Effects of Small Dams on Cold Water Stream Fish ... - CiteSeerX

American Fisheries Society Symposium , 2006 © 2006 by the American Fisheries Society

Effects of Small Dams on Cold Water Stream Fish Communities DANIEL B. HAYES Michigan State University, Department of Fisheries and Wildlife 13 Natural Resources Building, East Lansing, Michigan 48824 USA

HOPE DODD1 Illinois Natural History Survey, Center for Aquatic Ecology 607 East Peabody Drive, Champaign, Illinois 61820 USA

JOANNA LESSARD2 Michigan State University, Department of Entomology 243 Natural Science Building, East Lansing, Mighigan 48824 USA

Abstract.—Dams provide many benefits to society, yet they have profound impacts on aquatic ecosystems. In addition to blocking fish migration, small surface-release dams on coldwater streams generally increase water temperature below the dam. The goal of this study was to evaluate how small, surface-release dams affect fish communities, separating the total effect into components related to fragmentation and habitat alteration. The approach taken in this study was to synthesize results of two large studies conducted in the Laurentian Great Lakes basin. The first study focused on low-head barriers ( 0.99), but highly

EFFECTS OF DAMS ON FISH COMMUNITIES

significant differences were observed in the first dimension (P = 0.002) for high-impact hydrodam streams, but not in the second dimension (P = 0.761). Fish species richness averaged slightly higher in downstream sampling sites than upstream sites in reference streams (Table 3), resulting in a net increase of 1.7 species from upstream to downstream reaches. This difference was not statistically significant, however (P = 0.19). Stream reaches without dams showed a high degree of community similarity between upstream and downstream sampling sites (Table 3), with Sørenson’s index (SI) averaging 0.69 and Morisita’s index (MI) averaging 0.75. Fish species richness in upstream reaches of the streams with low-head lamprey barriers was similar to that in reference streams (Table 3). Species richness was much higher in downstream sections of streams with low-head lamprey barriers (P < 0.001; Table 3), producing a net difference of 4.3 species between upstream and downstream reaches. Both Sørenson’s and Morisita’s index indicated a lower degree of similarity in fish community between upstream and downstream reaches in streams with low-head lamprey barriers (Table 3). In the two low-impact hydrodam streams, mean fish species richness decreased from an average of 17.5 species in upstream reaches to 13.0 species in downstream reaches, yielding a net difference of 3.5 species. Given the small sample size, this difference was not significant (P = 0.31). Further, SI and MI indicated that fish community composition and structure were similar between upstream and downstream reaches (Table 3). In the eight streams with hydrodams that had a large temperature impact, mean species richness showed a pattern similar to that in streams with low-head lamprey barriers. Fish species richness increased from an average of 12.0 species in upstream reaches to 16.6 species in downstream reaches (P = 0.038), for a net difference of 4.6

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species. Despite a similar pattern in species richness, the structure and composition of the fish community showed a much lower degree of similarity between upstream and downstream reaches in streams with substantial water warming (Table 3). There was a strong, but variable, relationship between temperature change and community structure (r = -0.62, P = 0.032; Figure 2). For hydrodams, MI declined from high values when the temperature difference was less than 2°C, to low values (e.g., 0.20). In streams with low-head lamprey barriers, the frequency of occurrence for both species was similar between upstream and downstream reaches, and was similar to reference streams. Catch per unit effort of brook trout was higher in upstream reaches (P = 0.004), but CPUE was similar among reaches for brown trout (P = 0.68). Brook trout only occurred in one of the two low-impact hydrodam rivers, and density of brook trout in the downstream reach was approximately 17% of that in the upstream reach (Table 4). Brown trout occurred in both low-impact hydrodam rivers, and their density averaged approximately 400% higher in downstream reaches than in upstream reaches, but this difference was not significant (P = 0.74) due to small sample

9.7±0.8

10.5±0.9

17.5±3.5

12.0±2.4

Reference streams

Low-head lamprey barriers

Low-impact hydrodams

High-impact hydrodams

Upstream

Morisita’s Similarity Index 0.75±0.06

0.52±0.04

0.87±0.06

0.37±0.10

0.69±0.03

0.61±0.03

0.76±0.14

0.49±0.08

13.0±2.0

16.6±1.7

14.8±1.0

11.4±0.7

Downstream

Sørenson’s Similarity Index

Mean Species Richness

Table 3. Mean species richness (±1 SE), Sørenson’s similarity index and Morisita’s similarity index in study streams.

