Artículos de revistas: "Stream ecology"

1

Waters, Thomas F. "Stream Ecology". Ecology 77, n.º 6 (septiembre de 1996): 1953. http://dx.doi.org/10.2307/2265801.

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2

Findlay, Stuart. "Stream microbial ecology". Journal of the North American Benthological Society 29, n.º 1 (marzo de 2010): 170–81. http://dx.doi.org/10.1899/09-023.1.

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3

Füreder, Leopold y Georg H. Niedrist. "Glacial Stream Ecology: Structural and Functional Assets". Water 12, n.º 2 (30 de enero de 2020): 376. http://dx.doi.org/10.3390/w12020376.

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High altitude glacier-fed streams are harsh environments inhabiting specialized invertebrate communities. Most research on biotic aspects in glacier-fed streams have focused on the simple relationship between presence/absence of species and prevailing environmental conditions, whereas functional strategies and potentials of glacial stream specialists have been hardly investigated so far. Using new and recent datasets from our investigations in the European Alps, we now demonstrate distinct functional properties of invertebrates that typically dominate glacier-fed streams and show significant relationships with declining glacier cover in alpine stream catchments. In particular, we present and argue about cause-effect relationships between glacier cover in the catchment and temperature, community structure, diversity, feeding strategies, early life development, body mass, and growth of invertebrates. By concentrating on key taxa in glacial and non-glacial alpine streams, the relevance of distinct adaptations in these functional components becomes evident. This clearly demonstrates that further studies of functional characteristics are essential for the understanding of peculiar diversity patterns, successful traits and their plasticity, evolutionary triggered species adaptions, and flexibilities.

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4

Cecala, Kristen, Michael Dorcas y Steven Price. "Ecology of juvenile Northern watersnakes (Nerodia sipedon) inhabiting low-order streams". Amphibia-Reptilia 31, n.º 2 (2010): 169–74. http://dx.doi.org/10.1163/156853810791069029.

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AbstractThe juvenile stage for many reptiles is considered “the lost years” because of low capture probabilities, however understanding factors impacting juvenile survivorship and recruitment is critical for conservation of populations. We studied the ecology of juvenile Northern watersnakes, Nerodia sipedon, by intensively sampling a first-order stream and determined the occupancy of juveniles in 30 low-order streams in the Piedmont of North Carolina. Juveniles were relatively abundant within a single stream (n = 62 ± 9), and their capture probabilities were positively related to increasing stream-water temperatures. We also found that juveniles had high survivorship (ϕ = 0.87 ± 0.017). Occupancy of juvenile N. sipedon in low-order, Piedmont streams may be greater at streams that have confluences with high order streams or lakes, which potentially support adult N. sipedon populations. This study provides important information regarding the natural history of juvenile reptiles and indicates the importance of low order streams as habitat for N. sipedon populations.

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5

Soares, Bruno Eleres y Gabriel Nakamura. "ECOLOGIA FILOGENÉTICA DE COMUNIDADES DE PEIXES DE RIACHO NEOTROPICAIS". Oecologia Australis 25, n.º 02 (16 de junio de 2021): 433–48. http://dx.doi.org/10.4257/oeco.2021.2502.13.

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Neotropical stream fishes exhibit a complex evolutionary history and encompass both old and recent lineages. Patterns of species diversity of stream fishes are relatively well-studied for Neotropical streams, but not for patterns of clade distribution and historical factors that structure these assemblages, which are the main interests of phylogenetic ecology. Understanding the evolutionary context of communities provides important insights into large-scale mechanisms that structure them. This review aims to: (i) discuss the main concepts of phylogenetic ecology and its application to Neotropical stream fishes; and (ii) highlight the main methods applied in this background. The first section presents the main phylogenetic hypothesis of fishes and discusses how their gaps in Neotropical stream fishes hinder phylogenetic ecology. Afterward, we discuss the main concepts of phylogenetic ecology (phylogenetic signal, community phylogenetic structure, and phylogenetic diversity), as well as gaps and potential applications of these concepts and tools to understand Neotropical stream fish assemblages. The second section introduces the main methods to address the phylogenetic ecology, including a standardized procedure to edit fish phylogenetic trees, comparative methods, and indices and analytical tools to understand community structure and conservation importance. Finally, we discuss the perspectives to the next years to better understand the Neotropical stream fish assemblages in the light of past and current historical processes.

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6

Dolinsek, Ivan J., Robert L. McLaughlin, James W. A. Grant, Lisa M. O’Connor y Thomas C. Pratt. "Do natural history data predict the movement ecology of fishes in Lake Ontario streams?" Canadian Journal of Fisheries and Aquatic Sciences 71, n.º 8 (agosto de 2014): 1171–85. http://dx.doi.org/10.1139/cjfas-2013-0294.

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Little is known about the movements of most stream fishes, so fisheries managers often rely on natural history data from the literature to make management decisions. Observations of over 15 000 individuals from 37 species across 3 years were used to evaluate four aspects of the reliability of literature data for predicting the movement behaviour of stream fishes: (i) water temperature when fish enter streams; (ii) reasons for moving into the streams; (iii) stream residence times of migrants; and (iv) relative use of lake and stream habitats. Comparisons of our data for arrival times in the streams, water temperature at arrival, and time spent in the streams were highly correlated with literature data, whereas relative use of the lake was not. Further, our detailed data revealed two novel findings: (1) in many species juveniles were also moving into streams, even in those species where adults were clearly spawning in the streams; and (2) adult-sized individuals were moving into streams for nonreproductive purposes. Our results suggest that fishery managers can confidently use natural history information to gain general insights into the movement ecology of fishes, but should also recognize that this information remains incomplete in important ways.

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7

Findlay, Stuart, Robert Hall y William V. Sobczak. "Methods on stream ecology". Limnology and Oceanography 43, n.º 5 (julio de 1998): 1020–21. http://dx.doi.org/10.4319/lo.1998.43.5.1020.

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8

Stout, Ben. "Methods in Stream Ecology". Journal of the North American Benthological Society 27, n.º 1 (marzo de 2008): 223. http://dx.doi.org/10.1899/27.1.br.157.

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9

Wipfli, Mark S., F. Richard Hauer y Gary A. Lamberti. "Methods in Stream Ecology." Ecology 78, n.º 3 (abril de 1997): 960. http://dx.doi.org/10.2307/2266075.

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10

Fletcher, Melanie. "Methods in Stream Ecology". Freshwater Biology 53, n.º 12 (diciembre de 2008): 2639. http://dx.doi.org/10.1111/j.1365-2427.2008.02042.x.

