Diversion”) was

115 constructed through bedrock to drain Lake 627, a 37.4 ha, third order lake with a total watershed

116 area of 303.4 ha (Fig. 1). Water from Lake 627 would normally flow into downstream Lake 626,

117 but a small dike was constructed at this natural outlet and all discharge from Lake 627 went

118 instead through the Diversion and then to the wetland immediately below, starting on 23

119 November 2010 (Fig. 1; see Spence et al. 2018). The blasted bedrock was left in place to form

120 the banks of the channel (Fig. 1), similar to creation of diversion channels in other industrial

121 developments. We also sampled a natural lake-outlet stream (96 m; hereafter “Reference”) that

122 drains six upstream lakes with a total watershed area of 723.1 ha (Fig. 1; Beaty and Lyng 1989),

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123 located approximately 13 km south of the Diversion channel. The Reference stream comprises

124 part of an ELA long-term watershed monitoring program that began in 1969 (Schindler et al.,

125 1996).

126 Wire mesh fish-exclusion fences were installed above the head of each stream to prevent

127 large-bodied fish from entering. The Diversion fence was installed in 2011 and remained in place

128 for the duration of the study, while the Reference fence was installed in 2004 and removed in

129 2014 upon completion of an unrelated study in the upstream lake. Young of the year (YOY)

130 yellow perch (Perca flavescens) were observed in the Diversion in low numbers each year, and

131 YOY white sucker (Catostomus commersonii) were found in the Reference in 2015. Overall, fish

132 presence in both streams was low and limited to small-bodied fish.

133

134 Stream characteristics

135 Stream temperature and discharge were monitored throughout the study using data loggers

136 (except in 2014, when sampling did not occur because minimal operations were permitted during

137 this time of federal government cuts that threatened the closure of the ELA). Water temperature

138 (°C) data were recorded hourly with a single logger (HOBO Pendant Temp/Light, 64 k model

139 UA-002-64, Onset Computer Co., Cape Cod, MA) anchored near the bottom of each stream

140 (~0.25 m depth). Loggers were deployed after freshet in the spring and collected before ice-cover

141 in the fall of each year to capture spring, summer, and fall seasonal temperatures. Water stage

142 loggers (OTT Shaft Encoder SE 200 and OTT Thalimedes Data Logger, OTT MESSTECHNIK

143 GmbH & Co. KG, Kempten, Germany) were installed at the head of each stream and recorded

144 discharge measurements (m3·s-1) every 10 min. Mean daily discharge was calculated using stage-

145 discharge rating curves developed for each stream (Bruce and Clarke 1966). For the Diversion,

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146 stage was recorded at the start of the channel and was correlated with occasional discharge

147 measurements made in the open channel that allowed for a flow hydrograph to be created. For

148 the Reference, a recording concrete 120° v-notch sharp crested weir located at the upstream lake

149 outlet has monitored flow continuously since 1969 (Beaty and Lyng 1989).

150 Microhabitat parameters including stream bed characteristics and riparian habitat were

151 assessed on each invertebrate sampling date at each sampling site. Wet width, defined as the

152 perpendicular distance between stream banks that the water spans, and channel width, the

153 perpendicular distance between high water marks, were measured (in cm) at the upstream

154 boundary of each site. Mean depth was estimated by taking 8–10 stream depth measurements

155 (cm) evenly spaced across the wet width using a metre stick and calculating the mean. Substrate

156 type representing the entire site was determined visually using a size classification system

157 adapted from Bain et al. (1985). Substrate classifications included sand (< 2 mm), gravel (2–64

158 mm), cobble (64–256 mm), and boulder (> 256 mm). Riparian habitat (percent cover) was

159 visually classified as mud, rock, sand, moss, forbs, grass (includes sedge, rush, grass), shrub, or

160 tree for a 2 m² area on each stream bank (1 m perpendicular to shore and 2 m upstream from the

161 start of the sample site).

162

163 Invertebrate sampling

164 Invertebrate sample collection took place twice annually from July 2011 to August 2015, except

165 for 2014 when sampling did not occur. During each sampling event, three sites – one upper (U),

166 one middle (M) and one lower (L; see Fig. 1) – were sampled in each stream by kick netting a

167 2.0 m length section of the stream in a zigzag pattern from bank to bank using a D-frame net

168 (500 µm mesh; 305 mm width x 254 mm length). Samples were placed in plastic freezer bags

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169 and stored on ice in a cooler for transport to the field station. In the laboratory, samples were

170 washed with tap water through a series of three sieves (mesh sizes: 1 mm, 500 µm, and 250 µm)

171 before invertebrates were picked by eye and preserved in 70% ethanol. The remaining portions

172 of the sample were frozen in water at -20 °C and later thawed and re-examined under a

173 dissection microscope (MZ 8, Leica Microsystems, Wetzlar, Germany) at 50x magnification to

174 ensure all invertebrates were removed. Taxa were identified using the dissection microscope at

175 50x magnification, and taxonomic keys for aquatic insects (Merritt and Cummins 1996) and non-

176 insects (Thorp and Covich 2010). Identification to genus was possible for most insects (Insecta),

177 spiders (Dolomedes sp.), and leeches (Hirudinea). Sphaeriidae, Lymnaeidae, Planorbidae,

178 Lampyridae, and dipterans (Athericidae, Ceratopogonidae, Chironomidae, Empididae,

179 Simuliidae, Tabanidae, Tipulidae) were identified to family; Cladocera, Lepidoptera, and

180 Amphipoda to order; Copepoda, Acari (mites), and Oligochaeta to subclass; and Nematoda to

181 phylum. Voucher specimens were stored in 70% ethanol.

182

183 Statistical analysis

184 All statistical analyses were performed using R statistical software Version 3.5.3 (R Core Team,

185 2019). Stream daily mean temperature and discharge values were calculated by averaging the

186 logger data (hourly and every 10 min, respectively) for the four years invertebrate samples were

187 collected (2011–2013, 2015). Riparian habitat mean percent cover was calculated for each site

188 by averaging July sample estimates from both streambanks.

189 To quantify differences in macroinvertebrate communities over time in the two streams

190 we calculated abundance, taxa richness, and Shannon-Weiner diversity using the R package

191 “vegan” v2.5-3 (Oksanen et al. 2018). We then modelled variation in these community metrics

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192 across streams and over time using multiple regression. In each model, we included year (2011-

193 2013, 2015), and stream (Diversion or Reference) as factors, and the interaction between these

194 two variables. We then used the output of these models to perform Tukey pairwise post-hoc tests

195 using the R package “emmeans” (Lenth 2019) to test if each community metric differed between

196 streams in each study year. We checked for normality and homoscedasticity in each metric by

197 evaluating histogram and quantile-quantile plots of the model residuals. Abundance data were

198 log10(x+1) transformed and richness data were square root transformed for analysis to meet the

199 assumption of homoscedasticity. Diversity data did not require transformation.