594 HAYES ET AL.

Community Similarity


1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -2

595

Reference Streams Low-head dams Hydro dams

0

2

4

6

Temperature (C) change Figure 2. Relation between temperature change caused by hydrodams and community similarity as measured by Morisita’s Index. Low-head and reference streams data points are means ± 2 SE, and are included for reference relative to results for the hydrodams.

size. The frequency of occurrence of brook trout and brown trout was lower in downstream reaches of rivers with high-impact hydrodams than in upstream reaches. Mean density of brook trout and brown trout was also substantially lower in downstream reaches (P = 0.016), averaging only 1% of upstream density for brook trout and 33% for brown trout (P = 0.017; Table 4).

Discussion Results in our reference streams provide a strong basis for evaluating the patterns observed in streams with low-head lamprey barriers and hydrodams. The slight increase in species richness from upstream to downstream reference reaches is consistent with the river continuum concept (RCC), and with other studies showing increases in species richness in larger streams (Lyons 1996). Both

measures of fish community composition (i.e., SI) and fish community structure (i.e., MI) show that, on average, fish communities are highly similar over the scale of our sampling (typically 10–20 river km). Results of the correspondence analysis support this conclusion, indicating no significant difference in community composition of the numerically dominant species. It is important to note that measures of similarity are sensitive to the level of sampling effort and sampling variability. In this study, nearly all streams were sampled at three upstream and three down stream sites, and site length and width were similar, enabling comparisons among stream groupings. Streams with low-head lamprey barriers generally showed a greater discontinuity in species richness between upstream and downstream reaches than was observed in reference streams. It is interesting

0.9±0.3/pass 7 streams 1.0±0.3/pass 8 streams 248±248/ha 1 stream 370±290/ha 6 streams

Reference streams n=23 streams

Low-head lamprey barriers n=24 streams

Low-impact hydro dams n=2 streams

High-impact Hydro-dams n=8 streams

Upsteam

5±3/ha 3 streams

42±42/ha 1 stream

0.1±0.04/pass 8 streams

0.5±0.2/ pass 5 streams

Downstream

Brook Trout

672±332/ha 8 streams


0.1±0.04pass 6 streams


Upsteam




2.3±1.1/ pass 5 streams

Downstream

Brown Trout

Table 4. Measures of abundance (± 1 SE) and frequency of occurrence for brook trout and brown trout in study streams.

596 HAYES ET AL.


597

to note, however, that this discontinuity occurred due to higher species richness below dams rather than due to reduced richness above dams. In fact, the point estimate for species richness in upstream sections of streams with low-head lamprey barriers was higher (but not significantly so) than the point estimate for reference streams. More detailed analysis on patterns of species richness in streams with low-head lamprey barriers (Dodd 1999) suggest that the heightened species richness below low-head lamprey barriers is due primarily to an accumulation of species below these dams. Interestingly, this accumulation of species richness is not accompanied by higher overall density of fishes below dams (Dodd 1999). These observations indicate that low-head lamprey barriers tend to achieve their intended goal (i.e., prevent access to upstream spawning sites by sea lamprey) without fragmenting the populations and habitats of other fishes to such an extent that species richness in upstream reaches is compromised.

ing the idea that fragmentation by itself had relatively little influence on this attribute of fish communities. The increase in species richness below hydrodams is consistent with the observations in streams with low-head lamprey barriers, but we suspect that it is also partially due to increases in water temperature. Other studies (e.g., Brooker 1981) have shown that species richness in streams typically increases with increasing water temperature. This is one area where differences in the study designs may have substantial influence on the results. The low-head lamprey barrier streams and the references streams were selected from streams with direct connections to the Great Lakes themselves. The streams in the hydrodam study, on the other hand, generally did not have direct, unimpeded access to the Great Lakes. Thus, the presence of potadromous fishes in the lamprey barrier streams may create a situation where more migratory species are available to “accumulate” below these barriers.

The high degree of similarity indicated by the SI for lamprey barrier streams suggests that the composition of fish communities “perched” above lowhead lamprey barriers is not strongly altered by the presence of the dam. Morisita’s index suggests, however, that the upstream–downstream structure of the fish community differs to a greater extent than it does in reference streams. Thus, few species are “lost” above these barriers, but the relative abundance of some species is altered. Because of the high variability in density and sporadic occurrence of many species, it is difficult to point to individual species that are particularly susceptible to the fragmentation effect of low-head lamprey barriers (Dodd 1999). Results of the correspondence analysis likewise do not indicate any directional change in species composition.