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11

Trimble, Stanley W. "Methods in stream ecology". Journal of Hydrology 201, n.º 1-4 (diciembre de 1997): 388–89. http://dx.doi.org/10.1016/s0022-1694(97)00093-0.

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12

McNie, Pierce M. y Russell G. Death. "The effect of agriculture on cave-stream invertebrate communities". Marine and Freshwater Research 68, n.º 11 (2017): 1999. http://dx.doi.org/10.1071/mf16112.

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The impacts that land-use changes have on cave-stream fauna have not been considered widely in the investigations of land-use impacts on stream ecology. The present study examines how above-ground agriculture may influence cave-stream invertebrate communities. The invertebrate communities in four cave streams and their surface counterparts were sampled in 2014–2015, including two drained predominantly agricultural catchments and two drained forested catchments. These communities were examined alongside habitat and GIS land-use data to determine the relationship between above-ground land use and the stream communities. Invertebrate community composition and ecological health for surface streams was different between the agricultural and forest catchments. These differences were less pronounced within the cave-stream communities. Sedimentation was the principal agricultural stressor in the cave streams. The overall effects of agriculture were lower within the cave streams than on the surface; this is likely to be due to the reduced number of potentially deleterious stressors on cave streams.

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13

Kumar, M. Arun, S. Venu y G. Padmavati. "Habitat Ecology and Ichthyofaunal Diversity of Two Creeks and Their Associated Streams from Port Blair, South Andaman Islands". International Journal of Ecology 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/1649368.

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Habitat ecology and ichthyofaunal diversity were analyzed from two creeks and their associated streams in Port Blair: one was perennial and the other one was seasonal. Various habitat types like riffles, pools, and major and minor bends in both streams were studied. The perennial stream has 12 riffles and 14 pools from head point to the entering point of the creek. The seasonal stream has 15 riffles and 13 pools from the starting point to the sink. The perennial stream was found to have higher ichthyofaunal diversity than the seasonal stream: 1701 individuals constituting 8 orders, 30 families, 42 genera, and 54 species were recorded. Among these, 395 specimens represented by 21 species were found in perennial stream, 291 specimens with 11 species were found in seasonal stream, 863 specimens by 48 species were noted in creek, and 152 specimens constituting 14 species in sink were recorded. The physicochemical parameters of the habitats showed more or less a similar trend. The average dissolved oxygen value of the perennial stream was higher than that of the seasonal stream. Higher temperature values were noted during the postmonsoon season. This study has indicated a wide lacuna in the knowledge of the fresh water habitats and their inhabitants on these islands.

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14

Jones, Nicholas E. "Incorporating lakes within the river discontinuum: longitudinal changes in ecological characteristics in stream–lake networks". Canadian Journal of Fisheries and Aquatic Sciences 67, n.º 8 (agosto de 2010): 1350–62. http://dx.doi.org/10.1139/f10-069.

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Lakes and rivers are intimately connected in an alternating series of lentic and lotic reaches in many regions. The study of lakes and their outlets in hierarchical and branching river networks has not gained the attention of stream ecologists, and little effort has been focused on synthesizing the ecology of lake–stream interactions within a drainage network. Rapid and predictable changes in the ecological characteristics of streams occur at the interface with lakes. The influence that a lake might have on a stream is dependent on its position within the stream, stream type and size, lake size and shape, and the inlet and outlet positions. Little is known about the influences of multiple lakes within stream–lake networks and how these influences are determined by network shape and pattern. Fruitful collaborations and novel insights will come from the combined efforts of limnologists, stream ecologists, and landscape ecologists. Geographic information systems and network analyses will play an important role in summarizing aquatic landscape characteristics and creating a predictive science of aquatic networks. Lakes need to be more explicitly incorporated into ecological concepts in stream ecology, and reciprocally, streams need to be incorporated into ecological concepts involving lakes for the successful management and conservation of our aquatic resources.

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15

Brejão, Gabriel Lourenço, Cecília Gontijo Leal y Pedro Gerhard. "A ECOLOGIA DE PEIXES DE RIACHO SOB A PERSPECTIVA DA ECOLOGIA DE PAISAGENS". Oecologia Australis 25, n.º 02 (16 de junio de 2021): 475–93. http://dx.doi.org/10.4257/oeco.2021.2502.16.

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Landscape ecology emphasizes the interaction between spatial patterns and ecological processes, i.e., the consequences of spatial heterogeneity across various scales. It is an interdisciplinary science that seeks to understand the relationships between ecological patterns and processes considering different spatial and temporal scales. This understanding has been supported by the rapid development of a methodological framework, largely based on Geographic Information Systems (GIS). Thus, it has allowed understanding how ecological processes are affected by anthropogenic activities that trigger profound changes in ecosystems, such as habitat loss and fragmentation. Although commonly applied to studies in terrestrial ecosystems, there is a time lag in both theoretical development and methodological adaptation of landscape ecology applied to studies in streams, especially in Brazil. Methodological adaptations are necessary considering the particularities of aquatic environments in relation to terrestrial ones. For example, streams have a hierarchical spatial organization that results in local conditions dependent on the regional context. In fact, streams are connected to the landscape in which they are inserted through multiple spatial and temporal scales. This hydrologic connectivity, and the low ratio/proportion of aquatic/terrestrial areas, in turn results in anthropogenic impacts accumulating along the hydrographic networks. Considering the above, the objectives of this chapter are: (1) Introduce the general concepts of landscape ecology; (2) Present the main methods of spatial data acquisition and management relevant to stream approaches; (3) Describe the spatial and temporal scales relevant to stream ecology and (4) Discuss the potential of landscape ecology to assess human impacts on streams. Landscape ecology has much to offer to the study of stream fish in Brazil and has shown to be a promising approach for advancing this frontier of knowledge.

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16

LOWE, WINSOR H., GENE E. LIKENS y MARY E. POWER. "Linking Scales in Stream Ecology". BioScience 56, n.º 7 (2006): 591. http://dx.doi.org/10.1641/0006-3568(2006)56[591:lsise]2.0.co;2.

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17

Boyero, Luz. "Towards a global stream ecology". Trends in Ecology & Evolution 15, n.º 10 (octubre de 2000): 390–91. http://dx.doi.org/10.1016/s0169-5347(00)01957-1.

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18

Esteves, Katharina Eichbaum, José Marcelo Rocha Aranha y Míriam Pilz Albrecht. "ECOLOGIA TRÓFICA DE PEIXES DE RIACHO: UMA RELEITURA 20 ANOS DEPOIS". Oecologia Australis 25, n.º 02 (16 de junio de 2021): 266–82. http://dx.doi.org/10.4257/oeco.2021.2502.04.

