Great Indicators for Great Lakes
GLEI conclusions
Taconite Flowsheet 21st Century
Wood Bridge Inspections
Beach Data
Canada Lynx
Snowshoe Hare
Great Lakes Environmental Indicators project wraps up
Back in 1861, basic research on the human body found that a healthy person maintains a temperature of about 98.6 degrees Fahrenheit. A higher than normal temperature is an easy, effective indicator that something isn't right.
Of course, we can't put our hand on the forehead of the coastal region of the Great Lakes to get a quick read on its health. So, what can we use as effective indicators of the environmental health for this valuable freshwater resource? NRRI scientists, with collaborators around the entire U.S. Great Lakes basin, took on the task of identifying, and testing the effectiveness of 14 potential indicators. They also looked closely at ecological stressors (related to human activities) to the coastal zones, providing basic research that's critical to future monitoring efforts.
This massive five-year study, covering almost 5,000 miles of shoreline and nearly 112,000 square miles of land around the lakes, reached its conclusion this year. Indicators have been evaluated and stressors identified. The highly detailed report is now in the hands of those whose job it is to manage the complexity of uses and ecological balance of the largest freshwater system in the world.
The study began by dividing the large coastal region into 762 segment watersheds that feed into the Great Lakes. For each watershed, publicly available data were gathered and layered with NRRI's Geographic Information Systems technology to understand the stresses on the basin ecology: agricultural activity, land use and land cover, human population and development, point and non-point sources of pollution, air pollutants, and shoreline and soil characteristics.
Sampling at over 1,000 carefully selected sites around the Great Lakes allowed the scientists to discern relationships between the stressors and the plant and animal life in the basin. In general, stress related to agricultural activity and human population density/development had the largest impact on the biotic indicators (birds, amphibians, algae, fish, bugs and vegetation). Industrial activity, however, was most closely linked to polycyclic aromatic hydrocarbon (PAH) contamination and over half of the sites sampled were potentially at risk of PAH toxicity to larval fish. They also found that changes in land use are not as extensive in the Lake Superior basin as they are in the southern and eastern areas of the Great Lakes coast. The 14 indicators were grouped into five categories and are summarized next.
BIRD AND AMPHIBIAN INDICATORS:
High waders and quiet patience were essential elements for collecting data on birds and frogs living along the Great Lakes coasts. The goal of this group was to scientifically quantify the environmental pressures on these sensitive creatures and to develop their use as indicators. They found that Spring Peepers make excellent indicators of environmental condition and are found throughout the Great Lakes coastal zone. Three different bird indicators were developed for three different regions: Coastal Wetland birds, Laurentian Mixed Forest bird species and birds in the Eastern Deciduous Forest. The spring peeper and bird community provided excellent signals on the condition of the coastal region and signals that diagnose specific Spring Peeper impacts of land use in the coastal zone. These species can provide an excellent way to measure progress in maintaining an area's ecological health or ecological restoration.
DIATOM/ALGAE INDICATORS:
Collecting and identifying thousands of microscopic life forms produced great returns as indicators of environmental stress. Diatom algae are popular as bioindicators because their sensitivity and short lives record changes in conditions, while staying preserved in lake sediment which allows scientists to quantify human impact on the environment over time. This group focused on calibrating the sensitivity of some 2,000 diatom species to water clarity, nutrients, acidification and other stressors in the Great Lakes basin. They now have a microbiotic tool that can be used to infer water quality conditions in shoreline habitats, a notable advantage over traditional water chemistry measurements. They also documented the diatom flora of the coastal Great Lakes, which will be useful in future monitoring and paleoecological applications.
FISH AND MACROINVERTEBRATE INDICATORS:
Natural resource managers charged with monitoring water quality and protecting aquatic habitats need the most effective way to distinguish degraded water systems from the least-impaired. The variety of fish and bug communities associated with Great Lakes coastal habitats tolerate varying levels of environmental stress and, therefore, make excellent indicators of water quality and habitat conditions. For example, the Burbot, an unlikely candidate in the eyes of many anglers, proves to be a good indicator of low environmental stress, while the exotic European carp is consistently found in areas with high levels of human disturbance. With the information gathered from this project, scientists also "graded" the conditions of 53 reference sites, coastal locations that are the least impaired, and complementary impacted sites that have the greatest amount of human-related stress.
