Download or read book The Diversity and Composition of Benthic Macroinvertebrate Assemblages in Streams in the Mackenzie River System Northwest Territories written by Ryan William Scott and published by . This book was released on 2010 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impending natural resources development and concern about the effects of climate change have spurred increased efforts to study and monitor aquatic habitats in the Mackenzie River system. As part of Environment Canada's attempt to survey the system in advance of the construction of the Mackenzie Gas Pipeline, benthic macroinvertebrates were sampled at 50 streams spanning the geographical range of the Mackenzie system in the Northwest Territories, Canada, to assess spatial patterns in diversity and assemblage structure and the environmental factors driving them. Replicated, quantitative D-net samples were collected during the late summer of 2005 through 2008, mostly at crossings of the proposed pipeline route. 373 macroinvertebrate taxa were recorded, mainly aquatic insects, which were identified to the genus or species levels; other groups were identified to higher taxonomic levels. Ephemeroptera and Plecoptera diversity declined along a latitudinal gradient, while Trichoptera diversity declined in the middle of the latitudinal range and rose towards the far north. Chironomidae (Diptera) increased in diversity and abundance towards the far north, becoming dominant in the northern sub-arctic forest and lowland tundra of the Mackenzie Delta. Diversity, measured as the average generic richness per stream, correlated with a composite environmental variable representing stream size, but not much else; spatial trends in local generic richness were only apparent in the far north of the study area. Regional diversity was assessed using rarefaction curves and showed a clear decrease from south to north across the study area for most taxa; the major exception was the chironomid subfamilies Orthocladiinae and Chironomini, the former being diverse throughout the study area and the latter increasing in diversity on the tundra. Odonata, Hemiptera and Coleoptera were well-represented in the south of the study area, but decreased sharply in diversity and abundance in the north; another common order, Megaloptera, was entirely absent from the study area, as were crayfish. Community composition varied along a latitudinal gradient, with some species restricted to northern latitudes and many more species restricted to the southern areas. Composition varied by region, as did the environmental factors that control it. Streams in the north of the system are connected to hundreds of small lakes and tend to freeze in the winter, which increases habitat stability; assemblages in this region were characterized by relatively large chironomids that are usually associated with lentic habitats and by a lack of taxa that are intolerant to freezing. Substrate was the main factor explaining differences in assemblage composition in this region. Just to the south, alluvial streams are more common and permafrost is continuous with very shallow active layers, iv which likely results in intense discharge peaks and ice scour in the spring and flashy summer hydrographs. Invertebrates in this region were mainly short-lived, small sized orthoclads, baetids and chloroperlids; the annual disturbance regime seems likely to be an important factor shaping community composition in this region. Many streams in this region received input from saline springs, resulting in perennial flow, and these streams harboured several taxa that were absent or rare in other streams at similar latitudes, including several stoneflies (e.g. Pteronarcys, Sweltsa); the presence of flow during the winter was found to be a major factor affecting community composition in this region, which surrounded the town of Norman Wells, NT. Nutrient dynamics appeared to be important in structuring benthic assemblages in the southern portion of the study region, with highnutrient streams supporting a diverse fauna which included many taxa that were absent in the north, while communities in low-nutrient streams were more similar to the northern alluvial stream fauna. There was no spatial distinction between low- and high-nutrient streams in the southern region, and the difference may be due to the local conditions of permafrost, which is patchy and discontinuous in the region. Evidence that winter ice and permafrost conditions are important drivers of benthic invertebrate diversity and community composition in the Mackenzie system, along with the latitudinal gradients which are consistent with a temperature/climate gradient, raises the possibility that benthic assemblages may be useful as indicators of effects of global climate change on freshwater habitats in the Canadian north. More immediately, construction of the Mackenzie Gas Pipeline may affect stream habitat due to sedimentation, and plans for the operation of the pipeline have raised concerns about potential effects on permafrost conditions. Implications for development of a biomonitoring program utilizing benthic invertebrates and their potential as indicators of climate change are discussed.
