Clayton H. Riddell Faculty of Environment, Earth, and Resources

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Open Access
1999 Lake Winnipeg project: cruise report and scientific results
(Government of Canada, Natural Resources Canada, 1999) Simpson, S.L; Thorleifson, L.H.; Lewis, C.F.M.; King, J.W.
Following the 1997 Red River flood, a program of research was initiated to determine how large the floods can be, how often large floods have occurred in recent centuries, and whether natural factors may be changing the flood risk. As part of this program, 15 cores were collected from the south basin of Lake Winnipeg. Paleomagnetic profiles were used to select three apparently undisturbed, high-sedimentation rate cores for detailed chemical, physical, and biological analyses, to assess whether Red River floods are recognizable in the lake. A thousand-year paleomagnetic chronology was confirmed and augmented by Cs-137, Pb-210, palynology, radiocarbon dating, and inorganic geochemical relative age markers. While some parameters exhibit multi-century fluctuations, varying excursions, and 20th century shifts, grain-size results show the clearest signal of recurring events. Several layers of enhanced silt, 1-4 cm thick, with 6-15 % more silt than background are present, in several cases correlating core to core. A Red River flood origin for these silt excursions is plausible. The results also provide indications of increased contamination, nutrient influx, and more rapid sedimentation in the 20th century.
Open Access
2006 Yellow Perch Red River Delta Data (Appendix 12)
(2006) Department of Fisheries and Oceans
Open Access
2019 Lake Winnipeg Basin Program Symposium Summary Report
(2019-08) Environment and Climate Change Canada
Environment and Climate Change Canada (ECCC) held a Lake Winnipeg Basin Program Symposium on March 20th and 21st, 2019 in Winnipeg, Manitoba in conjunction with a number of other Lake Winnipeg-related events during Canada Water Week, including the Lake Winnipeg Research Consortium’s annual Science Workshop and the launch of “Lake Winnipeg DataStream” by the Gordon Foundation. Together, the week provided the space to share new knowledge derived from scientific studies conducted on the lake and in the basin, showcase on-the-ground actions on nutrient reduction, and highlight the important collaborative partnerships that are required to address the complex issues related to water quality and quantity, including climate change. Approximately 100 stakeholders attended each day of the Symposium representing government and non-governmental organizations (NGOs), scientists, Indigenous governments, organizations and communities and regional conservation districts.
Open Access
A meta-collection of nitrogen stable isotope data measured in Arctic marine organisms from the Canadian Beaufort Sea, 1983–2013
(2021-09-06) Ehrman, Ashley; Hoover, Carie; Giraldo, Carolina; MacPhee, Shannon A.; Brewster, Jasmine; Michel, Christine; Reist, James D.; Power, Michael; Swanson, Heidi; Niemi, Andrea; Walkusz, Wojciech; Loseto, Lisa
Abstract Objectives Existing information on Arctic marine food web structure is fragmented. Integrating data across research programs is an important strategy for building a baseline understanding of food web structure and function in many Arctic regions. Naturally-occurring stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) measured directly in the tissues of organisms are a commonly-employed method for estimating food web structure. The objective of the current dataset was to synthesize disparate δ15N, and secondarily δ13C, data in the Canadian Beaufort continental shelf region relevant to trophic and ecological studies at the local and pan-Arctic scales. Data description The dataset presented here contains nitrogen and carbon stable isotope ratios (δ15N, δ13C) measured in marine organisms from the Canadian Beaufort continental shelf region between 1983 and 2013, gathered from 27 published and unpublished sources with associated sampling metadata. A total of 1077 entries were collected, summarizing 8859 individual organisms/samples representing 333 taxa across the Arctic food web, from top marine mammal predators to primary producers.
Open Access
A New Trophic State Index for Lagoons
(2014-3-9) Gupta, Mukesh
This paper proposes a new nitrogen-based trophic state index (TSI) for the estimation of status of eutrophication in a lagoon system. Nitrite-nitrogen (NO2-N) is preferable because of its greater abundance in Chilika lagoon and its relation to other criteria of trophic state, for example, chlorophyll-a (Chl-a) and Secchi disk depth (SDD). Nitrite is preferable over nitrate because the former decreases the fluorescence and affects photosynthesis, thereby controlling primary production. This paper also computes TSI using Chl-a and SDD. The three parameters account for the biological, chemical, and physical characteristics of the lagoon. It will be possible to estimate the TSI of freshwater and brackish water lagoons and other water bodies using the new expressions taking into consideration the spatial and temporal variability in the dataset. Depending on the data availability, alternative TSI (Chl-a) and TSI (SDD) can account for the biological and physical contributions to eutrophication. The estimated TSI can account for Chl-a and NO2-N up to 322.18 mg m−3 and 61.99 μg L−1, respectively. The TSI based on these three parameters can serve as a complimentary and predictive tool for lagoon management and field programs to monitor the health of a lagoon.