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The great extent and diversity of ecological conditions of stream ecosystems in Brazil are widely recognized. In the last two decades, studies on stream fishes have contributed to the knowledge about their trophic ecology. However, the large amount of available information is yet fragmented. This chapter presents the state of the art of studies about feeding and trophic ecology of stream fishes in Brazil, an essential topic to understand ecosystem functioning. The review presented here was based on searches on different databases (Scopus, Web of Science, ASFA and Scielo). Results included studies that used different methods and approaches to evaluate the diet of fish species and assemblages, their relationship with morphology and ontogenetic variation, resource partitioning, seasonal and spatial variations, and anthropic impacts on trophic interactions. Finally, knowledge gaps and perspectives for future studies on fish trophic ecology are pointed out, including responses to anthropic influences, theoretical aspects, and the use of underexplored approaches to the subject, which may aid to our understanding of tropical streams

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19

Growns, IO y JA Davis. "Comparison of the macroinvertebrate communities in streams in logged and undisturbed catchments 8 years after harvesting". Marine and Freshwater Research 42, n.º 6 (1991): 689. http://dx.doi.org/10.1071/mf9910689.

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Changes in lotic macroinvertebrate communities 8 years after logging were examined in two sets of paired catchments (Sutton and Lewin) in south-western Western Australia by using analysis of variance, classification (TWINSPAN), and ordination (semi-strong hybrid multidimensional scaling). Both paired catchments contained an undisturbed stream and a stream where clearfelling had been taken to the stream edges. The Sutton catchment also contained a stream where clearfelling had occurred but a 100 m-wide strip of vegetation had been retained as a buffer zone. Differences in richness and abundance of animals between the undisturbed and clearfelled streams in the two catchments were obscured by differences between the sites within each stream. However, ordination of the samples revealed differences in the composition of the macroinvertebrate communities between the clearfelled and undisturbed streams in both catchments. Underlying environmental gradients that separated the invertebrate communities in the clearfelled streams from those in the undisturbed streams, in ordination space, were conductivity, the amount of coarse and fine particulate organic matter, and a reduction in total nitrogen. In all, 11 macroinvertebrate taxa were found to be associated with the separation of samples from the undisturbed and clearfelled streams, this response probably being due to increases in conductivity within the clearfelled streams. Macroinvertebrate community structure in the buffered stream was different from that in the undisturbed stream but was more similar to the latter than to that in the clearfelled stream. Physical and chemical parameters of the buffered stream were also more similar to those of the undisturbed stream. These results indicated that the 100 m-wide buffer zone appeared to be effective in ameliorating any disturbance due to clearfelling.

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20

Boulton, AJ. "Stream ecology and surface-hyporheic hydrologic exchange: Implications, techniques and limitations". Marine and Freshwater Research 44, n.º 4 (1993): 553. http://dx.doi.org/10.1071/mf9930553.

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In many streams with coarse substrata, there is continuous exchange between surface water and interstitial (hyporheic) water. Upwelling hyporheic water usually contains less dissolved oxygen and may provide nutrients that are limiting in the surface water. Downwelling stream water carries oxygen, surface detritus and other material to the hyporheic zone where microbes and invertebrates reside. The magnitude and direction of this hydrologic exchange can be measured using relatively simple techniques (such as dye injections and mini-piezometers) although there are some important limitations to consider. As hydrologic exchange has been shown to affect the distribution of benthic algae and invertebrates in some streams, this variable has implications for a variety of lotic studies including those of drift, leaf breakdown, benthic invertebrate colonization, sedimentation, and nutrient limitation. Experiments in flumes and artificial stream channels usually remove the influence of hydrologic exchange although it would be possible to incorporate this into their design. Stream ecologists should consider assessing the significance of the hyporheic zone to surface processes by quantifying the vectors of hydrologic exchange to ascertain how these may affect results of work conducted on the benthos at a variety of scales.

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21

Meyer, Judy L. "Stream Health: Incorporating the Human Dimension to Advance Stream Ecology". Journal of the North American Benthological Society 16, n.º 2 (junio de 1997): 439–47. http://dx.doi.org/10.2307/1468029.

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22

Turunen, Jarno, Jukka Aroviita, Hannu Marttila, Pauliina Louhi, Tiina Laamanen, Mikko Tolkkinen, Pirkko-Liisa Luhta, Bjørn Kløve y Timo Muotka. "Differential responses by stream and riparian biodiversity to in-stream restoration of forestry-impacted streams". Journal of Applied Ecology 54, n.º 5 (28 de marzo de 2017): 1505–14. http://dx.doi.org/10.1111/1365-2664.12897.

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23

Hughes, JMR y B. James. "A hydrological regionalization of streams in Victoria, Australia, with implications for stream Ecology". Marine and Freshwater Research 40, n.º 3 (1989): 303. http://dx.doi.org/10.1071/mf9890303.

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Annual, monthly, low and peak flow data were used to classify and ordinate 138 stream gauges in Victoria. Sixteen hydrological variables were used and low-flow and entire-flow regionalizations were derived. The low-flow regionalization was spatially indistinct and therefore unusable, but the entire-flow regionalization produced five distinctive and spatially significant regions. Least-squares relationships were calculated between mean annual runoff, catchment area and coefficient of variation of annual flows, and the 16 variables. Rivers in the dry western districts of Victoria exhibit high variability of annual, monthly and peak flows, and low specific low flows. The converse is true for rivers in the western highlands of Victoria. Stream regionalizations are a useful tool for stream ecologists, and may be used for generating hypotheses, for detecting representative rivers and for producing baseline stream surveys.

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24

Alves, Carlos Bernardo Mascarenhas, Paulo Santos Pompeu, Rosana Mazzoni y Marcelo Fulgêncio Guedes Brito. "AVANÇOS EM MÉTODOS DE COLETA DE PEIXES E CARACTERIZAÇÃO DE HABITAT DE RIACHOS TROPICAIS". Oecologia Australis 25, n.º 02 (16 de junio de 2021): 246–65. http://dx.doi.org/10.4257/oeco.2021.2502.03.

