Management of Wisconsin's South Shore Anadromous Fishery

A unique set of streams drain into the western-most region of Lake Superior along the central portion of Wisconsin's south shore. These streams extend from the Bois Brule River eastward around the Bayfield peninsula to the head of Chequamegon Bay. The most important of them include from west to east, the Brule, Flag, Cranberry, Bark, Pikes, Onion, Sioux, Whittlesey and the North Fish.

Together they annually produce the lion's share of Wisconsin's river and near shore trout and salmon fishery, providing more than 50,000 angler fishing trips each year. Most streams around Lake Superior receive their base flow from areas with fairly shallow aquifers lying on bedrock; those mentioned above gather their cold groundwater flow from a unique geologic feature known as the Bayfield Sand Plain. This area consists of a large glacially deposited region of deep sands, some areas reaching several hundred feet deep. This area extends from the headwaters of the Bois Brule in a northeast direction through the center of the Bayfield Peninsula. Groundwater specialists have projected that rain falling on this landscape seeps quickly into the soils, then to be stored in the aquifer for up to a century, before emerging as springs near the headwater reaches of these streams. Cold, clean water creates a perfect incubating and growth environment for trout and salmon. Steelhead, brown trout, coho salmon and smaller numbers of brook trout, chinook and pink salmon depend on these "natural fish hatcheries" for spawning and juvenile rearing habitat. Trout and salmon require stable gravel and well oxygenated water to hatch their eggs during the long months of incubation. Most ascend the streams during fall to lay eggs in gravelly areas where they incubate in nests during the winter period and emerge in early spring. Steelhead, a spring-time spawner, deposit their eggs in spring where they lie until emergence in June. Once emerging, at less than an inch in size, they then spend from one to two summers growing in the stream environment before they migrate to the lake to continue their growth to adulthood.

Fishery Declines - Stream produced trout and salmon fisheries lake-wide began fluctuating and generally declining by the mid 1980's, causing agencies to research reasons for these dramatic changes. The Wisconsin DNR Lake Superior Fisheries Work Unit began seeking ways to understand and develop strategies to reverse this trend about that same time.

Initial Response to the Decline - Biologists have long known that beaver dams can block ascending fish from reaching upstream spawning locations, making beaver control an essential tributary fish management activity. In the mid 80's beaver populations began to rise in response to fewer trappers participating in the sport as fur prices dropped. This increase in beaver numbers created a higher incidence of stream blockage and resulted in substantial reductions in trout and salmon production on many streams. The department's first response used monetary subsidies paid to trappers for each beaver removed from trout streams and produced maps of dam locations from plane flights that were provided to interested trappers. Due to the small gains made at high costs, this program was quickly dropped. In the late 80's trout stamp monies were earmarked annually to hire Federal trappers to remove blocking dams and problem beaver. This program has proved very successful and continues today where approximately 117 miles are managed in this way. This program also uses aerial flights along with intensive trapping during both the spring and fall season. Maps for trappers are also generated each fall to pin point beaver activity on other nearby streams in the northern counties of the state.

The efficiency of this program has been improved in recent years with joint federal and state employee surveillance walks of all streams during the fall pre-spawn period. Any problems noted are immediately trapped out and dams are removed. Program success greatly depends upon the cooperation of private stream-side landowners who report problems and provide access. Controlling problem beaver on these tributaries is an essential management activity and insures open access to these "wild fish hatcheries". Biologists also noted that as lake trout populations improved, lake survival of out-migrating stream salmonids appeared to be declining. It became apparent that out-migrating young trout and salmon were finding less food and increasingly becoming food items for other lake fish, and reducing the return of spawning adults to the streams. Fewer adult spawners returning to tributaries began impacting potential stream production. The Department tightened angler bag and size limits to compensate for these lower adult returns.

Recent Management Activities - The next challenge undertaken was to research factors limiting each stream's trout and salmon juvenile production. Once those limitations are known, strategies needed to be developed to overcome those restricting factors or more simply stated answer the question: What can we do about it? This process began when an intensive stream survey was conducted on the Brule River from 1987-1991, with results revealing a strong inverse relationship between high water events and year class strength. The survey began to give insight into that question. It was discovered that the most crucial time period for recruitment is between spawning and the time juvenile fish reach two inches. Untimely flood flows were reducing the survival of incubating eggs or killing newly emergent fry and small fingerlings that were weak swimmers. Flood flow timing from year to year resulted in reduced production and produced dramatic swings of smolting trout and salmon numbers migrating to the lake. The knowledge gained from the Brule study helped identify recruitment inhibitors that could also be applied to other south shore tributaries. Additionally, intensive habitat monitoring and fry/spawning surveys helped pin-point each stream's limiting factors to recruitment and increased awareness for targeting strategies for best success in trying to enhance each streams fishery. It became increasingly apparent that besides causing direct mortality, flood flows were further damaging critical spawning areas by both washing away important gravels and burying other areas under deep layers of sand.

To help address watershed issues and stream flow dynamics, the department funded several projects designed and carried out by scientists of the United States Geological Survey. They collected pertinent information on the North Fish Creek, Bark River, Sioux River, Whittlesey Creek, and the Cranberry River. Scientists verified that the power of flood events is presently twice that of the pre-settlement era. These flood events changed the character of some stream sections and even destroyed middle and lower river historical spawning reaches. This greatly impacted brook trout reproduction and reduced their potential future success in Bayfield peninsula streams. The other larger salmonids, although still limited, are better able to utilize this damaged habitat. Study results suggest that we need to develop strategies to "slow the flow" or reduce the speed that snowmelt and rainfall events drain off the land. It also suggested the need to concentrate on watershed areas upstream of critical spawning and rearing reaches.

