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This study explores three techniques of signage in an attempt to reduce the incidence of vehicle/deer collisions on highways in Minnesota. A simulated environment was created along a stretch of U.S. Highway 23 near Marshall, Minnesota with participants chosen from the University of Minnesota and the surrounding community. The simulation consisted of a standard warning sign as well as a prototype of the experimental signage. The prototype was comprised of a beacon light attached to the top of the warning sign designed to flash when deer were present. During the simulation, participants were exposed to the standard signage as well as the new signage with and without the beacon flashing. The main objective was to determine whether the prototype signs would modify driver behavior such that they decreased their speed. The study found that the prototype signage was effective in decreasing the speed of the participants when the beacon light was flashing. These results were consistent across the variations of age and gender. The results for the prototype signage with the beacon light turned off were essentially no different from the standard signage.

Researchers from the University of Toronto have developed a computer-based, decision support tool to assess the risks of vehicle-emitted chemical contaminants, affecting wildlife in the Twin Cities urban areas, as well as a decision support tool to assess the risks to birds and mammals of chemical contaminants released by vehicles.

Recessed culverts are often installed in Minnesota to facilitate aquatic organism passage (AOP) by providing a natural streambed through the culvert. The least expensive option when installing a recessed culvert is to allow the culvert to fill in with sediment naturally over time; however, previous field studies suggest that in many cases, sediment fails to deposit within the culvert. The objective of this research was to understand the function of a culvert set below the streambed elevation under various sediment transport conditions. Laboratory experiments were designed to assess the performance of recessed culverts across a range of geomorphic characteristics representative of Minnesota streams. These experiments explored the functionality of a culvert that is prefilled with sediment representative of the stream as a part of the installation process against one that is empty after installation and assessed the potential for headcutting and downstream degradation. The experiments evaluated the need for artificial roughness installations within recessed culverts in high gradient streams. Three sets of experiments were conducted examining: 1) the effect of sediment grain size, slope, and flow hydrograph on sediment transport through a single recessed box culvert, 2) the effect of bed roughness structures on sediment stability in a single recessed box culvert in high-gradient streams, and 3) the effect of culvert offset and skew on sedimentation in multi-barrel culverts.

Culverts can act as barriers to fish passage for a number of reasons including insufficient water depth or excess velocity. In addition, concern is being raised over behavioral barriers where culvert conditions elicit an avoidance response that deters or slows fish movement. Long culverts can block sunlight creating a potential behavioral barrier as fish approach a long, dark culvert. Scant information exists on low light as a potential barrier to fish passage, particularly with warm water species, such as the federally endangered Topeka Shiner. As some older culverts are being replaced with longer total lengths to improve safety by extending the culvert through re-engineered road embankments, information is needed to 1) determine when and if light mitigation strategies are necessary, and 2) to design appropriate light mitigation strategies if necessary. Based on literature review, field monitoring, and laboratory experiments, the effect of light on fish passage for Topeka Shiner and other small prairie stream fish was indiscernible. Therefore, no light mitigation for large box culverts (up to 150 feet in length) can be recommended for similar fish communities. Culverts that are very long or have very small openings may benefit from additional light.

In Minnesota there is not a standard culvert design used at road crossings to improve aquatic organism or fish passage. The design process for fish passage in Minnesota is currently based on the knowledge and experience of local county, state and DNR personnel. The design methodology attempts to maintain the natural stream dimensions, pattern and profile through the culvert crossing. If designed properly aquatic organisms and fish that can make it upstream to the culvert should be able to pass through the culvert. This research was conducted to better understand the hydraulic conditions related to the practice of recessing culverts and other fish passage design elements over a range of landscapes in Minnesota. The design elements analyzed included bankfull width, slope, channel materials, side barrels and recessed culverts. Nineteen culvert sites were survey around the state. The main criterion used to evaluate performance of the culverts was the presence or absence of adequate sediment in the recessed culvert barrel. Six of the fourteen sites with recessed barrels had no sediment accumulation. A likely reason that these culverts lack sediment was increased velocities due to improper sizing relative to bankfull channel width and the accumulation of sediment in the side barrels. Wider Rosgen "C" type channels also correlated with performance issues related to culvert design.

Various factors associated with conventional culvert design, including shallow water, perched inlets and high flow velocities, can cause difficulties for migrating fish and affect their genetic diversity and long-term survival. Conventional culvert design has traditionally been based on hydraulic conveyance, safety and cost. Recently, some alternative culvert designs have been developed to facilitate salmon migration on the west coat of the United States. These alternative designs focus on matching the natural dimensions and characteristics of the stream channel through the culvert. The intended purpose of these newer designs is to provide unimpeded passage of aquatic life, reduce maintenance costs and improve erosion control. Currently, some of these new designs are being implemented in Minnesota mostly when fish passage is a consideration. There are concerns about the additional costs associated with these alternative designs as well as whether they are really needed at some road crossings. The objectives of this research were to summarize state-wide fish passage concerns related to culvert road crossings on public waters and to perform a cost comparison between the conventional and the alternative culvert designs.

