Browsing by Subject "Great Lakes"
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Item Breeding Bird Communities Across an Upland Disturbance Gradient in the Western Lake Superior Region(2007) Miller, Christina; Niemi, Gerald J; Hanowski, JoAnn M; Regal, Ronald RThe coastal region of western Lake Superior to examine relationships to human land use. Eighty-four species were detected and 50 were abundant enough to be included in data analysis. Monotonic quadratic regression models were constructed for these 50 species by using species counts as the dependent variable and the proportion of human conversion of the landscape (residential, agriculture, and commercial/industrial land uses) within each study area as the independent variable. Twenty-seven bird species had significant regressions (P < 0.05), 18 of which generally avoided areas developed by humans and 9 of which were attracted to development. De-trended correspondence analysis using counts of these 27 bird species was used to investigate multivariate, community responses to development. The first DCA axis was interpreted as a gradient from urban avoiding to urban exploiting bird species and was strongly correlated with land cover variables related to human development. Our results advance the idea that breeding bird communities can be used as indicators of ecological condition and can diagnose potential causes for changes in these conditions. Further, our study points out the usefulness of bird monitoring data in regional planning efforts that incorporate goals for maintaining native biological diversity.Item Breeding Ecology and Conservation of Ground-Nesting Waterbirds in North America and Southeast Asia(2016-12) Claassen, AndreaWaterbird populations have declined around the world as a result of anthropogenic impacts from habitat loss and degradation, direct mortality, reproductive failure, and disturbance from humans and non-native and domestic animals. Specialist species are particularly at risk from changing environmental conditions and disturbances compared to generalist species. Plovers, lapwings, terns, and other waterbird species in the Order Charadriiformes nest on the ground, near water, and in exposed areas with little vegetative cover. As a result of their specialized breeding ecology and habitat requirements, nests of these species are therefore highly vulnerable to animal predation, flooding due to rainfall and hydrologic fluctuations, and disturbance from humans and domestic animals. Different social, economic, and political situations among world regions present distinct opportunities and challenges for implementing species conservation. In this study, I explore breeding ecology and conservation of threatened ground-nesting waterbirds in two different systems: 1) Piping Plovers Charadius melodus that breed on lakeshore beaches in the Great Lakes region of the United States, and 2) a community of six species, including River Tern Sterna aurantia, River Lapwing Vanellus duvaucelii, Great Thick-knee Esacus recurvirostris, Indian Thick-knee Burhinus indicus, Small Pratincole Glareola lactea, and Little Ringed Plover Charadrius dubius, that nest on river sand and gravel bars in the Mekong River basin in Cambodia. First, I examine factors affecting nest survival and renesting, and compare in situ and ex situ management scenarios to evaluate the potential efficacy of egg salvage as a means to augment the Great Lakes Piping Plover population. Second, I investigate factors affecting nest and chick survival of riverine birds in Cambodia, and evaluate the effectiveness of a direct payment nest protection program to improve reproductive success. Third, I examine factors affecting multi-scale habitat selection, and the consequences of habitat selection on reproductive success of riverine birds in Cambodia. This study provides valuable new information that will aid ongoing conservation efforts for threatened ground-nesting waterbirds such as the Piping Plover in North America and riverine birds in Southeast Asia. This work also has implications for conservation of threatened species more broadly.Item The causes and consequences of individual variation in survival and fecundity of Great Lakes piping plovers (Charadrius melodus)(2015-03) Saunders, Sarah PrairieThe piping plover (Charadrius melodus) is a small shorebird endemic to North America and restricted to three breeding populations: Atlantic Coast, Great Plains, and Great Lakes. Listed as federally endangered in 1986, the Great Lakes population has numbered from 17 to 71 known breeding pairs. Despite recovery efforts, the population is far from the federal recovery goal of 150 breeding pairs. The purpose of my dissertation research is to understand the causes and consequences of individual variation in survival and fecundity during key breeding stages through four distinct methods of investigation: life-history theory, quantitative genetic analysis, population demography, and behavioral assessment. Effective conservation of small wildlife populations requires the intersection of many scientific disciplines and I seek to achieve this unification through the four chapters of my dissertation. First, I investigate how age and parental experience with breeding, a mate, and a nesting location influence reproductive success (Chapter 1). In chapter 2, I investigate the heritabilities