Background
The Upper Au Sable River Watershed has a long history of producing high quality coldwater angling opportunities. The river first achieved fame during the latter half of the 19th century when teeming populations of Arctic grayling were discovered and exploited. During the 20th century, waters of the North, South, and Mainstem Au Sable produced nationally renowned fisheries for brook, brown, and rainbow trout. This reputation was achieved, in part, due to the inherent fish production potential of the system, but active management of fish harvest and aquatic habitat restoration efforts also played major roles.
Regulations: Restrictive angling regulations were the primary method used to protect fisheries early in the 20th century. For example, flies-only regulations were applied to a portion of the North Branch from 1907-1912, although they were repealed in 1913. During the 1950’s regulations restricting anglers on portions of the North, South, and Mainstem Au Sable River to the use of artificial flies were applied. At the same time, harvest limits were reduced and minimum size limits were increased. A variety of restrictive regulations, up to and including no-kill, have remained in force to the present day.
River Channel Management: Stream habitat manipulation was the second method used to restore or enhance trout populations during the 20th century. Logging activities such as stream clearing and log drives had robbed the river system of large woody debris (LWD) and the massive erosion associated with these activities caused the channels to become wider and shallower. During the 1930’s, large numbers of wooden structures were constructed in the North Branch Au Sable to improve trout habitat. Some structures were intended to provide fish cover but most were wing deflectors intended to deepen and narrow the channel or expose spawning gravel covered by sand deposited during and after turn-of-the-century log drives. In the late 1940’s, several sections of the North Branch were dredged to provide deep-water habitat. From 1948-1950 the Michigan Department of Conservation built or repaired 362 structures in the North Branch between the Sheep Ranch and Twin Bridges. During this era they de-emphasized wing dams and began constructing trout shelters to augment LWD and natural debris jams. They also placed many individual logs in the channel to either deepen the channel (digger logs perpendicular to flow), or provide trout cover (logs placed parallel to flow). From 1972-76 the Michigan DNR placed 1,049 structures in the Mainstem Au Sable between Grayling and Wakeley Bridge to improve habitat for trout. The total length of structures constructed was 24,892 feet and the total structure area was 113,177 square feet. From 1976-81 the Michigan DNR constructed over 720 structures on the North Branch Au Sable River between Dam 4 and the mouth. Habitat work was not conducted within the Dam 4- electrofishing station or upstream because this river reach was being used as a reference zone for regulation evaluations.
Additionally, a few trout shelters were constructed in the Mason Tract of the South Branch during the early 1970’s.
By the late 1980’s much of the older LWD placed into the rivers had deteriorated or disappeared. From 1994-96 the Au Sable River Watershed Restoration Committee reconstructed or repaired 779 of the structures originally placed in the Mainstem during 1972-76. In 1997-98 they repaired or reconstructed 503 structures in the North Branch between Dam 4 and the river mouth. Additional work was conducted upstream of Dam 4 in 1999 and the Restoration Committee expects to have most structures in the North Branch between Lovells and Dam 4 repaired by the end of 2000.
Sediment Control: Research conducted on Hunt and Poplar Creeks during the 1970’s and early 1980’s demonstrated that excess sand sediment in streams had profound adverse effects on trout populations and habitat quality. These findings led to an increase in efforts to control bank erosion and the use of sediment traps to remove excess in-channel sediment is to restore trout habitat quality. During the past 2 decades, sediment basins have been excavated at about a dozen locations in the upper watershed. Some traps were maintained for only a short time whereas others have been active for over a decade. DNR presently maintains traps on the South Branch, East Branch, and Mainstem Au Sable River.
Extensive efforts to stem erosion into upper watershed river branches have been conducted during the past 15-20 years.
These efforts were primarily funded by private sector dollars. The Au Sable River Restoration Committee, TU Chapter members, among others, have fixed eroding access sites, and controlled bank erosion with trees and rock rip-rap at innumerable sites in the upper watershed. These efforts have stopped or controlled most major sources of bank erosion in the upper watershed.