Open Access
A resource management scenario for traditional and scientific management of pink shrimp (Farfantepenaeus paulensis) in the Patos Lagoon estuary (RS), Brazil
(2013-01-11) Moura, Gustavo Goulart Moreira; Kalikoski, Daniela Coswig; Diegues, Antonio Carlos Sant’Ana
Abstract Background This article aims to discuss the incorporation of traditional time in the construction of a management scenario for pink shrimp in the Patos Lagoon estuary (RS), Brazil. To meet this objective, two procedures have been adopted; one at a conceptual level and another at a methodological level. At the conceptual level, the concept of traditional time as a form of traditional ecological knowledge (TEK) was adopted. Method At the methodological level, we conduct a wide literature review of the scientific knowledge (SK) that guides recommendations for pink shrimp management by restricting the fishing season in the Patos Lagoon estuary; in addition, we review the ethno-scientific literature which describes traditional calendars as a management base for artisanal fishers in the Patos Lagoon estuary. Results Results demonstrate that TEK and SK describe similar estuarine biological processes, but are incommensurable at a resource management level. On the other hand, the construction of a “management scenario” for pink shrimp is possible through the development of “criteria for hierarchies of validity” which arise from a productive dialog between SK and TEK. Conclusions The commensurable and the incommensurable levels reveal different basis of time-space perceptions between traditional ecological knowledge and scientific knowledge. Despite incommensurability at the management level, it is possible to establish guidelines for the construction of “management scenarios” and to support a co-management process.
Open Access
Ability to alter song in two grassland songbirds exposed to simulated anthropogenic noise is not related to pre-existing variability.
(Taylor and Francis, 2018) Curry, Claire M.; Antze, Bridget; Warrington, Miyako H.; Des Brisay, Paulson G.; Koper, Nicola
Organisms encounter noise naturally in the environment. However, increasing prevalence of human-caused noise seems to be resulting in behavioural changes in many animals that can affect survival and reproduction. Not all species react the same way to noise; some adjust their vocal signals while others do not. We hypothesized that species with more variability in their vocal signals would be better able to adjust their signals to be audible over anthropogenic noise. We tested this within a large-scale manipulative experiment by recording songs of two grassland songbirds, Baird’s sparrow (Ammodramus bairdii) and Savannah sparrow (Passerculus sandwichensis), both of which are found in areas increasingly affected by energy extraction noise. We compared these species because Savannah sparrows have more variability in their songs geographically and temporally compared to Baird’s sparrows. We recorded both species’ songs before, during, and after high-fidelity playbacks of oil well drilling noise. Surprisingly, both species changed parts of their songs in the presence of noise (Baird’s sparrow usually decreasing frequency and Savannah sparrow increasing frequency) and these changes were not related to seasonal, song, or syllable variability. We suggest instead that acoustically heterogeneous environments may favor the evolution of species that are capable of adjusting their songs in response to variable ambient noise.
Open Access
Adaptive learning, technological innovation and livelihood diversification: the adoption of pound nets in Rio de Janeiro State, Brazil
(2012-06-06) Idrobo, Carlos J; Davidson-Hunt, Iain J
AbstractThis paper examines the adoption of a technology to appropriate an ecologically constrained resource within the context of a restructuring fisheries sector utilising the conceptual lenses of adaptive learning and practice. Participant observation and semi-structured interviews were undertaken in the coastal community of Ponta Negra, Paraty, Rio de Janeiro, Brazil, from May 2010 to March 2011. The materials collected were translated and transcribed into English and then manually coded. Through a restorying process the English transcripts were developed into an analytical narrative that described the process of the adoption of pound nets and how this initiated a process of social differentiation between fishing households. The pound net technology constituted a new field of practice that both created and constrained opportunities for livelihood diversification. In this case, individual adaptations made to diversify household economies initiated a cascading process of social differentiation within a coastal community.