VEGETATION INDICATORS:
Native plants in the Great Lakes basin are struggling to survive with invasive newcomers. What can these plants tell us about the qualityof the Great Lakes basin ecosystem? This team tested the effectiveness of commonly used vegetative indicators, and discarded a few ineffective ones. They also developed new indicators such as the "species dominance index" which indicates the ecological integrity of a wetland by identifying dominant plant species and categorizing their form of dominance over other species. For example, giant reed grass and hybrid cattails indicate poor wetland quality because they are both a symptom of pollutants and a cause of stress by degrading the habitat for animals and fish. Plant height is also an effective indicator because many invasive plants are very tall, which shades out much of the native vegetation, reducing plant diversity.
CHEMICAL INDICATORS:
The clean, clear water left behind by invasive zebra mussels looks like a good thing, but in fact, they eat so much suspended sediment that potentially harmful ultraviolet (UV-A) light penetration into the water has increased. This may increase the risk to Great Lakes fish populations to a phenomenon known as PAH (polycyclic aromatic hydrocarbon) photoinduced toxicity. This group of scientists developed a relatively easy way to evaluate UV-A light exposure and PAH levels by measuring PAH compounds in lake sediment that can be used in a model to estimate this risk. UV-A and PAH exposure are key to understanding the vulnerability of the larval stages of the fish populations and, it follows that, if there are fewer larval fish there will be fewer adult fish.
Undoing some of the damage caused by development in Duluth's Lester River/Amity Creek watershed was the impetus of a $100,000 endowment to NRRI from UMD benefactor Ron Weber last spring. Weber's donation was recently matched with $100,000 by a second anonymous donor. Using that funding to match grants, and pulling in expertise from area agencies, has grown the project beyond one Lake Superior watershed.
NRRI received a $58,000 grant from the Minnesota Great Lakes Coastal Program to study the impact of human development on stream habitat and generate future growth scenarios for areas up the North Shore. The "smartgrowth" models will show the area 50 years into the future with current zoning ordinances, as well as alternative development models that will protect the streams.
Another grant of $35,000 from the National Fish and Wildlife Foundation will complement the smart-growth project by allowing NRRI's Geographical Information Systems lab to map the riparian corridors along nine North Shore watersheds (including the Lester/Amity systems) and identify high-risk areas.
A third grant of $73,000 was recommended for funding from the Minnesota Lake Superior Coastal Program. This will allow continued automated monitoring of water quality, including sediment that causes excess turbidity, and new mercury sampling for five trout streams: Kingsbury, Tischer, Chester, Amity and the Poplar River. The data will be downloaded to the LakeSuperiorStreams.org Web site for public and professional access.
NRRI gives taconite pellet process an efficiency boost
Small improvements in the enormous taconite pellet-making process can save the industry millions of dollars. NRRI's focus on improving the process flow sheet at the plants is critical to helping the Iron Range taconite industry remain competitive.
Once the low-grade taconite ore has been mined, it needs extensive crushing until it's a pulverized powder. NRRI's Salih Ersayin worked with a brainstorming team from Mittal Steel's (formerly Ispat Inland) Minorca plant, along with a consultant, to seek ways to improve the powder-making process. They discovered a way to increase cost savings by 10 percent while producing the same quality.
The ball mill tumbles steel balls around with the crushed rock to make the powder. Using a computer model, Ersayin was able to demonstrate that changing the ball size from 2 inches to 1.5 inches would be more energy efficient. This modification was combined with more efficient hydrocyclones to further improve the plant performance.
Understandably, the increased efficiency in the ball mill circuit meant "upstream" processes could still slow things down. Cobber magnetic separators and crushers were also upgraded.
"Just the simple change in the ball mill was significant," said Ersayin. "It cost the Minorca plant $20,000 a month per line for the smaller ball sizes, but it saved them, conservatively, about $400,000 a month."
Further "downstream," NRRI's Blair Benner is particularly skilled at finding ways to improve the processes that separate the iron minerals from the waste.
One separation process, flotation, adds chemicals and injects air to "float" low iron particles from the higher iron particles. The problem is that a significant amount of very fine high-iron particles also float. Coleraine research showed that it is possible to pre-classify the feed, basically separating it first into a coarse stream and then a fine stream. The fine stream could then be sent to the magnetic separator, which has iron recoveries approaching 99 percent. The coarse particles would go through flotation.
