Browsing by Subject "Lake Superior"

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2010 Lake Superior Mooring Deployment Campaign
(2021-03-10) Austin, Jay A; jaustin@d.umn.edu; Austin, Jay; University of Minnesota Duluth, Large Lakes Observatory
Since 2005, investigators at UM Duluth's Large Lakes Observatory have been deploying sub-surface moorings in Lake Superior to investigate thermal structure and currents. This submission contains all temperature and current data from deployments that occurred in 2010.
Acoustic Observations of Zooplankton Migration in Lake Superior
(2023-07) Murr, Ashley
The diel vertical migration (DVM) of aquatic organisms in marine environments is commonly studied using acoustic instruments because of their ability to sample with high spatial and temporal resolution for extended periods of time. The practice of using acoustic instruments in the Laurentian Great Lakes, however, is not as widespread. This research presents six years of Acoustic Doppler Current Profiler (ADCP) backscatter data from a site in Lake Superior to demonstrate that ADCPs can increase the resolution and robustness of data pertaining to the vertical migration of freshwater organisms, presumably zooplankton. We observed migratory behavior with sub-hour sampling over the course of entire seasons, including transitional seasons and the winter. The data distinctly reveals a diurnal signal consistent with DVM. In addition, with the high resolution of the data, we observe lunar and seasonal variation in the diurnal signal. We employ a simplified method using the change in measured intensity to isolate the diurnal signal, allowing us to compare data regardless of instrument modification, backscatter calibration, and range correction. We do not estimate abundance, biomass, population distribution, or species identification, instead we offer general observations on DVM patterns over days, months, and years to supplement standard biological sampling methods.
Adsorption of Freshwater Dissolved Organic Matter to Clay and Polyethylene Particles
(2019-08) Burrows, Alvin
Organic matter (OM), especially dissolved organic matter (DOM), plays several integral roles in aquatic systems. OM acts as a short-term sink of carbon and a food source for heterotrophs and shields biota from harmful UV radiation. It also facilitates the transport of nutrients, trace metals and pollutants in the environment. The uptake and transport of these compounds are related to the fate of the DOM to which they are bound. Suspended solids such as clays or microplastics can adsorb DOM into their interlayer spaces or onto their surfaces leading to: 1. Possible physical protection of OM that would have been mineralized or degraded by biota; 2. Increased transport of OM through the water column to the sediments (for sinking particles) or increased time for OM in the surface water (for less-dense microplastic particles); 3. Increased uptake by larger aquatic organisms. Increased particle-associated mobility (either by sinking through the water column or being transported at the surface via wind-driven processes) also increases associated nutrient, trace metal and pollutant transport, which in sufficient quantities, may perturb the aquatic system’s equilibrium and affect its chemistry. Microplastics, a new particle-type in aquatic systems, have been observed and documented in the world’s oceans since the 1970s, but their presence in the Laurentian Great Lakes was first recorded in 2013. The roles that microplastics and other particulates (both naturally occurring and anthropogenically impacted) play in aquatic environments need to be thoroughly studied so that a better understanding of their fate and environmental impact can be gained. The goal of this study was to qualitatively examine and compare the adsorption of open water Lake Superior DOM and DOM from a tributary stream to polyethylene microplastic spheres and to clays (kaolinite and montmorillonite). UV-VIS optical proxies were used to monitor changes in aromaticity (A254, SUVA) and molecular weight (E2:E3, S250-400, SR) within the remaining dissolved phase. Aromaticity proxies suggest that clays preferentially adsorbed aromatic species, while polyethylene had no significant effect on DOM composition. Changes in the amount of carbon remaining in the dissolved phase were measured using dissolved organic carbon (DOC) analysis while the amount adsorbed to the surface of the particulates was measured using elemental analysis (EA). DOC analysis did not show significant changes in the amount of dissolved organic carbon after sorption testing. EA was unable to provide a definitive answer for carbon adsorbed by polyethylene but suggests that kaolinite and montmorillonite adsorb similar amounts of carbon in both environments.
