Abstract
The modification of flows in lotic ecosystems can have dramatic effects on abiotic and biotic processes and change the structure of basal trophic levels. In high-gradient streams, most of the biota are benthic, and decreased flow may homogenize and reduce benthic current velocity, potentially changing stream ecosystem function. Grazing by macroinvertebrates is an important component of stream function because grazers regulate energy flow from primary producers to higher trophic levels. We conducted an experiment to examine how macroinvertebrate grazers facilitated or removed algal biomass across a gradient of benthic current velocity (0–40 cm s−1). We chose three grazers (Drunella coloradensis, Cinygmula spp., and Epeorus deceptivus) from a montane stream and conducted our experiment using 24 artificial stream channels that had three treatments: no grazers (control), single-grazer, and combined-grazer treatments. In the absence of grazers, algal biomass increased with benthic current velocity. Grazer treatments differed from the control in that more algal biomass was removed at higher velocities, whereas algal accrual was largely facilitated at low velocities. The transition from facilitation to removal ranged from 4.5 to 5.9 cm s−1 for individual grazer treatments and occurred at 11.7 cm s−1 for the combined-grazer treatment. Our data suggest that velocity plays a significant role in the facilitation and removal of algae by macroinvertebrate grazers. Additionally, the patterns revealed here could have general implications for algal accrual in systems where flow is reduced.
Similar content being viewed by others
References
Bergy EA, Boettiger CA, Resh RH (1995) Effects of water velocity on the architecture and epiphytes of Cladophora glomerata (Chlorophyta). J Phycol 31:264–271
Biggs BJF, Hickey CW (1994) Periphyton responses to a hydraulic-gradient in a regulated river in New Zealand. Freshw Biol 32:49–59
Biggs BJF, Kilroy C (2000) Stream periphyton monitoring manual. NIWA, Christchurch
Biggs BJF, Goring DG, Nikora VI (1998) Subsidy and stress responses of stream periphyton to gradients in water velocity as a function of community growth form. J Phycol 34:598–607
Brooks AJ, Haesler T, Reinfelds I, Williams S (2005) Hydraulic microhabitats and the distribution of macroinvertebrate assemblages in riffles. Freshw Biol 50:331–344
Cardinale BJ, Palmer MA, Ives AR, Brooks SS (2005) Diversity-productivity relationships in streams vary as a function of the natural disturbance regime. Ecology 86:716–726
Dahl J, Peckarsky BL (2002) Induced morphological defenses in the wild: predator effects on a mayfly, Drunella coloradensis. Ecology 83:1620–1634
Dewson ZS, James ABW, Death RG (2007a) Stream ecosystem functioning under reduced flow conditions. Ecol Appl 17:1797–1808
Dewson ZS, James ABW, Death RG (2007b) Invertebrate community responses to experimentally reduced discharge in small streams of different water quality. J N Am Benthol Soc 26:754–766
Dewson ZS, James ABW, Death RG (2007c) A review of the consequences of decreased flow for instream habitat and macroinvertebrates. J N Am Benthol Soc 26:401–415
Dodds WK (1991) Community interactions between the filamentous alga Cladophora glomerata (L) Kuetzing, its epiphytes and epiphyte grazers. Oecologia 85:572–580
Dodds WK, Clements WH, Gido K, Hilderbrand RH, King RS (2010) Thresholds, breakpoints and nonlinearity in freshwaters as related to management. J N Am Benthol Soc 29:988–997
Downes BJ, Lake PS, Schreiber ESG (1993) Spatial variation in the distribution of stream invertebrates—implications of patchiness for models of community organization. Freshw Biol 30:119–132
Dudley TL (1992) Beneficial effects of herbivores on stream macroalgae via epiphyte removal. Oikos 65:121–127
Dynesius M, Nilsson C (1994) Fragmentation and flow regulation of river systems in the northern 3rd of the world. Science 266:753–762
Feminella JW, Hawkins CP (1995) Interactions between stream herbivores and periphyton: a quantitative analysis of past experiments. J N Am Benthol Soc 14:465–509
Haglund AL, Hillebrand H (2005) The effect of grazing and nutrient supply on periphyton associated bacteria. FEMS Microbiol Ecol 52:31–41
Halpern BS, Silliman BR, Olden JD, Bruno JP, Bertness MD (2007) Incorporating positive interactions in aquatic restoration and conservation. Front Ecol Environ 5:153–160
Hart DD, Finelli CM (1999) Physical-biological coupling in streams: the pervasive effects of flow on benthic organisms. Annu Rev Ecol Syst 30:363–395
Hoffman AL, Olden JD, Monroe JB, Poff NL, Wellnitz T, Wiens JA (2006) Current velocity and habitat patchiness shape stream herbivore movement. Oikos 115:358–368
Holomuzki JR, Lowe RL, Ress JA (2006) Comparing herbivory effects of stream macroinvertebrates on microalgal patch structure and recovery. N Z J Mar Freshw Res 40:357–367