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Brule River Strategies

When it came to applying actions on knowledge gained, the Brule received the highest priority because it had both the greatest angler use and concern and best chance of responding to treatments. Additionally, the Lamprey Barrier/ Fishway gave us a unique ability to measure success by counting returning salmonids at the observation window. Initially, more restrictive regulations were enacted to protect juveniles, adult stream residents, and returning spawners. Efforts next focused on the amount and quality of gravel at spawning sites in the upper river (upstream of Co. Hwy B), the most limiting factor for recruitment. During research efforts, it became evident that juvenile abundance declined further away from spawning areas. Stable stream flows in the upper river provided the right environment to drastically improve the trout fishery. Successful results of the 1994 experimental projects directed management to further add an additional 830 yards (2.3 million pounds) of washed uncrushed gravel to 50 more locations. The Brule River Sportsman Club's volunteer assistance provided valuable manpower to improve many of the sites. Each site was annually monitored for spawning activity and hatching success. The results have been impressive to say the least as evident from the improving resident and migratory fishery.

It was also noticed through field surveys that high quality sections on numerous important feeder streams to the Brule, once historical spawning areas, were buried under a deep layer of sand.Most of the sand had accumulated in these small stream reaches over time and was limiting spawning activity and hatching success. Over a period of many decades, a combination of small woody debris and tag alders had fallen into the stream creating small dams that filled with sand.

This caused the stream to become wider and shallower, which limited the stream's ability to flush itself. Damaged sections were successfully rejuvenated by removing small woody debris, allowing the stream to cut a deeper stream channel, exposing gravel and many large cover logs that were quickly utilized by trout and salmon. Noticeable increases in spawning adults and fry have been documented at and near these improved sites. Portions of nine high-quality feeder streams totaling 8.3 miles have been restored in this fashion to date. One interesting find occurred on Sandy Run during the summer of 2004, when a 5-point elk antler shed was uncovered from the sand burying the stream bed.

Elk had last inhabited the Brule Valley in the 1870's. Log additions were the last habitat improvement technique used to improve the trout fishery. Large logs were added to selected sites to enhance overhead cover and scour soft bottom substrates, exposing stream bed gravels. The three reaches selected for this treatment technique were the silt-laden stretch downstream of Stone's Bridge, the sandy reach from Spring Lake to the Winniboujou Club and a portion of the Little Brule River near Dennis Road. Most of the additions were considered experimental and placed in a multitude of configurations to learn which design works best for future projects. Like many other similar projects carried out, it was found that the more complex and higher number of logs used per cluster provided the best results. Also, in order to sink the large logs in the mainstem of the river, logs were soaked to reduce their buoyancy.

Additional projects will likely be carried out in the future. All habitat actions on the Brule have been done upstream of the city of Brule, as the force of floods in downstream red-clay drainage area limits improvement success.

Bayfield Peninsula Strategies - Historical fisheries management activities on the other south shore tributaries concentrated efforts on the lower portions of the streams with enhancements involving rip rapping, and in-stream cover. As with the lower Brule, many of the other south shore tributaries drain red-clay soils making them vulnerable to extreme flood flows especially in downstream portions. Due to the extreme nature of the streams, many of the earlier projects failed to improve the fishery. Angling regulations were tightened to improve spawner abundance. One positive action in the past involved establishing fishery areas within each stream, now called the South Shore Fish and Wildlife Area, so land could be purchased to provide public access and protect stream banks. These streams have extremely stable groundwater flow, but fish production is limited to the timing and the frequency of flood events, similar to what was found on the lower Brule River. To enhance the fishery, department staff determined efforts must be concentrated near the headwater reaches, where stream flows were more stable. Improved reproduction in this part of the watershed should benefit the entire fishery. Similar to the upper portions of the Brule's tributaries many of the headwater sections were buried in sand. Debris accumulations, tag alder and remnant beaver dams caused the streams to fill with sand burying native gravel. Techniques similar to those used on the Brule's tributaries were applied to these streams.

Thus far, treatments have been applied on two tributaries of the Bark River, a Sioux River tributary named Four Mile Creek, and the Flag River. A total of 3.4 miles has been improved, while another fourteen miles of similar degraded habitat requires future attention. Work done on these three streams has produced excellent results. The streams are narrower, deeper, flow faster and now have a stream bottom type of 90% gravel instead of 90% sand. Efforts in the future need to target reducing flood flows to protect and improve stream conditions.

Newer Experiments - Most recently the department is experimenting on ways to rehabilitate brook trout populations, especially lake associated populations with potential to export some to the lake environment, termed "coaster brook trout". The migrating fish grow larger than their stream dwelling siblings. A few streams have been chosen for experimentation and include the Bois Brule and Bark Rivers and the Whittlesey and Graveyard Creeks. Tactics being used include regulations and habitat restoration in all four and additionally stocking in Whittlesey. Other projects include experiments to reduce channel and bank erosion and involve installation of engineered log jams (Whittlesey and Cranberry) and flow directing vanes (North Fish Creek).

Although the streams are damaged and can never be restored to their original condition, they still provide for a very valuable lake and stream salmonid fishery. Our fishery management objective is to rehabilitate habitat conditions continuing to improve them to be "the best that they can be".

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