Alternative Technology for Sediment Remediation
(University of Minnesota Duluth, 2000-11-02) Wu, Chuying
Duluth-Superior is a major port of the Great Lakes located at the extreme southwest end of Lake Superior in the cities of Duluth, Minnesota and Superior, Wisconsin. The harbor area occupies roughly 32 square miles and has 100 miles of waterfront. The harbor and lower St. Louis River have a history of water quality problems resulting primarily from municipal and industrial discharges in and upstream of the harbor. As a result, the harbor has been listed by the International Joint Commission as an Area of Concern (AOC) within the Great Lakes ecosystem. The 1995 progress report on the Remedial Action Plan (RAP) for the area identified sediment contamination as the major cause of many impaired uses in the St. Louis Estuary. Contaminants of concern include ammonia nitrogen, phosphorus, metals, oil and grease, PCBs, and PAHs. Contaminated sediments are thought to have detrimental effects on water quality, the diversity and abundance of aquatic and benthic organisms, human health, and disposal options for material dredged during harbor maintenance. The dredged material is stored in the Confined Disposal Facility (CDF) at the Erie Pier in Duluth. The CDF is nearing its capacity, and additional space is required for storage of dredged materials either by construction of a new facility or by extending the life for the one currently used. The Coleraine Minerals Research Laboratory (CMRL) of the Natural Resources Research Institute (NRRI) has, in the past, conducted several research programs to evaluate the construction of a sediment treatment plant at the Erie Pier CDF as an effective way of extending its life. CMRL is currently contracted by the US Army Corps of Engineers (ACE) to develop and engineer a plant to treat the sediment contained in the CDF. This study is being conducted in response to Section 541 of the Water Resource Development Act of 1996, initiated by Congressman Jim Oberstar, which states: "The Secretary shall develop and implement methods for decontamination and disposal of contaminated dredged material at the Port of Duluth, Minnesota". Various agencies including USEPA, Minnesota Pollution Control Agency (MNPCA), and NRRI conducted numerous research and survey projects. The sediments in the federal channels were analyzed as part of Dredged Material Management Plant (DMMP), and analyses revealed that metal concentrations in the sediments of all management units were comparable to those found in the regional soils, and that PCBs, pesticides, and PAHs were generally non-detectable. No PCBs and only low levels of PAHs were found in a survey study in Erie Pier CDF conducted by NRRI in 1997. Due to its relatively low contamination level, it is safe to study a number of variables before implementation of the technology to the other highly contaminated areas. The treatment plant should generate data on the effectiveness of using mineral processing technology for separation and decontamination of the sediments. In some cases, the separation products could be cleaned and used for other purposes such as brick manufacturing, landfill cover, beach nourishment, construction fill, and/or habitat enhancement.
Alternative Technology for Sediment Remediation Demonstration Plant
(University of Minnesota Duluth, 2000-11) Benner, Blair R; Wu, Chuying; Zanko, Lawrence M
Duluth-Superior Harbor is a major port on Lake Superior located between the cities of Duluth, Minnesota, and Superior, Wisconsin. The harbor and the lower Saint Louis River that discharges into the harbor area have a history of water quality problems resulting primarily from municipal and industrial discharges in and upstream of the harbor. The port is a major debarking point for grain shipments overseas and for taconite pellets for the lower Great Lakes ports. To allow navigation, the shipping channels must be dredged annually. The dredged material has been stored in a confined disposal area developed at the Erie Pier location in Duluth. This facility is nearing its capacity and other methods for handling the dredged material must be found. The Coleraine Minerals Research Laboratory, a division of the Natural Resources Research Institute of the University of Minnesota - Duluth, has been studying the application of mineral processing techniques for treating contaminated soils. The laboratory sampled the Erie Pier site and designed a demonstration plant to treat about 50 tph of material from the site. Based on the previous work and the plant design, the U.S. Army Corps of Engineers awarded the laboratory a contract to construct and operate the demonstration plant. The plant consisted of a feeder followed by a grizzly screen to remove large rocks and miscellaneous junk. The grizzly undersize was conveyed to a double deck screen equipped with water sprays. The screen undersize flowed to a sump and pump. The slurry was then pumped to an agitated tank. Material from the tank was pumped to two cyclones to make a size separation. Cyclone overflows were collected and channeled to settling ponds to allow the solids to settle and to provide water for the plant. Cyclone