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This paper brings some advances in fish data sampling and stream environments. Since the publication in 1999 of volume VI “Ecology of Stream Fishes” in the former Oecologia Brasiliensis journal, today Oecologia Australis, several progresses have occurred. Several methods of collecting fish themselves, have remained the same. However, in relation to the use of electric fishing, collection of eggs and fish larvae, and characterization of physical habitats in streams, there was remarkable development and improvement. The purpose of this article is to present the “state of the art” of these three aspects of sampling fish and habitats in streams. By the end, preparation methods of samples for genetic, stable isotopes and heavy metal analyses are briefly presented

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25

Minshall, G. Wayne, Kenneth W. Cummins, Robert C. Petersen, Colbert E. Cushing, Dale A. Bruns, James R. Sedell y Robin L. Vannote. "Developments in Stream Ecosystem Theory". Canadian Journal of Fisheries and Aquatic Sciences 42, n.º 5 (1 de mayo de 1985): 1045–55. http://dx.doi.org/10.1139/f85-130.

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Four significant areas of thought, (1) the holistic approach, (2) the linkage between streams and their terrestrial setting, (3) material cycling in open systems, and (4) biotic interactions and integration of community ecology principles, have provided a basis for the further development of stream ecosystem theory. The River Continuum Concept (RCC) represents a synthesis of these ideas. Suggestions are made for clarifying, expanding, and refining the RCC to encompass broader spatial and temporal scales. Factors important in this regard include climate and geology, tributaries, location-specific lithology and geomorphology, and long-term changes imposed by man. It appears that most riverine ecosystems can be accommodated within this expanded conceptual framework and that the RCC continues to represent a useful paradigm for understanding and comparing the ecology of streams and rivers.

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Luo, Zengliang, Qiting Zuo, Rong Gan y Junxia Ma. "Effect of human activity intensity on stream structure and connectivity in Shaying River Basin, China". Water Supply 18, n.º 3 (24 de julio de 2017): 754–66. http://dx.doi.org/10.2166/ws.2017.122.

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Abstract In order to quantify the relationship between human activity intensity and the evolution of stream structure and connectivity, the characteristics of spatial distribution and temporal evolution of stream structure and connectivity in different periods were studied by using river structure parameters and landscape ecology methods. The results indicate the following. (1) The mainstream trend of stream system, with the stream development coefficient decreased by 18.35% and 22.50% for the second- and third-level of stream, is obvious. (2) Human activity intensity has a significant impact on the change of stream structure and connectivity. Under the background of economy domination, the stronger human intervention is, the simpler stream structure will be, and the poorer stream connectivity will be. (3) From the view of time series, it is considered that human activities are the main reasons for affecting the change of stream structure and connectivity in the short term, while the natural factors have little effect. (4) The length of low-level streams is more affected by human activities than that of the high-level streams, but water surface ratio is opposite. This study can provide a reference for coordinating the contradiction between socio-economic development and protection of stream systems.

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27

Schlosser, Isaac J. "Stream Fish Ecology: A Landscape Perspective". BioScience 41, n.º 10 (noviembre de 1991): 704–12. http://dx.doi.org/10.2307/1311765.

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28

Hart, David D. y Dina M. Fonseca. "An important confluence for stream ecology". Trends in Ecology & Evolution 11, n.º 7 (julio de 1996): 272–73. http://dx.doi.org/10.1016/0169-5347(96)30027-x.

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Ludlam, John P. y Allison H. Roy. "Understanding effects of small dams on benthic metabolism and primary production in temperate forested streams". Fundamental and Applied Limnology / Archiv für Hydrobiologie 193, n.º 3 (21 de abril de 2020): 227–37. http://dx.doi.org/10.1127/fal/2020/1260.

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Dams can alter the chemical and physical conditions of downstream environments by increasing stream temperatures, altering nutrient limitation, reducing flow variability, and reducing fine sediment deposition. However, little is known about how fundamental stream ecosystem processes like productivity and respiration respond to dams. Nutrient diffusing substrates were installed in three dam streams and three control streams to evaluate the effect of dams on benthic gross primary productivity (GPP), respiration (R), and chlorophyll α production. Dam streams were an average of 5.6 °C warmer than control streams but GPP, R and chlorophyll α were not different between control and dam streams. Phosphorus enrichment increased heterotrophic R relative to controls (~1.8×) but not autotrophic GPP, R or chlorophyll α. Stream nutrient concentrations and nutrient limitation of heterotrophic R were similar in dam and control streams, suggesting that the dams had limited effects on nutrient transport downstream. Autotrophic GPP, R and chlorophyll α were limited by light and varied within and across streams, potentially masking our ability to detect differences caused solely by dams. Dams may alter stream ecosystem func- tion but consideration of other factors associated with and independent of dams is critical for predicting ecosystem responses to dams.

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30

Battin, T. J., A. Wille, R. Psenner y A. Richter. "Regional hydrology controls stream microbial biofilms: evidence from a glacial catchment". Biogeosciences Discussions 1, n.º 1 (31 de agosto de 2004): 497–531. http://dx.doi.org/10.5194/bgd-1-497-2004.

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Abstract. Glaciers are highly responsive to global warming and important agents of landscape heterogeneity. While it is well established that glacial ablation and snowmelt regulate stream discharge, linkage among streams and streamwater hydrogeochemistry, the controls of these factors on stream microbial biofilms remain insufficiently understood. We investigated glacial (metakryal, hypokryal), groundwater-fed (krenal) and snow-fed (rhithral) streams – all of them representative for alpine stream networks – and present evidence that these hydrologic and hydrogeochemical factors differentially affect sediment microbial biofilms. Average microbial biomass and bacterial carbon production were low in the glacial streams, whereas bacterial cell size, biomass, and carbon production were higher in the tributaries, most notably in the krenal stream. Whole-cell in situ fluorescence hybridization revealed reduced detection rates of the Eubacteria and higher abundance of α-Proteobacteria in the glacial stream, a pattern that most probably reflects the trophic status of this ecosystem. Our data suggest low flow during the onset of snowmelt and autumn as a short period (hot moment) of favorable environmental conditions with pulsed inputs of allochthonous nitrate and dissolved organic carbon, and with disproportional high microbial growth. Krenal and rhithral streams with more constant and favorable environments serve as possible sources of microbes and organic matter to the main glacial channel during periods (e.g. snowmelt) of elevated hydrologic linkage among streams. Ice and snow dynamics have a crucial impact on microbial biofilms, and we thus need better understanding of the microbial ecology and enhanced consideration of critical hydrological episodes in future models predicting alpine stream communities.

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Caetano, Dyego Leonardo Ferraz, Edson Fontes de Oliveira y Cláudio Henrique Zawadzki. "ICHTHYOFAUNA OF TRIBUTARY STREAMS OF THE CINZAS RIVER BASIN, PARANAPANEMA RIVER, BRAZIL". Oecologia Australis 25, n.º 01 (15 de marzo de 2021): 142–53. http://dx.doi.org/10.4257/oeco.2021.2501.13.