of three fitness-related traits (chick body mass, natal dispersal distance, and female timing of breeding) to determine which are strongly environmentally-determined and thus susceptible to impacts of global climate change. In chapter 3, I tease apart the relative influences of various developmental and environmental factors at pre-fledging, post-fledging, and adult stages to more precisely inform population recovery actions. In my final chapter, I test the hypothesis that captive-reared chicks have lower survival rates than those reared in the wild because of a lack of threat recognition. The insights gained from my research not only pertain to this small shorebird breeding in the Great Lakes, but also provide a more comprehensive framework for analyzing data on marked individuals with the goal of shaping conservation actions for an entire population. Further, the new analytical methods applied to ecologically complex data will be important to any study that uses long-term marking. Avian populations are predicted to become more threatened in the future, so it is increasingly critical to understand factors driving vital rates and to develop approaches to alleviate threats to population persistence.Item Climate change, the invasion of Bythotrephes longimanus, and recent changes in the zooplankton community of Lake Superior(2016-07) Pawlowski, MatthewIn recent decades, average summer surface temperatures in Lake Superior have increased and the invasive predatory zooplankton, Bythotrephes longimanus, became established. While climate warming and Bythotrephes have influenced zooplankton communities in other lakes, it is unclear how either have or will influence the zooplankton community in Lake Superior. A late spring ice out in 2014 provided an opportunity to observe the response of zooplankton in Lake Superior to inter-annual variation in temperature. To evaluate this response, I compared biomass estimates, phenologies, and community compositions of the zooplankton communities in western Lake Superior during the 2014 and 2015 growing seasons. I also compared the community compositions observed in these years to published literature to determine whether the community has changed in response to climate warming or planktivory by Bythotrephes. I evaluated the possible role of Bythotrephes in zooplankton community changes using a bioenergetic model to compare the consumptive demands of Bythotrephes to the production rates of their potential prey. Annual peaks in zooplankton biomass were correlated with peaks in surface temperature. Peak biomass in 2014 occurred approximately 20 days later than in 2015 suggesting that continued warming could have long-term effects on the timing of peak zooplankton biomass in Lake Superior. The amount of biomass at the peak did not differ between years nor did overall community structure suggesting that zooplankton biomass and species composition in Lake Superior may be more constrained by food availability than temperature. However, long-term comparisons of zooplankton community composition indicate that densities of Bosmina longirostris declined and the proportional contribution of Daphnia mendotae to cladoceran biomass increased since the 1970s. These community changes are more consistent with the expected outcome of planktivory by Bythotrephes than the expected outcomes of changes in temperature, primary production, or vertebrate planktivory. The results suggest that Bosmina is the cladoceran species most vulnerable to suppression by Bythotrephes in Lake Superior, which supports the hypothesis that Bythotrephes has altered the cladoceran community in Lake Superior. While consumption by Bythotrephes did not exceed total zooplankton production in Lake Superior during 2014 or 2015, future increases in Bythotrephes density and temperature could cause the top-down effects of Bythotrephes on the zooplankton community to increase. This work helps to clarify how climate warming and Bythotrephes could influence the zooplankton community and energy flow pathway in Lake Superior in the future.Item Comparing Ship-based to Multi-Directional Sled-based Acoustic Estimates of Pelagic Fishes in Lake Superior(2019-05) Grow, RyanShip-based down-looking acoustic surveys are commonly used to determine the biomass and population density of commercially important fish species for resource managers and scientists, particularly in the Great Lakes and marine systems. However, there are some limitations and biases inherent in traditional down-looking surveys. I examined the use of multi-directional sled mounted acoustics equipped with up, side, and down-looking capabilities to overcome these limitations while examining the Lake Superior pelagic fish community. In the western arm of Lake Superior, I concurrently deployed the sled mounted acoustics during traditional down-looking surveys to directly compare the fish densities obtained from each gear, which I then followed with a mid-water trawl to inform my acoustic data with species composition. My findings from a two-way ANOVA showed a significant difference between fish densities detected by the sled-based survey and the ship-based down-looking survey indicating 60% of the pelagic fish community was missed by the traditional down-looking survey. This study also sought to provide a baseline for future research looking to discover which species