underflow was stockpiled as a sand product. In addition to sending the cyclone overflow to the settling ponds, a belt filter press was tested for about two weeks to treat a portion of the overflow to produce a cake that could be easily handled and a clear filtrate that could be recycled. The objective of the program was to treat different types of materials found at the Erie Pier site to produce a coarse product (cyclone underflow) that contained less than 12 percent by weight particles finer than 200 mesh (75 microns). The underflow should be free draining so that it could be moved by loaders. The distribution of solids, water, inorganic compounds and organic compounds would be monitored. The settling characteristics of the cyclone overflow would be determined. A total of four separate samples were processed in the plant. Sample 1 was a sandy feed containing between 13 and 32 percent in the passing 200 mesh fraction. Sample 2 was a finer material that was removed from the site during construction of the settling ponds. Sample 2 contained between 30 and 52 percent in the passing 200 mesh fraction. Sample 3 was a fine sample dug from the north end of the site where the finest material should have been. Sample 3 was only run for one day due to a break down of the front-end loader used to transport the feed to the plant. The fourth sample was the drained cyclone underflow from the processing of samples 2 and 3. Maintaining a consistent feed to the plant was a continual problem. Clay material in the feed was difficult to disagglomerate and the material tended to form balls, which rolled down the screen decks. Additional water sprays and belting on the top screen deck improved the break up of the clay material but did not eliminate the problem. Another feed problem was the amount of vegetation in the feed. This material tended to bridge in the feeder and to plug the two screen decks, reducing screening capacity, at times significantly. Compounding the feed problem was the loss of the variable frequency drives on the two pumps. Loss of the drives effectively eliminated the ability to make any significant changes in the flowrate to the cyclones and, hence, the ability to affect the cyclone split. Attempts were made to control the cyclone feed by installing a by-pass line to return some of the cyclone feed back to the cyclone feed sump. These attempts were unsuccessful and on numerous occasions resulted in overloading the cyclone feed pump motor causing the motor to stop. Samples of the cyclone feed, overflow and underflow, as well as belt filter press cake and filtrate, when operating, were taken hourly. These samples were saved for future analysis. In addition to the saved hourly samples, a grab sample of each stream was taken hourly and made into a daily composite. The daily composites were filtered with a portion of the filtercake being used for size analysis and the remainder being air dried for chemical analysis. Sample 1 was processed at feed rates up to about 63 tph with no loss in performance. In all tests with Sample 1, the cyclone underflow contained less than 10 percent in the passing 200 mesh fraction. Weight recovery to the underflow ranged between 73.3 and 92.6 percent. In general, the heavy metals and organic material were concentrated in the cyclone overflow, but since the total weight recovery in the cyclone underflow was high, the majority of the heavy metals and organics in the feed remained with the cyclone underflow. The processing of Samples 2 and 3 were more difficult due to the large amount of vegetation contained in the feed. Plant feed rates were generally between 7 and 14 tph. The low feed rates were caused by the vegetation problem and by the need to feed the cyclone a low percent solids to try to make the desired size split. But even at the low percent solids in the feed, the cyclone underflow contained between 18 and 29 percent in the passing 200 mesh fraction. Weight recovery to the underflow ranged from 55 to 72 percent. Despite the high minus 200 content, the cyclone underflow was easy to dewater and formed into a steep sided conical pile. As with Sample 1, the heavy metals and organics were concentrated in overflow sample, which, due to the higher weight recovery, contained the majority of the heavy metals and organics from the feed. Since the cyclone underflows from Samples 2 and 3 still contained too many fines, the cyclone underflow pile was reprocessed through the plant. Resultant cyclone underflow contained between 10.9 and 14.7 percent in the minus 200 mesh fractions and recovered over 90 percent of the feed weight. Again the heavy metals and organics concentrated in the cyclone overflow. Performance of the belt filter press was very impressive. The resultant filtercake was very easy to handle by conveyor belts and would be very easy to haul by truck. The filtercake was almost dry to the touch. Filtrate from the belt filter press was very clean, with turbidity measurements less than 5 ntu. To produce these results required about 1.5 pounds of polymer flocculant for every 3900 gallons of cyclone overflow treated. Analysis of the filtrate indicated no residual polymer in the water.