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Streams are environments that are very affected by human activities such as pollution, deforestation of riparian forests and introduction of exotic species. In this context, it is important to know its biodiversity for monitoring and conservation. The present study inventoried the fish fauna of three tributary streams of the Jacarezinho River (Cinzas River basin, Paranapanema River) with different environmental characteristics: Água dos Anjos, Monjolinho and Ubá streams. Quarterly collections were performed in the period between October 2012 and July 2013 at the headwaters, in the middle and at the mouth of each stream, using electrofishing. We analyzed the parameters of species richness, total abundance, relative abundance, capture constancy, rarefaction curves of Coleman, and richness estimators ACE and ICE. We captured a total of 7102 individuals, distributed in six orders, 12 families and 33 species. The most abundant order was Characiformes (76.15 %), while the most abundant species were: Bryconamericus iheringii (39.5 %), Astyanax bockmanni (19.36 %), and Geophagus brasiliensis (7.52 %). The highest species richness was found in Água dos Anjos stream (26), followed by Monjolinho stream (25), and the Ubá stream (15). We recorded the occurrence of four non-native species (Bryconamericus exodon, Gymnotus inaequilabiatus, Poecilia reticulata and Oreochromis niloticus), which represent a risk to the biodiversity of the studied streams. The Ubá stream was considered the most conserved, but the presence of P. reticulata shows that it has also suffered from anthropic impacts. This non-native species is constantly associated to degraded environments, mainly when it occurs in high abundance. Our results suggest that the fish assemblages studied present different structures, probably due to the interaction among historical, abiotic, biotic, and anthropic factors. This study has been carried out for the first time in the Cinzas River basin and can help provide theoretical input for the elaboration of monitoring and conservation plans.

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32

Jones, Jeremy B. y Amanda J. Rinehart. "The long-term response of stream flow to climatic warming in headwater streams of interior AlaskaThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming." Canadian Journal of Forest Research 40, n.º 7 (julio de 2010): 1210–18. http://dx.doi.org/10.1139/x10-047.

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Warming in the boreal forest of interior Alaska will have fundamental impacts on stream ecosystems through changes in stream hydrology resulting from upslope loss of permafrost, alteration of availability of soil moisture, and the distribution of vegetation. We examined stream flow in three headwater streams of the Caribou–Poker Creeks Research Watershed (CPCRW) in interior Alaska over a 30-year period to determine (i) how stream flow varied among streams draining watersheds with varying extents of permafrost and (ii) evaluate if stream hydrology is changing with loss of permafrost. The three streams drained subcatchments with permafrost extents ranging from 4% to 53%. For each stream, runoff data were analyzed by separating base and storm flow contributions using a local-minimum method and with analysis of flood recession curves. Mean daily runoff during the ice-free season did not significantly vary among streams (mean = 0.57 mm·d–1), although the watersheds with lower permafrost had a greater contribution of base flow. Across years, flow was variable and was related with summer temperature in the watershed with low permafrost and with precipitation in the watershed with high permafrost. With climate warming and loss of permafrost, stream flows will become less responsive to precipitation and headwater streams may become ephemeral.

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von Schiller, D., E. Martí y J. L. Riera. "Nitrate retention and removal in Mediterranean streams bordered by contrasting land uses: a <sup>15</sup>N tracer study". Biogeosciences 6, n.º 2 (11 de febrero de 2009): 181–96. http://dx.doi.org/10.5194/bg-6-181-2009.

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Abstract. We used 15N-labelled nitrate (NO3−) additions to investigate pathways of nitrogen (N) cycling at the whole-reach scale in three stream reaches with adjacent forested, urban and agricultural land areas. Our aim was to explore among-stream differences in: (i) the magnitude and relative importance of NO3− retention (i.e. assimilatory uptake) and removal (i.e. denitrification), (ii) the relative contribution of the different primary uptake compartments to NO3− retention, and (iii) the regeneration, transformation and export pathways of the retained N. Streams varied strongly in NO3− concentration, which was highest in the agricultural stream and lowest in the forested stream. The agricultural stream also showed the lowest dissolved oxygen (DO) concentration and discharge. Standing stocks of primary uptake compartments were similar among streams and dominated by detritus compartments (i.e. fine and coarse benthic organic matter). Metabolism was net heterotrophic in all streams, although the degree of heterotrophy was highest in the agricultural stream. The NO3− uptake length was shortest in the agricultural stream, intermediate in the urban stream, and longest in the forested stream. Conversely, the NO3− mass-transfer velocity and the areal NO3− uptake rate were highest in the urban stream. Denitrification was not detectable in the forested stream, but accounted for 9% and 68% of total NO3− uptake in the urban and the agricultural stream, respectively. The relative contribution of detritus compartments to NO3− assimilatory uptake was greatest in the forested and lowest in the agricultural stream. In all streams, the retained N was rapidly regenerated back to the water column. Due to a strong coupling between regeneration and nitrification, most retained N was exported from the experimental reaches in the form of NO3−. This study provides evidence of fast in-stream N cycling, although the relative importance of N retention and removal varied considerably among streams. Results suggest that permanent NO3− removal via denitrification may be enhanced over temporary NO3− retention via assimilatory uptake in heterotrophic human-altered streams characterized by high NO3− and low DO concentrations.

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34

Scrimgeour, Garry J., William M. Tonn y Nicholas E. Jones. "Quantifying effective restoration: reassessing the productive capacity of a constructed stream 14 years after construction". Canadian Journal of Fisheries and Aquatic Sciences 71, n.º 4 (abril de 2014): 589–601. http://dx.doi.org/10.1139/cjfas-2013-0354.

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Using natural streams as references against which ecosystem structure and function could be compared, we examined the short-term (1–3 years) and long-term (14 years) effectiveness of a 3.4 km constructed stream in the Northwest Territories, Canada. The constructed stream variously showed little to marked improvements 14 years after construction (2011), relative to 1998–2000 and to reference streams, depending on the stream attribute. Many attributes related to stocks of organic matter remained well below reference levels in the constructed stream after 14 years. Leaf matter processing rates increased in the constructed stream to the point of convergence with reference streams in 2011, but the latter still had superior leaf retention abilities. By Year 14, benthic invertebrate composition in the constructed stream showed some convergence with reference streams, although densities generally lagged, especially in riffles. In 2011, growth of young-of-the-year Arctic grayling (Thymallus arcticus) from the constructed stream was substantially greater relative to 1998–2001, but remained well below contemporary reference levels. Our mixed results raise questions about the definition and time scale of successful restoration.