Open Access
Advances in the Integration of Watershed and Lake Modeling in the Lake Winnipeg Basin
(Government of Canada, 2010) Leon, L.F.; Booty, W.; Wong, I.; McCrimmon, C.; Melles, S.; Benoy, G.; Vanrobaeys, J.
Estimating non-point source pollution from watersheds and the effects of mitigation measures (e.g. beneficial management practices or BMPs) is an important step in managing and protecting water quality, not only at the basin level where it originates, but also at the receiving waters such as reservoirs, lakes or oceans. Lake Winnipeg is a prime example of such land-lake interactions, where eutrophication and increased algal blooms in the lake are fueled, as evidence suggests, from agricultural sources of nutrients in the region. Over the years, simulation models at the watershed level have been applied to aid in the understanding and management of surface runoff, nutrients and sediment transport processes. Similarly, models with different degrees of complexity are used to simulate the aquatic ecology and water quality in lakes. The Soil and Water Assessment Tool (SWAT) is a widely known watershed model, which provides estimations of runoff, sediment yield, and nutrient loads at a sub-basin level. Here we examine the application of SWAT to one of three pilot watersheds on the Lake Winnipeg basin in order to investigate the impacts and uncertainties of different BMPs on nutrient loading in the targeted catchment areas. We also explore avenues for scaling and propagating such loads and uncertainties into the receiving lake models.
Open Access
Agricultural Beneficial Management Practices for Lake Winnipeg – Cost-benefit analysis using an ecological goods and services approach
(The Thomsen Corporation, 2010-11) Thomsen, Joseph; Kulshreshtha, Suren; Lobb, David; Flaten, Don; MacDonald, K.Bruce
The objective of the research and analysis reported herein was to “Assess the costs and benefits of agricultural beneficial management practices (BMPs) for Lake Winnipeg in physical and economic terms, with an emphasis on the co-benefits in terms of ecological goods and services.” Lake Winnipeg is a large and key natural asset, whose watershed drains a major portion of the Canadian Prairies and part of the U.S. Great Plains. This includes almost all of the agricultural area of the Canadian Prairies. Due to a variety of factors, including increases in nutrient loading, Lake Winnipeg is experiencing increasing eutrophication. The assessment and estimation methods used were necessarily simple and straightforward. To estimate phosphorus (P) reduction potential of selected BMPs, observed levels of P exported from selected sub-regional watersheds were multiplied with measures of the performance of the BMPs relative to conventional practice. The selected study area includes the major sub-watersheds of the Manitoba portion of the Lake Winnipeg drainage basin, and comprises about 23 percent of Manitoba crop land area. (In conventional Census of Agriculture terms, the study area and surrounding regions include about 60 percent of Manitoba cropland and livestock). BMPs and their ecological goods and services (EGS) impacts and values were identified and estimated on the basis of evidence and information specific to Manitoba, Canadian Prairie, and other similar dryland agriculture, soil, and agroclimatic conditions. Economic and EGS impacts were evaluated using best available evidence from the literature and current Manitoba market prices and costs. Valuation and related methods were refined over several steps of the project. Several iterations of research revealed a significant lack of evidence as well as the data and information necessary to meet the valuation objectives of the project. Put simply, whereas the level of public awareness and concern for the current condition of Lake Winnipeg is high; and the available evidence solidly indicates that Lake Winnipeg is highly eutrophic, little to no quantitative evidence of the economic and EGS impact of the Lake’s condition was found. Main estimates are that the selected BMPs have the potential to reduce the annual export of P from Manitoba agriculture by approximately 10 percent, or just under 100 tonnes of the 1,200 tonnes of the P load to Lake Winnipeg that Manitoba agriculture is understood to currently account for. Cost-benefit ratios including EGS values or indicators for these BMPs range from 0.8 to 6.3. In other terms, relative to the estimated cost of treating outflow to the Red River by the City of Winnipeg of $164,697 per tonne of P removed, the cost of reducing P exports from agricultural sources in Manitoba using the BMPs ranges from $0 (net benefit) to $765,125 per tonne of P. Variability and uncertainty of the biophysical potential to reduce P exports to Lake Winnipeg from Manitoba agricultural sources is the greatest determinant of the viability of the BMPs from a cost benefit and EGS perspective. Best estimates of the physical capacity or potential of agricultural BMPs have a wide range, extending nearly an order of magnitude - from a reduction to an increase in P export. Unit costs and prices including EGS values are relatively small factors in comparison to the range of biophysical uncertainty and variability. Given the large size and key role of Lake Winnipeg and the Lake Winnipeg drainage area, a full and direct economic and EGS accounting and estimate of the value of the lake is warranted and strongly recommended. Amongst other things, it is recommended that this entail a coordinated effort with Manitoba government and related agencies and stakeholders. Information and data with which to do so is currently widely distributed amongst several different public and private agencies in Manitoba and other jurisdictions. Despite the key importance of Lake Winnipeg, research conducted for this project was not able to identify any initiative to draw the necessary quantitative information and data together in coordinated and systematic fashion. Cost-benefit analysis using an EGS approach could be improved by further investigation and development of quantitative evidence and supporting data of EGS associated with agricultural BMPs.