An Analysis of Microlitter and Microplastics from Lake Superior Beach Sand and Surface-Water
(2020-04-14) Minor, Elizabeth C; Lin, Roselynd; Burrows, Alvin; Cooney, Ellen M; Grosshuesch, Sarah; LaFrancois, Brenda; sdgrossh@d.umn.edu; Grosshuesch, Sarah; University of Minnesota Large Lakes Observatory
An Analysis of Microlitter and Microplastics from Lake Superior Beach Sand and Surface-Water. This report describes work done in 2018 to evaluate the presence/absence of microplastics within and near the Apostle Islands National Lakeshore. We wish to archive the information for preservation and availability for other interested parties.
The Anishinabe: A Unit on the History of the Bad River Band of Lake Superior Ojibway Indians
(American Indian Language and Culture Education Board, Madison, Wisconsin, 1981) Oxley, Shelley
This curriculum unit was developed through a grant from the Title IV-C Elementary and Secondary Education Act and the Wisconsin Department of Public Instruction (1979-82), with assistance from The Great Lakes Inter-Tribal Council and Wisconsin Indian tribes. This unit was written by Shelley Oxley for the Wisconsin Woodland Indian Project, Rhinelander, in 1981.
Anthropogenic climate change has driven Lake Superior productivity beyond the range of holocene variability: an organic and stable isotopic study of Human impacts on a pristine biogeochemical system
(2013-07) O'Beirne, Molly D.
Recent studies have noted that changes in Lake Superior's physical, chemical and biological processes are apparent - including a warming of the surface waters at a rate twice as great as the surrounding airshed in the last 20 years. These changes are often difficult to perceive as cause for concern when not placed within a historical context. In this study, bulk C and N elemental abundance and stable isotope analysis of sediments from three piston and corresponding gravity cores, representing a record of lake-wide paleoproductivity trends spanning the Holocene, allows for the historical comparison with recent (1800 A.D. to present) productivity trends. Overall, Lake Superior experiences a slow, steady increase in productivity consistent with the concept of `natural' eutrophication, which is characterized by gradual increases in TOC and TON, as well as the steady 13C-enrichment of bulk sedimentary organic carbon and 15N-enrichment of bulk sedimentary organic nitrogen compositions. Over the last 200 years bulk concentrations and stable isotope compositions of carbon and nitrogen from eight multicores sampled at high resolution indicate that the Lake Superior basin has undergone productivity changes in the last two centuries (1800 to present) which are unique in the context of the Holocene. Overall, lake-wide sedimentary bulk organic proxy data show increasing primary production between 1900 and present, as indicated by an ~2 ‰ increase in δ13C_org. The most recent increases in productivity are likely a response to increasing water temperatures and longer stratified periods reported in Lake Superior. Down-core variations in the δ13C composition of algal-derived short-chain n-alkanes do not exhibit the same trend as that observed for bulk sedimentary organic matter (δ13C_org). The δ13C of bulk sedimentary organic matter shows systematic 13C-enrichment over the last ~9000 years, while the δ13C values of aquatic derived n-alkanes exhibit a systematic 13C-depletion to present-day. Down-core variation in δ13C values of n-alkanes likely reflect multiple isotope effects associated with carbon partitioning and fractionation associated with the biosynthesis of n-alkanes.
