Figure 1.
Figure 2.
Figure 3.
1. Project Title: Fox River Walleye Habitat Improvement
2. Contact
Mr. Terrence L. Lychwick
Wisconsin Department of Natural Resources, 200 N. Jefferson, Suite 511, Green Bay,
WI 54301, USA
Tel.: (414) 448-5140; FAX: (414) 448-5129
3. Agencies Involved
Wisconsin Department of Natural Resources (DNR)
City of De Pere, Wisconsin, Department of Public Works
4. Restoration Goal
To enhance and/or create spawning habitat for walleye in three locations in the Fox River.
5. Project Type
Create new spawning habitat for walleye at two locations in the Fox River. Enhance spawning habitat in one location by increasing desirable substrate adjacent to a good quality, highly used spawning area.
6. Background and Rationale
The Fox River, a major tributary into Lake Michigan's Green Bay, has been subjected to a high degree of urbanization and industrialization since the turn of the century. Construction of power dams, locks and regularly maintained navigation channels, combined with an industrial setting including 15 pulp and paper mills and 11 municipal sewage treatment plants makes the Fox River one of the most densely developed industrial rivers in the world. As a result, water quality declined throughout this century. Because of high BOD levels, dissolved oxygen concentrations achieved only low levels and failed to exceed two parts per million during most of the year. Locks and dams effectively blocked upstream migration of most species, including walleye, limiting access to suitable spawning areas. In addition, most naturally occurring substrate was degraded or destroyed.
Implementing the 1972 Clean Water Act led to improved water quality by the late 1970's through reduction in BOD levels. When dissolved oxygen levels continuously exceeded 5 mg/L, the Wisconsin DNR attempted to rehabilitate walleye stocks by introduction of walleye fingerling in 1977 and fry between 1978-1984 (Schneider et al. 1991). By 1985, stock size and spawning densities at suitable spawning sites were sufficient to realistically expect successful reproduction. Reproduction was documented in 1985 and successful spawning sites were identified (Balcer et al. 1986).
Only limited areas of appropriate walleye spawning habitat exist along the Fox River below the De Pere dam. We speculated that if walleye stocks increased, additional spawning substrate would be required and that the increase of suitable habitat would in turn raise the probability of successful recruitment. As opportunities presented themselves, we worked with local municipal governments to incorporate walleye spawning substrate into design plans of proposed bank stabilization and construction projects along the Fox River. Between 1989-1992 three projects gave us this opportunity.
7. Regulatory Considerations
a) Preliminary meetings with municipality agreeing to the extent and requirement of in stream, habitat construction;
b) Completion of joint State/Federal Application for Water Regulatory Permits and Approvals;
c) Completion of Wisconsin DNR Water Regulation field investigation and/or assessment;
d) Obtain a Wisconsin DNR Navigable Water, Harbor and Navigation (Chapter 30) permit;
e) Conform and comply with Water Regulation and Zoning inspection reports.
8. Criteria
Preferred walleye spawning habitat:
Water depth less than 2.4 m (optimal 0.9-1.8 m);
Rock/cobble, gravel substrate (1.8 m cobble with interstitial
spaces containing smaller
materials);
Current velocities at the depth of the substrate are sufficient to minimize sedimentation.
9. Project Design
Three projects have been undertaken and designed to increase recruitment of walleye (Figure 1) since 1989. These projects include:
In 1989, as part of a stream bank stabilization/sewer repair project, creating 111 m2 of spawning habitat in three locations at the Brown County Fairgrounds.
In 1990, as part of a stream bank stabilization/shore front improvement project, enhancing and enlarging an existing walleye spawning site at Voyageur Park creating 3 066 m2 of additional habitat along 401 m of stream bank (Figure 2).
In 1992 establishing 2 973 m2 of spawning habitat, as part of the construction of a new boat launching/marina facility on the east shore of the Fox River (Figure 3).
We attempted to design criteria for the placement and type of materials used in the projects based on the characteristics found at sites in the Fox River where spawning densities were high and spawning had been successful. Each of the projects required that the following characteristics be designed into the project:
Site locations will require water depths < 1.8 m for placement of substrate. However, consideration was given to the range of river elevations that could be expected on an annual basis because of fluctuation in water elevations on Lake Michigan/Green Bay.
If possible, a 3:1 slope will be incorporated into the design in order to maximize the surface area available for spawning under various river elevations (Figure 4).
Substrate will be constructed of clean, silt free, dolomite limestone, crushed to size (5-15 cm) with 50-60% composed of 1.8 m material laid to a depth of at least 20 cm.
10. Implementation
In each of the projects, the Wisconsin DNR - Bureau of Water Regulations and Zoning informed Fisheries Management of proposals early in the project design process. By doing so, preliminary meetings were held with the municipality and their consultant engineers. At these meetings opportunities exist for discussion regarding the appropriateness of including spawning habitat into the design of the project. In some cases the addition of spawning habitat actually lowered the initial cost projections while maintaining the integrity of the project. In others it has only minimally added to the initial cost. In all cases, early intervention in the planning process will reduce labor and construction costs for placement of materials in the stream bed. In our situation there was an added benefit in that the municipalities chose to cover the cost of the habitat development.
In each case, methods and time of implementing the projects varied. Each will be discussed separately below:
1989, Brown County Fairgrounds:
Construction was conducted during July and August of 1989. A silt screen was in place during most of the construction period. After repair of the sewer line was complete, the shoreline was reconfigured and stabilized. Three locations along the shore were selected as sites to create spawning habitat. These sites were chosen because the configuration of the shoreline projected into the water forming small points. The surface area for each of the sites was approximately 122 m and extended from the stream bank about 2.4 m. Placement of materials was with a backhoe with construction done entirely from shore. The recommended materials were to be 0.6-1.8 m clean, crushed, dolomite limestone; however, 63 tonnes of 0.3-0.6 m material was placed before the mistake was noted. Walleye were able to use the new habitat in the spring of 1990.