200 Additional calculations were used to assess the stability and functionality of the

201 invertebrate communities found in each stream. Ordinal date was influential on community

202 structure, and therefore analyses of annual change were conducted using July samples only. Non-

203 metric multidimensional scaling (nMDS) ordination was used to visualize changes in benthic

204 invertebrate communities over time using the R package “vegan” (Oksanen et al. 2018). In

205 nMDS, community similarity increases with proximity of data points (Kruskal 1964). Annual

206 benthic invertebrate abundance was calculated as an average of the three sampling sites (U, M,

207 and L) for each stream due to the short length of the streams. Abundance data were square-root

208 transformed before calculating the Bray-Curtis dissimilarity matrix. To examine overall

209 persistence of taxa we calculated apparent species turnover rates using equations from Arnott et

210 al. (1999). To compare changes in functional feeding groups (FFGs) over time, taxa were

211 assigned to FFGs based on classifications in Merritt & Cummins (1996), and the percentage of

212 taxa belonging to each FFG was calculated for each stream and year by combining samples from

213 the three sites.

214

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215 RESULTS

216 The Reference had almost twice the mean daily discharge (0.038 m3·s-1) compared to that of the

217 Diversion channel (0.018 m3·s-1) during the five year study period (Table 1; Fig. 2a). The

218 Reference stream experienced two periods of no measurable flow (14 September 2011 to 15

219 February 2012, and 12 August 2012 to 26 April 2013). Both no-flow periods commenced in late

220 summer or early fall, were punctuated by occasional flow lasting a few days during the fall and

221 continued into winter or early spring. Although daily discharge in the Diversion was lower and

222 less variable than the Reference, at no point did the Diversion experience a period of no flow.

223 The Diversion has a small groundwater inflow that allowed flow to continue during these times

224 (K. Beaty, DFO, personal communication). The hydrology of the ELA region is driven by

225 snowmelt runoff in the spring (April) and rainfall in early summer (May-June). The streams

226 appear to have mainly been in low flow situations for periods starting in the late summer-fall and

227 during winter. Mean daily water temperatures were greatest during July and August of each year.

228 During July, mean daily water temperatures averaged 1.7°C warmer in the Reference (mean ±

229 SD: 23.2 ± 2.4°C) stream than in the Diversion (21.9 ± 1.9°C) (Table 1; Fig. 2b).

230 The Diversion exhibited pronounced changes in microhabitat characteristics over the

231 five-year study period (Fig. 1), while the Reference underwent little or no change. Riparian

232 vegetation cover increased from 0 to >30 % in the upper (U) and lower (L) reaches of the

233 Diversion, but was always lower than that of the Reference (55-100%; Table 2). The middle (M)

234 reach of the Diversion had less vegetation (7.5 %), likely due to the steep, rocky nature of this

235 section of channel. Algae (Spyrogyra sp.) and leaf litter increased over the duration of the study,

236 however, in the first year Spyrogyra sp. grew in dense mats compared to minimal amounts of

237 scattered leaf litter. Overall, sampling sites in the Reference were slightly shallower and more

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238 variable (14.7 ± 12.0 cm) in depth than the Diversion (18.1 ± 4.5 cm; Table 2). Sand was the

239 dominant substrate in the Diversion channel and became more prevalent over time, particularly

240 in upstream (U) and downstream (L) sites (Table 2).

241 A total of 5780 invertebrates from 89 taxa and 19 Orders were identified. The Diversion

242 had 3900 invertebrates from 63 taxa, and the Reference had 1880 invertebrates from 72 taxa.

243 After removing terrestrial Coleopterans, terrestrial Hemipterans, nematodes, zooplankton,

244 individuals too small to identify, and 19 taxa with a single occurrence, 5726 invertebrates (99%)

245 in 66 taxa (74%) were used for abundance, richness, and diversity analyses. Of these, 3875

246 invertebrates in 52 taxa were found in the Diversion and 1851 invertebrates in 59 taxa were

247 found in the Reference. The 19 taxa with a single occurrence comprised 8 and 11 taxa found in

248 the Diversion and Reference, respectively,

249 Invertebrate abundance, richness, and diversity each increased in the Diversion over time,

250 but there were no similar trends in the Reference (Figs. 3a-c). In the first three years of the study,

251 mean abundance did not differ between the Diversion and Reference (Table 3), but by 2015

252 mean abundance in the Diversion channel (mean ± SE; 394 ± 117) was more than double that of

253 the Reference (138 ± 30). In fact, of the 5726 invertebrates used for analysis in the study,

254 roughly two-thirds (68 %) were from the Diversion (3875 invertebrates); however, this

255 difference in overall abundance can mainly be attributed to the large increase in abundance found

256 in the Diversion in 2015 (Table 3; Fig. 3a). Invertebrate richness and diversity were both

257 significantly lower in the Diversion compared to the Reference in the first year of the study

258 (2011), but by the following year these metrics were similar for both streams and remained so for

259 the duration of the study (Table 3; Figs. 3b, c).

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260 Estimates of community composition were influenced by seasonal sampling date, which

261 was variable from year to year. Therefore, we compared annual changes in community

262 composition using only data from samples collected in July of each year, as sampling at this time

263 period was consistent among all years for both streams. Initially nMDS plots were generated

264 using two dimensions; however, because of high average stress (0.19), we re-analysed the data to

265 include a third dimension to minimize stress. Examination of the nMDS plot (stress=0.05)

266 suggests the invertebrate community in the Diversion became more like the Reference over time.

267 Diversion channel communities were most like Reference communities in the latter two years of

268 the study (2013 and 2015; Fig. 4).

269 Both streams had high annual turnover of taxa (>20 %) throughout the study (Table 4).

270 However, annual turnover rates decreased by approximately 15 % and 7 % per year in the

271 Diversion and Reference streams, respectively, indicating greater persistence of the benthic

272 community over time. The number of permanent taxa (i.e., taxa present in all subsequent years)

273 was similar between streams and increased steadily over time. The Diversion consistently gained

274 almost twice the number of invertebrate taxa that it lost, contributing to the increase in richness

275 (Fig. 3b). The number of taxa gained and lost in the Reference was similar each year except for

276 2015, in which similar losses and a large increase in new taxa occurred. Overall, a total of 19

277 taxa were found to be permanent in July samples, with five taxa common to both streams

278 (Chironomidae, Cordulegaster, Erpobdella, Eurylophella, Sphaeriidae; Table 4). The other eight

279 permanent taxa (Acari, Empididae, Hydropsyche, Lepidoptera, Ophiogomphus, Simuliidae,

280 Tabanidae, Tipulidae) found in the Diversion (for a total of 13) differed from the other six

281 permanent taxa (Aeshna, Amphipoda, Ceratopogonidae, Dolomedes, Paraleptophlebia,

282 Sympetrum) found in the Reference (for a total of 11).

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283 In July samples, Diversion communities were initially (2011-2013) numerically

284 dominated by Chironomidae (72-87 %), but in 2015 Hydropsyche (27 %), Simuliidae (23 %),

285 Chironomidae (18 %), and Sphaeriidae (13 %) were all present in high proportions (>10 %; Fig.

286 5). In contrast, annual abundances in Reference communities were comprised between 49 %

287 (2011) and 85 % (2015) of Chironomidae (6-40 %), Amphipoda (6-41 %), and Sphaeriidae (9-35

288 %). The most abundant taxa included Amphipoda, Chironomidae, Hydropsyche, Simuliidae, and

289 Sphaeriidae. In any given year these five taxa collectively comprised between 55-84 % of

290 invertebrates collected in the Diversion, and 31-83 % of invertebrates collected in the Reference.