Bacterial Community Dynamics on Suspended Particle Microscopic Islands and Implications for the Theory of Island Biogeography
(2016-12) Zhao, Xiaowei
Suspended particles and aggregates are ubiquitous in most of aquatic environments. Aggregates have enriched nutrient and organic matter concentration compared to equal volumes of surrounding water, which can provide a favorable microscopic habitat for microorganism in aquatic ecosystems. So far, very few studies have been done regarding the composition of bacterial communities on aggregates in freshwater. Spatial distributions of particle-associated (PA) and free-living (FL) bacterial communities were characterized and compared at five sites along a transect from the St. Louis River estuary to nearshore Lake Superior in July and October 2013. The bacterial richness, Shannon-Wiener diversity and evenness indices of PA bacterial communities were all higher than for FL communities. The PA bacterial community in nearshore Lake Superior was significantly different from PA communities in the estuary (harbor and river). The PA bacterial community varied monthly, but no spatial or temporal differences were observed in FL bacterial communities along the transect. Seasonal dynamics of bacterial communities associated with sinking particles (SP), artificial aggregates (AA), and aggregates-free water (AFW) were investigated and compared from October 2012 to December 2013 at two sites in nearshore Lake Superior and the Duluth-Superior Harbor. Clear seasonal changes were observed on SP, AA and in AFW bacterial communities, but the seasonal dynamic in AFW bacterial communities was less pronounced than SP and AA bacterial communities at the lake and harbor sites. Bacterial communities on SP, AA and in AFW were different between the lake and harbor sites. In addition, bacterial communities on SP and AA, as well as communities on AA and in AFW were significantly different from each other at both sites. Flocculent organic aggregates were used to test whether the Theory of Island Biogeography applies at a microbial scale, and to examine how bacterial community develop and evolve. Bacterial richness increased with closer colonizer distances on lake aggregates in harbor water, supporting Theory of Island Biogeography predictions. However, this trend was not observed on harbor aggregates in lake water. It was also observed that bacterial communities on different aggregate types had their own distinctive pattern of succession during the re-colonization process.
Bibliography of Water, Land and Socioeconomic Information
(1974-05) Green, Janet C; Grant, Christabel D; Neubert, Barbara A
This bibliography represents a first attempt to identify all the sources of information about the Lake Superior basin in Minnesota that would be useful to planners, managers and researchers from a wide spectrum of disciplines.
Biogeochemistry of southwestern Lake Superior and watershed, 2017-2021
(2023-09-28) Sterner, Robert W.; Lafrancois, Brenda M; stern007@d.umn.edu; Sterner, Robert W.; Large Lakes Observatory, University of Minnesota
Between 2017 and 2021, 1368 water samples were collected from Lake Superior and its watershed in the region generally between Duluth-Superior and Ashland, WI. Parameters include forms of carbon, nitrogen, and phosphorus, along with total suspended solids, chlorophyll, and phycocyanin.
Bluff to Beach: Sand sources, sinks, and pathways in far western Lake Superior – implications for the genesis and evolution of Minnesota Point
(2020-10) Swenson, John B
Building Superior Coastal Communities
(University of Minnesota. Minnesota Sea Grant, 2006) Schomberg, Jesse; Hagley, Cindy; Desotelle, Diane; O'Halloran, Sue
Changes to this region and its human population are inevitable. This paper provides a discussion of human-induced stresses and impacts on the Lake Superior basin (runoff, sediment and erosion, nutrient loading, increased water temperatures, bacteria and toxic contaminants). Development pressures (including subdivisions) and economic growth and industrial activities (logging, mining etc.) impact sensitive areas in the Lake Superior basin. Environmental indicators (forest cover, water storage, impervious surfaces) are summarized and explained. The paper describes fundamental management tools (natural resource inventory, comprehensive land use planning, zoning and conservation design). The document provides several examples of innovative coastal projects.
Climate change, the invasion of Bythotrephes longimanus, and recent changes in the zooplankton community of Lake Superior
(2016-07) Pawlowski, Matthew
In 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.