in aquatic systems are most effected by traditional survey biases, as well as future work into using alternate forms of acoustic sampling to inform fisheries management and research.Item Dataset for Factors Regulating Lake Periphyton Biomass and Nutrient Limitation Status Across Large Trophic Gradient(2021-05-25) Camilleri, Andrew; Ozersky, Ted; accamill@umich.edu; Camilleri, Andrew; Large Lakes ObservatoryThis data set contains results of a study on the response of Great Lakes periphyton to additions of nutrients. Nutrient Diffusing Substrata (NDS) with control, +nitrogen, +phosphorus, and +nitrogen and phosphorus treatments were deployed at 28 sites along the coast of Lake Superior, northern Lake Michigan, and Green Bay. Control NDS cups contained just 2% agar by weight while +nitrogen, +phosphorus, and +nitrogen and phosphorus treatments contained the agar and 0.5 M NH4Cl, KH2PO4, or both, respectively. Experiments were deployed between July 11-31, 2017 and retrieved 28-29 days later between August 8-28, 2017. Periphyton biomass as chlorophyll-a and ash free dry weight (AFDW) from NDS treatments is contained in the file “NDS_Chl_AFDW.csv”. Site locations and environmental parameters (water column nutrient concentrations, Kd, and chlorophyll) are contained in the file “SITES_PARAMETERS”.Item Development of Environmental Indicators for the U.S. Great Lakes Basin Using Remote Sensing Technology(University of Minnesota Duluth, 2006) Niemi, Gerald J; Johnston, Carol A; Wolter, Peter T.In 2001 we initiated a study of remote sensing technology to complement our development of environmental indicators for the U.S. Great Lakes coastal region. Our objectives were to: 1) quantify land use/land cover (LULC) and change for the U.S. portion of the Great Lakes basin between 1992 and 2001; 2) identify salient LULC change categories that are most likely to affect near-shore ecosystems; 3) recommend landscape indicators to guide managers toward long-term sustainable development; 4) develop methodologies to quantify SAV within near-shore areas of the Great Lakes; and 5) use historically low water levels in Lakes Michigan and Huron to produce a digital elevation model of recently exposed lake bed using radar interferometry to better model coastal wetland inundation events as lake water levels returns to normal. In addition, we completed four focused studies in the Great Lakes basin: 1) two studies to determine the degree of accuracy of Quiclcbird satellite imagery to identify specific vegetation types within a wetland; 2) an examination of 63 years (1940 to 2003) of land use change in a 100 km2 area in western Lake Erie; and 3) a study to test the use of Hyperion hyperspectral satellite imagery for mapping PhragmitesL an invasive plant species in the Great Lakes. All of the objectives were successfully completed, except objective 5 in which we had technical difficulties with the use of radar interferometry because of changes in ice and snow in the region. A total of six peer-reviewed publications have been completed and three additional publications are either in review or in preparation. The land use/land cover map produced for 1992 and 2001 will serve an extremely important baseline for future monitoring of change in the U.S. Great Lakes basin. A special issue of the Journal of Great Lakes Research is in preparation that summarizes additional work on this project. It is scheduled for publication in 2007.Item Dietary Niche and Growth Rate of the Nonnative Tubenose Goby (Proterorhinus semilunaris)(2019-05) Dawson , BradleyBasic life history knowledge is essential to determine if a nonnative species is potentially invasive. The nonnative tubenose goby (Proterorhinus semilunaris) arrived in the Great Lakes in the 1990s via ship ballast water, but remains poorly studied within North America, making it difficult to predict its effects on native ecosystems. Diet and growth patterns were examined from age-0 tubenose gobies within the estuary of the St. Louis River, a tributary to Lake Superior near Duluth, Minnesota. Dietary breadth and growth rates have important ramifications for survival, competitiveness, and dispersal ability of a fish species, influencing its potential success as an invasive species. I sampled tubenose gobies from shallow vegetated habitat via beach seine during summer and fall periods, and removed otoliths and aged fish on daily increments for growth modelling. Furthermore, stomach contents were identified and weighed to provide measures of fitness and dietary breadth between seasons (fall vs. summer) and between several locations within the estuary. Results suggest a low dietary breadth that overlaps with tadpole madtom (Noturus gyrinus); tubenose goby diet was mostly comprised of Crustacea, regardless of location or season. Growth modelling demonstrates that tubenose gobies reach a small maximum size and are short-lived, indicating an r-selected life history. The Gompertz function is preferred for modelling the growth of this species.Item Dynamic populations, dynamic landscapes: conservation science case studies of colonial waterbirds in the North American Great Lakes(2016-05) Wyman, KatherineColonial animals concentrate locally, presenting different conservation challenges and opportunities than more broadly-distributed species. The Double-crested Cormorant (Phalacrocorax auritus) and the