291 However, some of the years contained high proportions of additional taxa, particularly mayflies

292 that were absent or present in low abundances during July but abundant during spring or fall

293 samples. In the Diversion channel, Leptophlebia composed 10 % of the total in 2012, and in

294 2013 Eurylophella and Paraleptophlebia composed 16 % and 14 %, respectively. The Reference

295 community in 2012 was almost half (45 %) composed of Leptophlebia, and in 2011 the

296 dragonfly larva Ophiogomphus comprised close to a quarter (22 %) of all invertebrates collected

297 from this stream.

298 Identified taxa were classified into six different functional feeding groups (FFGs):

299 collector-filterer (42 %), collector-gatherer (34 %), predator (11 %), shredder (9 %), scraper (1

300 %), and other (3 %), which contained Acari (mites), and pupae of Chironomidae, Simuliidae, and

301 Lepidoptera (Merritt and Cummins 1996). Comparison of FFGs each year showed both stream

302 communities were composed mainly of collector-filterers (Diversion: 1-72 %; Reference: 9-49

303 %) and collector-gatherers (Diversion: 17-89 %; Reference: 9-42 %; Fig. 6), although Shredders

304 were absent or rare in the Diversion (0-1%) yet abundant in the Reference (6-42%). In 2015,

305 Diversion collector-filterers (72 %) were six times more abundant than in 2013 (12 %) due to the

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306 greater proportion of Hydropsyche, Simuliidae, and Sphaeriidae (Fig. 5). Predators were present

307 in greater relative abundance in the Reference (8-27 %) than the Diversion (5-13 %).

308

309 DISCUSSION

310 Our study demonstrates that a newly-created water diversion channel in the southern Boreal

311 region resembled a natural stream in a relatively short time span (

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329 both would have been the recipient of upstream subsidies that would have benefited colonization

330 of certain taxa in the newly-created channel, and recolonization in the Reference stream. The

331 short lengths of the Diversion and Reference streams may have had an influence on the overall

332 findings of our study by allowing resources to be accessible throughout the entire stream length,

333 as opposed to longer streams, where instream processing can provide suitable inputs (Doi et al.

334 2008, Jones 2010). Future research into the effect of newly-constructed channels, and their

335 influence on connectivity and watershed productivity, through their interaction across

336 ecosystems (e.g., lake-stream and freshwater-terrestrial boundaries) would benefit our

337 understanding of their effectiveness for restoration goals (Jones 2010; Polis et al. 1997;

338 Richardson and Sato 2015; Wallace et al. 2015).

339 Because the primary goal of this experimental water diversion was to isolate a lake to test

340 for watershed-level impacts of reduced flow (Spence et al. 2018), limited attention was paid to

341 the creation of diverse habitat features, such as pools and riffles, which are known to be

342 important for fish and benthic organisms in natural streams. As a result, the Diversion had a

343 lower slope and more homogenous stream depths than did the natural stream. The channel also

344 had consistently lower and less variable seasonal flows and cooler summer water temperatures

345 than did the nearby Reference stream. The lower flow rate and limited bankside riparian cover

346 (see below) should have promoted warmer, not cooler, stream temperatures, and therefore we

347 suspect that groundwater inputs to the channel likely counteracted these effects. This is

348 consistent with the observation that periods of no-flow conditions were not observed in the

349 Diversion, but were seen on occasion in the Reference stream during the course of this study.

350 Intermittent flow to streams draining portions of the watershed appear to be a common feature of

351 the Reference watershed (Parker et al. 2009), with predictions for an increase in the frequency

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352 and duration of no-flow periods under a warmer and drier climate (Schindler et al. 1996). The

353 ephemeral flow observed in the Reference stream likely favours highly mobile, fast growing taxa

354 with rapid reproductive rates adapted to tolerate these disturbances (Peckarsky 1983; Poff and

355 Ward 1990). The lower flows observed in the Diversion may have led to lower than expected

356 invertebrate abundance, richness, and diversity because of comparatively limited upstream

357 subsidies, particularly to filter-feeding and grazing taxa (Doi et al. 2008; Jones 2010; Wills et al.

358 2006). On the other hand, continuous stream flow in the channel may have allowed less mobile

359 and certain taxa to successfully establish and thereby increase the richness and diversity (Death

360 1995). Some taxa are especially sensitive to low flow or drought conditions, and while regularly

361 disturbed streams may have communities adapted to these conditions, disturbances in less

362 predictable streams could have negative impacts on abundance, richness, and diversity

363 (Peckarsky 1983; Holomuzki and Biggs 2000; Imbert and Perry 2000; Nelson and Lieberman

364 2002; Death and Zimmermann 2005). As well, low flows provide less space and decrease

365 instream habitat diversity that may cause taxa capable of migrating to leave (Dewson et al.

366 2007). We advocate that future studies, where possible, incorporate multiple reference streams

367 sampled over long time periods and quantify groundwater inputs, hydrologic regimes, and water

368 quality parameters throughout the entire year to better assess the suitability of newly-constructed

369 channels as fish habitat. Despite differences in physical habitat and limnological conditions, we

370 observed convergence in other metrics between the experimental and reference streams after

371 several years.

372 Similar to construction of other diversion channels, vegetation was not purposefully

373 planted along the banks (Williams and Hynes 1977; Malmqvist et al. 1991; Jones and Tonn

374 2004; Gabriel et al. 2010). Instead, the bedrock boulders were left in place and initially

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375 vegetation was absent. Bankside riparian vegetation colonized within the first year, and coverage

376 increased to almost 40% in some sections of the channel 5 years after construction (Fig. 1

377 photos). Despite annual increases, riparian vegetation within 10 m of the stream along the

378 Diversion was sparse compared to the Reference stream and comprised primarily of grasses and

379 small shrubs. The time required to develop a mature riparian streambank can ultimately shape

380 macroinvertebrate colonization and succession because of direct influences on allochthonous

381 inputs and light regimes (Gabriel et al. 2010; Wallace et al. 2015). For example, lack of canopy

382 structure in coastal streams has been shown to allow greater UV penetration, which in turn

383 promotes algal growth but reduces invertebrate biomass and community diversity compared to

384 heavily shaded reaches (Kelly et al. 2003). It is possible that the initial rapid algal growth

385 observed in the Diversion may have occurred in response to high UV conditions associated with

386 the lack of canopy. However, the remaining mature forest consisting primarily of black spruce

387 and white birch, was in close proximity (~10–15 m; Fig. 1), to the Diversion streambank and,

388 aided by wind, likely provided carbon inputs and resources to the invertebrate communities that

389 could have increased colonization rate for some collector-filterer and collector-grazer taxa.