Open Access
Air-Sea CO2 flux estimates in stratified Arctic coastal waters: How wrong can we be?
(AGU, 2019-01-03) Miller, Lisa A.; Burgers, Tonya; Burt, William; Granskog, Mats; Papakyriakou, Tim
Summer near-surface seawater sampling in the Canadian Arctic revealed potential for significant errors (nearly 0.1 μmol·(m-2 s -1)) in CO2 fluxes calculated from measured air-sea CO2 gradients. River runoff and sea ice melt strongly stratify these waters, often resulting in surface mixed layers only a few meters thick and isolated from waters sampled by shipboard underway systems. Samples collected with the underway system, rosette, and small boats exposed substantial near-surface gradients in CO2 partial pressure (pCO2) over the top 7 m at many stations. Distributions of temperature, salinity, and fluorescence indicated that the sources of the CO2 system gradients varied between stations, precluding simple corrections to align subsurface data with shallower conditions. Overall, the strong summertime sink of atmospheric CO2 implied by the underway data was not supported by shallower data.
Open Access
Algae, Cyanobacteria and Water Quality
(Agriculture and Agri-Food Canada, 2002-03) Scott, N.
Algae and cyanobacteria are tiny organisms that occur naturally in saltwater and freshwater. Individual organisms can often only be seen under a microscope, although with some species , individuals can join together to form colonies visible to the naked eye. It is important to understand the similarities and differences between algae and cyanobacteria as both groups can have distinct impacts on surface water quality.
Open Access
America's animal factories: how states fail to prevent pollution from livestock waste
(Natural Resources Defense Council, 1998) Natural Resources Defense Council and Clean Water Act
Factory farms, which mass-produce animals in assembly-line fashion, have harmed aquatic life, human health and ecosystems across the nation. As industrial-sized farms stagger under the vast burden of manure they are generating, environmental disasters are inevitable. The scale of this unprecedented outpouring of animal waste is staggering: 130 times the waste generated by humans in this country each year. This section details how animal waste is poisoning our water and air. It also explains why more disasters are likely to occur unless the nation takes serious steps not only to regulate the way animal factories currently handle their waste but also to turn towards more benign methods of raising animals and managing the wastes they generate.
Open Access
AN ANALYSIS OF DIGITAL WETLAND VEGETATION MAP COVERAGES. PRODUCED BASED ON AERIAL PHOTOGRAPHY AND SATELLITE IMAGERY NETLEY-LIBAU MARSH, 2001
(Water Science and Technology Branch, Environment Canada, 2014-06) Watchorn, K. Elise
Netley-Libau Marsh, the largest coastal wetland adjoining Lake Winnipeg, has been mapped by aerial photography in the past (Grosshans et al 2004; Verbiwski 1986), indicating a trend of vegetation loss, but a lack of historic aerial photography has limited mapping efforts to sporadic intervals. Landsat imagery, though of a coarser spatial resolution, has the advantage of high temporal and spectral resolution. In this study, a classified digital vegetation map was created for Netley-Libau Marsh in 2001 using GIS software, Landsat 7 imagery, and a visual classification methodology, for the purposes of comparison with an existing digital vegetation map produced by Grosshans et al (2004) from aerial photography obtained during the same year. Visual delineation and classification of Landsat multispectral imagery was a method suitable for producing wetland maps which distinguish vegetated from non-vegetated areas with a high degree of accuracy, as compared to the truthed Grosshans et al map. Whereas that photography-based mapping exercise distinguished 23 vegetation classes grouped under six marsh zones; this study was able to successfully distinguish five marsh zones – water, not vegetated, emergent wetland vegetation, wet meadow, and upland. Further distinction and categorization of three marsh zones into seven vegetation classes was also possible, but with a lower degree of accuracy. This report describes the methods used to evaluate differences in surface area of equivalent classes between the two mapping exercises. It also provides recommendation for the future analysis of Landsat images to produce a time series of classified digital vegetation maps that may be used to explore relationships between lake and river hydrology and wetland plant cover. This knowledge will be fundamental to guide management and remediation efforts for the benefit of Netley-Libau Marsh and Lake Winnipeg.