Black Tern (Chlidonias niger) in the North American Great Lakes provide two contrasting case studies of the challenges and opportunities for conservation and management of colonial waterbirds. I used a combination of historical datasets, new field studies, and statistical modeling to investigate issues surrounding conservation and management of these two birds in Great Lakes. The Double-crested Cormorant, focus of the first case study, has experienced extreme population growth and is now subject to population management at a majority of U.S. Great Lakes colony sites; effects of cormorants and their management on co-nesting waterbird species have remained largely unknown. I observed that nesting among Double-crested Cormorants increased frequency of agonistic interactions for Great Blue Herons (Ardea herodias), particularly when nesting on the ground. My research also showed that Black-crowned Night-Heron (Nycticorax nycticorax) colony growth was negatively associated with Double-crested Cormorant abundance and implementation of management, while Herring Gull (Larus argentatus) and Ring-billed Gull (Larus delawarensis) colony growth was positively associated. The Black Tern, subject of the second case study, has been declining for over half a century due to unknown causes, although wetland loss and degradation have likely contributed. I found a positive relationship between increasingly clumped vegetation in Great Lakes coastal wetlands and historical Black Tern colony abandonment. Under current conditions in the region, wetland type and area were critical parameters in delineating wetlands that were unsuitable for Black Terns from potentially suitable ones. In the ever-changing landscape of the North American Great Lakes, my investigations provide important results to inform future conservation and management actions for these two very different species.Item Ecology of Giant, Sulfur-Oxidizing Thioploca Bacteria in Great Lakes Sediments(2021-06) McKay, ElizabethMicroorganisms play a key role in regulating the cycling of carbon, oxygen, nitrogen, sulfur, and other important elements in aquatic ecosystems. Thioploca is a giant, filamentous bacteria that oxidizes sulfide and reduces nitrate, coupling the nitrogen and sulfur cycles in its benthic habitats. Thioploca can achieve high abundances in marine sediment where it is known to alter nitrogen and sulfur dynamics by removing toxic sulfide and recycling fixed nitrogen back into the sediment and water column. Thioploca can also achieve high abundances in freshwater sediments; however, its distribution and biogeochemical function are poorly understood in freshwater environments, making it difficult to determine how it impacts elemental cycling in these habitats. To analyze Thioploca abundance, factors affecting its distribution, and its biogeochemical function in the Great Lakes, I quantified Thioploca biomass and water column and sediment characteristics at 33 sites that spanned a gradient of depth and trophic conditions in the Apostle Islands region of Lake Superior and Green Bay in Lake Michigan. Sediment cores were also collected at eight of my study sites to analyze vertical Thioploca biomass distribution and sediment chemistry. Thioploca was common in both the Apostle Islands and Green Bay and reached biomasses of up to 250 g/m2 wet weight at some sites. While PCA and logistic regression analysis indicated that Thioploca may be more likely to be present under eutrophic conditions, Thioploca was also common and abundant at some oligotrophic sites in the Apostle Islands. Thioploca was more abundant in fine-grained than coarse-grained sediment, suggesting Thioploca distribution may be linked to depositional areas of lakes. At most sites, Thioploca was most abundant in the top 5 cm of sediment. Ammonia profiles in some sediment cores appear to indicate possible ammonia consumption in sediment layers with Thioploca, which suggests these freshwater Thioploca may interact with benthic nitrogen cycling differently than marine species of Thioploca. My results, along with other reports from the Great Lakes, suggest that freshwater Thioploca may be widespread throughout the Great Lakes. At the abundances observed, Thioploca is likely significantly influencing nitrogen and sulfur cycling in these areas, although many questions remain about Thioploca’s biogeochemical functioning in freshwater environments, including how it achieves high biomass in low sulfur environments, whether it reduces nitrate to ammonia or N2, and whether it promotes the recycling of fixed nitrogen or acts as a fixed nitrogen sink.Item Environmental Indicators for the US. Great Lakes Coastal Region(University of Minnesota Duluth, 2006) Niemi, Gerald J; Axler, Richard P; Brady, Valerie; Brazner, John; Brown, Terry; Ciborowski, Jan H; Danz, Nicholas P; Hanowski, JoAnn M; Hollenhorst, Thomas; Howe, Robert; Johnson, Lucinda B; Johnston, Carol A; Reavie, Euan D; Simcik, Matthew; Swackhamer, Deborah L.The goal of this research collaboration was to develop indicators that both estimate environmental condition and suggest plausible causes of ecosystem degradation in the coastal region of the U.S. Great Lakes. The collaboration consisted of 8 broad components, each of which generated different types of environmental responses and characteristics of the coastal region. These indicators