Co-creating Space for Self-Care and Community-Care in Cook County, Minnesota
(2022-05) McIntyre, Alison
Cook County is in the northeast corner of Minnesota’s arrowhead region, bordered to the north by Ontario, Canada to the south and east by Lake Superior and the south and west by rural Lake County and the Boundary Waters Canoe Area Wilderness. Its remote location and sparse population qualify Cook County as one of Minnesota’s few frontier-status counties. With an estimated population of 5,393, Cook County is among the least populous counties in the State of Minnesota (US Census Bureau, 2018). The year-round population of the county’s only city, Grand Marais, is just 1,351 (MNCompass, 2017). As a popular tourist destination, the number of people in the county varies greatly, reaching upwards of 75,000 during the busy summer months (Cook County, 2019). The racial and ethnic breakdown of county residents is 85% White, 1% Black/African American, 8% American Indian/Alaska Native, 3% two or more races, and 3% Hispanic/Latino. 40% of jobs are in leisure and hospitality and 13% of residents live below the poverty line (compared to 9.5% statewide average) (MNCompass, 2017). The Cook County Public Health and Human Services department recently completed a community health assessment which included two-year engagement process of reviewing local heath indicators, community surveys and meetings with citizen advisory council members, healthcare and other service providers. The resulting community health improvement plan identifies goals to improve health outcomes within the priority areas of behavioral health and healthy living access. Behavioral health care access is a priority issue within the community, particularly following the closure of the county’s only community mental health care clinic in late 2018. Rates of depression and anxiety are higher than state averages, nearly one in four adults (24%) in Cook County are diagnosed with depression, while 22% report a diagnosis of anxiety or panic attacks (Kjos, S.A., Kinney, A.M., Finch, M.D., Peterson, 2016). Among Cook County students, 43% of 8th graders, 52% of 9th graders, and 50% of 11th graders report feeling down, depressed or hopeless for several days or more (MN Department of Education, et.al., 2019). The ratio mental health providers in Cook County to residents (1:1,080) is significantly lower than the statewide average (1:430) (University of Wisconsin Population Health Institute, 2019).
Coastal Area Impervious Surface Assessment.
(Duluth, MN: Center for Community and Regional Research, University of Minnesota at Duluth., 2005) Stark, Stacey L; Schomberg, Jesse
Coastal Wetland Monitoring Survey Report: Clough Island
(University of Minnesota Duluth, 2014-06) Dumke, Josh; Brady, Valerie; Danz, Nicholas P; Bracey, Annie; Niemi, Gerald J
Better than average water quality at Clough Island wetlands (for chloride and conductivity), as compared to most other SLR estuary wetlands, demonstrates the island's distance from human development. However, these wetlands still are located in the St. Louis River estuary, and thus have poorer quality by many measures than nearby Lake Superior wetlands. In particular, Clough Island wetlands had poorly-developed wet meadow zones compared to Lake Superior wetlands. Most of the Clough Island wetland areas were dominated by an emergent vegetation zone. Submergent vegetation was very patchy, and research by US EPA (Angradi, pers. comm.) found that SAV abundance across the whole estuary varies yearly depending on turbidity levels. In addition, Island wetlands have higher exposure to wind and wave action than do wetlands in secluded bays, which also affects the development of extensive aquatic vegetation beds. Clough wetlands had both high quality and low quality vegetation species, with purple loosestrife and invasive cattail particularly prevalent at 1089. Therefore, floristic quality values were very similar to other estuary sites, but lower than nearby Lake Superior wetlands that had fen components. Clough Island wetland fyke net fish catches were skewed toward warmer water fish (e.g., sunfish) than nearby Lake Superior sites, and water temperatures were substantially higher in the SLR estuary than in Lake Superior wetlands. Clough Island wetland site 1089 also had the most invasive tubenose gobies comprising a fish catch. In contrast, site 1089 had the greatest fish taxa richness. Clough Island wetlands did not provide as much habitat for YOY fish as did highly vegetated, secluded bays. Site 1102 had the greatest number of habitats and included a floating bog mat. Thus, macroinvertebrate richness was highest at site 1102, and more sensitive macroinvertebrates were present at this site. Site 1201 had the fewest habitats, and it had the lowest taxa richness for fish and macroinvertebrates (although sampling effort was also lowest at this site due to the lack of habitats). An invasive, non-native snail (Bithynio, the faucet snail) was found in all wetlands, but made up 7% of the macroinvertebrates collected from site 1201. This was different from nearby Lake Superior wetlands, in which no invasive macroinvertebrates were found. Bird use at Clough Island was different in some ways from other estuary wetlands. Wind and wave exposure and lack of protection may explain why migrating waterfowl and waterbirds were less commonly observed at Clough Island wetlands relative to other estuary wetlands. However, the island's isolation, lack of human usage, and potential for lower numbers of predators may benefit breeding birds, and forest-dwelling songbirds that were detected in large numbers during the breeding season. This idea is reinforced by the detection of secretive marsh birds and the foraging by Common Tern.