Open Access
Analysis of the effects of the Pine Falls pulp mill on the benthic invertebrates in the Winnipeg River, Manitoba
(Department of Fisheries and Oceans, 1996-07-01) Wong, P.L.; Armstrong, L.; Bezte, C.L.; Wilkinson, P.; Lockhart, W.L.
In Oct. 1994 a comprehensive study was initiated to assess the effects of the Pine Falls Pulp and Paper Mill on the invertebrates in the Winnipeg River. A total of 20850 invertebrate specimens was collected belonging to eight major classes.
Open Access
An Annotated Bibliography on Lake Manitoba and Adjoining Waters
(Delta Marsh Field Station (University of Manitoba), 2003-11) Bortoluzzi, Tara
Lake Manitoba located in south-central Manitoba, is the thirteenth largest freshwater lake in North America, spanning approximately 4700 km2. The lake is an important resource for Manitoba in terms of fisheries, recreation, hydrology and wildlife. For the past few decades there has been a growing awareness, as a result of few studies on Lake Manitoba and its surrounding waterbodies that the water quality of the lake has been deteriorating for at least the past 30 years. This has increased the need for adequate information on the current and historical biological health of Lake Manitoba and adjoining water bodies, primarily to adequately assess of the impacts of a wide range of human influences and developments on the biological health of the lake and surrounding water bodies. This has resulted in a growing need for a comprehensive bibliography summarizing studies conducted on Lake Manitoba and adjoining water bodies. In this annotated bibliography the attempted has been to compile all substantive references addressing the current and historical biological health of Lake Manitoba. Selected water bodies that surround Lake Manitoba have also been included in the bibliography including Lake St. Martin, Waterhen Watershed, Pineimuta Lake and Marsh, Dauphin River, Fairford River, the Whitemud Watershed, and Delta Marsh. The lower Assiniboine River, from Brandon to the Assiniboine River Diversion (also known as the Portage Diversion) has also been included, along with the Assiniboine Diversion. In term of biological health, publication dealing with historical and current water quality conditions and water levels, and their effects in the above mentioned water bodies have been included in the bibliography. The effects of water quality and water levels include effects on the physical, chemical and biological features of the ecosystem. Publications containing information on historical regulation of Lake Manitoba and water levels in the lake have also been included. In total approximately 400 publications are included in this bibliography, spanning a period of over 125 years, with publications as early as 1876 included, continuing up until the beginning of 2002. In the bibliography the content of each publication has been concisely summarized. The summaries given for each publication, focus in material in the documents that pertains to Lake Manitoba and the other water bodies mentioned above. A summary table is also include in this report in Section two, to exemplify specific subject material that is contained in the publications such as various water quality parameters, and information on fisheries, flora, fauna, agriculture,recreational usage, soils and geology. The location and season of field studies is also given in the table. Locations where publications can be found, if known, are given to aid the reader in locating copies of the publications. A list of the various locations is given along with addresses, contact information, and hours of operation in Section three. Another section (section four) has also been included, which contains a brief list of historical photographs of Lake Manitoba, and select surrounding water bodies. From this bibliography it is apparent that there is a lack of information on the current and historical health of Lake Manitoba, and the majority of its surrounding water bodies. While the general hydrology of the Lake is relatively well documented, many aspects are inadequately understood, including the physical limnology and water chemistry of the lake. Water quality data is sporadically available on the lake as early as 1926. During the 1960s and 1970s there was a water quality monitoring program carried out at up to sixteen sites in the North and South Basins of the lake. However, the sampling program was reduced to six stations in 1973, with three in each basin, and in 1977 the program was eliminated all together. Furthermore, most of the data that were gathered from the sampling programs are unpublished. Today, only one sampling station exists in the entire lake located approximately 1 km offshore from the south end of the South Basin. The site has been monitoring since 1991. Much of the scientific data gathered on Lake Manitoba has been biological in nature, mostly concerning the lakes fishery. Relatively few published studies exist which have examined the algal or invertebrate composition of the lake. There is clearly an essential need for more scientific data to be gathered on the biological health of Lake Manitoba, as well as its surrounding water bodies. It should also be noted that due to the expansive amount of publications that have resulted from research studies that have been conducted at Delta Marsh only those that directly