390 Despite limited instream habitat diversity and sparse riparian vegetation in the initial

391 years following construction, the Diversion was quickly colonized by macroinvertebrates. Within

392 the first year invertebrate abundances in the Diversion were equivalent to the reference stream,

393 and thereafter were greater in abundance. Rapid invertebrate colonization occurred in the first

394 year following creation of a man-made lake-outlet stream in southern Sweden (Malmqvist et al.

395 1991), and in the first 4 months of a newly-constructed agricultural stream segment in the

396 southern Canadian Boreal (Williams and Hynes 1977). In contrast, a study in the northern

397 Barrenlands region of the Canadian Arctic found invertebrates were still much less abundant and

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398 diverse than reference streams eight years after the creation of a 3.4 km water diversion channel

399 (Scrimgeour et al. 2014). Macroinvertebrate taxa richness and diversity steadily increased

400 throughout the five years of monitoring, and suggests that earlier studies that sampled newly-

401 created streams for shorter time periods (i.e. 1-2 y; Williams and Hynes 1977; Malmqvist et al.

402 1991) may not have captured the full succession of the benthic community.

403 Turnover rates indicated that invertebrate communities were constantly changing

404 throughout the study through local colonizations and extinctions. The succession of species,

405 habitat specificity of many freshwater aquatic invertebrates, and observed changes in habitat

406 could have contributed to this (Merritt and Cummins 1996; Flory and Milner 1999; Milner and

407 Gloyne-Phillips 2005; Lepori and Malmqvist 2009). Turnover rates were similar between

408 streams for the duration of the study and this may reflect insect populations responding to

409 regional disturbances in a greater geographic extent than this study (Arnott et al. 1999). The

410 greater turnover rate in the Diversion observed in 2012, roughly one and a half years after the

411 channel was in operation, could be due to the initial colonization of the stream and the increase

412 in vegetation and resources resulting in a more diverse habitat suitable for a variety of taxa

413 (McCoy and Bell 1991; Muotka and Syrjänen 2007). The comparatively large increase in taxa

414 found in the Reference stream in 2015 could be attributed to the return of many, potentially rare

415 and ecologically important, species that were affected by low flow conditions observed in 2011-

416 2013 and the increased discharge observed in 2014. By contrast, in 2015 the comparatively more

417 stable habitat in the Diversion appeared to gain less new taxa but greatly increase the abundance

418 of certain taxa, particularly Hydropsyche and Simuliidae. Our focus on July data for annual

419 comparisons of diversity underestimates the true rates of macroinvertebrate turnover in these

420 streams as certain taxa (e.g. mayflies) were only collected in May or September samples. Still,

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421 the consistent timing of sampling and five year duration of this study provides an initial estimate

422 of turnover rates in communities that could be compared with future studies to understand

423 colonization patterns over long time periods and in relation to broader geographic influences,

424 such as climate change.

425 The order in which taxa colonized the Diversion was consistent with what has been

426 observed in north-temperate streams (Williams and Hynes 1977; Malmqvist et al. 1991; Mackay

427 1992). Chironomidae were among the first taxa collected and were the most abundant taxa the

428 first three years in the Diversion. Chironomidae are highly mobile invertebrates that can colonize

429 by drifting as larvae, crawling as larvae or adults, and aerially by oviposition from winged adults

430 (Williams and Hynes 1976; Milner 1994; Tronstad et al. 2007). The general absence of

431 Amphipoda and other shredders in the Diversion is likely due to the lack of leaf litter input to the

432 stream. The Diversion channel drains through forest and into a shallow wetland area before

433 entering the downstream lake, which may limit upstream migration into the channel and the

434 ability of this channel to be recolonized following disturbance (Peckarsky 1983; Mackay 1992).

435 The large abundance of Sphaeriidae seen in later years (2013 and 2015), and the large increase of

436 Hydropsyche and Sphaeriidae in year five likely reflects the rapid downstream drifting

437 colonization strategy compared to the slower, and potentially longer or seasonally dependent

438 life-cycles of winged adults laying eggs at sites with suitable resources. The increase in

439 abundance of these filter-feeding taxa could reflect changes in food availability as stream

440 productivity increased.

441 Convergence in the relative proportion of macroinvertebrate FFG between newly created

442 and reference streams is suggestive of improved ecological function of compensation streams

443 (Wallace and Webster 1996; Blasius and Merritt 2002; Compin and Céréghino 2007). The

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444 Diversion showed changes in FFG diversity over time that resulted in a macroinvertebrate

445 community more like the Reference stream, however the low abundance of shredder taxa in the

446 Diversion is indicative of the lack of riparian vegetation, including macrophytes, providing

447 organic matter to the stream (Wallace et al. 2015). Our findings were similar to those of an

448 artificial channel in Newfoundland, Canada, sampled 3-4 years after construction, whereby the

449 macroinvertebrate community had a greater representation of collector-filterer and collector-

450 gatherer taxa and underrepresentation of predators and shredders compared to natural streams

451 (Gabriel et al. 2010). Jones & Tonn (2004) found allochthonous carbon input to be important for

452 the development of invertebrate communities in Arctic streams. In this study, marked increase in

453 invertebrate abundance in the fifth year (2015) was largely influenced by the additional increase

454 of collector-filterer taxa (Hydrospyche and Simuliidae; Merritt and Cummins 1996). Collector-

455 filterer invertebrates gain most of their carbon from upstream processes (Wallace and Webster

456 1996), and their comparable percent abundance between the two streams by the third year and

457 increase in the fifth year in the Diversion is suggestive of a productive stream community with

458 instream carbon processing or sufficient inputs from upstream lakes. In addition, we did not

459 include suitable fish passes (Cahill et al. 2015) or the addition of beneficial habitats for fish and

460 invertebrates like rock structures (Scrimgeour et al. 2013), wood bundles (Gabriel et al. 2010),

461 stream vegetation (Lusardi et al. 2018), and suitable pool-riffle reaches (Scrimgeour et al. 2014)

462 found in nature-like fishways. These modifications would have provided a more complex stream

463 habitat to accelerate the accrual of suitable resources for colonization by a diversity of

464 organisms, and created a healthy, productive system more capable of responding to stochastic

465 events.