The substantially lower values of Sørenson’s and Morisita’s indices in streams with high-impact hydrodams strongly suggest that alteration of downstream habitat conditions (in this case, water temperature) has much greater influence than does fragmentation by itself. In fact, the plot of Morisita’s similarity index versus water temperature change (Figure ) suggests that hydrodams with no impact of water temperature have longitudinal patterns in community structure that is similar to reference streams. The significant difference in the first dimension, which was related to coldwater specialists, produced by the correspondence analysis is further evidence of a directional shift in species composition below the high-impact hydrodams. Although the thermal niche of brook trout, brown trout, rainbow trout, and slimy sculpin differ somewhat, the increase in temperature below the high-impact dams was enough to reduce the abundance of one or more of these species.

In streams with hydrodams causing substantial increases in downstream water temperature, upstream species richness was similar to both reference streams and streams with low-head lamprey barriers, providing additional evidence support-

The abundance and frequency of occurrence of

HAYES ET AL.

598

coldwater game fish (brook trout and brown trout) showed little difference between upstream and downstream reaches in reference streams. Point estimates of brook trout abundance in low-head lamprey barrier streams and low-impact hydrodam streams suggest that the downstream abundance of this species may be reduced due to fragmentation effects, but variability among streams and sites make this relationship uncertain. Brown trout show no clear pattern of decline from upstream to downstream in either the lamprey barrier streams or low-impact hydrodam streams, suggesting that fragmentation affects this species to a lesser extent than brook trout. The large decline in overall trout abundance below high-impact hydrodams demonstrates the degree to which thermal habitat alteration can affect these species. As such, dams on coldwater streams can pose a serious threat to these fisheries, but the principal effect of dams on these species is through habitat alteration rather than habitat and population fragmentation.

Acknowledgments The support of the Great Lakes Fishery Commission, the Michigan Department of Natural Resources, and Michigan State University is gratefully acknowledged.

References Brooker, M. P. 1981. The impact of impoundments on the downstream fisheries and general ecology of rivers. Advances in Applied Biology 6:91–152. Dauble, D. D., T. P. Hanrahan, D. R. Geist, and M. J. Parsley. 2003. Impacts of the Columbia River hydroelectric system on main-stem habitats of fall Chinook salmon. North American Journal of Fisheries Management 23:641–659. Dodd, H. R. 1999. The effects of low-head lamprey barrier dams on stream habitat and fish communities in tributaries

of the Great Lakes. Master’s thesis. Michigan State University, East Lansing. Dodd, H. R., D. B. Hayes, J. R. Baylis, L. M. Carl, J. D. Goldstein, R. L. McLaughlin, D. L. G. Noakes, L. M. Porto, and M. L. Jones. 2003. Low-head lamprey barrier effects on stream habitat and fish communities in the Great Lakes basin. Journal of Great Lakes Research 29(Supplement 1):386–402. Heinz Center. 2002. Dam removal: science and decision making. H. John Heinz Space Center for Science, Economics, and the Environment. Washington, DC. Kondolf, G. M., and S. Li. 1992. The pebble count technique for quantifying surface bed material size in instream flow studies. Rivers 3:80–87. Lessard. J. L. 2000. Temperature effects of dams on coldwater fish and macroinvertebrate communities. Master’s thesis. Michigan State University, East Lansing. Lessard, J. L., andD. B. Hayes. 2003. Effects of elevated water temperature on fish and macroinvertebrate communities below small dams. River Research & Applications 19:721– 732. Lyons, J. 1996. Patterns in the species composition of fish assemblages among Wisconsin streams. Environmental Biology of Fishes 45:329–341. Manly, B. F. J. 1994. Multivariate statistical methods a primer. Chapman and Hall/CRC, Boca Raton, Florida. Morisita, M. 1959. Measuring of interspecific association and similarity between communities. Memoires of the Faculty of Science, Kyushu University, Series E Biology 3:65–80. Morita, K., and A. Yokota. 2002. Population viability of streamresident salmonids after habitat fragmentation: a case study with white-spotted charr (Salvelinus leucomaenis) by an individual based model. Ecological Modeling 155:85–94. Poff, N. L., and D. D. Hart. 2002. How dams vary and why it matters for the emerging science of dam removal. Bioscience 52:659–668. Searle, S. R. 1987. Linear models for unbalanced data. Wiley, New York. Sørenson, T. 1948. A method of establishing groups of equal amplitude in plant sociology based on similarity of species content. Kongelige Danske Videnskabernes Selskabs Skrifter 5:1–34. Ward, J. V., and J. A. Stanford. 1983. The serial discontinuity concept of lotic ecosystems. Pages 29–42 in T. D. Fontaine and S. M. Bartell editors. Dynamics of lotic ecosystems. Ann Arbor Science, Ann Arbor, Michigan.

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Appendix 1. List of species and number of individuals in descending order of total catch.