Download or read book Benthic Macroinvertebrate Assemblages Across the Non perennial Stream System of the Konza Prairie Kansas written by Alice Belskis and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-perennial streams, those that do not continuously flow, make up 51-60% of the earth's streams by length. Yet, they are understudied relative to their perennial, or continuously flowing, counterparts. We sought to determine how benthic macroinvertebrate (BMIs) community structure and beta diversity patterns were related to abiotic factors in non-perennial streams, as they contribute to fauna in downstream perennial waterways. We sampled 38 sites across a non-perennial prairie stream network for BMIs and measured hydrological, biogeochemical, and other environmental variables. We identified the BMIs using DNA metabarcoding. We calculated local contributions to beta diversity (LCBD) to identify ecologically unique sites and calculated species contributions to beta diversity (SCBD) to determine taxa with the strongest contributions to beta diversity patterns across the stream network. Our results show that while LCBD was not influenced by abiotic factors, the richness and replacement components of LCBD were strongly influenced by a site's distance to an upstream groundwater seep. The top contributor to SCBD was Stenonema femoratum, followed by 7 genera of Chironomidae, Perlesta cinctipes, and Faxonius virilis. Importantly, our DNA metabarcoding approach allowed us to identify Chironomidae to the genus level, revealing their importance in SCBD. When considering BMI community structure, an NMDS (Non-Metric Multidimensional Scaling) analysis revealed that the percent flowing water at each site was driving the differences in species across the sites. Here we show that proximity to groundwater sources is key to BMI beta diversity patterns in non-perennial stream networks, and that Chironomidae taxa are important in producing these patterns. This study allows us to fill in some of the knowledge gaps surrounding non-perennial stream beta diversity patterns and provides us with an understanding of the factors that potentially influence these interactions.
Download or read book A Comparison of Benthic Macroinvertebrate Assemblages Between Perennial and Intermittent Headwater Streams of the Mattole River in Northern California USA written by Mason S. London and published by . This book was released on 2017 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermittent streams are common throughout the world and comprise 60% or more of total river lengths in the conterminous United States. Despite their prevalence, intermittent streams are understudied, particularly first-order headwater streams, which are vital for maintaining the function, health and biotic diversity of river networks. In June 2016, I sampled five intermittent and five perennial headwater streams in the Mattole River watershed in northwestern coastal California, USA, to compare benthic macroinvertebrate (BMI) assemblages between intermittent and perennial streams. BMI samples were collected using a 500μm mesh D-net at eight randomly located riffles along a 150-m reach, and then composited, on each of the 10 streams. Chemical (e.g. pH, dissolved oxygen, temperature, and flow) and physical (e.g. bed substrate composition, bank-full width, and slope) data were measured at each stream reach. BMI samples were identified using Standard Taxonomic Effort (STE). Major difference in assemblages among stream type were not detected except for a few individual taxa, families, and orders. Observed differences likely resulting from taxonomic differences in life history timing. The proportion of shredders was detectably lower in intermittent streams. Further studies with a temporal factor are needed to validate these findings.
Download or read book A Comparison of Benthic Macroinvertebrate Assemblages Among Kryal and Rhithral Lake Outlets in the North Cascade Mountains written by Kelley L. Turner and published by . This book was released on 2009 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Macroinvertebrate Community Composition in Stream Networks Across Three Land Cover Types written by Raj Kiran Parmar and published by . This book was released on 2018 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Land cover change strongly affects biodiversity in stream ecosystems, with several studies demonstrating the negative impacts of agricultural and urban expansion on local community richness. However, little is known of the effects of land cover on the variation among sets of local communities in stream networks, as well as the drivers of community variation in these systems. Using the metacommunity framework, this study takes a multi-scale approach to understand how macroinvertebrate communities are assembled across three catchment land cover types; native forest, agricultural and urban. Specifically, the aims of this study are to assess; (1) how stream network land cover influences alpha and beta diversity of macroinvertebrate communities and, (2) the relative role of local environmental conditions and spatial dispersal variables in structuring these communities. Benthic macroinvertebrate samples and local in-stream and riparian environmental variables were collected at 20 sampling sites in each of the six study stream networks in Auckland. Spatial distance proxies of macroinvertebrate dispersal in stream networks were calculated using geospatial techniques. Community alpha and beta diversity, environmental and distance variables were analysed using multivariate statistical techniques. Comparisons showed reference forest and impacted (agricultural and urban) networks supported distinct communities, with lower alpha diversity in the impacted stream networks. Unexpectedly, beta diversity in the impacted networks was greater than, or equal to the reference stream networks, with community dissimilarity almost entirely driven by species turnover. Overall, irrespective of land cover, macroinvertebrate communities were largely structured by local environmental conditions. Benthic substrate and the presence and composition of riparian vegetation were the most significant local environmental variables influencing community composition. Spatial dispersal limitation variables had a small, but significant, effect on inter-site community dissimilarity and overall community structure in each catchment. Network distance between local communities explained the greatest variation in community dissimilarity of the three distance types. This study identified potential drivers of macroinvertebrate community variation in Auckland streams, specifically highlighting the relative role of local environmental and spatial dispersal processes. The results of this study have relevance for biomonitoring and state of environment reporting of Auckland’s freshwater systems, as well as future stream rehabilitation projects.