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466 Construction of artificial channels to redirect water flow is a common, yet rarely

467 assessed, form of habitat compensation to support fish. Within five years of construction, a

468 newly created lake-outlet bedrock diversion channel supported a macroinvertebrate community

469 of similar richness and diversity but higher abundance than that found in a nearby natural lake-

470 outlet stream. The temporal convergence of habitat-assessment metrics between the Diversion

471 and Reference in this study support the idea that newly-created channels can quickly become

472 suitable habitat to support fish. However, we reiterate here that the time required for new

473 channels to resemble natural streams will be largely dependent on hydrological and limnological

474 processes that are highly context-dependent. The spatial scale and lack of planned features added

475 for habitat (i.e. pool-riffle sequences, rock cribs, coarse woody debris, riparian vegetation) of this

476 newly-constructed channel should be considered when applying results of this study to

477 management decisions. Furthermore, the taxonomic resolution and measures of diversity in this

478 study may not capture rare or sensitive species that require specific habitat characteristics for

479 their persistence and should be considered when setting restoration goals. Given the context-

480 dependent nature of new channels meant to support fish habitat objectives, we recommend that

481 monitoring programs include habitat indicators of aquatic and terrestrial resources in the

482 watershed when evaluating the success of restoration goals.

483

484 ACKNOWLEDGEMENTS

485 The authors thank Pete Cott for advice and logistical support, Ken Beaty, who oversaw the

486 creation of the diversion channel and, along with two anonymous reviewers, provided valuable

487 feedback on this manuscript. We also thank Ken Sandilands, Chandra Rodgers, Stephen

488 McGovarin, Philip Anderson, Joey Simoes, and the many staff and students at the IISD-ELA

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489 who assisted with this project. This manuscript is dedicated to the memory of Julie Dahl, who

490 inspired this study. Funding was provided by Fisheries & Oceans Canada (Winnipeg and

491 Yellowknife Fish Habitat Sections), Environment and Climate Change Canada, and DeBeers

492 Canada, Snap Lake Mine.

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493 REFERENCES

494 Arnott, S.E., Yan, N.D., Magnuson, J.J., and Frost, T.M. 1999. Interannual variability and

495 species turnover of crustacean zooplankton in Shield lakes. Can. J. Fish. Aquat. Sci. 56(1):

496 162–172. doi:10.1139/f98-152.

497 Bain, M.B., Finn, J.T., and Booke, H.E. 1985. Quantifying stream substrate for habitat analysis

498 studies. N. Am. J. Fish. Manag. 5: 499–500.

499 Beaty, K.G., and Lyng, M.E. 1989. Hydrometeorological data for the Experimental Lakes Area,

500 Northwestern Ontario, 1982 to 1987. Can. Data Rep. Fish. Aquat. Sci. 759: v + 280 p.

501 Blanchfield, P.J., Paterson, M.J., Shearer, J.A., and Schindler, D.W. 2009. Johnson and

502 Vallentyne’s legacy: 40 years of aquatic research at the Experimental Lakes Area. Can. J.

503 Fish. Aquat. Sci. 66(11): 1831–1836.

504 Blasius, B.J., and Merritt, R.W. 2002. Field and laboratory investigation on the effects of road

505 salt (NaCl) on stream macroinvertebrate communities. Environ. Pollut. 120(2): 219–231.

506 doi:10.1016/S0269-7491(02)00142-2.

507 Bruce, J., and Clarke, R. 1966. Introduction to hydrometeorology. Pergamon Press, New York.

508 Brunskill, G.J., and Schindler, D.W. 1971. Geography and bathymetry of selected lake basins,

509 Experimental Lakes Area, Northwestern Ontario. J. Fish. Res. Board Can. 28(2): 139–155.

510 doi:10.1139/f71-028.

511 Cahill, C.L., Erwin, A.C., Howland, K.L., Hulsman, M.F., Lunn, B.D., Noddin, F., Tonn, W.M.,

512 Baki, A.B., Courtice, G., and Zhu, D.Z. 2015. Assessing responses of fish to habitat

513 enhancement in Barrenlands streams of the Northwest Territories. N. Am. J. Fish. Manag.

514 35(4): 755–764. doi:10.1080/02755947.2015.1044626.

Page 24 of 43



Draft

25

515 Compin, A., and Céréghino, R. Spatial patterns of macroinvertebrate functional feeding groups

516 in streams in relation to physical variables and land-cover in Southwestern France. Landsc.

517 Ecol. 22: 1215–1225. doi:10.1007/s10980-007-9101-y.

518 Covich, A.P., Palmer, M.A., and Crowl, T.A. 1999. The role of benthic invertebrate species in

519 freshwater ecosystems: zoobenthic species influence energy flows and nutrient cycling.

520 BioScience, 49(2): 119–127. doi:10.2307/1313537.

521 Death, R.G. 1995. Spatial patterns in benthic invertebrate community structure: products of

522 habitat stability or are they habitat specific? Freshw. Biol. 33: 455–467. doi:10.1111/j.1365-

523 2427.1995.tb00406.x.

524 Death, R.G., and Zimmerman, E.M. 2005. Interaction between disturbance and primary

525 productivity in determining stream invertebrate diversity. Oikos, 111: 392–402.

526 doi:10.1111/j.0030-1299.2005.13799.x.

527 Dewson, Z.S., James, A.B.W., and Death, R.G. 2007. A review of the consequences of decreased

528 flow for instream habitat and macroinvertebrates. J. N. Am. Benthol. Soc. 26(3): 401–415.

529 doi:10.1899/06-110.1.

530 Doi, H., Chang, K.-H., Ando, T., Imai, H., Nakano S., Kajimoto, A., and Katano, I. 2008.

531 Drifting plankton from a reservoir subsidize downstream food webs and alter community

532 structure. Oecologia, 156: 363–371. doi:10.1007/s00442-008-0988-z.

533 Drury, D.M., and Kelso, W.E. 2000. Invertebrate colonization of woody debris in coastal plain

534 streams. Hydrobiologia, 434(1): 63–72. doi:10.1023/A:1004021924986.

535 ESRI (Environmental Systems Research Institute). 2019. ArcGIS Desktop 10.7. Redlands, CA.

536 Flory, E.A., and Milner, A.M. 1999. Influence of riparian vegetation on invertebrate assemblages

537 in a recently formed stream in Glacier Bay National Park, Alaska. J. North Am. Benthol.

Page 25 of 43



Draft

26

538 Soc. 18(2), 261–273. doi:10.2307/1468464.

539 Gabriel, C.M., Clarke, K.D., and Campbell, C.E. 2010. Invertebrate communities in

540 Compensation Creek, a man-made stream in boreal Newfoundland: The influence of large

541 woody debris. River Res. Appl. 26(8): 1005–1018. doi:10.1002/rra.1295.