included biotic communities of amphibians, birds, diatoms, fish, macroinvertebrates, and wetland plants as well as indicators of polycyclic aromatic hydrocarbon (P AH) photo-induced toxicity and landscape characterization. These components are summarized below and discussed in more detailed in 5 separate reports (Section II). Stress gradients within the U.S. Great Lakes coastal region were defined from 207 variables (e.g., agriculture, atmospheric deposition, land use/land cover, human populations, point source pollution, and shoreline modification) from 19 different data sources that were publicly available for the coastal region. Biotic communities along these gradients were sampled with a stratified, random design among representative ecosystems within the coastal zone. To achieve the sampling across this massive area, the coastal region was subdivided into 2 major ecological provinces and further subdivided into 762 segment sheds. Stress gradients were defined for the major categories of human-induced disturbance in the coastal region and an overall stress index was calculated which represented a combination of all the stress gradients. Investigators of this collaboration have had extensive interactions with the Great Lakes community. For instance, the Lake Erie Lakewide Area Management Plan (LAMP) has adopted many of the stressor measures as integral indicators of the condition of watersheds tributary to Lake Erie. Furthermore, the conceptual approach and applications for development of a generalized stressor gradient have been incorporated into a document defining the tiered aquatic life criteria for defining biological integrity of the nation's waters. A total of 14 indicators of the U.S. Great Lakes coastal region are presented for potential application. Each indicator is summarized with respect to its use, methodology, spatial context, and diagnosis capability. In general, the results indicate that stress related to agricultural activity and human population density/development had the largest impacts on the biotic community indicators. In contrast, the photoinduced P AH indicator was primarily related to industrial activity in the U.S. Great Lakes, and over half of the sites sampled were potentially at risk of P AH toxicity to larval fish. One of the indicators developed for land use/land change was developed from Landsat imagery for the entire U.S. Great Lakes basin and for the period from 1992 to 2001. This indicator quantified the extensive conversions of both agricultural and forest land to residential area that has occurred during a short 9 year period. Considerable variation in the responses were manifest at different spatial scales and many at surprisingly large scales. Significant advances were made with respect to development of methods for identifying and testing environmental indicators. In addition, many indicators and concepts developed from this project are being incorporated into management plans and U.S. EPA methods documents.Item Examining Decision-Makers’ Perspectives on Climate Change and Climate Preparedness in the Lake Superior Basin of Minnesota(2017-05) Meier, HollyThis study explores characterizations of climate change and climate preparedness within two subwatersheds of the Lake Superior basin. Twenty-seven key informant interviews were conducted with local decision makers, resource managers, and other leaders active in the subwatersheds. Study participants’ experiences, beliefs, and attitudes were documented and analyzed using qualitative methods. Findings indicate strong convergence around climate change beliefs and concerns and divergence on perspectives on climate preparedness. Further analysis revealed specific challenges and current actions associated with climate preparedness. A better understanding of climate change beliefs and perceived preparedness will provide insight into the resources and activities that can be leveraged for further climate preparedness. This study also reveals challenges that may need to be addressed to make efforts more effective. Study findings offer a framework for climate preparedness planning and provide evidence for a strategic approach to building adaptive capacity in the study communities. Findings will inform community engagement, outreach, education, and communication programming on climate preparedness.Item Final Data Summary Report: Phytoplankton Monitoring in the Great Lakes: 2007-2012 Funding Years(University of Minnesota Duluth, 2013) Reavie, Euan DThe Laurentian Great Lakes have a long record of adverse anthropogenic impacts on water quality and food webs. Tracking these impacts and their causes is critical so that remedial efforts can be directed where and how they are most needed. The EPA’s Great Lakes National Program Office (GLNPO) is now in its 30th year of comprehensive monitoring of the Great Lakes. Pelagic monitoring includes physical and chemical parameters, phytoplankton, zooplankton, benthic invertebrates and other measurements. These monitoring data have revealed significant changes in whole-lake conditions (e.g. Barbiero et al. 2009), thus justifying GLNPO’s mandate to track changes under the Great Lakes Water Quality Act of 1978. Specifically, phytoplankton collections provide important information on the primary food source at the bottom of the food web, and we aim to track long-term changes in the