Holomuzki JR, Feminella JW, Power ME (2010) Biotic interactions in freshwater benthic habitats. J N Am Benthol Soc 29:220–244
Karouna NK, Fuller RL (1992) Influence of four grazers on periphyton communities associated with clay tiles and leaves. Hydrobiologia 245:53–64
Lamberti GA, Resh VH (1985) Comparability of introduced tiles and natural substrates for sampling lotic bacteria, algae and macroinvertebrates. Freshw Biol 15:21–30
Ledger ME, Hildrew AG (1998) Temporal and spatial variation in the epilithic biofilm of an acid stream. Freshw Biol 40:655–670
Liess A, Hillebrand H (2004) Invited review: direct and indirect effects in herbivore periphyton interactions. Arch Hydrobiol 159:433–453
Malmqvist B, Wotton RS, Zhang YX (2001) Suspension feeders transform massive amounts of seston in large northern rivers. Oikos 92:35–43
McIntosh AR, Peckarsky BL, Taylor BW (2002) The influence of predatory fish on mayfly drift: extrapolating from experiments to nature. Freshw Biol 47:1497–1513
Oldmeadow DF, Lancaster J, Rice SP (2010) Drift and settlement of stream insects in a complex hydraulic environment. Freshw Biol 55:1020–1035
Opsahl RW, Wellnitz T, Poff NL (2003) Current velocity and invertebrate grazing regulate stream algae: results of an in situ electrical exclusion. Hydrobiologia 499:135–145
Palmer MA, Swan CM, Nelson K, Silver P, Alvestad R (2000) Streambed landscapes: evidence that stream invertebrates respond to the type and spatial arrangement of patches. Landscape Ecol 15:563–576
Passy SI, Larson CA (2011) Succession in stream biofilms is an environmentally driven gradient of stress tolerance. Microb Ecol 62:414–424
Peckarsky BL (1996) Alternative predator avoidance syndromes of stream-dwelling mayfly larvae. Ecology 77:1888–1905
Poff NL, Wellnitz T, Monroe JB (2003) Redundancy among three herbivorous insects across an experimental current velocity gradient. Oecologia 134:262–269
Poff NL, Olden JD, Merritt M, Pepin DM (2007) Homogenization of regional river dynamics by dams and global biodiversity implications. Proc Nat Acad Sci USA 104:5732–5737
Pringle CM, Blake GA, Covich AP, Buzby KM, Finley A (1993) Effects of omnivorous shrimp in a montane tropical stream: sediment removal, disturbance of sessile invertebrates and enhancement of understory algal biomass. Oecologia 93:1–11
Villeneuve A, Montuelle B, Bouchez A (2010) Influence of slight differences in environmental conditions (light, hydrodynamics) on the structure and function of periphyton. Aquat Sci 72:33–44
Vörösmarty CJ, Green P, Salisbury J, Lammers RB (2000) Global water resources: vulnerability from climate change and population growth. Science 289:284–288
Walters AW, Post DM (2011) How low can you go? Impacts of a low-flow disturbance on aquatic insect communities. Ecol Appl 21:163–174
Wellnitz T, Poff NL (2001) Functional redundancy in heterogeneous environments: implications for conservation. Ecol Lett 4:177–179
Wellnitz T, Poff NL (2006) Herbivory, current velocity and algal regrowth: how does periphyton grow when the grazers have gone? Freshw Biol 51:2114–2123
Wellnitz T, Poff NL (2012) Current-mediated periphytic structure modifies grazer interactions and algal removal. Aquat Ecol 46:521–530. doi:10.1007/s10452-012-9419-7
Wellnitz T, Poff NL, Cosyleon G, Steury B (2001) Current velocity and spatial scale as determinants of the distribution and abundance of two rheophilic herbivorous insects. Landscape Ecol 16:111–120
Wellnitz T, Troia M, Ring M (2010) Does ambient substrate composition influence consumer diversity effects on algal removal? Hydrobiologia 652:15–22
Yamada H, Nakamura F (2002) Effect of fine sediment deposition and channel works on periphyton biomass in the Makomanai river, northern Japan. River Res Appl 18:481–493
Zanetell BA, Peckarsky BL (1996) Stoneflies as ecological engineers—hungry predators reduce fine sediments in stream beds. Freshw Biol 36:569–577
Acknowledgments
We thank Megan Ring and Katie Weber for their assistance in the field and the Rocky Mountain Biological Laboratory for logistical support and allowing us access to Copper Creek. We also thank Matt Whiles, Heidi Rantala, and two reviewers for comments that helped improve earlier versions of our manuscript, and David Glover for assistance with SAS software. Funding was provided by the Office of Research and Sponsored Programs at the University of Wisconsin—Eau Claire, and a United States National Science Foundation CAREER Grant to T. W. (DEB-0642512).
Author information
Authors and Affiliations
Corresponding author
Additional information
Handling Editor: Michael T. Monaghan.
Rights and permissions
About this article
Cite this article
Hintz, W.D., Wellnitz, T. Current velocity influences the facilitation and removal of algae by stream grazers. Aquat Ecol 47, 235–244 (2013). https://doi.org/10.1007/s10452-013-9438-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10452-013-9438-z