1990, Voyageur Park:
Construction began in early summer of 1990 but instream work was done during July and August. The 907 tonnes of the appropriate material (0.6-1.8 m, clean, dolomite) was placed on a 3:1 slope extending 9 m into the water. The work was done entirely from shore using a backhoe. Placement occurred on nearly 402 m of shoreline, creating 3 066 m2 of spawning substrate. First spawning over the new substrate occurred in 1991.
1992, Fox Point Marina:
Construction of the launching ramp and parking ramp began in the
summer of 1992. A dike was created and the area dewatered to do
the instream work. A 61 ¥ 49 m area north of the piers and
launching area was established as spawning habitat. A total of
1 428 tonnes of 0.6-1.8 m stone,on a 3:1 slope were placed in
the area. Instream construction work was completed in early March
of 1993. First spawning over the material occurred in 1993.
Figure 1.
Figure 2.
Figure 3.
11. Degree of Environmental Intervention
Original materials of the stream bed were not removed. In all cases, the new material was placed over the stream bed's substrate. Silt screens and dikes were used to prevent downstream sedimentation and is recommended in all sites where soft sediments may occur. Construction occurred during low flow periods, February-March and/or July-August. These time periods also avoided spawning periods of other species. No mortality to fish or macroinvertebrates was documented during construction.
12. Cost
The costs for each of the three projects reflect the expense of delivery and placement of the materials in the stream bed. All costs were born by the municipalities. Engineering and on site supervision could not be separated from the total project costs. Because heavy equipment was already on site for other construction purposes, the cost of placing materials would be substantially higher if a habitat improvement project was attempted by itself. However, these costs illustrate the savings that can be made by taking advantage of opportunities in other construction projects.
Construction Costs:
Brown County Fair Grounds:
63.5 tonnes@ $5.24/tonne
111 m2 = $3.01/m2 $332.74
Voyageur Park:
907 tonnes@ $10.20/tonne
3066 m2 = $3.01/m $9 251.40
Fox Point Marina:
1429 tonnes @ $14.23/tonne
2973 m2 = $6.78/m2 $20 477.57
Subtotal Construction $30 061.71
Spring and Fall Assessment Costs (pre and post construction, 1987-1993):
Field Crew: 15 person weeks/year (7 years) $35 000.00
Biologist: 2 weeks/year (7 years) $9 800.00
Supplies & Expenses (7 years) $3 500.00
Subtotal Assessment $48 300.00
Total Costs of Projects to Date $78 361.71
13. Biological Assessment
Mark and recapture population estimates of spawning age walleye have been made by fyke net surveys each spring since 1986. Relative abundance of YOY walleye has been obtained through late fall electrofishing surveys in each year since 1987. In 1993 egg traps were randomly placed in the substrate at the Voyageur Park site and at all sites in 1994. We expect to continue these surveys through 1997.
14. Measures of Success
Although many variables may account for increased egg survival and fall fingerling recruitment, we have been encouraged by the results seen since improvements in habitat in the Fox River. In 1991, the first fall after spawning occurred on the Voyageur Park substrate, the relative abundance of fall fingerling walleye was 100 to 1 000 times greater than any other year-class we had measured. Since
then, the average annual recruitment of fall fingerling for the 1991-1993 period has been 200-300 times greater than the 1987-1990 average. However, all sites do not appear to be equally successful.
The Brown County Fair Grounds:
This site does not appear to be producing walleye. Little spawning activity occurs at the site and no egg deposition has been documented. We feel that the area created was not extensive enough to attract adult walleye. The smaller sized material way also be inappropriate.
Success Rating: 3
Voyageur Park:
This site has exceeded our expectation. The area was extensively used by spawning walleye prior to the habitat enhancement project but has now become the area with the highest spawning density of any net location in the river. In 1993, egg deposition over the substrate was estimated at 5.2 million eggs.
Success Rating: 5
Fox Point Marina:
We documented egg deposition at the site in 1994. An estimated 67 300 eggs were deposited over the substrate, low levels, considering the surface area available on site. In 1993, the first year of spawning at the site, walleye density and spawning activity was low. By 1994, spawning density increased. As the abundance of spawning walleye increases, as we expect as the 1991 year-class matures, more walleye may be attracted to this site.
Success Rating: 1
15. Key References
Balcer, M.D., McCauley, D.J., Niemi, G.I., and Brooke, L.T. 1986. Ecological assessment of factors affecting walleye ova survival in the Lower Fox River. Final Report to U.S. Environmental Protection Agency, Environmental Research Laboratory-Duluth, MN. Co-op Agreement #CR-811723-02-0. 78p.
Schneider, J.C., Lychwick, T.J., Trimberger, E.L., Peterson, J.H., O'Neal, R., and Schneeberger, P.L. 1991. Walleye rehabilitation in Lake Michigan, 1969-1989, p. 23-61. In P.J. Colby, C.A. Lewis, and R.L. Eshenroder [editors]. Status of Walleye in the Great Lakes: case studies prepared for the 1989 workshop. Great Lakes Fish. Comm. Spec. Publ. 91-1.
Correct citation for this contribution:
Lychwick, T.L. 1995. Fox River walleye habitat improvement, p. 272-281. In J.R.M. Kelso and J.H. Hartig [editors]. Methods of modifying habitat to benefit the Great Lakes ecosystem. CISTI (Can. Inst. Sci. Tech. Inf.) Occas. Pap. No. 1.