phytoplankton resulting from human influences, and so characterize causes of disturbance, their impacts, and remedial necessity. Phytoplankton are known to respond to stressors such as nutrient loading and invasive species, and ultimately integration with other program components (e.g., zooplankton, water quality) will allow the evaluation of interactions among trophic levels and provide a more holistic interpretation of causal factors in biological changes. The abbreviated objectives of the phytoplankton program are to: 1) collect phytoplankton from the Great Lakes in spring and summer excursions on board the R/V Lake Guardian; 2) identify and enumerate phytoplankton, maintaining quality assurance standards; 3) maintain and provide a database of phytoplankton data; 4) interpret phytoplankton data, including evaluation of long-term trends in phytoplankton and food web dynamics; and 5) dissemination of data and interpretations through reports, presentations and peer-reviewed journals so that results are available for aquatic management considerations. This report summarizes phytoplankton data collected under the USEPA’s Open Lake Water Quality Survey of the Great Lakes. Those unfamiliar with the project are directed to http://www.epa.gov/glnpo/monitoring/sop for a detailed background of the overall project goals, ideology and methods. Data and analyses in this report were generated by the Natural Resources Research Institute (NRRI), University of Minnesota Duluth (UMD) under the direction of Euan Reavie (Senior Research Associate -- NRRI), and this report fulfills the final task as agreed in cooperative agreement GL-00E23101-2.Item Habitat and landscape characteristics that influence Sedge Wren (Cistothorus platensis) and Marsh Wren (C. palustris) distribution and abundance in Great Lakes coastal wetlands(2013-08) Panci, HannahI analyzed habitat and landscape characteristics important to the Sedge Wren (Cistothorus platensis) and Marsh Wren (C. palustris) in Great Lakes coastal wetlands using breeding bird census data from two large projects in 2002-2003 and 2011-2012. Little is known about the population or distribution of these species in the Great Lakes region. For each of 840 survey points in coastal wetlands along the U.S. and Canadian shorelines, I used National Land Cover Data and Ontario Land Cover Data to calculate the percent cover of seven different land use classes within 500, 1000, and 2000 m buffers of each point. I combined these with climatic and landscape configuration variables as well as field-collected vegetation data to develop classification trees that predicted both Sedge and Marsh Wren presence and relative high abundance (≥3 wrens/site). After eliminating geographic variables, the best classification trees predicted Sedge Wrens to be present in wetlands with greater than 9% woody wetlands at the 2000 m buffer, and in high abundance in sites with less than 3% cattails and greater than 4% meadow vegetation. Marsh Wren presence was positively associated with emergent vegetation and cropland, and negatively associated with woody wetland at the 500 m buffer. Marsh Wrens were predicted to be in high abundance at sites with greater than 14% cattails. This classification tree analysis is a powerful predictive tool which significantly increases our ability to correctly predict the presence of these secretive wetland species. These results provide a basic understanding of characteristics of Great Lakes coastal wetlands important to two wetland-obligate bird species and can be useful in conservation decisions and management plans.Item Habitat associations and conservation of wetland-obligate birds(2019-06) Elliot, LisaA basic understanding of species-specific habitat associations is a prerequisite for the effective management of at-risk species. Many wetland-dependent birds in the Upper Midwest are at-risk due to habitat loss and degradation. To investigate the habitat associations of wetland-dependent birds, I: 1) determine the relative importance of habitat heterogeneity vs. wetland area for biodiversity and species abundance, 2) develop species-specific models of habitat associations for eight declining obligate wetland bird species that use coastal wetland habitat in the Great Lakes basin, and 3) provide general habitat models for these species that are useful across multiple regions. The central hypothesis of this work is that populations of wetland-dependent birds are influenced by a combination of landscape and proximate habitat features, regionally specific hydrologic conditions, and anthropogenic stressors. Findings from the analysis of habitat heterogeneity indicated support for a tradeoff between area and habitat heterogeneity but highlight the importance of wetland area as the primary driver of variation in species richness and abundance. Species-specific combinations of habitat heterogeneity and other wetland characteristics provided additional explanatory power. Findings from hierarchical multi-scale occupancy models for coastal wetland birds in the Great Lakes basin indicated that the eight focal species are eurytopic, with little variation in occupancy despite differences in remotely sensed landscape characteristics, including anthropogenic disturbance. These species use a high proportion of the coastal wetlands in at least some years. Thus, wetland loss is problematic