"We started with bench and then pilot scale testing here at our Coleraine lab so we knew it had potential," Benner explained. "When they scaled it up at Minntac they reported a three percent increase in iron recovery in the materials process, and an overall weight increase of 1.95 percent."
Saving three percent is significant with Minntac's annual production rate of over 14 million tons of pellets. Minntac also reported a reduction of about 24 percent in the amount of reagents that had to be added to flotation to reduce the silica level in the concentrate, which represents a significant cost savings.
Once the pellets are formed, they need to be fired at temperatures as high as 2,400 degrees Fahrenheit to make them hard enough for shipping. This is called the induration process. NRRI's Dave Englund uses computational fluid dynamic computer models to propose changes, and looks at how the changes will affect fuel use and productivity, air flow or heat transfer.
Currently, Englund is developing a model of taconite process fans that will simulate the fan operation under all operating conditions, mainly weather-related (temperature/humidity) and dampered (reduced flow) settings. If successful, the model can be used to predict airflow moving through the fan, allowing better control of the operation. This project is funded by the University of Minnesota, U.S. Steel/Cliffs and Iron Range Resources.
New technologies take guesswork out of bridge inspections
Over 4,000 of Minnesota's bridges are made with wood which means regular inspections for decay or disrepair are critical. NRRI researchers, working with the UMD Northland Advanced Transportation Systems Research Laboratory (NATSRL), have been integrating new technologies into the inspection process to make them more thorough and efficient.
"Ultimately we want a better understanding of the structural integrity of these bridges," explained Brian Brashaw, NRRI Forest Products program director. "The more we know about the bridge, the better we can take care of it and the longer it will last. That's being fiscally responsible."
Starting in 2003, the researchers upgraded the techniques for traditional inspections. The old way, visually checking the bridges and tapping them with a hammer to listen for decay, was enhanced with new tools that use various techniques for measuring drilling resistance and stress wave velocity. It's paid off. Just last summer, NRRI inspected 13 St. Louis County bridges and found two with damaged wood that the county fixed immediately. Several other bridges are slated for repair in the coming months based on these detailed inspections.
In 2005, a vibration technique was added that can rapidly assess the overall condition of the bridge superstructure, rather than individual components. A vibrating motor is attached to the bridge and sensors determine the frequency of the vibrations. A high frequency (very fast vibrations) mean the bridge is relatively stiff. A low frequency (slower vibrations) means it's not as stiff and there could be problems. The ability to measure any loss of stiffness over the years will indicate decay or damage that can be fixed before the problem worsens.
The researchers also correlated the vibration frequency to the actual deflection of the bridge deck when the bridge was loaded. "We put a fully loaded grave. Truck on the bridge and measured the deflections." Brashaw explained, "This helped us understand the useful relationship between the vibration response and the measured stiffness of the bridge deck, which will help inspectors and engineers better understand the condition of the bridge."
The improved research base has allowed the researchers to develop improved instrumentation, steps to future collaborations. Later this spring, the testing system will be used to evaluate its potential on short span steel and concrete bridges, other key links in our rural transportation system.
The research is funded by a $40,000 grant from the Northland Advanced Transportation Systems Research Laboratories.
NRRI, MPCA build site to publish bacteria data
A nice breeze, toes in the sand and splashing around in the water is balm for young and old on a sweltering summer day. But it's a scenario easily wrecked by a beach advisory. Regular monitoring of fecal bacteria has led to the posting of signs advising against water contact at a few area beaches.
But what does it mean? How much bacteria are too much? Will it make swimmers sick?
NRRI is helping get answers about bacteria levels at the beaches to the folks along Lake Superior's north shore about bacteria levels at the beaches. An easy-to-use web site, www.mnbeaches.org, is up and running and 2006 monitoring began in May. A quick click before packing the beach bag might save beach-goers from disappointment, or give them confidence to take the plunge. NRRI's Jane Reed and Norm Will designed the site, in conjunction with the Minnesota Pollution Control Agency (MPCA).
"The MPCA needed a site that the public can access easily and that they can update quickly to get their information out there," explained NRRI's George Host, who coordinates the project. "The site has a lot of information on minimizing risk of exposure, contamination and is rich in interpretive materials."