relate biological, chemical and influences from Lake Manitoba on the marsh and surrounding area, and influences on the lake from the surrounding watershed are included in this bibliography. The majority of studies conducted in Delta Marsh have also been previously sited in a bibliography compiled by den Haan (unpublished) that is currently in the final stages of complication and will be published later this year. Publications and theses resulting from work at the Delta Marsh can also be found in the Delta Marsh Field Station (University of Manitoba) Annual Reports that can be obtained through the Delta Marsh Field Station (University of Manitoba) (see locations list). It should also be noted that currently publications are still being added on a daily basis to the Manitoba Conservation and Environment Library, since the closure and the Manitoba Department of Natural Resources Library, and the transfer of its publications to the Manitoba Conservation and Environment Library. Approximately 1,000 publications are being added monthly to the library’s catalogue. As a result some publications, other than the ones included in this bibliography could exist on Lake Manitoba and the other surrounding water bodies; however they were not accessible during the compilation of this bibliography, so they may not have been included.
Open Access
Annual Exceedance Probabilities and Trends for Peak Streamflows and Annual Runoff Volumes for the Central United States During the 2011 Floods. Chapter D of 2011 Floods of the Central United States
(United States Geological Survey, 2014) Driscoll, Daniel G.; Southard, Rodney E.; Koening, Todd A.; Bender, David A.; Holmes, Rober R.
During 2011, excess precipitation resulted in widespread flooding in the Central United States with 33 fatalities and approximately $4.2 billion in damages reported in the Red River of the North, Souris, and Mississippi River Basins. At different times from late February 2011 through September 2011, various rivers in these basins had major flooding, with some locations having multiple rounds of flooding. This report provides broadscale characterizations of annual exceedance probabilities and trends for peak streamflows and annual runoff volumes for selected streamgages in the Central United States in areas affected by 2011 flooding. Annual exceedance probabilities (AEPs) were analyzed for 321 streamgages for annual peak streamflow and for 211 streamgages for annual runoff volume. Some of the most exceptional flooding was for the Souris River Basin, where of 11 streamgages considered for AEP analysis of peak streamflow, flood peaks in 2011 exceeded the next largest peak of record by at least double for 6 of the longest-term streamgages (75 to 108 years of peak-flow record). AEPs for these six streamgages were less than 1 percent. AEPs for 2011 runoff volumes were less than 1 percent for all seven Souris River streamgages considered for AEP analysis. Magnitudes of 2011 runoff volumes exceeded previous maxima by double or more for 5 of the 7 streamgages (record lengths 52 to 108 years). For the Red River of the North Basin, AEPs for 2011 runoff volumes were exceptional, with two streamgages having AEPs less than 0.2 percent, five streamgages in the range of 0.2 to 1 percent, and four streamgages in the range of 1 to 2 percent. Magnitudes of 2011 runoff volumes also were exceptional, with all 11 of the aforementioned streamgages eclipsing previous long-term (62 to 110 years) annual maxima by about one-third or more. AEPs for peak streamflows in the upper Mississippi River Basin were not exceptional, with no AEPs less than 1 percent. AEPs for annual runoff volumes indicated less frequent recurrence, with 11 streamgages having AEPs of less than 1 percent. The 2011 runoff volume for streamgage 05331000(at Saint Paul, Minnesota) exceeded the previous record (112 years of record) by about 24 percent. An especially newsworthy feature was prolonged flooding along the main stem of the Missouri River downstream from Garrison Dam (located upstream from Bismarck, North Dakota) and extending downstream throughout the length of the Missouri River. The 2011 runoff volume for streamgage 06342500 (at Bismarck) exceeded the previous (1975) maximum by about 50 percent, with an associated AEP in the range of 0.2 to 1 percent. In the Ohio River Basin, peak-streamflow AEPs were less than 2 percent for only four streamgages. Runoff-volume AEPs were less than 2 percent for only three streamgages. Along the lower Mississippi River, the largest streamflow peak in 91 years was recorded for streamgage 07289000 (at Vicksburg, Mississippi), with an associated AEP of 0.8 percent. Trends in peak streamflow were analyzed for 98 streamgages, with 67 streamgages having upward trends, 31 with downward trends, and zero with no trend. Trends in annual runoff volume were analyzed for 182 streamgages, with 145 streamgages having upward trends, 36 with downward trends, and 1 with no trend. The trend analyses used descriptive methods that did not include measures of statistical significance. A dichotomous spatial distribution in trends was apparent for both peak streamflow and annual runoff volume, with a small number of streamgages in the northwestern part of the study area having downward trends and most streamgages in the eastern part of the study area having upward trends.