Fish Populations: Refinement of electrofishing gear in the 1950’s provided an effective method of estimating fish populations in streams. Annual or semi-annual trout population estimates and angler census provided data to evaluate effects of the array of angling regulations applied to portions of the Au Sable River system after about 1950. The trout population estimates provide a long-term index of trout abundance at locations where electrofishing station boundaries have not changed over time. Trout populations have been estimated annually at some of the same "fixed-location" sites on the North and Mainstem Au Sable from the late 1950’s to the present time. Trout populations have been estimated at fixed locations in the South Branch Au Sable at Chase and Smith Bridges every year since 1974.
Arrays of different angling regulations were enacted between 1973 and the present time to stem declines in the abundance of trout in the Mainstem Au Sable, particularly larger brown trout. Size limits were increased and harvest limits were reduced from 1973-78. Slotted size limits were applied from 1979-1988, and no-kill regulations were imposed in 1989. None of these regulations stemmed the general decline in abundance in the Mainstem over this period. Population estimates of trout in the North Branch Au Sable were used as reference populations to help distinguish between effects of regulations and other environmental factors, such as climate, that affect fish populations. Thus, the same trout regulations were applied to the North Branch Au Sable for approximately 3 decades (10-inch minimum size limit for brown trout, 8-inch for brook trout, 5 fish creel limit), while different regulations were imposed on the Mainstem and South Branch.
Populations of larger brown trout at North Branch index stations were relatively stable from about 1972-1986 but they declined dramatically by 1990 and remained low throughout the decade. Anglers and riparians became intensely interested in returning the fishery in the watershed to its former level. There are many hypotheses for the declines. They include, increased angler wading and harvest, canoeing, fish diseases, increased predation, increased sedimentation, effects of toxic materials, changes in flow and temperature, declines in natural and man-made cover, and declines in river productivity resulting from reduced nutrient inputs.
Other Initiatives: In 1994, Jim Williams, a North Branch riparian, organized an Au Sable River Study Committee comprised of DNR resource personnel, professors from MSU, UM & CMU, a representative from the U.S. Forest Service, and an economist. On August 10, 1995, he held a meeting whose purpose was:
"To establish a forum from among the special interest groups, individuals, and public agencies who have the experience, knowledge, and desire to cooperate in the design and implementation of a comprehensive plan for the future of the Upper Au Sable River Watershed".
In 1995, the study committee drafted a proposal to improve habitat by adding LWD and organic material (deciduous leaves) to the river. They also planned to study water chemistry, plant and invertebrate communities, and stream morphology to determine if the habitat management methods were effective. A study to estimate and document the value of the river to the region was also proposed. Formation of a Watershed Council with the ability to raise funds for long-term protection and enhancement of the Upper Au Sable River watershed was a fundamental component of Jim’s vision. Unfortunately, this plan lost impetus with Jim William’s untimely passing.
In October 1999, Troy Zorn and Steve Sendek completed a (near final) draft Au Sable River Assessment. Written responses to public comments received on the draft document have been incorporated into the final draft. It should be available on the DNR’s web site by Fall 2000. The assessment describes the physical and biological characteristics of the river and is intended to serve as an information base for managing the river’s future. The management options section of the report includes a broad list of management options that will be used to guide river protection and rehabilitation over the next decade and beyond.
At a March 2000 meeting of the Au Sable North Branch Association, Kelley Smith, Chief of Fisheries Division, announced that the DNR would seek joint State and Federal funding for a habitat project based upon management options in the river assessment. An Au Sable Watershed Habitat Restoration Project Proposal was developed and first presented at a meeting of the Au Sable North Branch Association meeting on May 20, 2000.
Proposed Project Scope: The goal is to invest an average of $150,000 per year for 10 years in management options to improve habitat in the Upper Au Sable River Watershed. The project will not be focused entirely on single issues or rivers. Work will not be conducted in sections of the watershed affected by Consumers Energy projects.
Proposed Actions: The list of over 100 management options in the assessment was reviewed to derive a short list of proposed management actions that are being discussed with constituent groups to obtain their input and suggestions. We need to prioritize and define the scale for the management actions proposed for inclusion in a final project proposal. The management actions proposed, in no particular order of priority are:
The rationale for each proposed action is briefly discussed below. It is not possible to accomplish all the specific actions proposed below in a project of this size. That is why public comments are being sought to establish the priorities of constituent groups before a final project proposal is submitted for joint Federal and State funding.