542 Government of Canada. 2019. Fisheries Act. R.S., c. F-14, s. 2(1).

543 Griffith, M.B., and Perry, S.A. 1993. Colonization and processing of leaf litter by

544 macroinvertebrate shredders in streams of contrasting pH. Freshw. Biol. 30(1): 93–103.

545 doi:10.1111/j.1365-2427.1993.tb00791.x.

546 Harper, D.J., and Quigley, J.T. 2005. No net loss of fish habitat: a review and analysis of habitat

547 compensation in Canada. Environ. Manage. 36(3): 343–355. doi:10.1007/s00267-004-0114-

548 x.

549 Holomuzki, J.R., and Biggs, J.F. 2000. Taxon-specific responses to high-flow disturbance in

550 streams: implications for population persistance. J. N. Am. Benthol. Soc. 19(4): 670–679.

551 doi:10.2307/1468125.Imbert, J.B., and Perry, J.A. 2000. Drift and benthic invertebrate

552 responses to stepwise and abrupt increases in non-scouring flow. Hydrobiologia, 436: 191–

553 208. doi:10.1023/A:1026582218786.

554 Jones, N.E. 2010. Incorporating lakes within the river discontinuum: longitudinal changes in

555 ecological characteristics in stream-lake networks. Can. J. Fish. Aquat. Sci. 67: 1350–1362.

556 doi:10.1139/F10-069.

557 Jones, N.E., and Tonn, W.M. 2004. Enhancing productive capacity in the Canadian Arctic:

558 assessing the effectiveness of instream habitat structures in habitat compensation. Trans.

Page 26 of 43



Draft

27

559 Am. Fish. Soc. 133(6): 1356–1365. doi:10.1577/T03-136.1.

560 Jones, N.E., Scrimgeour, G.J., and Tonn, W.M. 2008. Assessing the effectiveness of a

561 constructed Arctic stream using multiple biological attributes. Environ. Manage. 42: 1064-

562 1076. doi:10.1007/s00267-008-9218-z.

563 Jones, N.E., Tonn, W.M., Scrimgeour, G.J., and Katopodis, C. 2003. Productive capacity of an

564 artificial stream in the Canadian Arctic: assessing the effectiveness of fish habitat

565 compensation. Can. J. Fish. Aquat. Sci. 60(7): 849–863. doi:10.1139/F03-074.

566 Kelly, D.J., Bothwell, M.L., and Schindler, D.W. 2003. Effects of solar ultraviolet radiation on

567 stream benthic communities: an intersite comparison. Ecology, 84: 2724–2740.

568 doi:10.1890/02-0658.

569 Kiffney, P.M., Clements, W.H., and Cady, T.A. 1997. Influence of ultraviolet radiation on the

570 colonization dynamics of a Rocky Mountain stream benthic community. J. N. Am. Benthol.

571 Soc. 16(3): 520–530. doi:10.2307/1468141.

572 Kruskal, J.B. 1964. Nonmetric multidimensional scaling: a numerical method. Psychometrika,

573 29(2): 115–129. doi:10.1007/BF02289694.

574 Larinier, M. 2008. Fish passage experience at small-scale hydro-electric power plants in France.

575 Hydrobiologia, 609(1): 97–108. doi:10.1007/s10750-008-9398-9.

576 Lenth, R. 2019. emmeans: estimated marginal means, aka least-squares means. R package

577 version 1.3.2. https://CRAN.R-project.org/package=emmeans

578 Lepori, F., and Malmqvist, B. 2009. Deterministic control on community assembly peaks at

579 intermediate levels of disturbance. Oikos, 118: 471–479. doi:10.1111/j.1600-

Page 27 of 43



Draft

28

580 0706.2008.16989.x.

581 Lepori, F., Palm, D., Brännäs, E., and Malmqvist, B. 2005. Does restoration of structural

582 heterogeneity in streams enhance fish and macroinvertebrate diversity? Ecol. Appl. 15(6):

583 2060–2071. doi:10.1890/04-1372.

584 Lusardi, R.A., Jeffres, C.A., and Moyle, P.B. 2018. Stream macrophytes increase invertebrate

585 production and fish habitat utilization in a California stream. River Res. Appl. 34(8): 1003–

586 1012. doi:10.1002/rra.3331.

587 Mackay, R.J. 1992. Colonization by lotic macroinvertebrates: a review of processes and patterns.

588 Can. J. Fish. Aquat. Sci. 49: 617–628. doi:10.1139/f92-071.

589 Malmqvist, B., Rundle, S., Bronmark, C., and Erlandsson, A. 1991. Invertebrate colonization of

590 a new, man-made stream in southern Sweden. Freshw. Biol. 26(2): 307–324.

591 doi:10.1111/j.1365-2427.1991.tb01737.x.

592 McCoy, E.D., and Bell, S.S. 1991. Habitat structure: the evolution and diversification of a

593 complex topic. In: Bell S.S., McCoy E.D., & Mushinsky H.R. (Eds) Habitat Structure.

594 Population and Community Biology Series, vol 8. Springer, Dordrecht. doi:10.1007/978-94-

595 011-3076-9_1.

596 Merritt, R.W., and Cummins, K.W. (Editors). 1996. An introduction to the aquatic insects of

597 North America 3rd edition. Kendal/Hunt Publishing Company.

598 Miller, S.W., Budy, P., and Schmidt, J.C. 2010. Quantifying macroinvertebrate responses to in-

599 stream habitat restoration: applications of meta-analysis to river restoration. Restor. Ecol.

600 18: 8-19. doi:10.1111/j.1526-100X.2009.00605.x.

601 Milner, A.M. 1994. Colonization and succession of invertebrate communities in a new stream in

Page 28 of 43



Draft

29

602 Glacier Bay National Park, Alaska. Freshw. Biol. 32: 387-400. doi:10.1111/j.1365-

603 2427.1994.tb01134.x.

604 Milner, A.M., and Gloyne-Phillips, I.T. 2005. The role of riparian vegetation and woody debris

605 in the development of macroinvertebrate assemblages in streams. River Res. Appl. 21: 403–

606 420. doi:10.1002/rra.815.

607 Milner, A.M., Knudsen, E.E., Soiseth, C., Robertson, A.L., Schell, D., Phillips, I.T., and

608 Magnusson, K. 2000. Colonization and development of stream communities across a 200-

609 year gradient in Glacier Bay National Park, Alaska, U.S.A. Can. J. Fish. Aquat. Sci. 57(11):

610 2319–2335. doi:10.1139/f00-212.

611 Muotka, T., and Syrjänen, J. 2007. Changes in habitat structure, benthic invertebrate diversity,

612 trout populations and ecosystem processes in restored forest streams: a boreal perspective.

613 Freshw. Biol. 52: 724–737. doi:10.1111/j.1365-2427.2007.01727.x.

614 Nelson, S.M., and Lieberman, D.M. 2002. The influence of flow and other environmental factors

615 on benthic invertebrates in the Sacramento River, USA. Hydrobiologia, 489: 117–129.