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35

Cionek, Vivian De Mello, Patricia Almeida Sacramento, Naiara Zanatta, Rafaela Priscila Ota, Daiany De Fatima Corbetta y Evanilde Benedito. "Fishes from first order streams of lower Paranapanema and Ivaí rivers, upper Paraná River basin, Paraná, Brazil". Check List 8, n.º 6 (1 de noviembre de 2012): 1158. http://dx.doi.org/10.15560/8.6.1158.

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This study was developed as a research of first order streams fish assemblages located in two Conservation Units in Northwestern Paraná, Brazil, with the purpose of providing information about ichthyofauna composition of these water bodies while they are still under protection. There were captured 2,557 individuals belonging to six orders, nine families and 10 species in three streams. The most abundant species were Phalloceros harpagos (44%) from Conceição stream, Astyanax aff. paranae (14%) and P. harpagos (12%) from Jurema stream, and Melanorivulus apiamici (9%) from Conceição stream. Trichomycterus sp. could not be identified into a specific level, meaning it can represent an undescribed species to science, registered for the first time at the upper Paraná River basin.

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36

Moore, Kelly M. S. y Stanley V. Gregory. "Summer Habitat Utilization and Ecology of Cutthroat Trout Fry (Salmo clarki) in Cascade Mountain Streams". Canadian Journal of Fisheries and Aquatic Sciences 45, n.º 11 (1 de noviembre de 1988): 1921–30. http://dx.doi.org/10.1139/f88-224.

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Emergent cutthroat trout fry (Salmo clarki) were observed in the margins, backwaters, and side channels, collectively called "lateral habitats," of three study streams with different riparian vegetation. Most fry remained in these lateral habitats until the end of their first summer. The abundance of cutthroat fry was proportional to the area of lateral habitat in each of the study streams. Average size and growth rate of fry were related to the effect of site elevation on stream temperature and the influence of riparian vegetation on the availability of invertebrate food. Lateral habitats are characterized by slow, shallow-water, abundant detritus and benthic invertebrate assemblages of high density. Stream margins and backwaters provide gradients of depth and velocity, cover, and access to food that are appropriate to the habitat requirements of fry. Because fry populations are closely related to the abundance and quality of lateral habitats in small streams, these habitats should be included in the assessment of habitat requirements of cutthroat trout.

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Wood, Petra B., Mack W. Frantz y Douglas A. Becker. "Louisiana Waterthrush and Benthic Macroinvertebrate Response to Shale Gas Development". Journal of Fish and Wildlife Management 7, n.º 2 (1 de mayo de 2016): 423–33. http://dx.doi.org/10.3996/092015-jfwm-084.

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Abstract Because shale gas development is occurring over large landscapes and consequently is affecting many headwater streams, an understanding of its effects on headwater-stream faunal communities is needed. We examined effects of shale gas development (well pads and associated infrastructure) on Louisiana waterthrush Parkesia motacilla and benthic macroinvertebrate communities in 12 West Virginia headwater streams in 2011. Streams were classed as impacted (n = 6) or unimpacted (n = 6) by shale gas development. We quantified waterthrush demography (nest success, clutch size, number of fledglings, territory density), a waterthrush Habitat Suitability Index, a Rapid Bioassessment Protocol habitat index, and benthic macroinvertebrate metrics including a genus-level stream-quality index for each stream. We compared each benthic metric between impacted and unimpacted streams with a Student's t-test that incorporated adjustments for normalizing data. Impacted streams had lower genus-level stream-quality index scores; lower overall and Ephemeroptera, Plecoptera, and Trichoptera richness; fewer intolerant taxa, more tolerant taxa, and greater density of 0–3-mm individuals (P ≤ 0.10). We then used Pearson correlation to relate waterthrush metrics to benthic metrics across the 12 streams. Territory density (no. of territories/km of stream) was greater on streams with higher genus-level stream-quality index scores; greater density of all taxa and Ephemeroptera, Plecoptera, and Trichoptera taxa; and greater biomass. Clutch size was greater on streams with higher genus-level stream-quality index scores. Nest survival analyses (n = 43 nests) completed with Program MARK suggested minimal influence of benthic metrics compared with nest stage and Habitat Suitability Index score. Although our study spanned only one season, our results suggest that shale gas development affected waterthrush and benthic communities in the headwater streams we studied. Thus, these ecological effects of shale gas development warrant closer examination.

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Hawkins, Charles. "Stream Ecology of the Greater Yellowstone Area". UW National Parks Service Research Station Annual Reports 33 (1 de enero de 2011): 237–38. http://dx.doi.org/10.13001/uwnpsrc.2011.3835.

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Stream Ecology is a graduate-level course offered every fall term at Utah State University by Chuck Hawkins, Professor of Watershed Sciences (USU). The AMK Ranch serves as base camp for our annual 3-day class field trip to the Greater Yellowstone Area. The USU Stream Ecology course serves a diverse range of students including those specializing in freshwater ecology and fisheries as well as students in hydrology, fluvial geomorphology, water quality, environmental engineering, and general natural resources management.

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39

Lester, Rebecca E., Wendy Wright y Michelle Jones-Lennon. "Does adding wood to agricultural streams enhance biodiversity? An experimental approach". Marine and Freshwater Research 58, n.º 8 (2007): 687. http://dx.doi.org/10.1071/mf06198.

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Riparian clearing and the removal of wood from channels have affected many streams in agricultural landscapes. As a result, these streams often have depauperate in-stream wood loads, and therefore decreased habitat complexity and lower levels of in-stream biodiversity. The introduction of wood was investigated as a possible rehabilitation technique for agricultural streams. Wood was re-introduced to eight streams in two separate high-rainfall, intensively grazed regions of Victoria, Australia and the effect on aquatic macroinvertebrate communities was measured. The addition of wood increased overall family richness and the richness of most functional feeding groups occupying edge and benthic habitats within the stream. Wood addition led to less overlap between benthic and edge macroinvertebrate communities, suggesting increased habitat heterogeneity within the stream ecosystem. Of all sampled habitats, wood supported the greatest density of families and was colonised by all functional feeding groups. Wood habitats also had the highest overall richness and supported the most taxa that were sensitive to disturbance. These findings suggest that re-introducing wood to agricultural streams is an appropriate rehabilitation technique where those streams are affected by reduced habitat complexity. Additional work is needed to confirm these findings over larger spatial and temporal scales.

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40

Meixler, Marcia S. y Mark B. Bain. "A GIS Framework for Fish Habitat Prediction at the River Basin Scale". International Journal of Ecology 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/146073.