Addition of LWD to selected sites is proposed, in part, because it promotes better trout survival. The reduced abundance of larger brown trout observed over the past decade or more, occurred primarily because natural mortality rates have increased from past levels. We propose that most LWD be comprised of whole trees, although other woody structure may be appropriate in some river reaches. Specific sites proposed for LWD additions were selected based on counts of large woody debris made while floating the river by canoe in 1998-99. Areas with a paucity of LWD were selected for consideration and prioritization. On the North Branch, we propose to add LWD between Twin Bridges and the river mouth. Efforts will be focused on reaches near angler access points. On the Mainstem, we propose to add LWD from Wakeley Bridge to the confluence with the South Branch and from Parmalee Bridge to Mio Pond. On the South Branch, we propose to add LWD from Chase Bridge to Downey’s and from Smith Bridge to the river mouth.
Removal of excess sand sediment is proposed at a variety of sites. Sediment traps require a long-term maintenance commitment to be effective. Sites on each major river branch are being considered (North, South, East, and Mainstem). Specific sites selected will be based on projected benefits, feasibility, and some consensus of the project committee that will be formed early this fall.
Match money for monitoring stormwater quality and quantity discharged to the upper river system from the Grayling and Roscommon storm sewers is proposed for consideration. The project committee will refine specific monitoring proposals.
We propose that some funds be used to pay a person to facilitate formation of a basin-wide watershed council. Watershed councils can be very effective in ensuring that the river is represented in land-use planning activities for the watershed. They can help prioritize and coordinate river protection and restoration efforts and help educate residents on river-related issues. The infrastructure and planning capabilities of watershed councils help them attract money for projects that is not available to government agencies.
The DNR will investigate the effects of state-owned dams on water temperatures on the upper watershed to determine if their removal would provide significant benefits to the system. This summer an electronic thermometer was placed downstream of Robinson Creek Flooding ( a tributary of the South Branch).
Removal of the Grayling dam to lower water temperatures, restore fish passage, and restore high-gradient habitat is also proposed for discussion. Lowering the level of the dam is an option that may decrease water temperature without eliminating the stump pond. Electronic thermometers were placed both up and down stream of the stump pond this summer to estimate its effect on water temperatures in the upper Mainstem. Another thermometer was placed downstream from Robinson Creek Flooding, a tributary to the South Branch. Additional dams will be investigated in future years. Specific measures proposed to mitigate environmental damage by dams will be based on our findings. In general, dams increase water temperatures, block fish access to spawning and rearing habitat, and bury high-gradient habitat that would otherwise be used for spawning. Finally, we suggest exploring the option of providing financial assistance to private dam owners to remove dams that adversely affect water temperature or fish movement.
We propose reactivating or establishing stream-flow gauges in the upper watershed. Streamflow volume and timing has many effects on river health. For example, trout reproductive success is reduced by high spring floods such as the flood that accompanied the illegal draw down of the Lake St. Helen dam in 1991. Data on streamflow can be used to assess effects of land development and stormwater drainage. Each of the USGS gauges previously maintained at Grayling on the Mainstem and East Branch could be reactivated for about $5,000 per year. A flow gauge on the North Branch Au Sable would also provide useful data.
Public Involvement in Project Development: The proposed project components listed above have been presented and discussed with the Au Sable North Branch Association, the Board of the Anglers of the Au Sable, the Michigan Council of Trout Unlimited, and the Federation of Fly Fishers-Great Lakes Council. These groups voted on each of the 6 major management actions proposed for the project. By show of hands, they ranked each component as a high, medium, or lower priority. Two additional presentations were made in July and August at the Grayling Township Hall. Comments and suggestions received at these meetings will be used to shape the final project proposal.
Implementation Plans: A small committee will be formed this September to formulate a more specific project proposal. When consensus is reached, we will begin the process of applying for joint State and Federal funding for the project. If funding is obtained, we hope to begin the project in 2001.
Written comments on this proposal may be directed to Andy Nuhfer, Hunt Creek Fisheries Research Station, 1581 Halberg Road, Lewiston, MI 49756 (nuhfera@state.mi.us) or Steve Sendek, Grayling Field Office, 1955 N. I-75 Business Loop, Grayling, MI 49738 (sendeks@state.mi.us).
RWOL
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