Download or read book Structure and Size Distribution of Benthic Macroinvertebrate Communities Along a Eutrophication Gradient in Streams of the Ottawa Valley written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Survey of Benthic Macroinvertebrate and Fish Populations in the Mackenzie River at Norman Wells N W T September 1980 microform written by Envirocon Ltd and published by . This book was released on 198? with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Major Element Composition of the MacKenzie River at Norman Wells Northwest Territories Canada written by Research Council of Alberta and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Relations of Benthic Macroinvertebrates to Concentrations of Trace Elements in Water Streambed Sediments and Transplanted Bryophytes and Stream Habitat Conditions in Nonmining and Mining Areas of the Upper Colorado River Basin Colorado 1995 98 written by Scott V. Mize and published by . This book was released on 2002 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Great Mackenzie Basin written by Canada. Parliament. Senate. Select Committee on Natural Food Products of Northwest Territories and published by . This book was released on 1908 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Changes in Stream Habitat Structure and Benthic Macroinvertebrate Assemblages in a Side Channel of the Middle Fork Nooksack River Following a Stream Enhancement Project written by Stephanie Matia Estrella and published by . This book was released on 2005 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Examining the Effects of PH and Macrophyte Diversity on Benthic Macroinvertebrate Assemblages in Adirondack Lakes written by Jacob A. Gaskill and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rapid Bioassessment Protocols for Use in Streams and Rivers written by and published by . This book was released on 1989 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Species Diversity of Benthic Macroinvertebrates in Three Michigan Streams written by Jeffrey C. Gislason and published by . This book was released on 1969 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Notes on Mammals Collected and Observed in the Northern Mackenzie River District Northwest Territories of Canada with Remarks on Explorers and Explorations of the Far North written by R. MacFarlane and published by . This book was released on 1905 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Patterns of Benthic Macroinvertebrate Communities and Habitat Associations in Temperate Continental Shelf Waters of the Pacific Northwest written by Timothy Seung-chul Lee and published by . This book was released on 2012 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macroinvertebrates constitute the backbone of megafaunal communities in benthic ecosystems around the globe. Many macroinvertebrates have vital roles in benthic ecosystems, ranging from enhancing habitat complexity to providing staple food sources for other organisms. Regardless of how familiar macroinvertebrates are to the general public, very few studies have attempted to describe benthic macroinvertebrate assemblages across large spatial scale in the continental shelf waters of the Pacific Northwest. This study describes different subtidal macroinvertebrate assemblages off Washington and Oregon based on species-substrata associations and the key species that distinguish one assemblage from another. Two data sets were used for this study: underwater footage collected by the submersible Delta during 1993-1995 geological surveys, and footage collected by the remotely operated vehicle (ROV) Hammerhead during macroinvertebrate surveys in late summer 2011. Footages from these surveys were used to document species-substrata associations and distinguish different assemblages based on species composition similarities and dissimilarities. In addition, I determined if a specific group of invertebrates, Asteroids (Echinodermata), were useful in explaining different assemblage patterns, after all other environmental parameters were taken into account. Findings of this study can be used not only to shed light on the structure of macroinvertebrate communities in the Pacific Northwest, but also as baseline data for future research on the direct and indirect effects of potential offshore installations on macroinvertebrate communities across the continental shelf waters.
Download or read book Relating Benthic Macroinvertebrate Community Composition and Habitat Complexity written by Scott C. Fetherston and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