Open Access
Anthropogenic landscape changes and their impacts on terrestrial and freshwater soundscapes
(Springer, 2019) Proulx, Raphael; Waldinger, Jessica; Koper, Nicola
Purpose of review: Quantifying the effects of anthropogenic sounds on wildlife at the landscape scale of observation has been notoriously difficult because these sounds are often confounded with the presence of infrastructure and loss of habitat through resource exploitation activities. In this paper, we review how anthropogenic landscape changes affect the power level and propagation of sounds in both terrestrial and freshwater ecosystems, as well as the behavioural response of organisms to novel acoustic habitats. Recent findings: Resource exploitation and other human activities change soundscapes both directly, by affecting sound production and propagation, and indirectly, by modifying landscape structure and species distribution patterns. Intermittent anthropogenic sounds are concentrated in the lower frequencies, tend to be louder than enduring sounds of the same origin, and create more patchy soundscapes. We identified key sensorial traits that are related to the auditory acuity of species in different taxonomic groups, including fish, birds, anurans, stridulating insects, and small mammals, and which may help us understand why certain species are more sensitive to anthropogenic changes to soundscapes. Summary: Prioritizing research in an increasingly noisy world requires a proper understanding of the auditory sensitivity of species, the characteristics of anthropogenic sounds (i.e., intermittent or enduring), and how sound production and propagation is affected by landscape structure. Further research on species’ sensorial traits would provide a framework with which to scale responses to anthropogenic sounds from individuals to communities, and better predict the impact of human activities on terrestrial and freshwater ecosystems.
Open Access
Appendix A - Water Quality Report
(International Joint Commission, 1976) International Garrison Diversion Study Board
The purpose of this part of the report is to describe the present water quality of Lakes Manitoba and Winnipeg and, to predict future water quality with and without the imposition of irrigation return flows, canal system seepage, operational wastes, municipal and industrial effluent and fish and wildlife return flows related to the planned Garrison Diversion Unit in North Dakota.
Open Access
Aquatic Communities and Contaminants in Fish from Streams of the Red River of the North Basin, Minnesota and North Dakota
(United States Geological Survey, 1995) Goldstein, R.M.
Available data on the ecology of aquatic organisms in the Red River of the North Basin, a study unit of the U.S. Geological Survey's National Water-Quality Assessment program, were collated from numerous sources. Lack of information for invertebrates and algae precluded a general summary of distribution and ecology throughout the basin. Data on fish species distributions in the major streams of the Red River of the North Basin were analyzed based on the drainage area of the stream and the number of ecoregions the stream flowed through. Species richness increased with both drainage area (log drainage area in square kilometers, R2=0.41, p=0.0055) and the number of ecoregions a river flowed through. However, theses two factors are autocorrelated because the larger the drainage, the more likely that the river will flow through more than one ecoregion. A cluster analysis identified five river groups based on similarity of species within the fish community. Analysis of trophic and taxonomic composition provided justification for the cluster groups. There were significant differences (p=0.05) in the trophic composition of the river cluster groups with respect to the number of predator species, omnivore species, benthic insectivore species, and general insectivore species. Although there were no significant differences in the number of species in the bass and sunfish family or the sucker family, the number of species in the minnow family and the darter subfamily were different (p=0.05) among the groups identified by cluster analysis. Data on contaminant concentrations in fish from the Red River of the North indicated that most trace elements and organochlorine compounds present in tissues were not at levels toxic to fish or humans. Minnesota and North Dakota have issued a fish consumption advisory based on levels of mercury and (or) PCBs found in some species.

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