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We present a geographic information system (GIS) framework to classify stream habitats and provide fish distribution predictions comprehensively at the landscape scale. Stream segments were classified into one of eighteen habitat types using three landscape attributes: stream size (three categories), stream quality (three categories), and water quality (two categories). An extensive literature search was undertaken to classify fish species into the same eighteen habitat types based on preferences for the three landscape attributes. We tested our framework in 39 sites throughout the upper Allegheny River basin in western New York. No difference was detected between observed and predicted numbers of fish species among stream habitats. Further, field collected bankfull width measurements, stream quality ratings, and water quality sampling results were largely consistent with predicted values. The habitat type expected to have the greatest fish species richness was large streams or small rivers with intact stream quality and suitable water quality. Our framework is rapidly applied, comprehensive, inexpensive, and built on widely available data thereby offering an efficient alternative to traditional field-based efforts for regional habitat classification and fish distribution prediction.

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41

Dauwalter, Daniel C., Dale K. Splinter, William L. Fisher y Richard A. Marston. "Geomorphology and stream habitat relationships with smallmouth bass (Micropterus dolomieu) abundance at multiple spatial scales in eastern Oklahoma". Canadian Journal of Fisheries and Aquatic Sciences 64, n.º 8 (1 de agosto de 2007): 1116–29. http://dx.doi.org/10.1139/f07-085.

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Fluvial geomorphic processes structure habitats important to stream fishes. We determined relationships between densities of smallmouth bass (Micropterus dolomieu) and ecoregions, watershed and reach morphology, and stream habitat in eastern Oklahoma, USA. Watershed and reach morphology were measured at 128 stream sites, and stream habitat and smallmouth bass abundance were measured in 1800 channel units. Variation in stream size, channel morphology, and substrate size constituted major physical differences among sites. Channel morphology differed among ecoregions in the largest streams. Densities of age-0 and age-1 and older smallmouth bass were approximately an order of magnitude greater in the Boston Mountains and Ozark Highlands streams than in Ouachita Mountains streams. Regression tree analysis explained less variation in age-0 (10-fold cross-validated relative error = 0.843) than in age-1 and older (relative error = 0.650) smallmouth bass densities and showed that stream size and channel-unit size were primary determinants of density. Channel morphology explained variation in densities in deep channel units of large streams, which was somewhat independent of ecoregion.

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42

Robison, E. George y Robert L. Beschta. "Characteristics of Coarse Woody Debris for Several Coastal Streams of Southeast Alaska, USA". Canadian Journal of Fisheries and Aquatic Sciences 47, n.º 9 (1 de septiembre de 1990): 1684–93. http://dx.doi.org/10.1139/f90-193.

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Coarse woody debris (> 0.2 m in diameter and 1.5 m long) was measured along five undisturbed low-gradient stream reaches; volume, decay class, and horizontal orientation in relation to channel flow of first-, second-, third-, and fourth-order coastal streams were determined. Debris was also classified into four influence zones based on stream hydraulics and fish habitat. Average debris length, diameter, and volume per piece increased with stream size. Eighty percent of debris volume of the first-order and the smaller second-order streams was suspended above or lying outside the bankfull channel, while less than 40% was similarly positioned in the fourth-order stream. Approximately one-third of all debris was oriented perpendicular to stream flow, regardless of stream size. First-, second-, and third-order streams had a higher proportion of recent debris in the channel than the fourth-order stream ([Formula: see text]19 vs. 8%), most new debris being attributable to a major 1984 windstorm. Tree blowdown had a major influence on debris distribution along the smaller stream reaches. Debris jams and accumulations in the largest stream were formed from floated debris. These characterizations are useful for evaluating the distribution and amount of woody debris associated with land-management activities.

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43

Pépino, Marc, Marco A. Rodríguez y Pierre Magnan. "Incorporating lakes in stream fish habitat models: are we missing a key landscape attribute?" Canadian Journal of Fisheries and Aquatic Sciences 74, n.º 5 (mayo de 2017): 629–35. http://dx.doi.org/10.1139/cjfas-2016-0221.

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Although lakes and rivers are intimately connected, more effort is needed to develop conceptual approaches accounting for lake–stream interactions within the drainage network. Lakes can buffer the impacts of environmental variability in streams and facilitate stream fish recolonization processes. However, lakes have rarely been incorporated in habitat models for stream fish. We examine whether including the presence of lakes in habitat models can improve our understanding of brook trout (Salvelinus fontinalis) abundance in streams. We quantified brook trout relative abundance in 36 streams over 3 consecutive years by single-pass electrofishing. Relative abundance of brook trout in streams was greatest when lakes were present in the stream network. Lakes had greater influence on relative abundance in headwater streams than in larger streams. These results emphasize the importance of considering lakes as a critical attribute in landscape fish habitat models, many of which focus on terrestrial landscape variables. We discuss potential gains from incorporating the presence of lakes in (i) multiscale habitat models, (ii) analyses of spatiotemporal distribution of thermal refuges, and (iii) metrics of habitat connectivity in lake–stream networks.

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44

Almirón, Adriana E., Mirta L. García, Roberto C. Menni, Lucila C. Protogino y Lia C. Solari. "Fish ecology of a seasonal lowland stream in temperate South America". Marine and Freshwater Research 51, n.º 3 (2000): 265. http://dx.doi.org/10.1071/mf98040.

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El Pescado (literally ‘the fish’) is a lowland stream in the pampean plain, entering the Rio de La Plata at 35˚55¢S,57˚45¢W, 70 km SW of the city of Buenos Aires. The stream develops as a potamon with variable flood frequency along its 36 km length. The water is slightly soft, with relatively high conductivity and dominance of HCO–3 , Na + and Cl – ions. Three fish families, Characidae (29%), Pimelodidae (14.6%) and Loricariidae (12.8%) are most abundant among 55 species. Differences in species composition among four stations with different environmental traits were observed. Flooding slightly affected the fish fauna. In open-water and rocky-bottom stations, both species number and number of individuals were correlated with conductivity, an indication of the decrease of fish density with floods. Species richness was well over worldwide means. Diversity values, higher than in small tropical streams in Venezuela and southern Brazil, ranged from 0.32 to 2.59, being higher during autumn and spring. The stream has a high persistence, with the composition of the fish community maintained or recovering as soon as flooding ends. One Synbranchus marmoratus specimen was found among rocks, the first record of this behaviour for the species.

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45

Isaak, Daniel J. y Wayne A. Hubert. "Production of stream habitat gradients by montane watersheds: hypothesis tests based on spatially explicit path analyses". Canadian Journal of Fisheries and Aquatic Sciences 58, n.º 6 (1 de junio de 2001): 1089–103. http://dx.doi.org/10.1139/f01-057.