616 doi:10.1023/A:1023268417851.

617 NRCAN (Natural Resources Canada). "052F13" ed. 3.4 [basemap]. 1:50,000. "National

618 Topographic Data Base (NTDB)". November 16, 2006. http://www.GeoGratis.gc.ca.

619 NRCAN (Natural Resources Canada). "052F12" ed. 5.1 [basemap]. 1:50,000. "National

620 Topographic Data Base (NTDB)". November 16, 2006. http://www.GeoGratis.gc.ca.

621 Oksanen, J., Blanchet, F.G., Friendly, M., Kindt, R., Legendre, P., McGlinn, D., …, Wagner, H.

622 2018. vegan: community ecology package. R package version 2.5-3. https://CRAN.R-

623 project.org/package=vegan.

624 Palmer, M.A., Swan, C.M., Nelson, K., Silver, P., and Alvestad, R. 2000. Streambed landscapes:

Page 29 of 43



Draft

30

625 evidence that stream invertebrates respond to the type and spatial arrangement of patches.

626 Landsc. Ecol. 15(6): 563–576. doi:10.1023/A:1008194130695.

627 Parker, B.R., Schindler, D.W., Beaty, K.G., Stainton, M.P., and Kasian, S.E.M. 2009. Long-term

628 changes in climate, streamflow, and nutrient budgets for first-order catchments at the

629 Experimental Lakes Area (Ontario, Canada). Can. J. Fish. Aquat. Sci. 66: 1848–1863.

630 doi:10.1139/F09-149.

631 Peckarsky, B.L. 1983. Biotic interactions or abiotic limitations? A model of lotic community

632 structure. In Dynamics of lotic ecoystems. Edited by T.D. Fontaine III and S.M. Bartell.

633 Ann Arbor Science Publishers, Ann Arbor, Mich. pp. 303–323.

634 Peckarsky, B.L. 1986. Colonization of natural substrates by stream benthos. Can. J. Fish. Aquat.

635 Sci. 43(3): 700–709. doi:10.1139/f86-085.

636 Poff, N.L. and Ward. J.V. 1990. Physical habitat template of lotic systems: recovery in the

637 context of historical pattern of spatiotemporal heterogeneity. Environ. Manage. 14: 629–

638 645. doi:10.1007/BF02394714.

639 Polis, G.A., Anderson, W.B., and Holt, R.D. 1997. Toward an integration of landscape and food

640 web ecology: the dynamics of spatially subsidized food webs. Annu. Rev. Ecol. Syst. 28(1):

641 289–316. doi:10.1146/annurev.ecolsys.28.1.289.

642 R Core Team. 2019. R: a language and environment for statistical computing. R Foundation for

643 Statistical Computing, Vienna, Austria. URL https://www.R-project.org.

644 Richardson, J.S. and Sato, T. Resources subsidy flows across freshwater-terrestrial boundaries

645 and influence on processes linking adjacent ecosystems. Ecohydrol. 8: 406–415. doi:

Page 30 of 43



Draft

31

646 10.1002/eco.1488.

647 Robinson, C.T., and Minshall, G.W. 1990. Longitudinal debelopment of macroinvertebrate

648 communities below oligotrophic lake outlets. Great Basin Nat. 50: 303–311.

649 Rosenberg, D.M., Berkes, F., Bodaly, R.A., Hecky, R.E., Kelly, C.A., and Rudd, J.W.M. 1997.

650 Large-scale impacts of hydroelectric development. Environ. Rev. 5(1): 27–54.

651 doi:10.1139/a97-001.

652 Schindler, D.W., and Lee, P.G. 2010. Comprehensive conservation planning to protect

653 biodiversity and ecosystem services in Canadian boreal regions under a warming climate

654 and increasing exploitation. Biol. Conserv. 143: 1571–1586.

655 doi:10.1016/j.biocon.2010.04.003.

656 Schindler, D.W., Bayley, S., Parker, B., Beaty, K., Cruikshank, D., Fee, E., Schindler, E., and

657 Stainton, M. 1996. The effects of climatic warming on the properties of boreal lakes and

658 streams at the Experimental Lakes Area, northwestern Ontario. Limnol. Oceanogr. 41(5):

659 1004–1017. doi:10.4319/lo.1996.41.5.1004.

660 Scrimgeour, G., Jones, N., and Tonn, W.M. 2013. Benthic macroinvertebrate response to habitat

661 restoration in a constructed Arctic stream. River Res. Appl. 29(3): 352–365.

662 doi:10.1002/rra.1602.

663 Scrimgeour, G.J., Tonn, W.M., and Jones, N.E. 2014. Quantifying effective restoration:

664 reassessing the productive capacity of a constructed stream 14 years after construction. Can.

665 J. Fish. Aquat. Sci. 71(4): 589–601. doi:10.1139/cjfas-2013-0354.

666 Spence, C., Beaty, K., Blanchfield, P.J., Hrenchuk, L., and MacKay, M.D. 2018. The impact of a

Page 31 of 43



Draft

32

667 loss of hydrologic connectivity on boreal lake thermal and evaporative regimes. Limnol.

668 Oceanogr. 63(5): 2028–2044. doi:10.1002/lno.10822.

669 Suter II, G.W., and Cormier, S.M. 2015. Why care about aquatic insects: uses, benefits, and

670 services. Integr. Environ. Assess. Man. 11(2), 188–194. doi:10.1002/ieam.1600.

671 Thorp, J.H., and Covich, A.P. (Editors). 2010. Ecology and Classification of North American

672 Freshwater Invertebrates. In 3rd edition. Academic Press.

673 Tiegs, S.D., Peter, F.D., Robinson, C.T., Uehlinger, U., and Gessner, M.O. 2008. Leaf

674 decomposition and invertebrate colonization responses to manipulated litter quantity in

675 streams. J. N. Am. Benth. Soc. 27(2): 321–331. doi:10.1899/07-054.1.

676 Tronstad, L.M., Tronstad, B.P., and Benke, A.C. 2007. Aerial colonization and growth: rapid

677 invertebrate responses to temporary aquatic habitats in a river floodplain. J. N. Am.

678 Benthol. Soc. 26(3): 460–471. doi:10.1899/06-057.1.

679 Vandenberg, J.A., Herrell, M., Faithful, J.W., Snow, A.M., Lacrampe, J., Bieber, C., Dayyani,

680 S., and Chisholm, V. 2016. Multiple modeling approach for the aquatic effects assessment

681 of a proposed northern diamond mine development. Mine Water Environ. 35(3): 350–368.

682 doi:10.1007/s10230-015-0337-5.

683 Wallace, J.B., and Webster, J.R. 1996. The role of macroinvertebrates in stream ecosystem

684 function. Annu. Rev. Entomol. 41(1): 115–139. doi:10.1146/annurev.en.41.010196.000555.