for these species and conservation planning should focus on protecting as many wetlands as possible. Finally, the regional comparison showed that these species have regionally specific habitat associations, but in most cases, associations estimated in one region can be informative when applied to other regions. In conclusion, habitat associations of wetland birds in the Upper Midwest are both species- and region-specific. Conservation of these species will depend primarily on protecting wetlands across a gradient of habitat characteristics at multiple scales and on reversing ongoing trends of wetland loss.Item Historical Water Quality Data Assessment of the Great Lakes Network(University of Minnesota Duluth, 2006) Axler, Richard P; Ruzycki, Elaine; Host, George E; Henneck, JeraldThe objective of this analysis was to assess a large body of water quality data collected across Parks of the Great Lakes Network over more than two decades, make recommendations on sampling and data issues, and to the degree possible, identify trends in water quality that could be derived from these data.Item Human Influences on Water Quality in Great Lakes Coastal Wetlands(2008) Morrice, John A; Danz, Nick; Regal, Ronald R; Kelly, John R; Niemi, Gerald J; Reavie, Euan; Hollenhorst, Thomas; Axler, Richard P; Trebitz, Annet; Cotter, Anne C; Peterson, Gregory SThis peer-reviewed article discusses water quality and chemistry issues with anthropogenic causes. Geographically, it covers the US coastal region of the Great Lakes. A map in the article suggests that only one sampling point was within Minnesota’s coastal region. The article focuses on water chemistry in coastal wetlands across the Great Lakes, but not specifically for Minnesota. Key points in the abstract are extracted and reproduced below. A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP), total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected, open coastal) and biogeography (two eco-provinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems.Item An Integrated Approach to Assessing Multiple Stressors for Coastal Lake Superior(2011) Niemi, Gerald J; Reavie, Euan; Peterson, Gregory S; Kelly, John R; Johnston, Carol A; Johnson, Lucinda B; Howe, Robert W; Host, George; Hollenhorst, Thomas; Danz, Nick; Ciborowski, Jan H; Brown, Terry; Brady, Valerie; Axler, Richard PThis peer-reviewed article summarizes research conducted under the Great Lakes Environmental Indicators (GLEI) project initiated by the authors in 2001. The authors assessed the status of Lake Superior’s coastal ecosystem relative to over 200 environmental variables collected from GIS data sets for the enture US Great Lakes basin. These were assessed using gradients including atmosphereic deposition, agriculture, human population and development, land cover, point source pollution, soils and a cumulative stress index. Relationships of biological assemblages of birds, diatoms, fish and invertebrates, wetland plants, soils and stable isotopes to these gradients were then assessed. Key findings are extracted and reproduced below. Biological indicators can be used both to estimate ecological condition and to suggest plausible causes of ecosystem degradation across the U.S. Great Lakes coastal region. Here we use data on breeding bird, diatom, fish, invertebrate, and wetland plant communities to develop robust indicators of ecological condition of the U.S. Lake Superior coastal zone. Sites were selected as part of a larger, stratified random design for the entire U.S. Great Lakes coastal region, covering gradients of anthropogenic stress defined by over 200 stressor variables (e.g. agriculture, altered land cover, human populations, and point source pollution). A total of 89 locations in Lake Superior were sampled between 2001 and 2004 including 31 sites for stable isotope analysis of benthic macroinvertebrates, 62 sites for birds, 35 for diatoms, 32 for fish and macroinvertebrates, and 26 for wetland vegetation. A relationship between watershed disturbance metrics and 15N levels in coastal macroinvertebrates confirmed that watershed-based stressor gradients are expressed across Lake Superior’s coastal ecosystems, increasing confidence in ascribing causes of biological responses to some landscape activities. Several landscape metrics in particular—agriculture, urbanization, human population density, and road density—strongly influenced the responses of indicator species assemblages. Conditions were generally good in Lake Superior, but in some areas watershed stressors produced degraded conditions that were similar to those in the southern and eastern U.S. Great Lakes. The following indicators were developed based on biotic responses to stress in Lake Superior in the context of all the Great Lakes: (1) an index of ecological condition for breeding bird communities, (2) diatom-based nutrient and solids indicators, (3) fish and macroinvertebrate indicators for coastal wetlands, and (4) a non-metric multidimensional scaling for wetland plants corresponding to a cumulative stress index. These biotic measures serve as useful indicators of the ecological condition of the Lake Superior coast; collectively, they provide a baseline assessment of selected biological conditions for the U.S. Lake Superior coastal region and prescribe a means to detect change over time.” Key points: “In general, the