Common name

Scientific Name

Total Catch

Eastern blacknose dace

Rhinichthys atratulus

3184

Mottled sculpin

Cottus bairdii

2621

Longnose dace

Rhinichthys cataractae

2477

Creek chub

Semotilus atromaculatus

2130

Rainbow trout

Oncorhynchus mykiss

1800

Common shiner

Luxilus cornutus

1740

Johnny darter

Etheostoma nigrum

1450

Brown trout

Salmo trutta

1314

White sucker

Catostomus commersoni

1203

Slimy sculpin

Cottus cognatus

854

Rainbow darter

Etheostoma caeruleum

748

Central mudminnow

Umbra limi

556

Rock bass

Amblophites rupestris

479

Brook trout

Salvelinus fontinalus

419

Fantail darter

Etheostoma flabellare

387

Hornyhead chub

Nocomis biguttatus

302

Blacknose shiner

Notropis heterolepis

292

Bluntnose minnow

Pimephales notatus

248

American brook lamprey

Lampetra appendix

246

Logperch

Percina caprodes

241

Black bullhead

Ameiurus melas

217

Brook stickleback

Culaea inconstans

212

600

HAYES ET AL.

Appendix 1 continued.

Common name

Scientific Name

Total Catch

Rosyface shiner

Notropis rubellus

199

Northern redbelly dace

Phoxinus eos

166

Pumpkinseed

Lepomis gibbosus

157

Lake chub

Couesius plumbeus

154

Blackside darter

Percina maculata

151

Northern hog sucker

Hypentelium nigricans

118

Coho salmon

Oncorhynchus kisutch

100

Green sunfish

Lepomis cyanellus

100

Bluegill

Lepomis macrochirus

98

Burbot

Lota lota

92

Cutlips minnow

Exoglossum maxilingua

88

Yellow perch

Perca flavescens

86

Smallmouth bass

Micropterus dolomieui

77

Warmouth

Lepomis gulosus

72

Threespine stickleback

Gasterosteus aculeatus

67

Spotfin shiner

Cyprinella spilopterus

63

Brassy minnow

Hybognathus hankinsoni

57

Blackchin shiner

Notropis heterodon

53

Largemouth bass

Micropterus salmoides

49

Shorthead redhorse

Moxostoma macrolepidotum 45

Common carp

Cyprinus carpio

44

Fathead minnow

Pimephales promelas

43

601



Common name

Scientific Name

Total Catch

Northern pike

Esox lucius

35

Pearl dace

Margariscus margarita

33

Sea lamprey

Petromyzon marinus

29

Stonecat

Noturus flavus

29

Northern brook lamprey

Ichthyomyzon fossor

20

Iowa darter

Etheostoma exile

20

River chub

Nocomis micropogon

20

Trout-perch

Percopsis omiscomaycus

19

Central stoneroller

Campostoma anomalum

14

Yellow bullhead

Ameiurus natalis

14

Brown bullhead

Ameiurus nebulosus

12

Fallfish

Semotilus corporalis

10

Emerald shiner

Notropis atherinoides

10

Chinook salmon

Oncorhynchus tshawytscha

9

Bowfin

Amia calva

9

White crappie

Poxomis annularis

9

Golden Shiner

Notemigonus crysoleucus

6

Spottail shiner

Notropis hudsonicus

6

Golden redhorse

Moxostoma crythrurum

5

Lake trout

Salvelinus namaycush

5

Mimic shiner

Notropis volucellus

5

Sauger

Sander canadense

4

602

HAYES ET AL.


Common name

Scientific Name

Total Catch

Silver shiner

Notropis photogenis

4

Striped shiner

Luxilus chrysocephalus

4

Redfin pickerel

Esox americanus vermiculatus 4

Black crappie

Poxomis nigromaculatus

3

Atlantic salmon

Salmo salar

2

Greater redhorse

Moxostoma valenciennesi

2

Ninespine stickleback

Pungitius pungitius

2

River darter

Percina shumardi

2

Ruffe

Gymnocephalus cernuus

2

Silver redhorse

Moxostoma anisurum

2

White bass

Morone chrysops

2

American eel

Anguilla rostrata

1

Channel catfish

Ictalurus punctatus

1

Chestnut lamprey

Ichthyomyzon castaneus

1

Finescale dace

Phoxinus neogaeus

1

Flathead catfish

Pylodictis olivaris

1

Pugnose minnow

Opsopoeodus emilie

1

Red shiner

Notropis lytrensis

1

Southern redbelly dace

Phoxinus erythrogaster

1

Walleye

Sander vitreus

1

Longnose sucker

Catostomus catostomus

1