Comparing Ship-based to Multi-Directional Sled-based Acoustic Estimates of Pelagic Fishes in Lake Superior
(2019-05) Grow, Ryan
Ship-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.
Conservation Design Toolkit for LakeSuperiorStreams.org Stormwater Pollution Prevention Pilot Project
(University of Minnesota Duluth, 2006) Axler, Richard P; Schomberg, Jesse; Will, Norman; Reed, Jane; Lonsdale, David; Granley, Mindy; Hagley, Cynthia
Duluth, Minnesota has 43 named streams, 12 trout streams, and borders both pristine Lake Superior and the Duluth-Superior-Harbor Area of Concern. Duluth's storm water infrastructure includes 93 miles of streams and wetlands, and urbanization and rural development impact these waters by increasing runoff and velocity, temperature, turbidity and sediment, road salt, organic matter and nutrients. In 2002, an EPA (Environmental Monitoring for Public Access & Community Tracking) grant established a Partnership called DuluthStreams between the City of Duluth, University of MinnesotaDuluth professionals at the Natural Resources Research Institute and Sea Grant Program, and the Minnesota Pollution Control Agency and Western Lake Superior Sanitary District. Their goal was to enhance public understanding of streams and their connections to watershed land use by using real-time data and interpretive materials to illustrate the nature and consequences of degraded stormwater and its real costs to society. This has included issues associated with too much runoff such as flooding, with a key issue in the region being sanitary sewer overflows from infiltration and inflow (I&I). These events have imposed risks to public health and environmental risks to the coastal zone of Lake Superior and the Duluth-Superior Harbor, and required costly programs to reduce stormwater flows from key neighborhoods and construct storage tanks for temporary storage of stormwater enhanced sanitary sewer flows. The consequences of excess water and peak flows have also included excess sediment and turbidity, and potentially excess nutrients and pathogens. High salt concentrations for significant periods in late winter and early spring runoff from winter road and parking lot de-icing can present additional stress to trout and their prey. Increasing impervious surface and direct and indirect removal of riparian vegetation increases peak temperatures, especially during base flow periods creating additional periods of stress to cold water species with the additional potential stress of lowered dissolved oxygen. In 2003, sixteen governments and groups in the North Shore Region joined to form the Regional Stormwater Protection Team (RSPT). The Team's mission is to protect and enhance the region's shared water resources through stormwater pollution prevention by providing coordinated educational programs and technical assistance. One of the vehicles that the RSPT has harnessed for its stormwater education campaign is the DuluthStreams website as part of a regional effort to provide water pollution information to the public. The project has now expanded to now include 22 communities, agencies and organizations. In 2005 the website was re-named lakesuperiorstreams.org to reflect the broader geographic region that it represents in terms of climate, soils, quality of life, natural resources, the Lake Superior watershed, and culture. The website now averages more than 300,000 "hits"/month and >75,000 "page requests"/mo with a national target audience that includes: the general public; students and teachers; contractors, consultants and developers; decision makers; and agencies (local, state, and federal). Additional information is best found by examining http://lakesuperiorstreams.org.
The Contribution of Black Carbon to Bulk Lake Superior Sediment
(2014) Rhoades, Brandon

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