U.S. Great Lakes coastal region of Lake Superior shows greater overall stress in the southern regions compared with relatively low overall stress in the northern regions. These patterns are primarily due to agricultural land use, higher human population densities, and point sources in the eastern and western portions on the south shore, while the north shore at the western end of Lake Superior is primarily forested with relatively sparse human population densities. Coastal regions of Lake Superior can be found at each of the extremes of the disturbance gradients. This includes relatively pristine watersheds in the northern regions with low human population densities and little agriculture that contrast with regions of relatively high populations with industrial activity such as Duluth-Superior in Minnesota-Wisconsin and Sault Ste. Marie Michigan at the other end of the gradient. The U.S. Lake Superior coastal region varies widely in the degree of human-related stress; generally, levels of stress decrease from south to north but with considerable variation, especially along the southern shore due to local agricultural activity and the presence of several population and industrial centers. In spite of a lack of latitudinal variation, there is human-induced, watershed scale variability across the Lake Superior coast. Compared to the other Great Lakes, Lake Superior coastal fish communities had more generally intolerant fish and more turbidity intolerant fish. Coastal fish community composition reflected the higher levels of suspended solids associated with human alteration to watersheds. The most disturbed sites on Lake Superior had greater proportions of non-native species and fewer bottom-feeding taxa.Item Microhabitat influence on young-of-year fish assemblages within the vegetated beds of the St. Louis River estuary(2017-07) Ramage, HannahCoastal wetlands within the Laurentian Great Lakes provide crucial habitat for an abundance and diversity of fishes during larval and juveniles stages; however, young-of-year fish habitat association studies at the microhabitat scale are rare. Because studies at this fine scale are crucial for understanding the habitat properties that support fishes at this critical life stage, I examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in aquatic vegetated beds throughout the estuary, across a gradient of aquatic vegetation types and densities. Canonical correspondence analysis, relating species abundances to environmental variables revealed that principally microhabitat variables, including plant species richness, depth, and aquatic plant cover explained difference in fish assemblages. In addition, I evaluated the specific habitat associations of non-native Tubenose Goby (Proterorhinus semilunaris) to provide insight on habitat overlap with native species and further invasion risk. Tubenose Goby were nearly ubiquitous (75% if study sites) and abundant (0.59 fish/m2) in the study site. Non-metric multidimensional scaling revealed that sunfish, Tadpole Madtom and Johnny Darter have the most potential for habitat overlap with Tubenose Goby. Generalized linear modelling revealed that Tubenose Goby occupied a specific microhabitat within vegetated beds consisting of dense cover and high plant species richness. Results from this microhabitat analysis at this critical life stage has potential to inform wetland management and restoration efforts within the St. Louis River estuary and other Great Lake Coastal Wetlands.Item Mid-project Data Report: Phytoplankton Monitoring in the Great Lakes(University of Minnesota Duluth, 2009) Reavie, Euan DThis report is intended for audiences who are familiar with the USEPA’s Open Lake Water Quality Survey of the Great Lakes. Those unfamiliar with the project are directed to http://www.epa.gov/glnpo/monitoring/sop for a detailed background of the overall project goals, ideology and methods. This report fulfils the task of “Preliminary Report” (due July 28, 2009) as agreed in contract GL-00E23101-2. Results herein focus on 2007 phytoplankton data from GLNPO’s Great Lakes open water biological monitoring program. The main objectives of this report are to (1) present general characteristics of the 2007 phytoplankton assemblages, (2) reconstruct long-term phytoplankton trends in the context of phytoplankton data collected prior to 2000, and (3) use various observational and statistical techniques to confirm that data quality objectives, mainly taxonomic consistency, have been met. Since the initiation of the University of Minnesota Duluth’s (UMD) involvement in the monitoring program, significant efforts have been allocated to taxonomic assurance. Following the transition of the project to a new contractor in 2001, several data quality issues related to inconsistencies in taxonomic identifications arose resulting in temporary termination of the phytoplankton program in 2004. Part of UMD’s agreement was to ensure that the new phytoplankton data collected in 2007 meet specific taxonomic criteria. In other words, taxonomy for 2007 needed to match that from pre-2000 samples so that long-term analyses were reliable. It is our opinion that we have met taxonomic criteria and that, with continued taxonomic workshops, we are building a reliable long-term phytoplankton database that will be a valuable tool to track ecological shifts in the lakes.