Diversity and complexity of vegetation in native sedge wetlands of southern Minnesota have become threatened by reed canarygrass (Phalaris arundinacea). The consequences for wildlife of widespread conversion of diverse sedge communities to reed canarygrass dominated communities are largely unknown. We conducted a study to determine the effects of reed canarygrass on the plant and wildlife (birds, mammals, and invertebrates) communities. We hypothesized that wildlife would be negatively affected by the invasion of reed canarygrass. To test our hypothesis, we selected 4 sites that had native vegetation (native) and paired those sites with sites invaded by reed canarygrass (invaded). We determined the characteristics of the plant and animal communities at all or a subset of the paired sites during 2006-2007. The plant community at invaded wetlands had lower richness and diversity of species than native wetlands. However, richness and diversity of the bird community was not different during 2007 and greater at invaded sites than at native sites during 2006. In contrast, diversity of mammals was lower at invaded sites during 2006, but no differences were detected during 2007. Similarly, richness and diversity of invertebrate families was lower at invaded sites than at native sites. Our results did not consistently support the hypothesis that there is a clear negative impact of reed canarygrass on wildlife.

Element occurrence records and previous studies at Camp Ripley document the occurrence of Blanding's turtles in the Brainerd/Baxter area. Protecting the species requires the protection of habitats critical to their conservation, as well as an understanding of the ways that Blanding's turtles use wetlands and uplands. This report summarizes research into the occurrence and habits of Blanding's turtles. During the project, researchers captured and marked 60 Blanding's turtles: 37 females, 12 males, and 11 juveniles. None of the turtles were found in the immediate area of the bypass, and no monitored turtles moved in or out of the bypass area. Researchers identified four areas in the Brainerd/Baxter area where turtles appeared to be concentrated. Monitored turtles used an array of aquatic habitats including inland shallow fresh marshes (type 3), inland deep fresh marshes (type 4), inland open fresh water (type 5) and shrub swamps (type 6). These wetlands ranged in size from 1.5 ha to 111 ha. Although there was considerable diversity on wetland features, the majority of turtles spent 90 percent of their days in shrub swamps. Researchers located a total of 11 nests during the 1998 field season. They found reproductive females in upland habitats from May 19 to June 18. Clutch sizes for the turtles ranged from eight to 20 eggs with a mean clutch size of 15.8 (n = 11). On the basis of current surveys, Blanding's turtles appear to be distributed throughout the Brainerd/Baxter townships. Researchers developed recommendations to help ensure the future viability and preservation of Blanding's turtle populations in the Brainerd/Baxter area. As a staff paper, this publication is intended for internal use by the Minnesota Department of Transportation (Mn/DOT). Distribution is limited.

This guide assists Minnesota culvert designers in identifying; selecting; and implementing appropriate designs for maintaining aquatic organism passage (AOP) and stream connectivity at road-stream intersections. It was synthesized from existing literature and culvert design documents; a survey of Minnesota practitioners; research; and input from local; regional; and national experts. Culvert designs that create excessive velocity; physical barriers; or shallow depth can disrupt AOP and may be detrimental to the continuity of water flow; sediment; and debris transport vital to stream health. Conversely; the recommended culvert designs in this guide account for stream parameters such as slope and substrate that vary across Minnesota landscapes. A set of best practices captures critical design elements based on stream characteristics; which can be summarized as follows: 1.) Design the culvert to be similar to the stream channel (reference reach) by matching its slope; alignment; bankfull width; and flow depth to maximize AOP; 2.) Provide a continuous sediment bed with roughness similar to the channel; while maintaining continuity of sediment transport and debris passage; and; 3.) Design for public safety; longevity; and resilience. Culvert design that improves AOP and accounts for sediment transport is expected to reduce long-term maintenance costs and increase culvert life span.

This report documents existing reports on culvert design for aquatic organism passage in Minnesota and nationally. The review is designed to build upon the work of Hansen et al. 2009 and 2011 to: 1) summarize current aquatic organism passage practices, 2) summarize aquatic organism passage needs for Minnesota species, 3) discuss the importance of roughness or streambed sediment within a culvert in different systems (high, medium, or low slope) in single and multiple barrel systems, and 4) summarize physical experiments of sediment transport and geomorphic processes through culverts.