685 Wallace, J.B., Eggert, S.L., Meyer, J.L., and Webster, J.R. 2015. Stream invertebrate

686 productivity linked to forest subsidies: 37 stream-years of reference and experimental data.

687 Ecology 96(5): 1213–1228. doi:10.1890/14-1589.1.

Page 32 of 43



Draft

33

688 Warner, R.F. 2012. Environmental impacts of hydroelectric power and other anthropogenic

689 developments on the hydromorphology and ecology of the Durance channel and the Etang

690 de Berre, southeast France. J. Environ. Manage. 104: 35–50.

691 doi:10.1016/j.jenvman.2012.03.011.

692 Williams, D.D., and Hynes, H.B.N. 1976. The recolonization mechanisms of stream benthos.

693 Oikos, 27: 265–272.

694 Williams, D.D., and Hynes, H.B.N. 1977. Benthic community development in a new stream.

695 Can. J. Zool. doi:10.1139/z77-138.

696 Wills, T.C., Baker, E.A., Nuhfer, A.J., and Zorn, T.G. 2006. Response of the benthic

697 macroinvertebrate community in a northern Michigan stream to reduced summer

698 streamflows. River Res. Applic. 22: 819–836. doi: 10.1002/rra.938.

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1

1 Table 1. Physical characteristics of the Diversion and the Reference streams. Mean (range)

2 seasonal daily discharge and July water temperature are shown for each year of sampling.

3 Temperature data was not collected in 2014.

Stream Length (m)

Height (m)

Slope (%)

Year Daily Discharge (m3 s-1) †

Temperature (°C)

Diversion 138 1.66 1.2 2011 0.012 (0.001 - 0.072) 20.0 (15.8 - 25.0)2012 0.012 (0.001 - 0.054) 23.6 (18.1 - 27.6)2013 0.029 (0.004 - 0.163) 21.5 (18.5 - 25.3)2014 0.099 (0.001 - 1.513) -2015 0.020 (0.004 - 0.079) 21.5 (18.1 - 26.2)

Reference 96 2.32 2.4 2011 0.045 (0.000 - 0.206) 23.3 (20.9 - 26.8)2012 0.015 (0.000 - 0.103) 24.6 (20.0 - 31.4)2013 0.042 (< 0.001 - 0.367) 22.8 (16.1 - 29.5)2014 0.083 (0.002 – 0.410) -2015 0.042 (< 0.001 - 0.193) 22.7 (18.3 - 27.5)

4 † daily discharge for the open water season (after spring freshet to freeze up), approximately

5 early May to late November

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1

1 Table 2. Habitat characteristics of upstream (U = upper), midstream (M = middle) and

2 downstream (L = lower; see Fig. 1) sites within the Diversion and Reference streams sampled in

3 July of each year.

Stream Year SiteWet width (cm)

Channel width (cm)

Max. depth (cm) Substrate‡

Riparian cover§(%)

Diversion 2011 U - 187 13.0 S 0M - 215 18.0 S 0L - 280 18.0 G, S 0

2012 U 162 - 22.0 S, C, G 20M 140 - 16.0 S, C

Draft

1

1 Table 3. Results of multiple regression models describing variations in invertebrate abundance, taxa richness, and Shannon-Weiner

2 diversity in the Diversion and Reference streams. Significant annual differences (Tukey) between streams are noted (in bold).

3 Tukey test (Diversion vs. Reference)Response variable

Predictor variables Model significance R2 Year Estimate ± se t-ratio p

Abundance Stream x Year F7, 40 = 6.47, p < 0.001 0.53 2011 -12.0 ± 66.3 -0.18 0.86

2012 9.50 ± 66.3 0.14 0.89

2013 83.8 ± 66.3 1.27 0.21

2015 256 ± 66.3 3.86

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1

1 Table 4. Changes in the occurrence of benthic invertebrate taxa during the first five years since

2 creation of the Diversion channel (2011-2015) and in a nearby Reference stream. Values were

3 calculated from presence/absence data from upstream, middle and downstream sites sampled

4 during July of each year.

TaxaLocation Year n Richness Gained Lost Permanent Turnover (%)Diversion 2011 74 8 - - 4 -

2012 181 13 9 4 8 61.92013 288 19 10 4 13 43.82015 969 25 12 6 - 20.5

Reference 2011 101 18 - - 4 -2012 164 16 8 10 7 52.92013 152 16 7 7 11 43.82015 589 32 21 5 - 27.1

5

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Figure 1. Map of the IISD-Experimental Lakes Area (IISD-ELA) indicating study watersheds (grey outline), aerial photographs of study streams with sampling locations, and the inset map (top right) of the study

location in Canada. The Diversion channel was opened in late fall 2010, and riparian vegetation increased over the first five years of operation (images on right from 2012 and 2015). Maps were produced using

ArcGIS Desktop v10.7 software; data sources: NRCAN and IISD-ELA. [Colour online.]

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Figure 2. (a) Mean daily discharge and (b) water temperature in the Diversion and Reference streams determined by in situ water stage and temperature loggers, respectively. Note: temperature data were not

collected in 2014. [Colour online.]

243x203mm (72 x 72 DPI)

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Figure 3. (a) Total abundance, (b) taxa richness, and (c) Shannon-Weiner diversity of macroinvertebrates collected from the Diversion channel during the first five years of operation, and from a Reference stream.

Grey points represent the six samples collected per year in each stream and diamonds represent the annual mean (± 95% CI). Asterisks indicate years with a significant difference between streams (Tukey test; p <

0.05). [Colour online.]

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Figure 4. Non-metric multidimensional scaling (nMDS) ordination of macroinvertebrate benthic communities in Diversion and Reference streams from annual sampling during the first five years of channel operation

(2011–2015) using a Bray-Curtis dissimilarity index (stress = 0.05). Polygons encompass all years from the same stream. No samples were collected in 2014. [Colour online.]

135x135mm (72 x 72 DPI)

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Figure 5. Relative abundance of invertebrate taxa collected during July from upstream, midstream, and downstream sites in the Diversion and Reference streams. Taxa comprising more than 5% of the total

annual abundance of invertebrates are shown with all remaining taxa grouped as “Other”. See Table 4 for invertebrate abundance. [Colour online.]

203x127mm (300 x 300 DPI)

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Figure 6. Relative abundance of macroinvertebrates grouped into functional feeding groups (FFG) over the first five years in a newly-created Diversion channel and a Reference stream. Data are from upstream, midstream, and downstream sites (see Fig. 1) collected in July of each year. Taxa were assigned to FFG

based on classifications in Merritt and Cummins (1996) and Thorp and Covich (2010). See Table 4 for the abundance of invertebrates collected each year. [Colour online.]

203x127mm (300 x 300 DPI)

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