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We studied how the features of mountain watersheds interact to cause gradients in three stream attributes: baseflow stream widths, total alkalinity, and stream slope. A priori hypotheses were developed before being tested in a series of path analyses using data from 90 stream reaches on 24 second- to fourth-order streams across a fifth-order Rocky Mountain watershed. Because most of the conventional least squares regressions initially calculated for the path analyses had spatially correlated residuals (13 of 15 regressions), spatially explicit regressions were often used to derive more accurate parameter estimates and significance tests. Our final working hypotheses accounted for most of the variation in baseflow stream width (73%), total alkalinity (74%), and stream slope (78%) and provide systemic views of watershed function by depicting interactions that occur between geomorphology, land surface features, and stream attributes. Stream gradients originated mainly from the unidirectional changes in geomorphic features that occur over the lengths of streams. Land surface features were of secondary importance and, because they change less predictably relative to the stream, appear to modify the rate at which stream gradients change.

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46

Manna, Luisa Resende y Carla Ferreira Rezende. "VARIAÇÃO INTRAESPECÍFICA EM PEIXES DE RIACHO COM ÊNFASE NA ECOLOGIA TRÓFICA". Oecologia Australis 25, n.º 02 (16 de junio de 2021): 301–22. http://dx.doi.org/10.4257/oeco.2021.2502.06.

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Assessing intraspecific variability in community structure and functioning are still scarce for stream-dwelling fish. However, measuring ecological traits for individuals is important since species’ response for environmental conditions occurs at the individual level, especially in streams which suffers constantly physical disturbances. Intraspecific variability can be measured for several ecological traits, such as morphology, diet, life-history, and habitat use that varies between populations or within populations. Here, we present some methods and studies that evaluated intraspecific trophic variability in stream-dwelling fish. Results revealing the role of individual variation in structure of biological populations and/or assemblages were selected, and principal issues were discussed. There are a lot of statistical tools that can test individual variation including functional indexes and multivariate analyzes. Results generated from such individual analyzes have high potential to explain the functioning of stream fish populations and communities.

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47

Minshall, G. Wayne, Todd V. Royer y Christopher T. Robinson. "Response of the Cache Creek macroinvertebrates during the first 10 years following disturbance by the 1988 Yellowstone wildfires". Canadian Journal of Fisheries and Aquatic Sciences 58, n.º 6 (1 de junio de 2001): 1077–88. http://dx.doi.org/10.1139/f01-056.

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We evaluated the effects of disturbance on stream benthic macroinvertebrates at the ecological scales of time, stream size, and burn extent in six segments of Cache Creek over the first 10 postfire years. Postfire changes in macroinvertebrate taxa richness, density, and dominant taxa in the burn streams were significantly different from those in the reference stream. Chironomidae and Baetis typically comprised 4060% of the macroinvertebrate assemblages of burned streams but only 1518% of the assemblage in the reference site. Coefficients of variation for the 10-year period indicated that richness, density, biomass, and Baetis abundance were more variable (1.23.5 times higher) in the burn streams than in the reference stream and that variability in Chironomidae abundance in burn sites increased with stream size. Fire effects were not attenuated progressively with increasing stream size, probably because the proportion of the catchment burned did not decrease. However, similar-sized streams in which 6871% of their catchments burned were more severely disturbed than those in which only 3947% burned. Long-term effects on the macroinvertebrate community were due largely to the loss of terrestrial vegetation and increased runoff, which caused severe alterations in stream channel conditions and large-scale bedload movement.

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Poole, Geoffrey C. "Stream hydrogeomorphology as a physical science basis for advances in stream ecology". Journal of the North American Benthological Society 29, n.º 1 (marzo de 2010): 12–25. http://dx.doi.org/10.1899/08-070.1.

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Besemer, Katharina, Gabriel Singer, Iris Hï¿½dl y Tom J. Battin. "Bacterial Community Composition of Stream Biofilms in Spatially Variable-Flow Environments". Applied and Environmental Microbiology 75, n.º 22 (18 de septiembre de 2009): 7189–95. http://dx.doi.org/10.1128/aem.01284-09.

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ABSTRACT Streams are highly heterogeneous ecosystems, in terms of both geomorphology and hydrodynamics. While flow is recognized to shape the physical architecture of benthic biofilms, we do not yet understand what drives community assembly and biodiversity of benthic biofilms in the heterogeneous flow landscapes of streams. Within a metacommunity ecology framework, we experimented with streambed landscapes constructed from bedforms in large-scale flumes to illuminate the role of spatial flow heterogeneity in biofilm community composition and biodiversity in streams. Our results show that the spatial variation of hydrodynamics explained a remarkable percentage (up to 47%) of the variation in community composition along bedforms. This suggests species sorting as a model of metacommunity dynamics in stream biofilms, though natural biofilm communities will clearly not conform to a single model offered by metacommunity ecology. The spatial variation induced by the hydrodynamics along the bedforms resulted in a gradient of bacterial beta diversity, measured by a range of diversity and similarity indices, that increased with bedform height and hence with spatial flow heterogeneity at the flume level. Our results underscore the necessity to maintain small-scale physical heterogeneity for community composition and biodiversity of biofilms in stream ecosystems.

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50

Vrieze, Lance A. y Peter W. Sorensen. "Laboratory assessment of the role of a larval pheromone and natural stream odor in spawning stream localization by migratory sea lamprey (Petromyzon marinus)". Canadian Journal of Fisheries and Aquatic Sciences 58, n.º 12 (1 de diciembre de 2001): 2374–85. http://dx.doi.org/10.1139/f01-179.

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This study used large laboratory mazes and natural stream waters to test the role of olfactory cues, including a pheromone released by larvae, in spawning stream localization by migratory sea lamprey (Petromyzon marinus). We found that migratory lamprey strongly prefer stream water over lake water and that this response is dependent upon a functional olfactory system. Responses persisted among migratory lamprey even after stream water was diluted a thousand times but were not seen among non-migratory lamprey. Experiments using waters from five streams demonstrated that a larval pheromone is a key determinant of stream attractiveness: water from streams with larval populations were consistently more attractive than those without, and adding larval odor to the latter reversed this relationship. Larval odor was attractive at low, realistic concentrations, especially when presented together with natural stream water, suggesting that streams contain other odors that synergize the actions of the pheromone. Some, but not all, of the activity of the larval pheromone could be explained by two bile acids released by larvae (petromyzonol sulfate and allocholic acid). Together, these results strongly suggest that migratory lamprey locate streams using a larval pheromone. This cue could be useful in lamprey control.

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