One area of NRRI's expertise is pulling together scientific data and making it understandable to the general public as well as accessible to agency resource managers. A click on the "Beach Data Viewer" will reveal graphs and maps that track fecal coli form and E. coli bacteria on Lake Superior's popular beaches. A click on an aerial photo of Park Point, for example, shows which beaches have advisories and the bacteria levels at each beach. Beach watchers will also be able to track bacteria levels over a couple of months or even years. Water temperature and precipitation are also tracked showing how water quality changes after a rainstorm.
"In general, the rule of thumb is to be cautious about swimming in urban lakes and streams after a rainstorm," said NRRI water quality scientist Rich Axler. "Sanitary sewers can overflow, human waste can flow from cracked sewer lines and animal droppings get washed into the water... it happens all over the country."
Fecal coli form live naturally in the gut of warm-blooded animals. When found at higher levels in the water that doesn't necessarily mean the each is unhealthy, but indicates that there may be disease-causing bacteria, viruses or parasites present that could be harmful to people. Because the risk isn't clear, advisories simply let people know what the scientists suspect at a given time.
Funding for the web site and the new data visualization tool has been provided by grants from the MPCA, Environmental Protection Agency, City of Duluth and the Minnesota Lake Superior Coastal Program, as part of the lakesuperiorstreams.org project. Host and Axler designed the site for potential expansion to cover beach information at lakes all over Minnesota.
Just follow the trail of the snowshoe hare
Ask UMD graduate student Nick McCann about his current NRRI research project and you'll get a big grin. He spends an inordinate amount of time focused on animal excrement, specifically, snowshoe hare pellets.
He's quick to explain why counting hare pellets in the Superior National Forest is important. Snowshoe hare are the primary food source of the Canada lynx. The pellet counts offer another way for forest managers to locate lynx, a species listed as federally threatened in 2000.
"The theory is really quite simple," McCann explained. "If pellet counts indicate how many hares are in the forest, then perhaps hare distribution can tell us where the lynx are spending their time."
First, McCann had to scientifically determine if pellet counts truly indicate how many hares are using an area of the forest. Using six study grids in the Superior National Forest (approximately 33.4 acres each) he counted pellets and trapped hares in 36 box-traps. Preliminary results are showing that pellet counts randomly placed on the study grid are correlated with the number of snowshoe hares trapped.
The second step was to determine what types of forests hare prefer by correlating pellet counts with forest cover. This is made easier using geographical information system (GIS) analysis to identify forest cover-types that yield disproportionately high or low pellet counts at transects dispersed throughout the forest.
"Our data shows that hares are spending a disproportionately high amount of time in areas of upland shrub and less time in aspen/white birch areas of the forest," McCann explained.
The last question, then, is whether these are also the forest cover-types known to be preferred by the Canada lynx? Yes. Data from GPS-collared lynx in the Superior National Forest correlates well with data from the pellet-count study. Where there are snowshoe hares, there are likely to be Canada lynx.
"For forest managers, this means they can narrow down their search for lynx by doing a hare pellet count. At least, it will tell them where the lynx are not," said McCann.
Make it colorful
NRRI's Northern Lights Technology Center added a new 3-D printer to its rapid prototyping line-up. The Z Corporation 510 produces high definition three-dimensional objects and prototype parts faster, with sharper colors than ever before possible. Now, NRRI has even more technology to turn an idea into something real.
Northern Lights Technology Center supports industry and university research by providing the best solutions for design and rapid prototyping services. These services will assist companies with product introductions into the marketplace, which will help to retain and create new jobs. It provides CAD design and modeling services, stereolithography, selective laser sintering, fused deposition modeling, three-dimensional printing and metal casting.
Michael Lalich, director
Center for Water and the Environment, Gerald Niemi, director
Center for Applied Research and Technology Development, Donald Fosnacht, director
Center for Economic Development, Elaine Hansen, director
NRRI Now
Nora Kubazewski, managing editor
June Kallestad, editor/writer
Trish Sodahl, layout
The Natural Resources Research Institute was established by the Minnesota Legislature in 1983 to foster economic development of Minnesota's natural resources in an environmentally sound manner to promote private sector employment.